Maize cultivation in India is gaining rapid momentum due to its good market price and high demand of grains for poultry feed, animal feed and export industry . As a result, acreage under maize cultivation is increasing. Increase in acreage and availability of crop at different stages resulted in insect pest and disease pressure .Among the pests, insects like Fall Armyworm , Stem borer, Cob borer and disease like Wilt and Downy mildew incidence are major menace in maize cultivation.

Disease :

Downy mildew is a fungal disease caused by organism Peronosclerospora sorghi. Source of Primary infection is soil borne hibernating fungal spores which germinate in saturated wet soil under favourable climatic conditions and swimming zoospores affect young plants. Secondary infection takes place through rain and wind dispersal of spores from infected plants. Alternate host of pathogens are sugarcane,sorghum and grasses.

Symptoms:

1. Symptoms appear on 10 days crop
2. First symptom appear as chlorotic stripes in younger leaves. All leaves show chlorotic streaks and wilt.
3. Surest indicator of disease is appearance white infected plants randomly in the field and downy fungal covering on underside of leaves.

4. As the plant ages leaves become narrow, brown, abnormally erect and appear as dried out
5. At later stages mature tassels become malformed leading to crazy top symptoms
6. Ear formation is interrupted and sterility of seed occurs .

Control measures :

1. Seed treatment of metalaxyl 70%WP or Metalaxyl 31.8% ES as per recommended dose
2. Uprooting of infected plants at early stage of infestation and burning the plants will minimize further spread of disease
3. Spraying of Metalaxyl +Mancozeb @2.5 g.lit of water at 10-15 days after sowing ( need based Second spray of same dose at 25 days)
4. Spray Azoxystrobin18.2% + Difenoconazole 11.4% 0.3 grams in 1 lit of water.
5. Adopting recommended spacing, population and Fertilizer schedule

Some times farmers get confused due to downy mildew infestation with Iron deficiency . Following are difference of DM and iron deficiency symptom:◙ White plants with white streaks of iron deficiency appear wide spread in the field, while DM infected white plants appear randomly in the field. ◙ Downy white growth will not appear on under side of leaves in Fe deficient plants(Observe early in the morning for downy growth)