Evaluating Organic Weed Management Strategies for Echinochloa crus-galli (Barnyard Grass/Weed Millet) Control in Open Organic Vegetable Fields in Finland

Abstract

Weed controlling in an organic farm is challenging, particularly controlling invasive species like Echinochloa crus-galli. The study was conducted to evaluate the effectiveness of organic weed management strategies for Echinochloa crus-galli. The studies are based on the challenges in organic farming which created by Echinochloa crus-galli in the open organic vegetable farm at Kiipula Garden. This research investigated the effect of green manure (Vihervauhti), Sunflower (Helianthus annuus), and marigold (Tagetes patula) in controlling the above-mentioned weed in controlled greenhouse conditions due to less feasibility of conducting the open field experiment during autumn. This research covers the experimental treatment of suppressing the weed by green manure, sunflower, marigold and a combination of these methods. Allopathic effects on crop growth are additionally monitored in separate treatments, as allopathic plants are used in weed suppression. The aim of this research is to provide the most sustainable integrated approach for controlling Echinochloa crus-galli in an organic farming setting. The key finding is that the weed suppression is successful with green manure. The intensity of the suppression is increased when green manure is used with sunflower and marigold, although the allelopathic effect of sunflower and marigold inhibits the growth of cucumber. The results lead to the practical recommendation for organic farmers in weed management while protecting the yield and environment. Further studies in results in open field and long-term impacts are recommended.