Act Now to Preserve Seed Grain Quality JUL 19 2013 | Producers | Blog Post
Opportunities to maximize the quality of your seed and commodity crop are within reach, even though the growing season often presents crop production challenges in the form of insects, disease and weather. By acting accordingly, and at the right time, you can improve seed quality and maximize grain grade potential. Watch your bottom line improve by implementing these four actionable tactics aimed at enhancing and preserving quality.
Action #1: Manage Disease
Controlling in-crop disease is the first tool to manage success. During the growing season, pulses can be devastated by disease, and usually very quickly. From a seed testing laboratory standpoint, the most common seed borne pulse disease we observe is Ascochyta spp. in peas. There are three fungi present in western Canada that cause the Ascochyta blight complex, each which vary in severity and prevalence.
Most producers refer to this disease as Ascochyta, but you may also hear the term Mycophaerella blight, which is the most widespread of the three fungi. During the past testing season, we analyzed seed samples with Ascochyta infection rates as high as 21.5 per cent, while average infection rates tended to be in the 3-4.5 per cent range. Other seed borne diseases BioVision analysts see in pulses are Botrytis and Anthracnose. Seed-borne infection of these pathogens have traditionally been below 2.0 per cent in seed grown in Alberta.
In addition to damaging seed quality, disease can impact the grade designation and, ultimately, the commodity price assigned upon crop delivery. Weather, presence of inoculum, and host crop will dictate disease severity. Crop scout throughout the growing season, then sharpen your pencil and evaluate the economics of applying a foliar fungicide.
Action #2: Scrutinize Your Pre-harvest Herbicide Application
Are you planning a pre-harvest herbicide application for your seed fields? Each and every year, western Canada farmers opt to use pre-harvest application of herbicides to control tough perennial weeds, due to the effectiveness and affordability. Unfortunately, in the lab, we often observe abnormal seedlings within the germination test when the crop is sprayed just prior to harvest with glyphosate. The seeds will sprout, but after a few days in the germination growth chamber, the shoot and root almost cease growing. Also, secondary root hairs do not branch from the primary root, which is typical for healthy seedlings. These stunted seedlings will be classified as “abnormal” in a germination test, as they are believed to not have the capacity to produce a viable plant. Read herbicide manufacturer labels carefully, then re-schedule your seed crop weed control for a later date.
Action #3: Plan Your Harvest and Handling to Maximize Quality
Harvest time can make or break your pulse seed crop – literally. Pulses are classified into the Fabaceae family and are termed dicots (dicotyledons), as the seed has two embryonic cotyledons. This structure makes the seed vulnerable to cotyledon detachment and splitting.
First, be extremely aware of the seed moisture content at harvest. As the moisture percent falls, the two cotyledons become sensitive to mechanical damage and can easily crack and split. The result is poorly germinating seed and grain that is downgraded. The difference between No. 1 Canada Green Peas and No. 2 Canada Green Peas in Split Percent (%) is merely 0.5 per cent. In the lab, we routinely observe mechanical damage symptoms, which are the absence of a shoot in the germination test, combined with roots that stop growing shortly after they emerge from the seed. Plan to harvest your peas on the tough side (>16 per cent moisture) to mitigate seed coat cracking and cotyledon separation.
Secondly, safe handling systems are a must for pulses. Search out innovative options to transfer your pulses to and from storage to reduce the risk of mechanical damage.
Action #4: Protect Your Inventory
The crop cycle is now complete, and you have taken all possible steps to produce the best quality crop possible. The next step is to protect your inventory by maintaining industry standard safe storage moisture content. Aeration will be necessary if you harvested your crop tough, to avoid spoilage. If drying the grain is required, be cognizant that high temperatures (>45oC) will damage seed germination and as little as 0.1 per cent heated kernels will downgrade your commodity peas to a lower class. It is rare for insects to infest pulses in bins, but various weevil populations can grow while the crop is in storage. Protect you inventory with a continual monitoring program, and then take action if needed.