Lentils Disease Fertility & Soil Field Management Seeding Weeds
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Lentil Input Study: An Agronomic and Economic Analysis of Seeding Rate, Herbicide Strategy, and Fungicide Use

Saskatchewan produces approximately 94% of the lentils grown in Western Canada. Due to the poor competitive nature of this crop as well as the increasing presence of herbicide-resistant weeds, one of the major limiting factors for lentil production is effective weed control. Herbicide layering (using two to three herbicides in sequence) and increased seeding rates are both strategies that can be used to improve weed control in lentils. The current recommended seeding rate of 130 plants per square metre (m²) for red lentils may not be adequate enough to provide effective crop-weed competition, yet too high of a seeding rate produces a thicker crop canopy that could increase disease pressure and result in more fungicide use. A study was conducted to evaluate different combinations of common agronomic practices on red lentil yield and to determine which of these agronomic practices would provide the best economic return to producers.

Key Findings

Disease Risk Decisions

Disease development in lentils is impacted by many factors, particularly previous crop history, moisture conditions, soil texture, and varietal genetic resistance. If one or more of these factors are high risk (frequent cropping, high moisture, heavy clay soil, poor varietal disease resistance), then there will likely be a seeding rate by fungicide interaction, meaning that the seeding rate used will influence fungicide performance.

Therefore, based on this study:

Seeding Rates & Critical Period of Weed Control

In this study, seeding rates played a significant role in yield and can be contributed to early season weed management during the critical period of weed control (CPWC). The CPWC is the period of crop growth when weeds must be controlled in order to prevent yield loss. For lentils, the CPWC is from the 5-node to the 10-node (approximately canopy closure) stage (Fedoruk et al. 2011). Previous research found that the removal of weeds at the 5-node stage caused a 4% yield loss in lentils but later removal of the weeds at the 7-node stage resulted in a 16% yield loss (Fedoruk et al. 2011). The most effective weed management strategy in the current study was using a higher seeding rate (>130 seeds/m²) with a residual herbicide in order to better reduce weed competition during the CPWC of lentils. While the benefit of the residual herbicide will be more evident in weedier conditions, the benefit of increased seeding rates will be realized under low or high weed pressure.


This project was jointly funded through Saskatchewan Pulse Growers, Western Grains Research Foundation, and the Canada-Saskatchewan ADF program (administered by Saskatchewan Ministry of Agriculture). Special thanks to Indian Head Agriculture Research Foundation, Irrigation Crop Diversification Corporation, Western Applied Research Corporation, Wheatland Conservation Area, East Central Research Foundation, and the University of Saskatchewan for conducting trials for this project at their sites. Various crop protection products were provided in-kind.

Research Project

Lentil input study

Jessica Weber Western Applied Research Corporation

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