Efficacy of botanical extracts against termites on maize (Zea mays (L.)) under field condition in western Ethiopia

Abstract

Maize (Zea mays L.) is grown popularly in the world. It is severely attacked by termites. Insecticides are widely used to control, but could not minimize termites’ damage mainly because of resistance development and easily break down of the active ingredients. Hence, field experiment was conducted with the aim of evaluating different botanical crude extracts from leaves of Croton macrostachys (Hochst), Jatropha curcas L. and Phytolacca dodecandra L. for the management of termites.  The experiment was conducted at Wollega University (wu) under irrigation and rain fed conditions. Leaves of the botanicals were collected from experimental sites in western Ethiopia and dried under shade. The dried leaves were grounded to a fine powder using a small hand-operated manual grinder and the powder was further sliced with analytical mill and sieved through a 0.25 mm pore size mesh to make uniform fine dust particle. The treatments were C. macrostachys, P. dodecandra, J. curcas, C. macrostachys + P. dodecandra, C. macrostachys +J. curcas, P. dodecandra + J. curcas, C. macrostachys + P. dodecandra + J. curcas. Untreated check was used for comparison. For treatment preparation, 300 g. of each botanical leaf powder was soaked in 1000 ml distilled water for 72 hrs. The mixtures were filtered with clean cheese cloth and stored in a beaker of 250 ml capacity. The experiment was laid-out in a Randomized Complete Block Design (rcbd) in four replications. Shallow holes for maize seed planting were prepared well ahead of planting on the experimental plots. From the stock solution of each botanical, 20 ml was drenched to each planting hole 10 days before planting and continued at all maize growth stages. Treatments were applied using 30 ml capacity Syringe. Data on termite damage symptoms were collected two days before planting and two days after treatment application at every growth stage. The results revealed that mixed botanicals treatments were significantly (p<0.05) superior to non-mixed botanical treatments in the management of termites. The highest number of foraging termites, galleries and mounds were recorded in the untreated check plot, while the lowest was recorded in the mixed botanical treatments. Moreover, the highest number of maize stand count, maize cobs and maize yield were recorded from plots that received mixed botanicals and the lowest were recorded from the untreated plot. In conclusion, mixtures of C. macrostachys, J. curcas and P. dodecandra can be used as part of an integrated termites’ management.