Pests and Diseases From Pansy Downy Mildew To Sycamore Sooty Bark Disease


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Common Name:- Pansy Downy Mildew
P_pansydwmldw Downy mildew of pansies is a fungal-like disease caused by Peronospora violae(Bremiella megasperma). It causes pale blotches on the upper surfaces of the leaves and fuzzy grey mould growth on the underside of leaves. Eventually the whole leaf die...
Caused by:- The fungal-like organism Peronospora violae
Control:- Remove infected leaves as soon as the discolouration on the upper s...

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Common Name:- Pansy Leaf Spot
P_pansylfspt Pansy Leaf Spot is caused by several fungi including Centrospora violae, Ramularia deflectens, and Phyllosticta minima Alternaria violae. These fungi are especially rampant when the weather is cold, wet, and windy or when seedbeds are crowded an...
Caused by:- Various Fungi
Control:- Spray with systemic insecticides, but fungicides can reduce infecti...

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Common Name:- Pansy Powdery Mildew
P_pansypwdmldw Powdery mildews are one of the most widespread plant diseases. They affect virtually all kinds of plants from cereals and grasses, to fruit trees, and broad-leaved shade trees.
Pansy Powdery mildew is a fungal disease that is particularly p...
Caused by:- Various Fungi
Control:- Powdery mildew does not like wet conditions, it is worst when the w...

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Common Name:- Pansy Sickness or Stem Rot
P_pansyskness Pansy Sickness is also called Stem Rot and is caused by the soil-borne fungus Pythium violae. The symptoms are difficult to catch early as it starts at the base of the plant near the soil where the tissues becomes watersoaked and soggy. The plant ...
Caused by:- The Fungus Phytium violae
Control:- It is important to remove infected plants as soon as possible and d...

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Common Name:- Papery Bark Disease
P_paperybk Two diseases are often called Papery Bark which attacks many apple and stone fruit trees. One is also called Sappy bark and is caused by the fungus Trametes versicolor. This mainly affects older branches and is introduced by wounds to the bark or ...
Caused by:- The FungusTrametes versicolor
Control:- In both cases trees should be invigorated by ensuring good drainage...

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Common Name:- Parsnip Canker
P_psnipcnkr Parsnip Canker can be a serious disease of parsnips especially in wet soils. It is caused mainly by the fungus Intersonilia pastinaceae, though other fungi, like Phoma and Mycocentrospora, can cause this disease. It causes the storage root to dark...
Caused by:- Various Fungi
Control:- Prompt removal and disposal by burning of debris from infected sour...

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Common Name:- Parsnip Viruses
P_parsnipvirus There are several viruses that infect Parsnips, but two Parsnip yellow fleck virus (PYFV) and Parsnip mottle virus (PMV) are most prevalent. The symptoms are yellow markings on the leaves often as bands on the leaves or a mottling or mosaic patter...
Caused by:- Various Viruses
Control:- Promptly remove any infected plants and burn, as feeding insects on...

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Common Name:- Pea and Bean Weevil
P_pandbeanweevil Sitona lineatus feed on peas vetch, lentil, and beans in gardens but is usually a minor pest causing little damage to the crop, but in some countries it can be a major pest. As an adult, this Weevil feeds on the leaves of many leguminous species...
Caused by:- The Weevil Sitona lineatus
Control:- Spraying with a knock down insecticide and also soaking the soil wi...

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Common Name:- Pea Downy Mildew
P_peadnymldew Pea Downy mildew is caused by the fungus-like plant pathogen Peronospora viciae which is worldwide in distribution. It is a fungus-like microorganism which overwinters on diseased plant debris in soil and is most severe on young plants.
The...
Caused by:- The Fungus-Like Peronospora viciae
Control:- Good hygiene is the first line of defence. Always remove all plant ...

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Common Name:- Pea Leaf and Pod Spot
P_pealfpodspot Peas can suffer from such a wide range of diseases it is a wonder it is usually an easy crop to grow. some of the diseases that affect peas are:-
Bacterial diseases
Bacterial blight, Brown spot
Fungal Diseases
Alternari...
Caused by:- Various Fungi usually Ascochyta
Control:- This diseaseis agravated by wet conditions and is also carried over...

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Common Name:- Pea Marsh Spot
P_peamarshspot Circular brown areas develop in the center of the seeds or cotyledons, which later forms a cavity. The peas are spoilt for consumptionand sale.
The cause is a lack of manganese. This is most prevelant where there is a high organic content, ...
Caused by:- Manganese Deficiency
Control:- Foilar feeding with a fertiliser which contains manganese and impro...

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Common Name:- Pea Moth
P_peamoth The pea moth Cydia nigricana, attack field and garden peas along with sweet peas and vetch. It is about 6mm long with a 12mm wingspan. It is brown in colour with black and white bars on the front edge of its forewings and antennae. They emerge fr...
Caused by:- The Moth Cydia nigricana
Control:- Planting early and don’t delay harvesting or late planting will mis...

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Common Name:- Pea Powdery Mildew
P_peapowmildw Powdery mildews are one of the most widespread plant diseases. They affect virtually all kinds of plants from cereals and grasses, to fruit trees, and broad-leaved shade trees.
The fungus “Erysiphe pisi” causes powdery mildew of peas and be...
Caused by:- The Fungus Erysiphe pisi
Control:- Attacks of powdery mildew start in dry seasons and are worst in she...

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Common Name:- Pea Thrips
P_peathrips There are over 6,000 species of thrips known around the world, with over 300 of these in Europe and about 150 native to Britain. Pea thrips Kakothrips pisivorus, also known as thunderflies as they often take to the air in large numbers in thundery...
Caused by:- The insect Kakothrips pisivorus
Control:- Activity peaks in hot dry conditions when a careful watch is needed...

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Common Name:- Pea Viruses
P_peaviruses Peas are susceptible to a large number of viruses which are usually transmitted by aphids. Many of these viruses can occur singularly or in combination.
Viruses infecting peas belong to three distinct virus groups. Pea Enation Mosaic is the...
Caused by:- Several Viruses
Control:- Once infected there is no cure for viruses. As most viruses are tra...

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Common Name:- Pea Wilt
P_peawilt Peas Wilt diseases is caused by the fungus Fusarium oxysporum f. sp. pisi. Several races of the fungus occur and may cause different symptoms. Typically, plants are yellow, stunted, wilted, and often die. Plants may also show a yellowish to orange...
Caused by:- The Fungus Fusarium oxysporum f. sp. pisi
Control:- Growing resistant varieties are probably the only defence to this f...

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Common Name:- Peach Aphids
P_peachaphid Peach aphid Brachycaudus schwartzi attacks Peaches, Nectarines Almonds and other related plants.
It is a transmitter of viruses and other diseases and should be treated as soon as possible.
The leaves many become yellowish/green curl...
Caused by:- The aphid Brachycaudus schwartzi
Control:- From Spring onwards a lookout for aphids on peach trees is needed a...

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Common Name:- Peach Leaf Curl
P_peachleafcurl1 Peach leaf curl is one of those hard to avoid and yet is preventable diseases of peaches, almonds, nectarines, apricots and ornamental Prunus. The infection is carried in the air and gets in the flower and leaf scales over the winter and when the ...
Caused by:- The Fungus Taphrina deformans
Control:- One of the best ways to avoid this fungus is to arrange a cover to ...

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Common Name:- Pear and Apple Canker
P_nectriacanker2 Areas of the bark sinks inwards. It is most often associated with a wound or bud. The bark changes colour and shrinks and cracks forming concentric rings of bark which easily peels off. As the fungus grows around the stems the upper branches and l...
Caused by:- The Fungus Nectria galligena
Control:- This fungus spreads mainly by wind blowing the spores in spring. Th...

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Common Name:- Pear and Cherry Slugworm
P_pandcslugworm The Pear and Cherry Slugworm (Caliroa cerasi) attacks Hawthorne, mountain Ash, Plums, Sorbus and Quince. It is actually a bottle green insect larvae, of a sawfly, which covers its body in a black slimy mucilage which makes it look like a slimy sl...
Caused by:- The Sawfly larvae of Caliroa cerasi
Control:- Spray with a contact insecticidal spray such as soon as they are no...

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Common Name:- Pear Bedstraw Aphid
P_pbedstrawaphid Pear-bedstraw aphid (Dysaphis pyri) is a large, pinkish-brown aphid with a mealy waxy coating and is the commonest aphid on pears. It attacks the young shoots and causes the leaves curl and discolour due to the honeydew produced by their excretion...
Caused by:- The Aphid Dysaphis pyri
Control:- There are many ways to eradicate aphids. Spray with insecticide, bo...

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Common Name:- Pear Boron Deficiency
P_pborondif Pear Boron-deficiency can cause pitting and distortion on the fruit surface, but also causes patches of dead brown cells inside the fruits which affects the texture and taste. Some varieties are more prone to this problem. See also other problems ...
Caused by:- Too much Lime on Sandy soil.
Control:- The cause of Boron Deficiency can be too much lime and or drought c...

