Botanical biopesticides have an influence on tomato quality through pest control and are cost-effective for farmers in developing countries

Abstract

Synthetic insecticides heavily applied to manage agricultural pests are highly hazardous to the environment and non-target organisms. Their overuse through repeated treatments in smallholder farming communities is frequent. Botanical biopesticides are ideal for sustainable pest management in agricultural environments by keeping synthetic insecticide use at a minimum. Here we evaluated a locally prepared neem seed extract (NSE) alongside emamectin benzoate against both lepidopteran pests Helicoverpa armigera (Hübner) and Spodoptera exigua (Hübner) on tomato Lycopersicon esculentum Mill under natural field conditions in Pakistan. We compared pest severity, fruit injury, quality, marketability, and cost:benefit ratio (CBR) between treatments. The concentration of azadirachtin A in the NSE was 26.5 ppm. NSE at 2% (20 mL/L) and the emamectin benzoate at the recommended field rate in Pakistan were sprayed weekly throughout the fruiting stage. The pest larvae were significantly more abundant on fruits than on flowers and leaves. Fruit injury and losses were significantly more important in untreated control compared to NSE and emamectin benzoate treatments. NSE efficacy varied with respect to the cultivars used and the seasons. Cultivar Eden harboured more pests than Adventa, and emamectin benzoate suppressed more pest individuals than NSE. Both the insecticidal treatments were comparable in terms of marketable yield productions as well as unmarketable, uninjured, and recovered fruit yields. NSE generated a higher CBR (1: 9.26) than emamectin benzoate (1: 3.23). NSE suppressed pests by acting as an antifeedant, similar to its synthetic counterpart. Smallholder growers can thus use NSE as a cost-effective solution in tomato pest management in Pakistan.

Safeguarding Tomato Cultivation: Challenges and Integrated Pest Management Strategies in North India

“…For instance, neem oil, extracted from the neem tree (Azadirachta indica), disrupts insect growth and development, inhibits feeding, and acts as a repellent against various pests such as aphids, whiteflies, and spider mites. Botanical extracts, such applied using plant-derived compounds with insecticidal properties, such as neem oil or pyrethrins, to control pests [62,63]. Biopesticides contain naturally occurring substances that disrupt pest behaviour, physiology, or development.…”

Unlocking the Potential of Agrifood Waste for Sustainable Innovation in Agriculture

“…Neem oil is a known biocide that has been traditionally used as it contains numerous biological active substances, the most relevant being the limonoid azadirachtin, a known insecticide that interferes with egg-laying, molting, pupation, the development of adults, respiration, and consumption [15]. The oil-extraction process leaves behind neem cake as a by-product, which is a substrate that still contains pesticide compounds, as demonstrated by Nicoletti et al [16], who successfully used neem cakes to obtain a crude extract rich in azadirachtin, nimbin and salannin, observing that the composition and the concentration of these compounds was highly variable between the different cakes screened.…”

“…The oil-extraction process leaves behind neem cake as a by-product, which is a substrate that still contains pesticide compounds, as demonstrated by Nicoletti et al [16], who successfully used neem cakes to obtain a crude extract rich in azadirachtin, nimbin and salannin, observing that the composition and the concentration of these compounds was highly variable between the different cakes screened. Azadirachtin has been found to have a pesticidal action on Helicoverpa armigera and Spodoptera exigua, two lepidopteran pests of tomato crops [15]. Besides limonoids, neem cake also contains saponins [17], which are known to interfere with the waxy covering of insects and to cover their spiracles, blocking respiration [18].…”