Genetic improvement and agronomy for enhanced wheat competitiveness with weeds

The rapid development of herbicide resistance in weeds, and environmental imperatives, have forced the consideration of non-chemical tactics such as crop competition for weed management. This review of wheat–weed competition examines the plant traits associated with wheat competitiveness, and the opportunities for plant breeding or manipulating crop agronomy to differentially favour the growth of the crop. Many studies have proven that enhancing crop competitive ability can reduce weed seed production and crop yield loss, although a number of difficulties in conducting this research are identified and suggestions are made for improvement. It remains to be seen whether crop competitiveness will be considered as a priority by farmers and plant breeders. Farmers require precise information on the reliability of agronomic factors such as increased crop seeding rate or choice of variety for enhancing crop competitive ability in different environments. Plant breeders need to know which plant traits to incorporate in varieties to increase competitive ability. A thorough analysis of the benefits and costs of enhancing wheat competitiveness is needed. Competitive wheat crops should be available as part of reliable and economical integrated weed management packages for farmers.