THE USE NATURAL SELECTION TO COMBAT ALFALFA STEM NEMATODE
Proposed by: Trent Wilde
Presenter: Wilde, T. , Agricultural Extension Agent, Utah State University Extension, Delta, UT 84624
Producers have been left without an effective pesticide for controlling alfalfa stem nematode owing to regulations and policy decisions. In response, producers are implementing non-traditional solutions to combat alfalfa stem nematode. An alternative based on principles of natural selection is to plant alfalfa, harvest the alfalfa for hay over the productive stand life of the crop, and harvest alfalfa seed from the thinning crop at the latter end of the stand life. This management practice results in seeds being collected only from the most durable plants, and stands established from the ‘naturally selected’ seeds are expected to have a longer productive life. This practice was implemented in areas of Millard County, Utah infested with alfalfa stem nematode. According to data collected from producers, alfalfa stands established from ‘naturally selected’ seeds had a productive stand life of 5-6 years as compared to a 1-2 year productive life for stands established from other commercially available alfalfa seed. Such increase in the productive stand life of alfalfa reduces replanting costs and lost productivity by up to $1200/acre over the life of the stand.