STAND ESTABLISHMENT OF WINTER-WHEAT IN OKLAHOMA - A SURVEY

Timely and adequate stand establishment of winter wheat (Triticum aest ivum L.) is critical in the southern Great Plains, where wheat is freq uently grazed by livestock in the winter followed by grain harvest. Po or stands reduce forage yield potential. Percentage of viable wheat se ed planted that produced seedlings was determined by surveying wheat f ields during the 1992 and 1993 planting seasons. Causes of poor emerge nce were identified. Data collected included: cultivation practices pr ior to planting, type of planting equipment, depth of planting, and se eding rate. Seed samples for germination tests, seed size determinatio ns, and planter calibrations were collected at each location. Actual s tand counts and seeding depth measurements were made about 2 wk after planting. Average emergence rate was 57% of viable seed planted in bot h years. Inaccurate planting depth and variation in planting depth wit hin a field were identified as major causes of poor emergence. Other c auses for poor emergence were placing seed in dry soil and use of smal l seed. Oklahoma wheat fields have too few wheat plants for the number of viable seed planted. Limiting cultivation depth prior to seeding, using depth gauges on individual row openers, and not planting seed we ighing less than 7 oz/1000 seed can help improve wheat stands.