Evaluation of the potential of chili pepper and neeem leaf aqueous extracts to control fall armyworm (spodoptera frugiperda) on maize plants.

Abstract

FAW is a cosmopolitan and highly polyphagous insect pest that attacks more than 80 plant species. (PrasannaB., 2018). In response to the damage caused by FAW, a number of control measures have been used. Most farmers have been using synthetic insecticides due to their faster pest knockdown effect however synthetic insecticides have various side effects among which include being non-biodegradable, non-specific, hazardous to handle and are too costly to (Oyewusi., 2019). Due to the side effects of synthetic insecticides, farmers have resorted to the use of botanical insecticides in the control of FAW (CABI & FAO, 2019). This is because they are locally available, specific, environmentally friendly and biodegradable (Okweche, Ogunwolu, & Adeyemo, 2013). The main objective of the study was to evaluate the potential of chili pepper and neem leaf aqueous extracts to control fall armyworm (Spodoptera frugiperda) on maize plants. Its specific objectives where to compare the effectiveness of CPE, NLE, and their combination on the third larval instars of FAW using both the contact and feeding method all trials done within the laboratory. The experiment was laid out in a randomized complete block design; consisting of three treatments each replicated three times. Treatments which were used consisted of extracts from the leaves of neem tree(NLE), extract from dried chili pepper (CPE) and a combination of dried chili pepper extract with neem leaf extract (CPE +NLE) plus water as the control. Each treatment was applied through two methods, the contact and feeding application of the extracts all of them in the laboratory. The results were analyzed using the Chi-square t-Test and student t-Test. The results revealed that the application of Neem leaf extract and chili pepper extract plus their combination caused a significant death of fall army worm 3rd larval instars compared to untreated control experiment irrespective of the method of application. When using feeding method of application, highest larval mortality was observed in the NLE (72%) and a combination of NLE and CPE (72%) and lowest observed in CPE (22%) as shown in table 5. When using contact application of extracts as shown in table.4, highest larval mortality was observed in CPE (61%) and a combination of NLE and CPE (61%) and lowest mortality observed in CPE (22%). Therefore, the use of NLE and CPE as botanical insecticides in the control of FAW in maize production will make a contribution in the improvement of the crop yield, reduce on the sided effects of synthetic insecticides and increase food production by farmers. Keywords—Chili, neem leaf, fall army worm, maize plants, botanical insecticides.