By Shannon Chant, MSc, PAg, Regional Crops Specialist – Swift Current
Lentil plants have an indeterminate growth habit, so they will continue to flower until there is some form of stress, such as lack of moisture, nutrient deficiency or high temperature. There is some variability between varieties, ranging from early (100 days) to very late (110 days), based on seeding on May 1. This can be much shorter in dry years and much longer in cool, wet years, when the weather does not provide a stress to promote lentil maturity. Because of the crop’s indeterminate growth, lentil producers normally use a desiccant or pre-harvest weed control product to even out the crop and/or control weeds.
With higher amounts of precipitation than normal in a lot of regions of the province this year, there have been some concerns with weed populations in lentil, as well as some crops with uneven maturity levels. You should use a desiccant like diquat for quick dry down of crops and a harvest aid if weed control is a concern. Registered active ingredients for use as a harvest aid include glyphosate, Good Harvest (glufosinate) and Heat (saflufenacil). Page 63 of the 2016 Guide to Crop Protection has a table of herbicides for use as a harvest aid or desiccant for a number of crops grown in Saskatchewan. Lentil canopies are often quite dense prior to harvest, so using the water volumes on the label is very important to obtain good coverage.
For each product there are a few important things to note. They include:
- Diquat – for rapid plant tissue dry down to facilitate harvest;
- Glyphosate – not for crops grown for seed;
- Good Harvest – not for crops grown for seed; and
- Heat – red lentil only, for rapid plant tissue dry down to facilitate harvest, and may be tank mixed with glyphosate when used prior to harvest.
Due to concerns with Maximum Residue Limits (MRLs) in countries that import Saskatchewan-grown lentils, it is important to check with your grain buyer prior to treating your lentil with a desiccant or harvest aid to ensure that you will have no problems marketing your lentils. Just because a product is registered for use in Canada does not mean that MRLs are established in all importing countries. If you have a contract with a specific buyer, check with that buyer before using a specific product to make sure your lentils will be accepted. If you do not have a contract with a specific buyer, calling a few buyers in your area might be a good idea to see what your options are. Saskatchewan Pulse Growers put together an information sheet called “Be Aware of Market Risks Involved with Crop Protection Products This Season,” which has information on potential marketing concerns for peas, lentils, chickpeas, beans and faba beans that can help with your decision.