Brinjal Diseases PDF

# Diseases of Brinjal ## S.N. | Name of disease | Pathogen ------- | -------- | -------- 1 | Fruit rot/Phomopsis blight of Brinjal | _Phomopsis vexans_ 2 | Little Leaf of Brinjal | Phytoplasma-like organism (PLO) 3 | Bacterial Wilt of Brinjal | _Pseudomonas solanacearum_ 4 | Alternaria leaf Spot |...

# Diseases of Brinjal ## S.N. | Name of disease | Pathogen ------- | -------- | -------- 1 | Fruit rot/Phomopsis blight of Brinjal | _Phomopsis vexans_ 2 | Little Leaf of Brinjal | Phytoplasma-like organism (PLO) 3 | Bacterial Wilt of Brinjal | _Pseudomonas solanacearum_ 4 | Alternaria leaf Spot | _Alternaria melongenae_, _A. solani_ 5 | Damping off | _Pythium aphanidermatum_ 6 | Cercospora Leaf Spot | _Cercospora solani_- _melongenae_, _C. solani_ 7 | Verticillium wilt | _Verticillium dahliae_ ## 1. Fruit rot/Phomopsis blight of Brinjal This disease was first time reported in 1914 from Gujrat and since appears from several parts of country causing seedling blight, leaf spot and fruit rot. Phomopsis blight is an unsightly disease that not only harms eggplants but also makes them inedible and unmarketable. This disease causes over 50 per cent losses in production and productivity in various parts of the world. ### Pathogen It is caused by fungus _Phomopsis vexans_ (Perfect stage- _Diaporthe vexans_) _Phomopsis vexans _is a pycnidial fungus with an apparent sexual form in the genus Diaporthe, easily seedborne and producing large numbers of conidia. Pycnidia with or without beak are found in the affected tissue. They are globose or irregular. Conidiophores in the pycnidium are hyaline, simple or branched. The fungus produces large number of alpha and beta conidia. Conidia (Pycnidiospores) are hyaline, one celled and sub cylindrical. Ascospores are hyaline, narrowly ellipsoid to bluntly fusoid with one septum. ### Symptoms: * Phomopsis blight and fruit rot can cause disease on eggplant leaves, stems, and fruit. and also causes seedling damping off. * Small circular, grey to brown colour spots with light centers develops in leaves. * Lesions often become numerous and cover large areas of leaves. * Severely infected leaves torn become yellow and wither (shrivel or dry up). * Pale to light brown sunken, soft with surrounding margin of black fruit bodies spots develop on the old fruits. * If conditions become dry, infected fruit become shrivelled, dry and form black mummies. * Affected fruit are much larger with minute, sunken, dull dusky spots and soft & watery but later may become black and mummified. * Severely affected fruits show rotting of the entire flesh. ### Mode of spread and survival: The fungus survives in the infected plant debris in the soil. It is seed borne. It is specific to brinjal and when once the seed are sown or the seedling transplanted in infected soil, the organism becomes active and infects the plants. The spores are spread by rain splashes. The fungus spreads through implements and insects. ### Management: * Deep summer ploughing, collection and destruction of diseased plant debris. * Use healthy seeds collected from healthy fruits and healthy field. * At least three-year crop rotation is required with any non-host crop. * Seed should not be taken from diseased fruit. * Seeds should be dipped in hot water at 50°C for 30 min. spraying with difolation 0.2% or captan 0.2% in the nursery and field at 7 – 10 days interval controls the disease. * Seedling treatment with carbendazim (1 g/kg seed) or Thiram (2 g/kg seed) for 30 minutes * Spraying the crop in the field with zineb 0.2% or Bordeaux mixture 0.1% is effective in controlling phomopsis blight. ## 2. Little Leaf of Brinjal ### Economic Importance: This disease of brinjal was reported from India in 1938 and as far as known it occurs only in India and Sri Lanka. In almost all the states of the country it has become a serious problem facing brinjal cultivation. The yield loss is hundred per cent in the diseased plants. ### Causal organism: It is caused by Mycoplasma-like organism (MLO)/Phytoplasma-like organism (PLO) Little leaf was first considered a disease caused by a virus. In 1969 it was attributed to a mycoplasma-like organism, closely related to aster-yellows and curly top. ### Symptoms: * The characteristic symptom is the stunting of the plant particularly reduction in size of the leaves, which are malformed into tiny chlorotic structure. * The petioles are so short and the leaves appear to be sticking to be stem. * Such leaves are narrow, soft, smooth and yellow. Newly formed leaves are much more shorter. * The internodes of the stem are also shortened. * Auxiliary buds get enlarged but their petioles and leaves remain shortened gives the plant a bushy appearance. * Mostly, there is no flowering but if flowers are formed they remain green. Fruiting is rare. ### Mode of spread and survival : It is a sap transmissible disease. It occurs in nature on _Datura fastuosa_ and _Vinca rosea_. In nature the disease is transmitted by leaf hoppers, _Hishimonas phycitis_ (Cestius phycytis) and while _Empoasca devastans_ is a less effective vector. Perpetuation of the phytoplasma is through weed host. This disease has a very wide host range. ### Management: * The severity of the disease can be reduced by destruction of affected plants. * Eradication of volunteer crops/plants previous season and Solanaceous weeds that can carry the disease. * Change the transplanting of brinjal in late June or early July in order to avoid high populations of the vectors. * New crop should be planted only when diseased plants in the field and its neighbourhood have been removed. * Imidacloprid 17.8 SL @ 1 ml/3 lit. or Thiomethoxam 25 WDG @ 1gm/3lit or Buprofezin 20 SC @ 2 ml/lit. has been recommended for vector control. * Although mycoplasmas are reported to be suppressed by tetracyclines, field application of this method has not yet been recommended. * Cultivars such as Pusa Purple Cluster, Arka Sheel, Aushy, Manjari Gota and Banaras Giant show moderate resistance to resistance in the field.