Field Efficacy of Botanical and Chemical Insecticides against Maize Fall Armyworm [(Spodoptera frugiperda (J.E. Smith)] in Central Zone of Tigray, Ethiopia

Maize (zea mays) is one of the most important crops to feed Ethiopia's growing population and a significant source of revenue for many farmers with limited resources. However, the production of this crop is constrained by the invasion and widespread infestation of the fall army worm. Fall armyworms affect maize plant in whole from seed germination to defoliation of the leaves and damage to the ears which consequently leads to poor crop yield. Therefore the current study was initiated with a specific objective to screen effective insecticides and botanicals in controlling maize fall armyworm and thereby increase maize productivity. The experiment was carried out at Axum agricultural research center Rama research site during 2020. It was laid out in a randomized complete block design (RCBD) replicated three times having 5x5m2 plot size, 1.5 and 1m spacing b/n reps and plots. The treatments consisted of three synthetic insecticides Coragen 200 SC(chlorantraniliprol) at 0.25lt/ha, Karate 5%EC(lambda-cyhalothrin) at 1lt/ha, abema 3%EC (abamectin20g/l + emamectin benzoit 10g/l) at 1lt/ha and three botanical extracts Azadirachta indica, Schinnes molle and Nicotaia glauca at 50 gm/l with untreated check. The results showed that application of insecticides (coragen, abema, karate) and botanical extracts (Azadirachta indica); significantly reduced the fall armyworm larvae by (86, 82, 53 and 30)% respectively, compared to the untreated check at 7 days after spray. The least number of larvae was recorded in plots treated with coragen and abema (1.05and1.27 larvae per plot). FAW infestation was significantly decreased in plots treated with Coragen and abema (13 and 14%) compared to the infestation level in the untreated plots (56%) at 7 days after 2nd spray. Comparatively the neem seed kernel sprayed plots showed significant reduction (30.62%) than the untreated check (56.26%). Similarly a week after spray one and two these insecticides were still effective in reducing the leaf damage. The highest leaf damage (up to 7 scale) was recorded on the untreated check and the lowest leaf whorl damage (1) was recorded on coragen treated plots after spray. The other non target insects (un identified) were recorded in each plot and significantly low in all treated plots (P ≤ 0.05) than in the untreated check. The yield obtained was higher in the treated plots but statistically non significant difference with the untreated check. In the present study; coragen (chlorantraniliprole) at twice spray were recommended to control maize fall armyworm and Azadirachta indica as eco-friendly option of FAW integrated pest management.