WHAT’S THE POINT WITH GREENPOINT AG
VARIETY SELECTION A CRITICAL FACTOR TO NEXT SEASON'S HARVEST BY M A R K E . J O H N S O N As harvest progresses, growers are beginning to think about variety selections for next season. Variety selection is a management decision that is critical to next season’s harvest. In all crops, yield potential is set when variety selection is made. Agronomic and pest management practices can maintain the genetic yield potential of a variety by minimizing limiting factors, but they cannot increase it. This places a premium on variety selection and on the way in which it is done. “Variety selection is not about identifying which lines did best over the past year – it is about predicting which lines will do best in the future,” says Jim Rouse, Director of Agriculture at Iowa State University, pointing out the pitfall of only looking at the top of last year’s variety test. Yield is the result of the interaction between genetic potential and the environment. A variety should be chosen for a field because it has the genetic characteristics to perform well given the environment in that field. While yield is always the ultimate goal,
selecting a variety from a trial based solely on yield without regard to the environmental conditions in which it grew may not result in a good performance in the future. Contrary to the claims of local meteorologists, predicting rainfall patterns and temperatures for the coming growing season is unattainable. But, when attempting to predict growing conditions for the upcoming year, growers know a great deal about the environment in which their crops will develop. A grower knows soil characteristics, fertility levels, crop history, and the past incidence of pests and pathogens. When choosing a variety, the first criteria should be availability. Management plans based on varieties in short supply usually end up including poorly adapted varieties added at the last minute. The second decision should be which, if any, GM traits are needed. The benefits of these traits are great if they eliminate a pest that is a limiting factor or fit into a weed control system already in place. The third criteria are the
Variety selection is not about identifying which lines did best over the past year – it is about predicting which lines will do best in the future.
22
Cooperative Farming News
