Genetic variation for biomass and residue production in lentil: I. Relation to agronomic traits

Sufficient crop residues on soil surfaces are needed for protection from water and wind erosion in the U.S. Pacific Northwest. The lentil (Lens culinaris Medik.) crop grown in this region lacks sufficient crop residues which leads to severe soil erosion in subsequent crops. The objectives of this study were (i) determine the relationship between physiological and morphological traits that affect biomass and residue production, and (ii) identify suitable selection criteria for increasing biomass and residue production by lentil crops. Thirty nine breeding lines were evaluated at three sites each year from 1993 to 1995. Straw yield in 1993 was correlated with days to newer (r = 0.72**), days to maturity (r = 0.82**), plant height (r = 0.76**), harvest index (r = -0.97**), and seed yield (r = -0.71**). In addition there were significant correlations between straw yield and harvest index (r = -0.48**) in 1995, and between straw yield and seed yield (r = 0.59**) in 1994. The regression coefficient (b) indicated that for each day that flowering and maturity were delayed, there were increases of 214 kg/ha and 734 kg/ha straw yield, respectively. A 1 cm increase in plant height resulted in a 277 kg/ha increase in straw yield. Results indicated that plant height could be used for indirect selection for increased biomass. Seed yield can also be improved by selecting for larger vegetative biomass while keeping harvest index constant.