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Common Name:- Pear Juniper Rust
P_pearjnprst Pear Juniper Rust is caused by the rust fungus Gymnosporangium sabinae(G. fuscum). Like most rust diseases it requires two different host to complete its life cycle from year to year. With this fungus juniper is the winter host and pear is summer...
Caused by:- The Fungus Gymnosporangium sabinae
Control:- It is important to break the disease cycle and remove infected leav...

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Common Name:- Pear Leaf Blister Mite
P_pearlfblstmte Fallen leaves of vine maple (Acer circinatum) showing damage by Pear leaf Blister Mites.
The Pear-Leaf Blister Mite(Phytoptus pyri previously Eriophyes Pyri) is the same mite that causes Blister Mite in other plantslike Apple, Pear, Quince...
Caused by:- The Mite Phytoptus pyri(Eriophyes Pyri)
Control:- Spraying with a systemic insecticide or oils will help, but the mai...

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Common Name:- Pear Midge
P_pmidge Pear Midge is a tiny fly (Contarina pyrivora), the larvae of which damage immature pears. This pest is widespread and can be quite damaging to the crop. The adult is only 2.5-4mm long and darkly coloured and emerge from the soil in April and May, ...
Caused by:- The insect larvae of Contarina pyrivora
Control:- There is not much you can do once an outbreak has occurred, but pic...

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Common Name:- Pear Scab
P_pscab Pear scab is most prevalent in mild, damp seasons. It is caused by the fungus Ventura pirina which is closely related to the apple scab fungus Venturia inaequalis. The fungus overwinters on fallen leaves in the form of spores, which can be splashe...
Caused by:- The fungus Ventura pirina
Control:- Good husbandry is essential in preventing this disease. Therefore r...

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Common Name:- Pear Stony Pit Virus
P_pspvirus Stony pit causes deformity and pitting of pear fruits and is caused by a virus. Symptoms begin as early as three weeks after petal fall, when dark green spots form on the fruit. Areas surrounding these spots continue to grow while spots stop, resu...
Caused by:- A virus
Control:- Some varieties are more prone to this virus and as with any virus o...

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Common Name:- Pear Sucker
P_pearsucker Pear sucker (Psylla pyricola) also called Pear Psylla can be a major pest for orchards, but is less common in gardens. The nymphs appears in the spring on developing leaf and blossom trusses later in the summer they move to the leaves. Where the p...
Caused by:- The Sucking Insect Psylla pyricola
Control:- Encouraging their natural preditors like beetles and lacewings shou...

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Common Name:- Pedicil Necrosis
P_pednecrosis Pedicel Necrosis or Infloresent Necrosis is where the flower buds develop normally then suddenly droop and die. The pedicel behind the bud discolours and dies. Some grapevines are prone to this problem. So far no link has been found with any virus...
Caused by:- Physicological Probably Too much Nitrogen
Control:- Feed the plants with potassiun in the spring and autumn. Avoid too ...

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Common Name:- Pelargonium Rust
P_pelargoniumrust1 This fungus is specific too Zonal Pelargoniums Ivy-leaved pelargoniums are not affected. It produce dark brown, fungal pustules on the underside of the leaves. They are arranged in concentric circles and there is a yellowing of the leaves above th...
Caused by:- The Fungus Puccinia pelargonii-zonalis
Control:- The spores germinates and infect best when the temperature is betwe...

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Common Name:- Pelargonium Viruses
P_pelviruses There are many viruses that can attack Pelargoniums, which are often called Geraniums, Some are more specific to Pelargoniums like Pelargonium line pattern virus (PLPV) or Pelargonium zonate spot virus (PZSV) and some are more catholic in their h...
Caused by:- Several Viruses
Control:- Once the symptoms appear there is no cure with viruses and removing...

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Common Name:- Peony Leaf Blotch
P_peonylfblotch Peony leaf blotch is caused by the fungus Cladosporium chlorocephalum (formerly Cladosporium paeoniae). It has also been called measles or stem spot. The infections on young stems first appear as elongated, reddish-brown streaks. As growth contin...
Caused by:- The Fungus Cladosporium chlorocephalum
Control:- Good husbandry is essential in eradicating this disease and stems s...

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Common Name:- Peony Wilt
P_peonywilt Peony wilt is a fungal infection by Botrytis paeoniae, which attacks the leaves and stems of peonies, including tree peonies, causing the foliage to collapse and flowers die before opening. The basal parts of the flower stalk, which are wilting, l...
Caused by:- The fungus Botrytis paeoniae
Control:- Spraying with fungicides will help, but is not always effective. Th...

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Common Name:- Periwinkle Rust
P_periwklerust Periwinkle rust is caused by the fungus Puccinia vincae. It causes numerous raised chocolate brown pustules primarily on the underside of the host's leaves. Infected plants often fail to produce flowers, develop an erect habit and may become disto...
Caused by:- The Fungus Puccinia vincae
Control:- Because this fungus invades the roots fungicidal control is not rec...

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Common Name:- Pestalotiopsis Leaf Spot
P_petotpsis Pestalotiopsis is a genus of fungi that causes leaf and stem necrosis in many plants from palms to shrubs. The symptoms vary with the particular specie. It attacks foliage that has been injured or weakened by unfavourable weather or growing condit...
Caused by:- Several Fungi of the Genus Pestalotiopsis
Control:- Prune damaged foliage and twigs as soon as possible in the spring. ...

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Common Name:- Petal Base Holes
P_petalbsehle Holes at the base of the petals of some flowers are usually caused by bees and a few insects trying to get to the flower nectar. This often happens in plants like beans where the nectar is more difficult to obtain. Once a hole is made other insect...
Caused by:- Bees and Insects
Control:- This problem is usually of very minor incidence and can be ignored ...

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Common Name:- Petunia Foot Rot
P_petrtrot Petunia root rot can be a devastating fungal disease of petunias. It is caused by the fungus Phytophrhora ccryptogea which lives in contaminated soils as resting spores. The fungus causes a blackening of the lower parts of the plant and the roots....
Caused by:- The Fungus Phytophthora cryptogea
Control:- Once the infection takes a hold the best practice is uprooting the ...

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Common Name:- Petunia VIruses
P_petvirus There are over 100 viruses that can attack Petunias. The symptoms they cause will be the only way to identify them. Some will have no visual symptoms, but cause a decline in its growth and others will cause yellow flecking, spotting, mosiacing and...
Caused by:- Several viruses
Control:- There is nothing that can be done once the virus has established it...

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Common Name:- Phellinus ignarius
P_phellinusig Phellinus ignarius is a polypore bracket fungus that often attacks birch, alder or willow trees The fruiting body has a brown cap growing at the edges. The pores are about 2.5cm ling and can be stacked on top of each other. This mushroom is grown ...
Caused by:- The Polypore Fungus Phellinus ignarius
Control:- There is no cure for this fungus because the mycelium is inside the...

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Common Name:- Phellinus Pomaceous
P_phellinusfm There are several species of Fomes fungi(Phellinus pomaceous) which attack a variety of trees. from Apple to Pine trees, and causing fungal fruiting bodies to appear on the ...
Caused by:- The Fungus Phellinus pomaceous(Fomes pomaceous)
Control:- There is little that can be done except pruning out the infected br...

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Common Name:- Phlox Eelworm
P_phloxeelwrm The Phlox eelworm Ditylenchus dipsaci is thankfully, quite rare. It is, like most eelworms, microscopic and lives in the stems of the phlox. And overwinters in the buds at soil level. It does not enter the roots therefore root cuttings will be fre...
Caused by:- The Nematode Ditylenchus dipsaci
Control:- Usually the only remedy is to plant something else in the spot, but...

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Common Name:- Phlox Powdery Mildew
P_phloxpmldw Powdery mildews are one of the most widespread plant diseases. They affect virtually all kinds of plants from cereals and grasses, to fruit trees, and broad-leaved shade trees.
The fungi that causes Powdery Mildew on Phlox is Erysiphe cicho...
Caused by:- The fungi Erysiphe cichoracearum and Sphaerotheca fuliginea
Control:- Maintaining good air circulation will help reduce powdery mildew pr...

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Common Name:- Phomopsis Canker
P_phomopsiscnkr Phomopsis Canker is caused by several species of the Phacidiopycnis (Phomopsis) fungus. It attacks a range of plants including Pines, Conifers, American and European Cranberries, Blueberry. Some species of Phomopsis are notifiable diseases in cert...
Caused by:- Several species of Phacidiopycnis (Phomopsis) Fungi
Control:- Spraying is not very effective, but a winter tar or oil wash may li...

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Common Name:- Phormium Mealybug
P_phoriummbug The Phormium mealybug or New Zealand Flax Mealybug Balanococcus(Trionymus) diminutus (formally Pseudococcus diminutus) is a small soft bodied insect that inhabits the tight confines of the leaf base of New Zealand Flax(Phormium Tenax). It is abou...
Caused by:- The insect Balanococcus(Trionymus) diminutus
Control:- The best control for this insect is removal of infected plant parts...

