Effects of Azadirachta indica products on the management of Ootheca mutabilis on Telfairia occidentalis in Calabar, Southeast Nigeria

Abstract Field experiments were conducted from 2003 to 2006 to evaluate the use of neem, Azadirachta indica , seed powder and extract and their time and intervals of application in the management of Ootheca mutabilis on Telfairia occidentalis (Fluted pumpkin) in Calabar, Cross River State. Seed powder and extract were used as soil drench and foliar spray at the rates of 20 kg ha −1 and 30 kg ha −1 , respectively. The control treatment had no A . indica application. In the second experiment, 30 kg ha −1 of A . indica seed powder was soil drenched at seed germination and symptom expression using three intervals (7, 14 and 21 days after germination (DI)). The treatments were arranged as factorial experiments in a randomised complete block design (RCBD) and replicated three times. The lowest population of O. mutabilis (1.97 per stand) was observed when 30 kg ha −1 of the powder was soil drenched as against 3.93 on foliar application and 12.56 on the control. The interaction was also significant where the lowest population of O. mutabilis per stand was 1.40 and 1.44 observed when 30 kg ha −1 of each factor was combined. The percentage defoliation was 3.20% and 2.24% in 2003 and 2004 in plots that received soil application and 7.32% and 7.38 on the foliarly treated plots, respectively, while 45.98% and 55.79% defoliation was observed on the control. The highest yield of 4.03 t ha −1 was observed when A. indica seed powder was applied into the soil. Application of A. indica seed powder at germination and at 7 days interval (7 DI) resulted in significantly ( P  ≤ 0.05) lower population of O. mutabilis (1.69–3.08 per stand) than 7.05–9.61 per stand that was observed when application was at symptom expression, while the percentage defoliation was 4.96–8.92 at germination compared to 30.42–41.38 observed when application was done at symptom expression. Application of A. indica seed powder at germination and at 7 DI resulted in significantly ( P  ≤ 0.05) higher harvestable vines and leaves of 3.29 t ha −1 and 4.01 t ha −1 than 1.37 t ha −1 and 2.21 t ha −1 that was harvested at symptom expression in 2005 and 2006, respectively. The use of A. indica products in the management of O. mutabilis is confirmed in this study and should be encouraged especially for resource poor farmers, this product is easy to obtain and processed with relatively low toxic effects.