Climate Change and Ecologically Based Weed Management

Abstract

It was estimated that about 50% more food is need to be produced by 2050 in order to feed the increasing world population. Worldwide, weeds constitute a major constraint to the crops production causing substantial yield losses. Weeds may have a greater growth and reproductive response capacity than crops, in the climate change scenario, due to their greater genetic diversity than most crops. The climate change is predicted to have profound impacts on crops and crops associated weed invasion, losses caused, management and interactions with other biological organisms. The negative effect on crops was observed to be additive when impacts of weeds and climate change were combined. Hence in the era of climate change, weed management is critical to attain future food production goals. The currently available and widely used herbicides-based weed management options are influenced by climate change and are known to enhance greenhouse gas emissions, cause water pollution, reduce biodiversity, and intensify weed menace with evolution of herbicide resistant weeds and emergence of difficult to control weeds in the form of weed shifts. Thus, the current challenge is to design alternative ecologically based sustainable weed management systems that use minimal external inputs, reduced losses due to weeds, maintain sustainable food production systems with minimal environmental foot print. The ecologically based weed management (EWM) systems aim at an understanding of weed ecological processes, identifying and incorporating in agroecosystems the ecological factors that minimize weeds negative impact while enhancing crop growth and productivity. This chapter discusses the current research on the impact of climate change on weeds and their management in agroecosystems and possible EWM approaches for enhancing crop productivity while mitigating the adverse impact of climate change in a sustainable manner. The components of EWM include preventive measures to curtail weed seed production; addition to soil seedbank and dissemination; weed seedling recruitment reducing methods like soil solarization, stale seed bed technique; application of components of conservation agriculture viz. minimal tillage, soil mulching with crop residues, and crop rotations; enhancing weed and crop diversity; weed suppressive cover crops inclusion in cropping systems; enhancing crop competitiveness by selecting method of crop establishment, selection of competitive cultivar, measures for quick crop canopy cover; mechanical means of weed management including robotic or green on green or green on brown advanced smart-machine technology for automatic weed control utilizing artificial intelligence; and location-specific biocontrol measures; usage of site, weeds, and need-based herbicides usage using real-time weed/crop detection/recognition equipment and site specific need based integration of them. The EWM tactics must be integrated with other agronomic farming practices that optimize health and productivity of resources and crop, minimize the impacts of other pests and changing climatic factors influence, and reduce economic risks.