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Common Name:- Phosphorus Deficiency
P_phospdef Phosphorus(P) is one of the three main chemicals along with Nitrogen(N) and Potassium(K) in fertilisers(NPK) that is needed in any plant with a few exceptions like Proteas which do not tolerate high levels in the soil. Phosphorus deficiency in pla...
Caused by:- Various causes
Control:- It can be controlled by applying bone meal or superphosphate to rem...

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Common Name:- Phytophthora
P_phytophthora Phytophthora is a genus of soil-borne fungi which cause root rot of herbaceous and woody plants. Some of them cause Damping Off Disease and P. infestans is an oomycete or water mold that has been around for over 150 years causing potato and tomato...
Caused by:- Several species Of The Fungi Phytophthora
Control:- There are no treatments to clear up infected plants so they should ...

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Common Name:- Phytotoxicity
P_phytxcty Phytotoxicity is a term used to describe the degree a chemical is toxic, harmful or lethal to plants i.e. plant poisoning. This picture shows phytotoxicity due to a certain fungicide. Such damage may be caused by a wide variety of compounds, inclu...
Caused by:- Various causes
Control:- There are several ways to reduce the chances of phytotoxicity. Gard...

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Common Name:- Pierce Disease
P_piercedis Pierce's disease is caused by the bacterium Xylella fastidiosa that tends to live in the xylem of grapevines where it produces a gel which prevents nutrients transport. Leaves on vines with Pierce's disease will turn yellow and brown, and eventual...
Caused by:- The bacterium Xylella fastidiosa
Control:- If caught early enough the infected branch could be pruned below th...

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Common Name:- Pigeons
P_pigeons Pigeons Columba oenas is the type species of the family of doves and pigeons Columbidae. It is a very useful and helpful bird to mankind. It has been used in war to transmit messages, in helping search and rescue, as an ornamental bird bred for t...
Caused by:- The Bird Columba palumbus
Control:- The best way to avoid pigeon damage is to net the crops or fruits a...

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Common Name:- Pinapple Gall Adelgid
P_pnplegladelgid Most spruce trees are attacked by one of two species of gall forming adelgids, which are related to aphids. The pineapple or pseudocone gall adelgid Adelges abietis and the Cooley spruce gall adelgid Adelges cooleyi both of which feeds on the pla...
Caused by:- Two Species of adelgids
Control:- Although the old galls can be unsightly this pest has little lastin...

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Common Name:- Pine Adelgid
P_pineadelgid The Pine Adelgid Pineus pini(Chermes pini) is aphid-like insects in the family Adelgidae that primarily feeds on pines(Pinus), Spruce(Picea), Larch(Larix) and Silver Fir(Abies). It is closely related to the Pine Bark Adelgid Pineus strobi. They fe...
Caused by:- The Adelgid Pineus pini
Control:- There is usually no need for spraying as there are plenty of predat...

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Common Name:- Pine Bark Adelgid
P_pinebarkadel The Pine Bark Adelgid Pineus strobi is aphid-like insects in the family Adelgidae that primarily feeds on pines(Pinus), Spruce(Picea), Larch(Larix) and Silver Fir(Abies). It is closely related to the Pine Adelgid Pineus pini.
The immature a...
Caused by:- The Adelgid Pineus strobi
Control:- There is usually no need for spraying as there are plenty of predat...

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Common Name:- Pine Needle Blight and Casts
P_pinenbltcst Pine Needle Blight and Casts can affect all pines. Needle cast fungi often are quite host-specific and can be an indication of the fungus involved. These diseases are caused by several fungi some of which are Bifusella linearis, Cyclaneusma minus,...
Caused by:- Several Fungi
Control:- Control of needle cast in urban forest trees is usually not necessa...

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Common Name:- Plane Anthracnose
P_plnantnose Symptoms of the fungal plant pathogen Apiognomonia veneta on the leaf of a Platanus occidentalis tree. Picture from Wikimedia Commons.
Plane anthracnose caused by the fungus Apiognomonia veneta(Gnomonia platani) is more commonly known as Sy...
Caused by:- The Fungus Apiognomonia veneta(Gnomonia platani)
Control:- Plane and sycamore trees should be planted where they receive good ...

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Common Name:- Plum Blossom Wilt
P_plmbloswlt Plum Blossom Wilt is a fungal disease, which also affects apples, pears, plums, cherries and related ornamental trees. It kills blossoms, spurs and small branches. The problem is caused by two Sclerotinia species of fungi S. laxa (Monilinia cinere...
Caused by:- Two Species of Sclerotinia Fungi.
Control:- Spraying operations can only be effective when they kill the spores...

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Common Name:- Plum Fruit Moth
P_plmftmoth The Plum Fruit Moth Cydia (Grapholita) funebrana is as serious a pest of plums and Prunus species. The moths appear during April and May, flying mostly in the evenings (before sunset) around plum trees and laying one, occasionally two eggs on the ...
Caused by:- The Moth Cydia (Grapholita) funebrana
Control:- On isolated trees a pheromone plum moth trap can be used between Ma...

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Common Name:- Plum Gall Mite
P_plmgllmte Plum Leaf Gall mites(Phytoptus similis (Nalepa)) are microscopic members of the arachnid class(mites, spiders, false scorpions, harvestmen etc.) and the Eriophyidae family(Gall mites). They attack a wide range of fruit and ornamental garden plants...
Caused by:- The MIte
Control:- Spraying in the spring with fungicides should stop the attack, but ...

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Common Name:- Plum Leaf-Curl Aphid
P_plmlfcrlaphd Plum Leaf-Curling Aphids Brachycaudus helichrysi occurs on various Prunus species in large colonies on young shoots and the undersides of leaves. They suck the sap from the leaves which causes the leaves to become tightly curled, crumpled and dist...
Caused by:- The Aphid Brachycaudus helichrysi
Control:- Several natural enemies, like ladybird beetles, lacewings, syrphid ...

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Common Name:- Plum Pox(Shakra)
P_plumpox Plum pox disease is caused by a virus the plum pox virus (PPV). It is also known as Sharka, and can infect a variety of stone fruit species including peaches, apricots, damsons, greeng...
Caused by:- The Plum Pox Virus
Control:- The only way to control this disease is to destroy all infected tre...

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Common Name:- Plum Rust
P_plumrust1 The top of leaves become discoloured by yellow-orange spots found in mid-summer onwards. The underside of the leaf is covered with numerous brown/black markings. In extreme cases the whole tree will be affected and the leaves fall early. The fung...
Caused by:- The Fungus Tranzschelia pruni-spinosa
Control:- This disease is common and widespread. Consistent attacks may weake...

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Common Name:- Plum Sawfly
P_plumsawfly The Plum sawfly Hoplocamps fuava lays its egg in the embryonic plum at flowering time. The cream/white larvae burrow into the young plum causing exude a sticky resin. It also distort and causes the fruit to fall early. After being fully fed, the l...
Caused by:- The sawfly Hoplocamps fuava
Control:- Remove damaged fruit from the tree as well as any that have fallen ...

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Common Name:- Pocket Plum
P_pocketplum Plum pocket also called bladder Plum gall, is caused by the fungus Taphrina pruni, which is related to the Peach Leaf Curl fungus, that affects apricot and black cherry, plums, damsons ...
Caused by:- The fungus Taphrina pruni
Control:- Remove infected branches, witches’ brooms and fruit before spores a...

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Common Name:- Pollen Beetles
P_pllnbtles Pollen Beetles of the Meligethes genus is more of a nuisance than a pest and Meligethes aeneus is the most abundant pollen beetle in the UK. Mostly, the beetles do little harm although occasionally they may nibble into unopened flower buds.
...
Caused by:- The Beetles of Meligethes Genus
Control:- Pollen beetle larvae are attacked by at least three major species o...

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Common Name:- Poor Pollination
P_prpolnatrs Poor pollination can have a myriad of causes, from Cold weather, Hot weather, Too dry, too wet, soil pH imbalance, Mineral and/or Nutrients Levels too high, or too low, fungi and bacteria attack, lack of pollination species for self-infertile plan...
Caused by:- Many causes
Control:- If insect pollinators are scarce and the plant is self fertile shak...

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Common Name:- Poplar Bacterial Canker
P_popbaccnkr Most poplar cankers are caused by fungi. Poplars are attacked by several different types of canker. Poplar Bacterial Canker is caused by the bacteria Xanthomonas populi, but another bacteria Pseudomonas syringae pv. syringae may also attack poplar...
Caused by:- The Bacteria Xanthomonas populi
Control:- Good husbandry and cleaning pruning tools between use and pruning o...

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Common Name:- Poplar Yellow Leaf Blister
P_popyellfbltr Poplar Yellow Leaf Blister is caused by the fungus Taphrina populina, a plant-parasitic member of the Class Archaeascomycota which is related to the fungus that causes Peach Leaf Curl.<...
Caused by:- The Fungus Taphrina populina
Control:- Spraying with a suitable fungicide before bud break and when the le...

