Integrated weed management in sunflower: challenges and opportunities

Abstract

The purpose of effective weed management is the inclusion of the best measures and strategies to make sustainable sunflower production, and unfavourable for weeds. Weed management strategy based on single approach, and use of only herbicide-tolerant sunflower hybrids, and application only post-emergent acetolactate synthase inhibiting (ALS)- herbicides, are not sustainable strategies. Application of pre-emergent herbicides in herbicide-tolerant sunflowers would protect the crop for the first four to five weeks of growth and should also provide flexibility for timing of post-emergent herbicides application. Moreover, over reliance on a single herbicide and herbicides with the same mode of action in herbicide-resistant sunflower, can lead to weed population shifts, spread of herbicide-resistant weeds, and herbicide-resistant volunteer plants in subsequent crops. The risk of transfer of the trait for herbicide tolerance into weeds belonging to related species is elevated. Herbicide-resistant weeds pose significant threats, and until we find a better solution to manage herbicide-resistant weeds, farmers will need to implement more diversity into weed management. Additional challenges are that no new herbicidal modes of action developed in the past 30 years, and some herbicides has been banned in many countries. Integrated weed management (IWM), is a sustainable approach to managing weeds by combining biological, cultural, physical, and chemical tools in a way that minimizes economic, health, and environmental risks. Therefore, increasing concern over herbicide side effects on human health and the environment, herbicide resistant weeds, weed shifts, invasive weeds, and slow development of new herbicides are some reasons for urgent need of implementation of integrated weed management in sunflower production.