Sustainable weed control in cucurbit crops: A scoping study

Abstract

Weeds have a significant impact on the production of cucurbit crops in Australia, and yet relatively little work has been conducted to develop integrated and sustainable forms of weed management in these crops. In this project we sought to scope the impact of weeds on cucurbit production, identify current techniques used by growers and assess their effectiveness and sustainability, and explore innovative approaches used in Australia and overseas. The research included a review of Australian and international literature, and consultation with cucurbit growers, herbicide producers and distributors. Weeds were reported to have a significant impact on cucurbit crop yield and quality, making crop management problematic. Significant weeds include fat hen ('Chenopodium album'), blackberry nightshade ('Solanum nigrum'), caltrop or cathead ('Tribulus terrestris'), pigweed/purslane ('Portulaca oleracea'), African lovegrass ('Eragrostis curvula'), barnyard grass ('Echinochloa' spp.), and nutgrass ('Cyperus rotundus'). A successful integrated weed control strategy usually involves a mix of herbicide use, plastic mulch, cultivation, chipping, crop rotation and farm hygiene. Diligence and timing are important factors in a successful approach. However, the ongoing success of this approach is not assured, due to lack of herbicide options, noted instances of herbicide resistance, and questions about the long-term sustainability of plastic mulch. Innovation is therefore required to sustain Australia's cucurbit industry. Options include registering new herbicides, developing a viable biodegradable mulch film, and exploring promising techniques such as living and killed mulches, controlled traffic farming, stale and false seedbeds, and thermal weeding.