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Common Name:- Potassium Deficiency
P_potashdef Potassium is important to plant growth and development it provides the appropriate ionic environment for metabolic processes and growth regulation. Potassium helps plants grow faster, Use water better and be more drought resistant, Fight off dise...
Caused by:- Various causes
Control:- Foliar feedind in the short term will help with this deficiency. Ap...

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Common Name:- Potato Black Dot
P_potblkdot Black dot is a fungal disease caused by the fungus Colletotrichum coccodes and is a superficial blemish on potato tubers and also the plants.
In the plant it can infect the vascular system causing wilt, and some tubers may rot.
The s...
Caused by:- The Fugus Colletotrichum coccodes
Control:- There does not appear to be any resistant varieties, early varietie...

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Common Name:- Potato Black Leg
P_potblkleg Potato Blackleg is a bacterial rot caused by the bacterium Pectobacterium atrosepticum (formally known as Erwinia carotovora pv. atroseptica). The infection starts as a black lesion at the base of the stem, which leads to foliage collapse followed...
Caused by:- The Bacteria Pectobacterium atrosepticum
Control:- There are no chemical controls available to gardeners for blackleg....

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Common Name:- Potato Common Scab
P_potcomscab Potato Common Scab is a bacterial disease of potato skin, which cause rough, scabby patches on the surface of the tubers.
Common scab is caused by the bacteria Streptomyces scabies which can be serious on potatoes, beetroot, carrots, radish...
Caused by:- The Bacteria Streptomyces scabies
Control:- In a garden where irrigation is available, scab can be reduced by k...

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Common Name:- Potato Cyst Eelworm
P_potcysteel Cysts of yellow potato cyst nematode Picture by Bonsak Hammeraas, Bioforsk - Norwegian Institute for Agricultural and Environmental Research, Bugwood.org.
There are two forms of Potato Cyst Eelworm or Nematode that attack and damage potatoes...
Caused by:- Two Nematodes of the Heterodera Genus
Control:- Infestations of Potato Cyst Eelworm can be predicted by monitoring ...

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Common Name:- Potato Dry Rot
P_potdryrot Potato Dry rot is caused by the fungus Fusarium several species of which have been attributed as causing Potato Dry Rot. Some are Fusarium sambucinum, Fusarium graminearum, Fusarium. solani var coeruleum, and Fusarium avenaceum; F. sambucinum is ...
Caused by:- The Fusarium fungi species
Control:- Dry rot can be reduced or even halted if a proper storage environme...

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Common Name:- Potato Early Blight.
P_potearblight Potato Early Blight is a common and sometimes serious disease which also attacks other members of the Solanaceae family. It is caused by the fungus Alternaria solani which has a worldwide distribution and can withstand repeated wet and dry conditi...
Caused by:- The Fungus Alternaria solani
Control:- Try to get all the potatoes out from the ground at harvest time.<br...

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Common Name:- Potato Gangrene
P_potgangrrot Potato Gangrene is a rot of the potato tuber usually in storage and is caused by the fungus Phoma exigua var. foveata which is a soil bourn pathogen.
Stems may become infected and in turn infect tubers. Infection of tubers mainly through sk...
Caused by:- The fungus Phoma exigua var. foveata
Control:- Potato Gangrene can be reduced if a proper storage environment is p...

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Common Name:- Potato Hollow Heart
P_potholhrt Potato Hollow Heart is a physiological disorder where the center of the tuber is hollow often in a star shape. This is often preceded by a brown center. To date no pathogen is associated with this condition and the tubers are safe to eat after cut...
Caused by:- Abrupt Changes In Growing Conditions
Control:- Avoid abrupt changes in growing conditions and manage watering sy...

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Common Name:- Potato Internal Rust Spot
P_potintrstspt Potato Internal Rust Spot is believed to be a physiological condition, probably due to low levels of calcium. It often occurs on light sandy soils which lave low organic content. Stress and high temperatures later in the season is also implicated ...
Caused by:- Soil lacking in Calcium and or Organic Matter
Control:- Incorporate organic matter into the soil before planting and apply ...

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Common Name:- Potato Late Blight
P_potblight Potato Late Blight is one of the worst disease problems for the potato grower and in history it is the cause of the Irish famine from 1845 to 1855. It can wipe out the plants almost overnight and, worse still, it can infect the tubers from the abo...
Caused by:- The Fungus Phytophthora infestans
Control:- Try to get all the potatoes out from the ground at harvest time.<br...

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Common Name:- Potato Powdery Scab
P_potpowscab Potato Powdery scab is caused by the fungus or slime mould Spongospora subterranea which first shows as small raised pimples beneath the skin. It also infects tomato roots and a few other plant species and is widespread in potato growing countries...
Caused by:- The Fungus Spongospora subterranea
Control:- Planting powdery scab-free seed will aid in control, as will avoidi...

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Common Name:- Potato Silver Scurf
P_potsilscurf Silver Scurf is a fungal disease of the potato tuber skin or periderm. It is caused by the fungus Helminthosporium solani and can infect tubers by either primary or secondary infection. Primary infection is caused by infected plant debris and seed...
Caused by:- The Fungus Helminthosporium solani
Control:- There does not appear to be any resistant varieties, but a visit to...

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Common Name:- Potato Spraing
P_potspraing Potato Spraing is a disease of potato tubers caused by two viruses the Potato Mop-Top Virus and the Tobacco Rattle Virus. Both viruses causes similar symptoms which are arcs of brown streaks in the flesh of the potato. Tobacco Rattle Virus is tran...
Caused by:- Two Viruses
Control:- Some varieties show good levels of resistance. Visit <a href="http:...

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Common Name:- Potato Viruses
P_potvirus Alfalfa mosaic virus on potato leaves. Picture from Wikimedia Commons.
Potatoes can be infected by many different viruses most will reduce yield and or tuber quality, but some are often symptomless or
In many cases, the symptoms are...
Caused by:- Various Viruses
Control:- Some varieties show some resistance to some viruses, therefore A vi...

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Common Name:- Potato Wart Disease
P_potwartdis Potato wart disease, caused by the fungus Synchytrium endobioticum, which is soil-borne and affects a number of other Solanum species. It was once a very serious disease of potato and is subject to quarantine restrictions around the wold. These q...
Caused by:- The Fungus Synchytrium endobioticum
Control:- Follow <a href="http://www.defra.gov.uk/planth/ph.htm"><font color=...

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Common Name:- Powdery Mildew
P_powderymldw Although several Powdery Mildew fungi are non specific, often different powdery mildew fungi tend to infect either plants in the same family or only one species of plant. Some powdery mildew occur on top of the leaves, stem, flowers and fruit and ...
Caused by:- Various Fungal spores
Control:- The best method of control is prevention therefore good hygiene and...

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Common Name:- Primula Brown Core
P_primulabrowncore Primular, Polyanthus and related plants grows slowly and leaves will yellow early. Plants wilt easily and the root system deteriorates. If roots are cut lengthwise there is a distinctive brown discolouration in the core. The fungus builds up in th...
Caused by:- The Fungus Phytophthora primulae
Control:- Remove infected plants as soon as possible. Soak the soil with Jaye...

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Common Name:- Privit Thrips
P_privetthrip The Privet Thrips, Dendrothrips ornatus (Thysanoptera: Thripidae) is an insect that is mainly a summer pest. Especially if the summer is hot and dry. In some countries they are called thunder flies. Although the plants recover well from attacks th...
Caused by:- The Insect Thrip Dendrothrips ornatus
Control:- There are several natural enemies such as <a href="/pests/269?telep...

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Common Name:- Proliferation Mutation
P_prolifmut One of many mutations or disorders that can affect plants is proliferation, which can affect of a range of plants. It is when one or more buds form in an already open bloom. The reasons for this is not known, but is probably the imbalance of hormo...
Caused by:- Various causes
Control:- There is rarely any need to take control measures unless it is happ...

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Common Name:- Pyracantha Leaf Miner
P_pycnthalfmnr Pyracantha(Firethorn) Leaf Miner Phyllonoryceter leucographella is the larvae of a moth of the Gracillariidae family and was unknown in the UK until about 1989.
This moth lays their eggs on the midrib of leaves of Pyracantha. They are pale ...
Caused by:- The Leaf Miner Phyllonoryceter leucographella
Control:- Leaf miners are difficult to control since they spend most of their...

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Common Name:- Pyracantha Scab
P_pyrcntrscab Pyracantha scab is a fungal disease of the blossoms, leaves and fruit of Pyracantha(firethorn), resulting in early leaf fall, loss of flowers and disfigured fruit. It is caused by the fungus Spilocaea pyracanthae, which also attacks Cotoneaster, E...
Caused by:- The Fungus Spilocaea pyracanthae
Control:- There are some fungicide sprays that will cure this scab, but spray...

