Features Agronomy Soybeans
Ontario field crop report: May 23

May 23, 2014, Ontario – Corn planting progress in southwestern Ontario has been slow, but planted acreage improves moving east, according to Greg Steward in the latest field crop report from OMAF. 

Cereals
Winter wheat: Early wheat fields in the southwest are at flag leaf (GS 37-39), reports Peter Johnson. Wet soils have prevented herbicide application in many fields. Bromoxynil/MCPA products and Infinity are the safest herbicides for application at flag. In fields without red clover, pre-harvest glyphosate is an option. Yield loss associated with weeds present now has already occurred; any herbicide applications are to facilitate harvest only. Disease levels remain low, with mildew and septoria in the bottom of the canopy. Timing is right for first fungicide applications in many fields. Fungicide applied at this stage will increase yields more than earlier applications. 

Spring cereals: It is now too late for spring cereal seeding in all but the most northern areas. Shift to soybeans. Early cereals are at tillering stage (GS 21-22). Emergence looks excellent. Weed control should be accomplished before tillering. Early nitrogen (N) applications should already be applied.

Forages
Forage growth is seven to 10 days behind normal, according to Joel Bagg and Jack Kyle. First-cut yield expectations are variable in some areas, with winter-injured, older, and fall-harvested stands showing reduced potential. Dairy haylage harvest will be in full swing in many parts of the province the week of May 26th. Generally, first-cut alfalfa haylage is targeted at an optimum 40 per cent NDF to balance digestible energy with adequate fibre. “Scissors-cut” field sampling and rapid laboratory analysis, and “PEAQ sticks” are useful tools to predict optimal harvest dates. If practical, delayed harvest of stressed fields will improve plant health and yield. With a cool spring the maturity of grasses is usually more than alfalfa. The most advanced fall rye is at boot stage; triticale is slightly behind. Many dairy farmers target harvest at flag-leaf for nutrient quality. Delaying to early-head will reduce digestible energy, but increase yield. Some winter-damaged alfalfa fields are being harvested early to plant to silage corn. Planting as soon as possible and adequate moisture are essential to successful yields.

Pasture grass is advancing quickly with orchardgrass now starting to head. Using a quick rotation to graze all paddocks before grass becomes mature is important. In a rotational system look to the last paddock in the rotation and adjust rotation speed to arrive at it before grasses head out. To maintain good growth throughout summer, do not overgraze. Leaving 7-10 cm (or more) green material will allow the plants to recover quickly. Applying 40 kg N/ha after the 1st or 2nd rotation will stimulate growth. Now is the time to evaluate your pastures and determine if extra forage will be required during the grazing season. If you will need to source extra forage, consider planting an annual crop for grazing.

Soybeans
Soybean seeding has been slow, with only about five per cent of soybeans seeded in western Ontario as of May 22, reports Horst Bohner. Eastern Ontario has made better progress with about 50 per cent seeded. Some fields that received N intended for corn or winter wheat are now being switched to soybeans. There is the concern that N fertilizer can lead to excessive top growth and poor pod set. Ontario research has shown that N fertilizer has little impact on soybean yields in most situations. The soybean plant will use the most available form of N first (available soil N or fertilizer). Once this N has been used it will then start nodulation to fix N from the air. The fertilizer N will be used before nodulation will occur, so nodulation will be delayed. Under extreme conditions, there can be plant lodging and increased white mould in these fields. It is recommended that seeding rates be reduced 10-20 per cent and wider rows (15 inches or wider) be used in fields that have received N fertilizer. Nitrogen fertilizer is not recommended for “normal” soybean fields since there is no economic return.

Canola
Between 50 and 60 per centof the intended acres have been planted, notes Brian Hall. Late-planted canola still has excellent yield potential. Maturity is delayed by half the number of days seeding is delayed. Canola planted the week of May 19 is expected to mature the first week of September, and be ready to harvest seven to 10 days later. Place seed three-quarters of an inch deep into a firm moist seedbed for rapid even emergence, even flowering and maturity. Warmer temperatures and wind can quickly dry out the top one inch of soil, often causing poor and uneven emergence. Weather during flowering and pod fill has the biggest yield impact. Canola planted now may require one to two foliars for swede midge. Monitoring has begun, though no catches have been reported. Check updates on the Ontario Canola Growers Association website. Soil moisture and temperature will speed emergence of overwintering midge.

Edible beans
Plant high-quality certified seed with excellent germination. Lower germ seed often has reduced vigour resulting in uneven emergence and reduced stands even with higher seeding rates. Recommended rates for white or black beans in 15-inch rows is 150,000 seeds/ac (three to four seeds/ft of row), 110,000 in 21-inch rows (3.5 to 4.5 seeds/ft.) and 90,000 (4.5 to five seeds/ft.) in 30” rows. Dry beans require considerable moisture for germination. Plant half an inch deep into moist soil. Emergence problems due to non-uniform depth result in uneven maturity. The potential 10 per cent yield advantage of narrow rows by using a drill is lost if accurate depth control cannot be achieved. Crusting is the major risk of rolling or packing and should only be done when absolutely necessary.

Corn
Corn planting progress in southwestern Ontario has been slow, with many areas receiving more than 40 millimetres of rain over the past week, according to Greg Stewart. Planted acreage improves moving east with 75 per cent completion in eastern Ontario. Provincially, planting stands at 40 per cent. Switching from full season hybrids is in play now. Reduce hybrid ratings by 100 CHU/wk of delay in short season areas (< 2800 CHU); in 2800-3200 CHU areas still plant full season hybrids if planting can occur by May 25, in some situations, wet soils may have already eliminated planting before May 25 so switch to be ready for next planting window. Areas >3200 CHU should plant full season hybrids until the end of May. Considerations on hybrid switching: 1) OCC performance trial data (yield moisture). Identify compromise of less CHU requirements with only modest yield reduction. 2) Consider company data details on CHU to silking, test weight, and standability. 3) Switch first fields with more difficult fall harvest options - poorly drained, difficult access. 4) Do I have high moisture corn options or relatively low drying costs that allow me to plant full season hybrids further into planting season than average?

May 23, 2014  By OMAF