Potential for yield loss reduction and profitability assessment of pesticide control of groundnut leaf miner among soybean genotypes

Abstract

Groundnut leaf miner (GLM) is currently a threat to soybean production in Uganda due to the great yield losses as a result of the severe damage it causes on leaves leading to reduced photosynthetic area. GLM is a fairly new pest on soybean in Uganda, having initially been observed in soybean fields in 2011 in eastern Uganda. The objective of this study was to determine the yield loss caused by the groundnut leaf miner and effectiveness and profitability of commonly used pesticides for the control of the groundnut leaf miner (Aproaerema modicella Deventer) (GLM), when tested with popular soybean (Glycine max) genotypes grown in Uganda. In a split plot RCBD design, pesticide protection (treated vs. untreated) formed the main plots; and six commercial soybean varieties (Maksoy 1N, 2N, 3N, 4N, 5N; and Namsoy 4M) as subplots. The study was done in two locations in eastern Uganda (Iki Iki District Agricultural Training and Information Centre (Iki Iki DATIC) and National Semi-Arid Resources Research Institute, Serere (NaSARRI) with two planting rounds at Iki Iki. These sites were chosen because they are hot spots for GLM. GLM severity and soybean yield were significantly affected by the pesticide protection. Overall, percentage grain yield losses caused by GLM on the different soybean varieties ranged from 37.3% to 65.7% and the highest loss was displayed by Maksoy 5N. Grain yield loss recorded at Iki Iki DATIC (53.1%) was remarkably higher than that recorded at the NaSARRI (49.1%). Economic analysis showed marginal returns to be dependent on location, with the Iki Iki DATIC having 0.6 and NaSARRI 1.1. This study has shown that the groundnut leaf miner, a recently emergent pest of soybean is becoming a big threat to soybean production and that chemical control alone may not be economical in managing the pest.

Assessment of Diversity Indices and DNA Barcoding of Parasitic Fauna Associated with Groundnut Leafminer (GLM), Aproaerema modicella Deventer (Lepidoptera: Gelechiidae)

“…In severe infestation, the crop gives burnt up appearance (Ranga Rao and Rameshwar Rao, 2013). The leafminer damage reduces the photosynthetically active leaf area and thereby causes yield losses ranging from 50 to 100 per cent (Namara et al, 2019).…”

Combining ability and heterosis of tropical maize under acidic soil conditions

“…Grain yield is an essential quantitative trait in maize, particularly under stressful environmental conditions [23]. The positive and significant SCA effect indicates that hybrids produced from a combination of specific lines are suitable for developing high-yielding hybrids with different heterotic [24]. Hybrids with high SCA values generally originate from a combination of two parents (or one parent) with the highest GCA values [25].…”

Review of the biosystematics and bio‐ecology of the groundnut/soya bean leaf miner species (Lepidoptera: Gelechiidae)

“…Their larvae are leaf miners that are major pests of groundnut (Arachis hypogaea L.) and soya bean (Glycine max (L.) Merr.) (Rawat & Singh 1979;Shanower et al 1993a;Buthelezi et al 2013;Namara 2015;Ibanda et al 2018;Namara et al 2019). They also impact minor crops such as pigeon pea (Cajanus cajan) (Shanower et al 1993a;Buthelezi et al 2013), Lablab purpureus (Shanower et al 1993a), and lucerne (Medicago sativa) (Sandhu 1978;Shanower et al 1993a;Du Plessis 2003;Buthelezi et al 2013).…”

“…2018; Namara et al . 2019). They also impact minor crops such as pigeon pea ( Cajanus cajan ) (Shanower et al .…”