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Common Name:- Pythium Root Rot
P_pythiumrtrt Pythium disease on Cowpea Picture by Howard F. Schwartz, Colorado State University, Bugwood.org.
Pythium Root Rot is a common plant disease caused by a genus of organisms called Pythium of the Pythiaceae family. They are closely related to ...
Caused by:- Various Species of the Pythium Genus
Control:- Remove infected plants as soon as possible along with the soil arou...

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Q
Common Name:- Quince Leaf Blight
P_quincelfblt Quince Leaf Blight is caused by the fungus Diplocarpon maculatum which is related to the fungus causing black spot in roses. It can be a nuisance on quince trees(Cydonia oblonga), the flowering quince (Chaenomeles) and all varieties of quince in h...
Caused by:- The FungusDiplocarpon mespili(Fabraea maculata)
Control:- Spray your quince tree with a copper based fungicide immediately an...

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Common Name:- Quince Powdery Mildew
P_quincepwdmld Powdery Mildew on Corgette.
Quince Powdery mildew is caused by the fungus Podosphaera leucotricha and also infects apples, pears, and other fruit trees. This fungus is found in nearly all parts of the world where these fruits are grown are ...
Caused by:- The Fungus Podosphaera leucotricha
Control:- The best method of control is prevention therefore good hygiene and...

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Common Name:- Quince Rust
P_qncerust The Quince Rust is caused by the fungus Gymnosporangium clavipes and like most rust diseases needs two hosts to complete its life cycle. The full name of this disease is Cedar-Quince Rust. Cedar-Hawthorn Rust (G. globosum), and Cedar-Apple Rust (G...
Caused by:- The Fungus Gymnosporangium clavipes
Control:- Monitoring rust canker on red cedar trees and temperatures during w...

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R
Common Name:- Rabbits
P_rabbit Rabbits are sometimes a problem in the garden as they eat herbaceous plants to the ground and chew the bark of trees at soil level which can kill the tree. They also dig a warren of tunnels in the soil thereby making a mess.
Caused by:- Rabbit (Oryctolagus cuniculus)
Control:- A strong wire mesh fence with mesh size no larger than 25mm buried ...

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Common Name:- Raspberry Beelte
P_rasbbtle The raspberry beetle Byturus tomentosus and it's larve, is one of the most destructive and annoying pest of raspberries, blackberries and loganberries, especially as they are not found until the ripe raspberries are picked and are being prepared f...
Caused by:- The Beetle Byturus tomentosus
Control:- The early fruiting berries are most likely to be affected, therefor...

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Common Name:- Raspberry Cane Blight
P_raspcnblt Raspberry Cane Blight is caused by the fungus Leptosphaeria coniothyrium which survives in the soil and enters the base of canes through splits in the bark, often the result of cane-midge attacks.
Dark patches appear on the canes, in May or...
Caused by:- The Fungus Leptosphaeria coniothyrium
Control:- Once spotted cut out and burn any affected canes. Cut back to below...

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Common Name:- Raspberry Cane Spot
P_raspcnspot Raspberry Cane Spot is caused by the fungus Elsinoë veneta which also affects Loganberry and Blackberry fruits. The symptoms are small purple spots that appear on the canes in May or June and gradually increase in size to form cankers which look l...
Caused by:- The Fungus Elsinoë veneta
Control:- Once spotted cut out and burn any affected canes. Cut back to below...

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Common Name:- Raspberry Leaf and Bud Mite
P_rasplfbdmite Raspberry Leaf and Bud Mite Phyllocoptes gracilis belongs to the Eriophyoidea or Tetrapodili which is a superfamily of herbivore mites. These mites are tiny sap-sucking pests that lives on the underside of the leaves during summer and overwinters ...
Caused by:- The Mite Phyllocoptes gracilis
Control:- Many acaricide and insecticides have been removed from sale due to ...

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Common Name:- Raspberry Rust
P_rasprust Raspberry Rust caused by Phragmidium rubi-idaei is a common, but rarely a serious fungal disease, but it can cause early leaf drop and reduced vigour.
This rust fungi like most Rust<...
Caused by:- The Rust Fungi Phragmidium rubi-idaei
Control:- Spray with a systemic fungicide as well as other fungicides especia...

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Common Name:- Raspberry Spur Blight
P_raspsprblt Raspberry Spur Blight is a common fungal disease caused by the fungus Didymella applanata it also occasionally attacks loganberries and is is particularly common during wet seasons. It causes purple patches in early Summer, centred around the buds...
Caused by:- The Fungus Didymella applanata
Control:- Spray with a systemic fungicide as well as other fungicides especia...

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Common Name:- Raspberry Viruses
P_raspvirus There are many viruses that attack Raspberries. Sometimes red varieties are immune to the effects whereas black varieties are not. Some viruses are notifyable and you should inform your local Plant Health Inspector or Caused by:- Various Viruses
Control:- There is no cure for viruses and plants are best destroyed as soon ...

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Common Name:- Rats
P_rats There are two main species of rats found around the world, both originate in the plains of Asia. The most common is the brown rat Rattus norvegicus and the black rat, Rattus rattus. The black rat is mainly associated with the plague in the middle ...
Caused by:- The mamals Rattus norvegicus and Rattus rattus
Control:- There are several things that can be done to discourage them in y...

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Common Name:- Red Spider
P_redspider1 Two genus of pest have the common name Red Spider mite. One is the Fruit Tree Red Spider mite — Panonychus ulmi — which mainly attacks vine as well as fruit trees such as apple, pear, cherry, currant bush and cane fruits. The other red spider ...
Caused by:- Red Spiders Tetranychus urticae & Panonychus ulmi
Control:- The best control is to spray with a systemic insecticide, but this ...

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Common Name:- Redberry Mite
P_redbrymte The Redberry Mite Acalitus essigi are microscopic members of the arachnid class(mites, spiders, false scorpions, harvestmen etc.) and the Eriophyidae family(Gall mites). This mite is highly specialised and can be a serious pest of commercially-pro...
Caused by:- The Eriophyid mite Acalitus essigi
Control:- Spraying in the spring with horticultural oils, in the dormant peri...

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Common Name:- Reversion
P_reversion Flowers of the George Lindley Taber variety of azalea, featuring a single flower from the same plant, in a reversion to the Omurasaki sport. Picture from Wikimedia Commons.
Reversion is when a plant known for a particular leaf shape, varieg...
Caused by:- Various Causes
Control:- Shoots that have reverted are usually much more vigorous than the v...

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Common Name:- Rhododendron Bud Blast
P_rhodbdblst Rhododendron bud Blast is a fungal disease of Rhododendrons and Azaleas caused by the fungus Pycnostysanus azaleae, which affects the tight dormant flower buds. This fungus is associated with infestations of the
Caused by:- The fungus Pycnostysanus azaleae
Control:- Treating Rhododendron Bud Blast is best done by a two pronged attac...

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Common Name:- Rhododendron Lacebug
P_rhodolacebg Rhododendron Lacebug Stephanitus rhododendri is a pest of species of rhododendron, sycamore, azalea, and evergreen trees.
Lace bugs nymphs and adult stages, live on the underside of leaves along with blackish fecal material stuck to the lea...
Caused by:- The insect Stephanitus rhododendri
Control:- Eliminating lace bugs before hatching is necessary to avoid visible...

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Common Name:- Rhododendron Leaf Hopper
P_rhodolfhpr The Rhododendron Leafhopper Graphocephala fennahi also known as the Rhododendron Cicada or the Green and Scarlet Leafhopper is a striking Green and purple insect that was native to the Americas until around 1900 when it was introduced to Europe an...
Caused by:- The insect Graphocephala fennahi
Control:- Repeated spraying in the Spring and Early Summer should eradicate t...

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Common Name:- Rhododendron Leaf Spot
P_rhodolfspt Septoria azalea leaf spot. Picture by Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services.
Rhododendron Leaf Spot is usually a fungal problem which results in rounded spots on the leaves. Seve...
Caused by:- Various Causes
Control:- If the leaf Spots are from fungi, which is more prevalent during we...

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Common Name:- Rhododendron Petal Blight
P_rhodoptlblt Rhododendron Petal Blight is caused by the fungus Ovulinia azalea although other fungi like Cercospora handelii, Phytophthora ramorum and Botrytis cinerea also causes these spots. Some of these fungi also affects other trees and plants.
It ...
Caused by:- The Fungus Ovulinia azalea and others
Control:- Remove and destroy infected flowers as soon as possible to minimise...

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Common Name:- Rhododendron Powdery Mildew
P_rhodopowmdw Rhododendron Powdery Mildew is caused by a few fungi probably from the Erysiphe (Microsphaera) Genus of fungi. Infection occurs in the spring or early summer, or may be carried over from the previous growing season. The symptoms are diffuse pale ...
Caused by:- Erysiphe (Microsphaera) Genus of Fungi
Control:- Spraying with fungicides containing Sulphur from early spring at re...

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Common Name:- Rhododendron Rust
P_rhodorust Chrysomyxa rhododendri on Spruce tree. Picture by Joseph O'Brien, USDA Forest Service, Bugwood.org.
Rhododendron Rust is mainly caused by fungi from the genus Chrysomyxa. Many of these had been identified as Chrysomyxa rhododendri. Like mos...
Caused by:- Mainly Chrysomyxa species of Fungi
Control:- As with any fungal disease one of the best ways of preventing it is...

