In vitro screening of Coronopus didymus and Nasturtium officinale for weed and pest control in agro-ecosystems

Allelopathy is a viable alternative in agro-ecosystems for weed and pest control. The present work was aimed at evaluating the herbicide and pesticide ability of Coronopus didymus (L.) Sm. and Nasturtium officinale W.T. Aiton The allelopathic effect of selected weeds was calculated by sandwich method and dish-pack bioassay. Aqueous extracts of both plants were also used to determine the effects on crop growth in seedlings (wheat and maize). Leachates of C. didymus and N. officinale had an inhibitory effect on the growth of lettuce seedlings by 98.8% and 98.5% respectively in dish pack bioassay; lettuce seedling radicle elongation inhibition was 1.9% and 22.1% respectively compared with untreated control. The inhibition effect for wheat and maize was of no importance. Micro-spectrophotometric technique was used for fungicidal assessment. Both plant extracts (3.125 mg/mL) demonstrated substantial pesticide activity against pathogenic strains Pyricularia oryzae Cavara and Fusarium fujikuroi Nirenberg. C. didymus reported maximum total phenolic content (214.6983 μg GAE/g dry sample) and N. officinale (124.181 μg GAE/g dry sample). Identification of new active compounds can aid in weed and pest management.