Field Evaluation of Foliar Insecticides for Postflowering Mung Bean Insects, Pangasinan, Philippines 1979-80

Three trials on farmers’ mung bean fields planted on Dec 11 in the village of Pao, Manaoag municipality, Pangasinan province evaluated 16 foliar insecticides against post-flowering mung bean insects, predominantly Heliothis. Each insecticide was applied 25 and 35 days after crop emergence (Test 1 and 2) at 700 l/ha spray volume to 4 replicated plots (50 m2) by a manually operated, 19-1 knapsack sprayer with a fan jet nozzle in randomized complete block design. All plots, including the check received preflowering insecticide - 0.5 kg ai Azodrin/ha on 2 and 12 days after crop emergence (DE). Decis at 0.03 kg ai/ha was included in each trial as the standard check. Plastic sheeting (1-m wide) was held between plots to prevent spray drift. Mung bean (300,000 plants/Via) was broadcast sown and harrowed into tilled seedbeds (plowed and harrowed by draft animal power) on fields previously planted to puddled rice during the monsoon season. Fields were irrigated once to ensure even germination. Rainfall was 6 mm, RH averaged 79%, and the mean daily maximum and minimum temperatures were 32°C and 18°C, respectively for the 25-60 DE crop interval.