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Common Name:- Robins Pincushion
P_robpincshn Robin's pincushion gall, Moss gall or Rose bedeguar gall develops on the common dog rose(Rosa canina) in late summer and autumn. This gall like most other galls are induced by insects feeding on the plant. In this case it is a wasp Diplolepis rosa...
Caused by:- The Wasp Diplolepis rosae
Control:- Controlling gall insects is best done before or just after the wasp...

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Common Name:- Root Aphids
P_rootaphids Root Aphids have a similar life cycle as normal Aphids, but instead of attacking the above ground parts of the plant they attack the roots of the plant. Like ordinary Aphids they suck th...
Caused by:- Various Aphids
Control:- Insecticides and insecticidal soaps can be applied as a soil drench...

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Common Name:- Root Knot Eelworms
P_rootkntneel Root Knot Eelworm is caused by several species of belonging to the Meloidogyne(Heterodera) Genus. In the northern climates it is mainly a pest of the greenhouse, but can infes...
Caused by:- Nematodes of the genus Meloidogyne(Heterodera)
Control:- Clear up infected plant debris and weed out unwanted plants.<br /> ...

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Common Name:- Root Mealybugs
P_rtmealybug Root or Ground Mealybugs are insects in several Genus like Cataenococcus, Geococcus, Pseudoccous or Rhizoecus of the family Pseudococcidae, and there are many species around the world. They prefer warm areas and therefore in the UK there are main...
Caused by:- Various Genus of the Pseudococcidae Familly
Control:- Root Mealybug is very difficult to control and every efforts should...

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Common Name:- Rose Aphids
P_roseaphid Roses are attacked by two types of aphids namely Greenfly and Blackfly. These aphids suck the sap and therefore take the strength out of Roses if not checked as soon as possible. They also transmit other viruses and diseases to the roses.
T...
Caused by:- The insect aphid Macrosiphum rosae
Control:- As an emergency quick solution I squish them between the fingers ...

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Common Name:- Rose Black Spot
P_blacksopt3 Rose black spot is specific to roses and all types are susceptible. It is caused by the fungus Diplocarpon rosae which kills the cells on the leaves of roses leaving brown to black spots on leaves. The spots may join together or remain separate.
Caused by:- The Fungus Diplocarpon rosae
Control:- Rake up and destroy fallen leaves in the autumn. Prune out all stem...

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Common Name:- Rose Bloom Balling
P_roseblmball Rose Bloom Balling is a condition where the flower bud develops normally to full size and starts to open, but the petals fail to open. It is caused by cool, damp conditions, often in a partially shady site, where the outer petals become waterlogge...
Caused by:- Weather Conditions
Control:- The only option is to cut off the damaged buds and wait for new o...

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Common Name:- Rose Grey Mould
P_mildew1 Rose Gray Mould is a common disease of hundreds of plants. It is especially problematic during periods of high rainfall and cool temperatures. It is caused by the fungus Botrytis cinerea
Caused by:- The fungus Botrytis cinerea
Control:- Controlling this fungus is often difficult as it is so widespread...

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Common Name:- Rose Leaf-rolling Sawfly
 p_roselfrlsfly The rose Leaf-rolling Sawfly Blennocolpa phyllocolpa lays its eggs in late Spring/Early Summer on the underside of the leaf and secrete a chemical that induces the leaf margins to curl downwards and inwards along their length forming a tube which ...
Caused by:- The Sawfly Blennocolpa phyllocolpa
Control:- Pick off any rolled up leaves before July as this when the larvae...

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Common Name:- Rose Leafhopper
P_roselfhpper The Rose Leafhopper Edwardsiana rosae can be a serious pest of rose, pear, apple and some hardwood trees by sucking the sap from the leaves. It resembles the White Apple Leafhopper, with whom it may co-exist, in appearance, habits, and damage to i...
Caused by:- The insect Edwardsiana rosae
Control:- Thorough spraying of infested plants with insecticide, preferably s...

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Common Name:- Rose Powdery Mildew
P_rosepwdmldw Rose Powdery Mildew is caused by the fungus Podosphaera(Sphaerotheca) pannosa. It is only one of many powdery mildews most of which are host specific to certain from cereals and grasses, to fruit trees, and broad-leaved shade trees.
The ma...
Caused by:- The Fungus Podosphaera(Sphaerotheca) pannosa
Control:- Improve circulation by pruning and keep the tree growing healthil...

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Common Name:- Rose Replanting Sickness
P_roserpltskns Rose sickness is a problem with roses where a rose has been removed and a new rose put in its place. The new rose either does not perform well or in some cases never properly establishes and dies. This problem lasts in the soil for many years.
Caused by:- Symbiosis fungi
Control:- Watering the soil with soil sterilant or removing most of the soil ...

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Common Name:- Rose Root Aphids
P_rosertaphd Rose Root Aphid Maculolachnus submacula have a similar life cycle as normal Aphids, but instead of attacking the above ground parts of the plant they attack the roots. Therefore they are...
Caused by:- The Aphid Maculolachnus submacula
Control:- Insecticides and insecticidal soaps can be applied as a soil drench...

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Common Name:- Rose Rust
P_roserust Rose rust is caused by the fungus Phragmidium tuberculatum and some other Phragmidium related species. Unlike most Rust, which have two hosts and each host produces spores that can only infect the other host, Rose Rust produces overwintering spore...
Caused by:- The Fungus Phragmidium tuberculatum
Control:- In the European Community the products permitted under organic regi...

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Common Name:- Rose Stem Canker and Dieback
P_rosestckrdbk There are several fungi that cause Rose Stem Canker and dieback. The most prevalent is Coniothyrium wernsdorffiae and others are Coniothrium fuckelii(Diaplella coniothyrium), Cryptosporella umbrina(Diaporthe umbrina), Phomopsis, Coniothyrium and A...
Caused by:- Various Fungi
Control:- Ensuring vigorous growth and removal of dead canes and stubs will h...

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Common Name:- Rose Viruses
P_rosevruses Rose Virus diseases like all other viruses can only be seen under an electron microscope. Therefore the only way to identify a virus is usually by the leaf and flower patterning or the stunting effect of the virus.
Virus symptoms may only a...
Caused by:- Various Viruses
Control:- The only cure is to remove and destroy by burning the infected plan...

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Common Name:- Rosy Apple Aphid
P_rosyaphd Rosy Apple Aphid, Dysaphis plantaginea, is one of several species of aphids that infest apple trees and like every aphid species suck the sap from the leaves and buds. The body of this aphid has a very waxy coating and usually a slight purplish or...
Caused by:- The Aphid Dysaphis plantaginea
Control:- Control depends on proper timing of insecticide applications. Overw...

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Common Name:- Rust
P_rust2 There are many different fungi that causes rust in various plants or trees. The name is very descriptive as rust often looks like a piece of iron going rusty. Often, but not always it is Orange-brown pustules that develop initially on the undersid...
Caused by:- Various Fungal spores
Control:- In the European Community the products permitted under organic regi...

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S
Common Name:- Salt Damage
P_saltdamage Salt in high concentration damages plants in many ways. First it raises the osmosis pressure of the soil by its high concentrations of sodium and chloride ions. This makes it difficult for the plant to take up water even though it is abundant. Thi...
Caused by:- Too much salts
Control:- Where you cannot avoid salt ensure good drainage so the salty wat...

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Common Name:- San Jose Scale Insect
P_sanjsescle The San Jose scale Quadraspidiotus perniciosus (Aspidiotus perniciosus, Comstockaspis perniciosa, Diaspidiotus perniciosus) insect is an extremely important pest pest of Apple, Peach, Pear and Plums and many more trees and plants. It is a quaranti...
Caused by:- The Scale Insect Quadraspidiotus perniciosus
Control:- Insecticidal sprays applied to developing overwintered individuals,...

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Common Name:- Sappy Bark
P_paperybk Sappy bark, which is also called pPapery Bark, is a fungal disease that causes the sapwood to go become spongy especially in wet weather. It is caused by the fungus Trametes versicolor and is a fungal disease of apple and some stone fruit trees. T...
Caused by:- The FungusTrametes versicolor
Control:- Trees should be invigorated by ensuring good drainage, maintaining ...

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Common Name:- Sawflies
P_sawfly The Blackheaded Ash Sawfly Tethida barda Adult and larvae. Picture by David Cappaert, Michigan State University and Lacy L. Hyche, Auburn University, Bugwood.org.
Sawfly is the common name for insects belonging to suborder Symphyta of the o...
Caused by:- Various Sawflies
Control:- Picking the larvae by hand can be done if the infestation is not ...

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Common Name:- Scale Insects
P_scaleinsects1 Scale insects are sap-sucking, limpet-like insect pests that weaken the growth of the host plant and can infest a wide range of ornamental plants and fruit trees.
They are usually easily seen as scales or shell-like bumps on plant stems and...
Caused by:- Several types of insects
Control:- In warm environments, like greenhouses, biological control can be u...

