By Mitchell Japp, MSc, PAg, Provincial Specialist, Cereal Crops; Matthew Bernard, MSc, PAg, Provincial Specialist, Oilseeds; Dale Risula, MSc, PAg, Provincial Specialist, Special Crops
Dry conditions in early 2019 followed by precipitation later in the growing season has significantly improved the outlook for crops. But, that later precipitation has led to some varied crop stages. The variability of maturity between fields, and even within a field, means difficult harvest decisions might have to be made this year.
Oilseed crops appeared to be most severely affected by the dry conditions, with patchy emergence and delayed, stunted growth in some regions. Cereals and pulses seemed to fare a bit better. However, crops were generally stressed until precipitation was received. Few, if any, tillers in cereals developed, but late tillers may have emerged after rainfall, depending on timing. In June, there were canola fields with stages ranging from cotyledon to bolting. Late tillering in cereals and uneven germination and emergence in oilseeds will lead to a range of stages at harvest.
It is important to remember that the majority of the yield in cereals will be in the primary head. While some of those other heads may look attractive, the likelihood of those tillers reaching maturity prior to a frost are low. As a result, it is best to focus on the head on the primary stem. For oilseeds, it might be more important to consider maturity on the branches. With new high-yielding hybrids, increasingly lower seeding rates and/or poor emergence resulting lower plant stand densities, individual plants might be compensating with increased branching. Although this might mitigate lower-than-normal survival rates in the spring, this could delay maturity, since more time is needed for the plants to take up the additional resources necessary to complete pod fill on those additional branches.
Fields with variable stages must be scouted to understand which stage will contribute most to yields. In fields where the majority of the crop is delayed, swathing, desiccating or applying pre-harvest weed control too early might result in sacrificing some yield, as well as increase the potential for higher green seed or damaged seed. If areas with substantial differences in maturity are large enough, it could be worthwhile to harvest these areas separately. Of course, this is not always feasible, especially as delayed maturity risks pushing harvest later into the year.
For more information on harvesting crops with variable maturity, please see this issue’s articles Pre-harvest Herbicide and Desiccant Applications, Swathing and Straight Cutting and Greenfeed and Straw Management.