Field Evaluation of Insecticides for Asian Corn Borer on Vegetable Corn, Pangasinan, Philippines, 1980

• Published in: Insecticide and acaricide tests 1981-01, Vol.6 (1), p.74-74
• Main Authors: Litsingerand, J. A., Cruz, C. G. dela, Paragna, F.
• Format: Article
• Language: English
• ISSN: 0276-3656
• DOI: 10.1093/iat/6.1.74a

Five trials on farmers’ fields evaluated 33 insecticides on vegetable corn for Asian corn borer in early monsoon season in Pao village, Manaoag municipality, Pangasinan province, Philippines. The 75-day corn variety precedes puddled rice. Corn (2-4 seeds/hill; 50-cm between hills) was planted by hand in furrows 1-m wide and received 60 kg N|/ha. The trial fields were planted 1-2 months later than the surrounding farmers’ fields in order to obtain high corn borer populations. Ridomil applied as a seed treatment (2 g ai/kg seed) ensured protection against downy mildew Sclerosporaphilippinensis Weston which normally infects late plantings. Sprays were applied 4 times in 650 l/ha spray volume by a manually operated 19-1 knapsack sprayer with a fan jet nozzle. Azodrin served as a check in each trial. Granulars were applied once by hand in the whorls. Plot size was 100 m2 in a randomized complete block design replicated 4 times. Rainfall was 522 mm, RH averaged 85%, and the mean daily maximum and minimum temperatures were 32° and 24°C, respectively, from 20 days after crop emergence to harvest. At harvest 50 plants/plot were examined and cut open to record the number of corn borer tunnels and larvae + pupae (inside and outside the stems). Yield was based on 25 m2 . Ears were sorted by length to select those which were marketable (> 10 cm). Insect damaged ears are marketable to local consumers.