Developing an Integrated Weed Management System for Herbicide-Resistant Weeds Using Lentil (Lens culinaris) as a Model Crop

Abstract

The escalating evolution of weed species resistant to acetolactase synthase (ALS)-inhibitor herbicides makes alternative weed control strategies necessary for field crops that are dependent on this herbicide group. A fully integrated strategy that combined increased crop seeding rates (2X or 4X recommended), mechanical weed control with a minimum-tillage rotary hoe, and reduced-rate non–ALS inhibitor herbicides was compared with herbicides, rotary hoe, and seeding rates alone as a method of controlling ALS inhibitor–tolerant Indian mustard as a model weed. The full-rate herbicide treatment had the lowest weed biomass (98% reduction) and the highest yield of all treatments in 3 of 4 site-years, regardless of seeding rate. The fully integrated treatment at the 4X seeding rate had weed suppression rates equal to the full herbicide treatment at the recommended seeding rate. The fully integrated and reduced-rate herbicide treatments at the 4X seeding rate reduced weed biomass by 89% and 83%, respectively, compared with the control at the recommended seeding rate. The rotary hoe treatment alone resulted in poor weed control (≤38%), even at the highest seeding rate. Fully integrated and reduced-rate herbicide treatments at 2X and 4X seeding rates had yields equal to those of the full herbicide treatment at the recommended seeding rate. Partially or fully integrated weed control strategies that combine increased crop seeding rates and reduced-rate non–ALS inhibitor herbicides, with or without the use of a rotary hoe, can control weeds resistant to ALS-inhibitor herbicides, while maintaining crop yields similar to those achieved with full-rate herbicides. However, combining increased seeding rate, reduced-rate herbicides, and mechanical rotary hoe treatment into a fully integrated strategy maximized weed control, while reducing reliance on and selection pressure against any single weed control tactic.

Hoeing as a Possibility for Mechanical Weed Control in Winter Oilseed Rape (Brassica napus L.)

“…For beans (Vigna sinensis L.), mechanical and chemical weed control were found to show no significant differences in weed occurrence and yield [27]. A study with lentils (Lens culinaris) concluded that an integrated approach consisting of increased sowing density, mechanical weed control, and reduced herbicide application rate had the same effect on yield and weed suppression as the standard approach of standard sowing density, full herbicide application and no mechanical weed control [28]. In a study with organically cultivated OSR hoeing significantly reduced the number of weeds [29].…”

Cultural weed management practices shorten the critical weed-free period for soybean grown in the Northern Great Plains

“…The dose-response work by Redlick et al (2017a) eloquently showed the trade-off between plant densities and herbicides for effective weed management and the importance of plant stand densities for improving herbicide efficacy and reducing the necessity for herbicides for weed management in lentil (Lens culinaris Medik.) (Redlick et al 2017b). Increasing soybean plant densities by 50% above the standard density did not translate into a shortening of the CWFP.…”

Assessing the Stability of Herbicide-Tolerant Lentil Accessions (Lens culinaris Medik.) under Diverse Environments

“…Pre-emergence herbicides are effective in controlling weeds early in crop growth, but weeds germinating after crop emergence at the pre-flowering stage pose a threat to lentil production [ 8 ]. Weeds can be controlled using mechanical and manual weeding, soil sterilization, and high seed rate density [ 9 ], but these methods are either inefficient or very expensive [ 10 ]. Post-emergence herbicides like imazethapyr and metribuzin are effective at controlling weeds in many legume crops, including lentils [ 6 , 11 ], chickpeas [ 8 ], and soybeans [ 12 ].…”