TekTalk
| MOST OF THE CORN IS IN, NOW TO SOYBEANS...OMAFRA | 05/14/12 |
| This past week's OMAFRA Field Crop Report Corn: Greg Stewart Corn planting ranges from 50 to 95% complete; provincially corn planting is estimated at 80%. In most areas rainfall has not been intense and soils remain in good shape despite large acreages without significant residue cover. Corn requires about 180 CHU to emerge. Corn planted April 16 - 20 is emerging this week. Most reports suggest that emergence and seedling vigour are good; earlier planted corn that had tissue damage from cold temperatures is recovering. Nitrogen application using UAN (28%) will cause some corn leaf burn, but impact on yield is usually negligible. Guidelines for post-emerge UAN application: 1) UAN (fan nozzle) and herbicide– max. 2 leaf corn, 2)UAN (fan nozzle) no herbicide - max. 3 leaf corn. Cereals: Peter Johnson/Scott Banks Winter wheat is advancing rapidly with warmer temperatures. The window for herbicide applications is closing as fields reach flag leaf stage. Flag leaf herbicide applications run a high risk of crop injury. If weeds are a harvest issue, pre-harvest glyphosate is the best option on advanced fields. Early wheat at Harrow is just beginning to head (GS 50). The crop is 1- 2 weeks ahead of normal development. Cool night temperatures through stem elongation will result in a shorter crop, which should help reduce lodging problems. Disease pressure remains low, with powdery mildew beginning to ramp up in lush fields and susceptible varieties. Timing is excellent for the first fungicide spray, if two applications are planned. Spring cereals have jumped over the last week, with early fields well into tillering (GS 23-25). Weed control is becoming critical for maximum yield. Disease pressure remains very low. Soybeans: Horst Bohner Planting progress has been slow over the last week although a few areas did make headway. Less than 10% of the crop has been planted to date. Soil potassium levels have slipped in Ontario with estimates that up to 20% of Ontario fields may be below ideal levels for soybeans. Applying potassium in the spring before planting is an acceptable practice for fields with low soil test levels. Any field with less than 10 ppm K in soil test results may suffer significant yield losses, especially in dry years. A 50 bu/ac crop removes about 70 lbs/acre of potassium. Glyphosate burndowns should be applied 5-7 days before planting to ensure adequate translocation into perennial weeds. If perennial weeds are getting large (12.5 cm (5") or taller), increase the rate of glyphosate. If annual weeds are the target, a 3 day pre-plant interval is adequate. |
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