Pink Stem Borer:
Symptoms:
- Caterpillar is smooth and pink coloured. Moth is medium sized stoutly built having straw coloured forewings with dark brown longitudinal streak in the middle of the wing.
- Larvae congregate inside the leaf whorls and feed on the central leaves causing typical ‘pin holes’ and later bore into the central shoot and severe feeding results in drying of the central shoot called dead heart formation or dead heart symptoms in the early stage of the crop.
Management:
- Cultural Control- Collection and burrying stubble and stalks or ploughing and destroying crop residue, removal of infested plant parts or infested plants through hoeing are recommended. Intercropping maize with cowpea reduces the incidence of this insect.
- Mechanical Control- Bird perches @ 10 in number/ acre should be erected for facilitating field visits of predatory birds.
- Biological Control- Release eggs of Trichogramma minutum @ 20,000/acre at weekly interval 4-5 times starting with complete germination of the crop checks this pest effectively.
- Chemical Control- Spray of Cypermethrin 10% EC @ 220-300ml dissolve in 250-300 lit. of water/acre.
Downey Mildew:
Symptoms:
- Chlorosis, white stripes, stunting with downy fungal growth on both leaf surfaces are the characteristic symptoms. Malformation of tassels in infected plants.
Management:
- Cultural Control- Destruction of plant debris. Removal and destruction of collateral hosts. Grow resistant hybrids like DHM-1, DHM-103, DMR-5 and Ganaga II. Deep summer ploughing. Crop rotation with pulses.
- Biological Control- Soil application of Pseudomonas fluorescens or Trichoderma viride @ 1 kg / acre + 25 kg of well decomposed FYM (mix 10 days before application) or sand at 30 days after sowing.
- Chemical Control- Seed treatment with Metalaxyl-M 31.8% ES @ 2.4 ml/kg seed. Spray of Mancozeb 75% WP or Ziram 80 % WP or Zineb 75 % WP @600-800g dissolve in 250-300 lit. of water/acre starting from 20th day after sowing.
Leave a Reply