Evaluation of harvest aids application timing for lentil dry down

Non-Peer ReviewedHarvesting stage is a critical step for lentil producers to maintain high seed yield and good quality. Desiccating lentil with desiccants/harvest aids can dry down lentil evenly and quickly, and control late-growing green weeds, which enhances lentil harvest efficiency and allows early harvesting. Since the harvest aids are applied at a late growth stage, high herbicide residue in seeds may cause commercial issues with marketing lentil. Application timing of harvest aids is critical for producers. Improper application timing may reduce yield and thousand seed weight, but increase herbicide residue in seeds. Therefore, the objective of the harvest aids application timing (% seed moisture) trial was to evaluate the responses of lentil to different herbicide application timings at Saskatoon and Scott, Saskatchewan, over 2 years (2012 and 2013). For this trial, glyphosate (900 g a.e. ha-1), saflufenacil (50 g a.i. ha-1), and the combination of glyphosate plus saflufenacil (900 g a.e. ha-1 and 36 g a.i. ha-1) were applied when seed moisture content was 60%, 50%, 40%, 30% and 20%. Apart from these herbicide treatments, there was also an untreated control, which is desiccated naturally. Significant relationships between evaluated variables and application timing on the basis of seed moisture content were detected. Also, this trial indicated that early application timing (60% application seed moisture) could result in reductions in lentil yield and thousand seed weight. Glyphosate residue in seeds was less than 4 mg kg-1 when glyphosate was applied alone at 30% and 20% average seed moisture. Glyphosate residue decreased when adding saflufenacil to glyphosate. Saflufenacil residue consistently increased with earlier application timing of the harvest aids