Effects of Boerhavia diffusa L. nom. cons. and Chromolaena odorata (L.) R. M. King & H. Rob. extracts on some field insect pests of okra (Aabelmoschus esculentus (L.) Moench)

Abstract

<p>A field study was carried out to assess the efficacy of some botanicals in the control of field insect pests in two varieties of okra. Dry leaf extract of <em>Chromolaena odorata</em> (Siam weed) and fresh and dry root extracts of <em>Boerhavia diffusa</em> served as treatments which were compared with Lambda-cyhalothrin and a control. The experiment was fitted into a randomized complete block design with three replications. Data collected were subjected to Spearman’s correlation analysis and a two-way analysis of variance and significant different means were separated using Fishers Least Significant Difference (LSD) test at 5 % level of probability. The results revealed that treated plants generally performed better than the untreated plants as they were taller, had more leaves, branches, wider stem girths and gave higher fruit yield. Fresh root extract of <em>B. diffusa</em> performed better in most parameters measured. A significant positive correlation was observed between insect pest populations, and between growth and yield parameters, while there was a significant negative correlation between overall yield and insect pest population. NHAe 47-4 okra variety performed better than F1-Lucky variety. Fresh root extract of <em>B. diffusa</em> is recommended for management of <em>B. tabaci </em>(Genadius, 1889)<em> </em>and <em>Amrasca biguttula </em>Ishida, 1912<em> </em>in okra.</p>

Evolution of the Secondary Metabolites in Invasive Plant Species Chromolaena odorata for the Defense and Allelopathic Functions

“…Aqueous ethanol leaf extracts of C. odorata were applied to Aabelmoschus esculentus (L.) Moench once a week for 4–7 weeks after its planning. The treatments resulted in the reduction of the population of whitefly, Bemissa tabaci Gennadius, and leafhopper, Amrasca biguttula Ishida on Aabelmoschus esculentus [ 71 ]. The methanol extracts of C. odorata leaves also showed ovicidal, antifeedant, and larvicidal activity on a leaf-eating insect, Spodoptera litura Fabricius [ 72 ].…”