1. Root rot (Charcoal rot)
Causal organism : Macrophomina phaseolina
Symptoms: Affected plant exhibits brown discoloration at the stemclose to soil. Leaves become yellow, droop and plants die in patches.Bark shredding is noticed in stem and root. The fungus produces dark 290 brown sclerotia. It also forms pycnidia bearing hyaline, single celled,elliptical conidia.
Favourable Conditions : Day temperature of 30˚C and above; Prolonged drought followed by copious irrigation.
2. Leaf blight
Causal organism : Alternaria sesame
Symptoms:Spots are round to irregular, necrotic with concentric rings in The center. Several spots coalesce leading to blight.3. Powdery mildew
Causal organism : Erysiphe cichoracearum
Symptoms: Leaves show white powdery growth on the upper surface.Often the entire lamina is covered by fungal growth. Severe infection leads to malformation of leaves. The white growth consists of hyaline,septate mycelium, conidiophores and chains of conidia.
Favorable Conditions : Dry humid weather; Low relative humidity.
Causal organism : Candidatus Phytoplasma
Symptoms: The floral parts are altered into green leafy, phylloid structures. Plant exhibits clusters of leaves at the axil and also at the terminal portion which gives a bushy appearance to the plant. The phytoplasma is transmitted by the jassid vector, Orosius albicinctus.
1.Seed treatment: Treat the seeds with any one of the followingP. fluorescens @ 10g/kg of seed, T. viride @ 4g/kg of seed, Thiram @4g/kg of seed, Carbendazim @ 2g/kg of seed291
2.Powdery mildew: Apply any one of the following. Sulphur dust 25kg/ha or Wettable sulphur 25 kg/ha
3.Alternaria blight: Spray Mancozeb 1000g/ha
4.Root rot: Soil application of P. fluorescens or T. viride – 2.5 Kg / ha +50 Kg of well decomposed FYM or sand at 30 days after sowing. Spotdrench Carbendazim – 1 gm/ litre
5.Phyllody :Remove and destroy infected plants.To control vector, spray Monocrotophos 36 or Dimethoate 30 EC 500 ml/ha combined with inter cropping of Sesamum + Redgram (6 : 1)