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Common Name:- Sciarid Flies
P_fungusgnats Scairid Flies or Mushroom flies are aslo called Fungus Gnats because it has been proven to carry various fungus spores on its body from one place to another. The main species is Bradys...
Caused by:- Many Genus and species of the Order Diptera
Control:- Allow the surface of composts to dry out a little before watering t...

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Common Name:- Sclerotinia Rot
P_slerotina Sclerotina Rot is caused by the fungal pathogen Sclerotinia sclerotiorum which has of a wide range of host from leaves, stems, fruit and roots in storage. The spores(sclerotium (plural sclerotia) which resides in the soil for at least five years n...
Caused by:- The fungus Sclerotinia sclerotiorum
Control:- As with any fungal disease one of the best ways of preventing it ...

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Common Name:- Scorching
P_scorch Scorch is caused by too much sun or by chemicals that the plant cannot cope with. It is particularly prevalent when water is on the leaves. The water droplets concentrate the sun rays and kill the cells of the leaves or petals. This is one reason ...
Caused by:- Too Much Sun
Control:- Take care when watering water in the early evening or very early in...

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Common Name:- Seiridium Canker
P_seiridcnkr Seiridium cankers, also called coryneum canker, are caused by the fungus Seiridium unicorne which needs a wound or crack in the outer defences of the tree. This is why trees under drought or other stress may succumb easily.
All Seiridium ca...
Caused by:- The Fungus Seiridium unicorne
Control:- The best control for Seiridium cankers is irrigating trees during p...

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Common Name:- Shakra(Plum Pox)
P_plumpox Plum Pox disease is caused by a virus the plum pox virus (PPV). It is also known as Sharka, and can infect a variety of stone fruit species including peaches, apricots, damsons, greeng...
Caused by:- The Plum Pox Virus
Control:- The only way to control this disease is to destroy all infected tre...

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Common Name:- Shanking
P_shanking Shanking is the technical term, where grapes do not ripen properly. It is also applied to Cabbages and other winter crops in the field that do not develop. In all cases it is caused by a restriction of the flow of plant nutrients. In grapes indiv...
Caused by:- Inadequate Growing Conditions
Control:- Use a foliar spray feed as soon as possible during berry developmen...

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Common Name:- Sharka
P_plumpox Sharka or Plum Pox disease is caused by a virus the plum pox virus (PPV) and can infect a variety of stone fruit species including peaches, apricots, damsons, greengages, plums, nectar...
Caused by:- The Plum Pox Virus
Control:- The only way to control this disease is to destroy all infected tre...

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Common Name:- Shieldbugs
P_shieldbugs The Green Shieldbug Acrosternum hilare Picture by Frank Peairs, Colorado State University, Bugwood.org.
There are several Genus of Shieldbugs which are named after their sheild like shape. They are also called chust bugs, and Caused by:-
Various Members of the superFamily Pentatomoidea
Control:- Usually no action is needed as they are rare and can be ignored, bu...

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Common Name:- Shothole Borers.
P_shotholebrs Shothole borer Scolytus rugulosus Picture by Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org.
Many species are known as Shothole Borers which are tiny brown or black beetles from the family Scolytidae that attack m...
Caused by:- Various species of the Scolytidae Family
Control:- White latex paint or stem wrappers on trunk and stems can protect t...

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Common Name:- Shothole leaves
P_shothole Stigmina fungus on Prunus picture byWhitney Cranshaw, Colorado State University, Bugwood.org.
Shothole in the leaves of plants is caused by a variety of different causes such as bacterial or fungal pathogens as well as some insect pests. I...
Caused by:- Various Bacteria, fungi and insects
Control:- To most effective prevention of leaf spot, apart from spraying with...

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Common Name:- Silver Fir Adelgid
P_blsmwlyadel Silver Fir Adelgid is known as the Balsam Woolly Adelgids, Adelges piceae and is a is a tiny, non-flying, sap sucking insect that attacks mainly Abies species of trees.
They are...
Caused by:- The Adelgid Adelges piceae
Control:- Spraying with insecticides is effective, but costly and is difficul...

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Common Name:- Silverleaf Fungus
P_slvrleaf Silverleaf Fungus Chondrostereum purpureum(Stereum purpureum) is found in temperate climates world-wide and attacks most species of the tree family Rosaceae, particularly the genus Prunus. The disease is progressive and often fatal and is more of ...
Caused by:- The Fungus Chondrostereum purpureum
Control:- Since the fungus produces most of its infectious spores in autumn a...

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Common Name:- Slime Flux
P_slimeflux Slime flux is a bacterial disease also called Bacterial Wetwood which attacks many trees such as apple, ash, aspen, beech, birch, cottonwood, elm, fir, hickory, maple, mulberry, oak, p...
Caused by:- Various Bacteria, Fungi and Yeast
Control:- It can be difficult to prevent the stem damage that leads to the de...

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Common Name:- Slime Moulds
P_slimemlds Fruiting slime mold. By ancient trail near confluence of East and West forks of the Hood River - east bank. Trail starts at end of Iowa Drive, Hood River, OR 97031. Picture by Adrian Eugene Fields from Wikimedia Commons.
Slime moulds were f...
Caused by:- Various species of the Protista Kingdom
Control:- No chemical control is necessary as plant growth is usually not aff...

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Common Name:- Slugs
P_slugs1 Slug is a gastropod molluscs that lacks a shell and most have evolved from snails that gradually lost their shells. In the Uk there are 29 species and most live on living and decaying plant tissue. Some plants like Delphiniums, Hostas, Marigolds, ...
Caused by:- Several species of slugs
Control:- There are hundreds of methods for killing or eradicating slugs some...

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Common Name:- Small Ermine Moths
P_smlermmths There are several species of Small Ermine Moths, which are small, whitish, elongated moths having a row of black dots along the sides of the body when the wings are folded and are about 1cm long. Some can defoliate certain plants trees or shrubs f...
Caused by:- Various species of Ermine Moths
Control:- Light infestations can be pruned out. Otherwise Spray forcible with...

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Common Name:- Smuts
P_smuts Corn Smut Ustilago maydis Picture by Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org.
Smuts are multicellular, parasitic, basidiomycete fungi of the order Ustilaginales that c...
Caused by:- Various Fungi of the Ustilaginales
Control:- The in most cases the fungus is present throughout the plant the in...

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Common Name:- Snails
P_snails1 Snails! What can I say, you either love them or hate them. I cannot make up my mind, but on the whole I hate them as they destroy many of my plants by eating them. On the other hand they do me a service in converting plant matter to fertiliser. Th...
Caused by:- The Snail Helix aspersa or Capaea species
Control:- There are many ways to get rid of snails from the garden, but none ...

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Common Name:- Snow Moulds
P_snowmld Snow mould fungi are active when the temperature is just above freezing and in moist conditions. These conditions occur most frequently under snow cover or anything else that covers the grass, such as fallen leaves.
Snow mould in grass is c...
Caused by:- Two Fungi Fusarium nivale or Typhula incarnata
Control:- The best way of preventing or reducing snow mould problems in lawns...

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Common Name:- Snowdrop Grey Mould
P_sndrpgrymld Grey mould on snowdrops(Galanthus [Gk. gala, milk; anthos, flower]) is caused by the fungus Botrytis galanthina and is closely related to the grey mould fungus Botrytis cinerea. This fungus only attacks Galanthus spp. especially in mild damp winte...
Caused by:- The Fungus Botrytis galanthina
Control:- Dig up affected plants along with some soil, and destroy preferable...

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Common Name:- Soft Rot
P_softrot Soft Rot is also called Bacterial Soft Rot as it is usually caused by various bacteria. Tubers, root and fruit are usually affected, but there is a wide range of host like potato, sweet...
Caused by:- Various Bacteria
Control:- Good husbandry and disease management is based primarily on sanitat...

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Common Name:- Soft Scale Insect
P_sftscleinct There are many kinds of Scale Insects all are specialised, limpet-like, immobile insects attached to some part of a host from which they suck the sap often exuding the sap sugars called...
Caused by:- The Scale Insect Coccus hesperidum
Control:- In warm environments biological control can be used in greenhouses ...

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Common Name:- Solomon Seal Sawfly
P_solslswfly The larval stage of Solomon’s Seal Sawfly Phymatocera aterrima can completely defoliate Polygonatum species and hybrids by early summer. These slow moving, grey, caterpillar-like larvae seems to suddenly appear from early June to July. During this...
Caused by:- The Sawfy Phymatocera aterrima
Control:- Remove the larvae from the underside of damaged leaves.<br /> Spra...

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Common Name:- Sooty Canker
P_sootyckr Sooty canker is a wilt disease of branches and is caused by the fungus Nattrassia mangiferae (formerly Hendersonula toruloidea) and usually occurs over several seasons. This fungal spores can cause lung disease in humans.
The fungus enters ...
Caused by:- The fungus Nattrassia mangiferae
Control:- Wear masks when handling the black spore infected branches.<br /> ...

