Synthesis and application of biodegradable seed coatings to assess the infestation of chickpea (Cicer arietinum L.) seeds by pests

Abstract

Pulses such as chickpeas face significant damage caused by pests during their growth and storage. The overuse of synthetic pesticides on seeds requiring several cycles of active ingredient applications results in increased expenses and environmental risks by contaminating soil, water, and air. These risks of seed damage without use of harmful pesticides can be reduced by coating the seeds with biodegradable seed coatings. The objective of the study was assessing the effectiveness of biodegradable seed coating in managing stored grain pests and to examine its effects on the germination of chickpeas. For this study chickpea (Cicer arietinum L.) seeds were coated with biodegradable coatings like polyvinyl alcohol with multinutrients, neem oil, chitosan and mucilage-starch nanocrystals. The characterization of coatings was carried out using Fourier Transform Infrared Spectroscopy, X-ray Diffraction and Scanning Electron Microscope. Germination of coated and uncoated chickpea seeds was observed by paper-towel method after 5 and 10 days. Chitosan coated seeds had greatest root length (3.10 ± 0.05 cm), shoot length (3.93 ± 0.08 cm), dry weight (0.24 ± 0.05 g), fresh weight (0.43 ± 0.05 g), germination rate (98.87 %) and vigour index (639.09 ± 0.05) followed by polyvinyl alcohol with multinutrients coated seeds, mucilage-starch nano crystals coated seeds and control group after ten days. The lowest root length (0.97 ± 0.14 cm), shoot length (1.53 ± 0.12 cm), dry weight (0.1 ± 0.005 g), fresh weight (0.21 ± 0.14 g), germination rate (65 %) and vigour index (163.75 ± 4.72) were displayed by neem oil-coated seeds. The impact of stored grain pests was evaluated and it was shown that neem oil had the highest efficacy in controlling pulse beetle infestations followed by chitosan, polyvinyl alcohol with multinutrients and mucilage-starch nano crystals. Neem oil coating enhanced pest mortality by 95 % after 15 days, reduced seed damage by 16.3 % and minimized seed weight loss by 10.6 % after 30 and 45 days. Biodegradable seed coating is a cost-effective and environment friendly way to improve seed performance and protect crops sustainably.