Genotype by environment interaction
A plant breeder's success might be measured by how widely their varieties are grown. A successful variety will be grown in many more environments than the plant breeder tested it in. When a farmer finds that the grain quality trait they expected from the variety was not expressed, they have experienced a genotype by environment interaction (G X E) . Breeders make their best attempt to avoid G X E surprises by testing a new variety for several years across a wide geographic area. Yet, G X E is often unpredictable and is an ongoing challenge for the plant breeder.