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Common Name:- Sooty Mould
P_sootymld The Sooty Moulds is a secondary affliction which grows on and feeds on the honeydew excreted by insects and which falls on the leaf surface. Plant leaves and stems or branches in extreme cases, become blackened and are usually sticky to the touch....
Caused by:- Usually Various Sap Sucking insects
Control:- There is no direct control measures for sooty mould, but deal with ...

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Common Name:- Sparrows
P_sparrows The Sparrows Passer domesticus is probably the most often seen of British birds, also known as House Sparrows they live in close proximity to man and build their nests in holes, thatch, hedges, sheds, warehouses and anywhere with an easy source of...
Caused by:- The Bird Passer domesticus
Control:- NOTE: The Dunnock, a close relative of the house sparrow and a prot...

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Common Name:- Spinach Leafminer
P_beetleafminer4 There are at least two Spinach Leafminer of the Pegomya species. One Pegomya hyoscyami is the same as the beet leafminer. They are small anthomyiid flies whose larvae attack the leaves of spinach, beets, Swiss chard, lambs quarter, and other weed...
Caused by:- The Larvae of Pegomya species
Control:- If the infestation is not large it is possible to remove the affect...

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Common Name:- Splitting
P_splitting Fruits such as apples, cherries, pears, plums, tomatoes and others of various kinds are prone to splitting. This is not a disease, but is usually due to environmental conditions. The main environmental conditions is sharp changing in growing condi...
Caused by:- Environmental Conditions
Control:- The best way to avoid splitting is to keep conditions as even as po...

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Common Name:- Springtails
P_springtails There are many Genus and species of Springtails, which belong to the Order Collembola. Their habitats range from snow covered with algae to the intertidal areas on the shoreline. All require a moist or wet environment and can emerge any time of th...
Caused by:- Insects from the Order Collembola
Control:- In the house Springtails are easily eradicated by several means suc...

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Common Name:- Squirrels
P_squirrels Squirrels belong to the large taxonomic family Sciuridae. The family includes tree squirrels, ground squirrels, chipmunks, marmots (including woodchucks), flying squirrels, and prairie dogs. Squirrels are indigenous to the Americas, Eurasia, and A...
Caused by:- Members of the Family Sciuridae
Control:- Any management methods needs to be over a wide area as squirrels ...

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Common Name:- Stem and Bulb Eelworm
 p_narcissuseelworm1 There are many, many Eelworm(nematode) a few are benficial and sold as biological control for such things as slugs and leatherjackets etc, but most are pests in various plants. Most are microscopic and live in the soil, but there is also some that...
Caused by:- The Nematode Ditylenchus dipsaci
Control:- Good hygiene by removing dead plant materials, crop rotation, wee...

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Common Name:- Stink Bugs
P_shieldbugs The Green Shieldbug Acrosternum hilare Picture by Frank Peairs, Colorado State University, Bugwood.org.
There are several Genus of Stink Bugs which are named after their sheild like shape. They are also called chust bugs, and Caused by:-
Various Members of the superFamily Pentatomoidea
Control:- Usually no action is needed as they are rare and can be ignored, bu...

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Common Name:- Storage Rots
 p_storerots Fruits, Bulbs, Roots and Tubers start to rot during storage. In many cases the rot is initialised when the plant was producing the above storage items and the storage conditions makes rotting inevitable.
In some cases the rotting agent is p...
Caused by:- Various Fungi, Bacteria, Viruses or Worms.
Control:- Properly clean and sterilise storage containers or rooms.<br /> Al...

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Common Name:- Strawberry Black Eye
P_stbryblkeye Strawberry Black Eye is a physiological problem caused by a late frost when the Strawberry flowers have opened. The frost damages the central florets of the flower causing it to turn black, but the petals remain white. Affected flowers will not se...
Caused by:- Frost Damage
Control:- Avoid planting strawberries in areas known tho be frost pockets o...

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Common Name:- Strawberry green Petal
P_stbrygnptl It is believed that a virus or less likely a phytoplasma is responsible for the flowers of strawberries to revert to forming leaves, which is known as Strawberry Green Petal.
The flowers are reduced in size with green petals and few if any ...
Caused by:- A virus or phyotplasma
Control:- Destroy and replace plants as soon as yields begin to fall, usually...

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Common Name:- Strawberry Grey Mould
P_stbrygrymld Strawberry Grey mould is caused by the fungus Botrytis cinerea which is widespread and also attacks many other plants. See below.
At flowering time, spores, blown by the wind, enter open flowers and lie dormant until the fruits begin to rip...
Caused by:- The Fungus Botrytis cinerea
Control:- Controlling this fungus is often difficult as it is so widespread s...

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Common Name:- Strawberry June Yellows
 p_stbryjnyell Strawberry June Yellows is a is a phytoplasma disease that affects strawberry plants. A pytoplasma is a very small (1 micrometre) bacteria like organism that are parasites of plant phloem tissue that transport nutrients around the plant. They are ...
Caused by:- The phytoplasma Candidatus Phytoplasma australiense
Control:- Plants should be removed and destroyed to protect other plants in t...

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Common Name:- Strawberry Leaf Spot
P_stbrylfspt Strawberry Leaf Spot is caused by the fungus Mycosphoerella fragarics and is perhaps the most common of strawberry diseases. It is also called spot disease, sun-burn, sun-scald, Leaf Blight, and sometimes mistaken for strawberry rust.
The f...
Caused by:- The Fungus Mycosphoerella fragarics
Control:- There are varieties that has varying degrees of resistance to thi...

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Common Name:- Strawberry Mite
P_stbymites There are several Tarsonemid mites that attack strawberries which all give similar symptoms. Strawberry mite Phytonemus pallidus(Steneotarsonemus) also known as the Cyclamen Mite is le...
Caused by:- The Tarsonemid Mite Phytonemus pallidus
Control:- A broad spectrum insecticide may cause more damage than a specifi...

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Common Name:- Strawberry Red Core
P_stbryrdcore Strawberry Red Core is a disease of the roots of the strawberry plant and is caused by the fungus Phytophthora fragariae. It is also known by other names such as Strawberry Red Stele, Lanarkshire disease because it was first reported from that are...
Caused by:- The Fungus Phytophthora fragariae
Control:- Disease incidence and severity can be minimised by having well drai...

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Common Name:- Strawberry Seed Beetle
P_stbrysdbtle The Strawberry Seed Beetle Harpalus rufipes is a significant pest of several crop species -- including grains, legumes and strawberries. It has a world wide distribution. The beetle is noted for removing and feeding on only the seeds from the surf...
Caused by:- The Beetle Harpalus rufipes
Control:- No effective insecticide is known, therefore it is best to keep are...

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Common Name:- Strawberry Viruses
P_stbryvirs Strawberry Crinkle Virus Cytorhabdovirus (SCrV) Picture by Dr W. Jelkman, Biologische Bundesanstalt für Land- und Forstwirtschaft, Bugwood.org.
There are probably over 30 viruses that can affect Strawberry plants(Fragaria species). Virus i...
Caused by:- Various Viruses
Control:- There is little that can be done when viruses strike and the only t...

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Common Name:- Sweetcorn Smut
P_smuts Corn Smut Ustilago maydis Picture by Florida Division of Plant Industry Archive, Florida Department of Agriculture and Consumer Services, Bugwood.org.
Sweetcorn Smut is caused by the fungus Ustilago maydis which is wind blown and infect any...
Caused by:- The Fungus Ustilago maydis
Control:- It is spread by water (rain or other) splashing from the infected p...

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Common Name:- Swift Moth
P_swftmoth The Common Swift Moth Picture by Jeffdelonge from Wikimedia Commons.
There are several species of Swift Moths, but the two most troublesome to gardeners are the Ghost Moth Hepialus humuli and the Common Swift moth Korscheltellus lupulina (f...
Caused by:- Moths of the Family Hepialidae
Control:- The Ghost Moth Picture by Engeser from Wikimedia Commons.There is n...

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Common Name:- Sycamore Anthracnose
P_sycantnose American sycamore (Platanus occidentalis L.) with anthracnose. picture by Joseph O'Brien, USDA Forest Service, Bugwood.org
Sycamore anthracnose is caused by the fungus Apiognomonia veneta(Gnomonia platani) which is the same fungus that caus...
Caused by:- The Fungus Apiognomonia veneta(Gnomonia platani)
Control:- Sycamore and Plane trees should be planted where they receive good ...

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Common Name:- Sycamore Sooty Bark Disease
P_sycmrestybrk Sycamore Sooty Bark disease is caused by the fungus Cryptostroma corticale which is a relatively new disease (1945) to the UK. It prefers warmer climates and has been known on stored Maple logs under the bark and is also known as MAPLE Bark diseas...
Caused by:- The Fungus Cryptostroma corticale
Control:- There is no treatment, making Sooty Bark Disease impossible to prev...

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