Insect pest damage to leaves of cowpea (Vigna unguiculata L. Walp): comparative effects of aqueous extracts of Piper guineensis, Allium sativum and Myristica fragrans

Abstract

Utilization of plant extracts in pest management is a cheap, environmentally friendly alternative to chemical pesticides. This study was designed to investigate the effects of aqueous extracts of Piper guineensis, Allium sativum and Myristica fragrans on field insect pest damage to leaves of cowpea, prior to flowering. Ife brown cowpea seeds were cultivated on beds assigned to four treatment groups (including a control), in a completely randomized design. 200g/litre of each plant material was used to prepare the stock solution. Field application of extracts was done in the evenings, thrice a week for two months, and data on leaf parameters was collected monthly. Analysis of variance revealed significant differences between the treatment groups at 5% probability level. Only Piper guineensis treated cowpea plants had significantly higher total number of leaves and total leaf area than the control, as well as significantly lower number of damaged leaves, percentage leaf damage, and damaged leaf area, in both months. Piper guineensis was more effective in controlling insect pest damage to leaves of cowpea than Allium sativum and Myristica fragrans.

Potential of Dual-Purpose Organic Amendment for Enhancing Tomato (Lycopersicon esculentum M.) Performance and Mitigating Seedling Damage by Mole Cricket (Gryllotalpa africana spp.)

“…This is consistent with reports of improved performance of cowpea plants treated with Piper extracts [57]. The higher number of plant leaves and tomato yield is likely due to a combination of better crop nutrition resulting from the high nutrient content of the dual-purpose organic input and improved crop health [31,56,57,60]. In addition, the anaerobically produced dual-purpose organic amendment applied as foliar spray possibly enhanced nutrient uptake by tomato plants that increased plant performance to a comparable level with the commercial inorganic fertilizer input.…”

“…The higher comparable tomato leaves and yield performance recorded in the organic and inorganic treatments confirmed the locally produced dual-purpose organic amendment as a sustainable alternative for managing tomato pests and diseases, and improving soil fertility and plant nutrition. This is consistent with reports of improved performance of cowpea plants treated with Piper extracts [57]. The higher number of plant leaves and tomato yield is likely due to a combination of better crop nutrition resulting from the high nutrient content of the dual-purpose organic input and improved crop health [31,56,57,60].…”

“…The efficacy of Piper as insecticide is due to the active ingredient isobutyl amides (natural lipophilic amides piperine and piperiline) plant secondary metabolites that act as neurotoxins in insects [56]. In addition, cowpea plants treated with Piper extract had lesser insect pest leave damage [57]. Furthermore, combination of powders of Tithonia diversifolia leaves, Piper guineense seeds and oil palm bunch residue ash reportedly reduced pest infestation and acted as bio-stimulant that increased the growth of plantain plantlets in the nursery [58].…”

Germination and Root Nodule Formation of Soybean (Glycine max (L.) Merr.) in Ridomil and Chlorpyriphos Treated Soil

“…Seeds were obtained from the germplasm collection of Department of Genetics and Biotechnology, University of Calabar, Calabar, and were of the same cultivar type; TGX 728-ID. Prior to planting, seeds were soaked in tap water for 5 minutes, and floating ones discarded [16]. 15 seeds were planted in each container, at a depth of 2cm.…”

Efficacy of Kigelia africana Lam. (Benth.) leaf and stem bark ethanolic extracts on adult cowpea seed beetle, [Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae)] affecting stored cowpea seeds (Vigna unguiculata)

“…It is consumed by human due to its high protein content and also used as feed for livestocks ( Fouad et al., 2020 ). It is regarded as one of the cheapest sources of protein to many families where assess to animal protein and other means of getting protein are difficult ( Nta et al., 2013 ). Cowpea also constitutes the main source of revenue to resource-poor farmers ( Musa and Olaniyan, 2015 ).…”