This meeting was hosted by the Huron Research Station. Thanks for breakfast and an excellent tour. We appreciate the work conducted for Ontario Agriculture at the Huron Research Station.
Synopsis: Rainfall has been excessive in many areas but things are actually starting to get dry in some regions. This has been a year with many issues mostly due to the weather. (Frost, hail, ponding, etc.) This has lead to more management opportunities for farmers than other years. Soybean replants have been very few locally but there has been considerable “patching”. There are still soybeans that need to be seeded in Bruce, Grey, and other northern counties but overall unseeded acreage is expected to be relatively small. Corn is variable and has just started to turn dark green over the last few days. Some fields look tremendous. It’s taken longer than usual to turn in colour this year. Soil labs report low pre-sidedress N soil test results this week even in fields that received spring applied broadcast N. N losses are a concern especially in water logged fields. Pre-emergent residual herbicides held well this year overall.
Corn: There have been some reports of damage to corn from tank mixing fungicides with Atrazine in the US. This could be an adjuvant issue although the cause is unclear right now. First year research conducted by Dr. Hooker last year showed only a 1 bu/ac yield response to applying a foliar fungicide to corn at the V5-V6 leaf stage. This research is ongoing so it will be fascinating to see how it will turn out this year with such a different growing season. The most consistent yield response to foliar fungicides on corn is at tassel. The best predictors of a yield response have been foliar diseases and in fields where corn follows corn. There is lots of plant to plant variability in corn this year. In some cases it was caused by the frost earlier in the growing season. Many fields have now lost the pale green colour. Excess rainfall has hampered corn growth in some areas and caused concerns about N loss through denitrification or leaching. Research has shown that 2-4% of N can be lost per day in saturated soils. If more N is deemed necessary, most corn is too large for streamer nozzle application of UAN at this point and drop nozzles will need to be employed. Broadcasting urea is also an option but should be done when leaf tissue is dry. Some burning will occur when urea lands in the whorl but will be outweighed by yield advantages if N is in short supply. Surface application of UAN or urea may benefit from additives that reduce the volatilization risk (i.e. urease inhibitors) but at this point in the season there is little point in using slow release formulations (i.e. nitrification inhibitors or coated urea). This spring may have set up plants for lodging this fall with shallow roots. Also, it’s quite possible that corn harvest will be later this fall than usual with wetter corn.
Soybeans: With recent heat the crop is now growing vigorously but “tile run” soybeans are widespread this year. Many fields are still pale green as adequate nitrogen is not yet being supplied by the nodules. In another weeks’ time the crop is expected to look much darker. Dr. Hooker explained the small plot SMART soybean trials on soybeans with 8 different varieties. In these trials where nitrogen fertilizer was applied soybean are much darker green and larger, although this is not the case in every field situation. Nitrogen research in soybeans continues to show no yield gain despite this visual difference now. Double cropped soybeans showed a greater response to nitrogen fertilizer than spring seeded crops in trials last year. In this area most soybeans look good but there have been considerable replants on heavy clay soils further south. A few growers have had to seed 3 times to achieve an adequate plant stand. The last part of the growing season has much more influence on yield than the first part of the growing season, so it could still turn out to be a high yielding year. Early planted soybeans have started to flower (R1 growth stage). However, many fields have not begun to flower yet, which is later than last year. Under ideal conditions soybeans will flower by June 21st but it’s not unusual for a full season variety to initiate flowering after July 5th. Plant growth stage, variety, temperature, and calendar date all play a role in flowering. The earliest growth stage soybeans can flower is the 3rd trifoliate. Sometimes it will take to the 8th trifoliate before they begin to flower if conditions are not ideal.
A few soybean aphids have been reported in Ontario but no one at this meeting has seen any. Soybean aphids initially colonize in pockets. Plants in these pockets can have hundreds, even thousands of aphids on them at first. Once the aphids get crowded on the plants, they produce aphids with wings so they can colonize new plants. Populations then change from several hundred per plant in small pockets, to only a few per plant on more plants across the field. This continues to occur, particularly when the plants are still in their V stages. Insecticide trials have not shown any yield response when spraying V stage infestations. In fact, a spray application during the V stages can actually cause problems as it wipes out the natural enemies to the aphids. During the R1 to R5 stage of soybeans, an insecticide application is required once 80% of the plants in the field have at least 250 aphids per plant and the population is on the increase.
Considerable acreage of soybeans receives a tank mix with CropBooster. Peter Sikkema has conducted a number of trials with the product. There is no herbicide antagonism but yields have not been statistically improved with the addition of this foliar feeding product.
Edible Beans: Most edible bean stands look acceptable although a few of the early planted fields were replanted. Root rots are a concern. Inter-row cultivation is the only option for improving soil air exchange and stimulating root growth. Side-dressing additional nitrogen if none was applied at planting can also help stimulate root growth. Monitor emerged fields for leafhoppers. Seed treatments provide control of moderate populations of leafhoppers. Later planting will mean the crop is harvested in October this year. The fall harvest season will not necessarily be dragged out since a lot will depend on the summer.
Agricorp Update: Deadline for reporting acreage is June 30th. There are 5 ways to report:
phone 1-888-247-4999; (phones answered during business hours)
fax 1-519-826-4118;
email contact@agricorp.com (not preferred);
mail Agricorp Box 3660, Station Central Guelph, ON N1H 8M4; or
online www.agricorp.com (click online tools).
Next Meeting: Thanks to David Townsend who chaired this week. This was the final meeting for this spring so we hope to see everyone next year. If you have questions or comments about these minutes please contact Horst Bohner horst.bohner@ontario.ca or Peter Johnson peter.johnson@ontario.ca