Assessing New Zealand wheat genotypes on canopy closure and light interception as an Integrated Weed Management Strategy

Abstract

Globally, weeds are major biotic stressors in crop production systems, causing yield losses of up to 35%. Herbicides have been a cost-effective way to mitigate yield losses due to weeds. However, extensive use has resulted in the development of herbicide resistance across multiple weed species and herbicide mode-of-action groups. In the face of herbicide resistance and increasing weed control costs, the development of economically viable integrated weed management strategies is increasingly important. Non-chemical weed management (NCWM) approaches are thus required to provide opportunities to reduce herbicide use, mitigate herbicide resistance, reduce the cost of weed management while increasing the life expectancy of chemicals. Crop competition is a NCWM approach that has been successfully implemented overseas but needs further assessment in New Zealand context. This study assessed the variability of some traits related to above-ground competitive ability in New Zealand wheat cultivars. Non-destructive measurements, including light interception and ground cover, of fifteen New Zealand commercially available and pre-commercial cultivars, were performed. Results show significant differences within this pool, suggesting that there potentially exist cultivars that are more weed-competitive than others.