The 2009 ASHS Annual Conference

Covering a cool season crop such as lettuce often increase the incidence of heat-stress related physiological disorders such as rib discoloration, tipburn, and premature bolting, so its use is often limited to early production and very light covering materials. These disorders are controlled by both genotype and environment. Management practices to reduce crop losses under row covers and in the field are limited and will be discussed. Breeding for improved resistance to the disorders is the most appropriate long term solution.