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Ontario field crop report: July 11

July 11, 2014, Ontario – With higher land costs, and lower forage yields in some parts of Ontario, there is interest in following winter wheat and other cereals with a forage crop to help supplement inventories, according to Joel Bagg and Jack Kyle in the latest Ontario field crop report from OMAF.

This approach can produce some extra feed, and provide excellent cover crop benefits. There are a few double-crop forage options that can provide some low input, good quality forage. Each option has its advantages and disadvantages, and every situation is different. The challenge is getting the wheat harvested, the volunteer wheat controlled, and the next crop seeded in a timely manner. Competition from volunteer wheat can be a significant problem. Without vernalization, winter wheat will not form a stem in the fall to provide significant growth, and yields are very limited. A lot of volunteer wheat can result when light weight grain goes through the combine. One approach to reduce the problem is to do some light tillage (at least behind the combine swath) to encourage the grain to germinate. A burndown with glyphosate seven to 10 days later will remove much of the volunteer grain. Of course this takes time, and as the calendar gets later some options are lost.

1) Summer seeding oats or oat-pea mixtures for forage can provide moderate to high quality forage, depending on the stage at cutting. Harvested in the fall, these annuals will be killed by winter and another crop can be seeded any time in the spring.

2) Italian ryegrass can produce some exceptionally high quality forage suitable for dairy cows. It is usually harvested in the fall and again in late-May, but there is some risk of winterkill. It can be followed by corn silage, soybeans, or sorghum-sudangrass.

3) Fall rye or winter triticale can produce high yields of moderate to high quality forage, depending on the stage of development at cutting in May. They can be followed by corn silage, soybeans, or sorghum-sudangrass. 

4) Summer seeding alfalfa rather than waiting until next spring can provide the benefit of a full yield next year without the usual establishment year yield loss. 

Pastures
Good moisture levels have supported excellent pasture growth. If a paddock is mature, consider clipping or making hay on some of these paddocks, this will stimulate new growth providing quality forage for later grazing. Continuous monitoring of pastures will allow adjustments to the stocking rate or the amount of forage made available to meet the livestock needs. Clipping thistles and other weeds before seed set will help reduce future weed pressure in the pasture. Now is the time to plan for a summer seeded annual forage crop like oats, to provide fall grazing or for extra stored forage. 

Soybeans
Soybean fields are now beginning to flower (R1 growth stage), reports Horst Bohner. Flowering has generally been later this year due to delayed planting and less heat. Late-seeded fields and replanted fields are still in the vegetative growth stages. Rainfall continues to be sporadic with some areas receiving excess moisture while other areas are relatively dry. Many fields are struggling to close the canopy in the southwest due to poor stands and slow growth. Early season competition from weeds cuts yields. Even in glyphosate tolerant varieties weeds must be controlled early in order to maximize yields. No significant soybean aphid populations are present to date.

Nutrient deficiencies are evident in fields with low soil reserves or because root growth is limited. Potassium (K) deficiency results in yellowing around the margins of the leaf. Since the crop requires a tremendous amount of this  nutrient, foliar liquid fertilizers do not deliver enough lbs/acre of actual K to significantly increase yields. Broadcast application of dry fertilizer in crop has worked on occasion but is highly dependent on the amount of rainfall after application. The best time to apply K is during the fall prior to the soybean crop, or the spring before seeding. Soybean cyst nematode (SCN) symptoms are now becoming evident in affected fields. Scout fields for stunted, yellow plants. SCN damage is often confused or misdiagnosed as K deficiency, herbicide injury, compaction, or root rot damage. If beans show yellowing between the leaf veins but the veins remain dark green, they are suffering from manganese (Mn) deficiency. Ontario research has shown that for fields with a history of Mn deficiency, a foliar application of Mn can provide 4 bu/ac. Mn deficiency is more likely on clay soils or muck soils. Yield increases are only evident if a true Mn deficiency is present. Applying Mn to either conventional or glyphosate tolerant varieties that show no symptoms will not provide a yield benefit. Ideally, Mn should not be mixed with glyphosate because it reduces the effectiveness of the glyphosate and the efficacy of the Mn.

July 11, 2014  By Stefanie Croley