Comparative BLUP, YREM-based performance and AMMI model-based stability of horse gram [ Macrotyloma uniflorum (Lam.) Verdc.] genotypes differing in growth habit

In India, horse gram [ Macrotyloma uniflorum (Lam.) Verdc.] is generally preferred as a contingent crop when the onset of rain is delayed or region-specific popular crops fail to establish due to early season drought. The uncertain and delayed rainfall very often forces farmers to plant horse gram beyond the recommended month of sowing (September). The productivity of horse gram significantly reduces with delayed sowing. Taking cues from other legumes, we hypothesized that genotypes with in-determinate growth habit perform better and are more stable than those with semi-determinate and determinate growth habits across delayed dates of sowing. To test this hypothesis, we assessed comparative grain yield potential based on best linear unbiased predictor and yield relative to environment maximum, and additive main effects and multiplicative interaction model-based stability of horse gram genotypes differing in growth habit across early (August), recommended (September) and delayed (October) dates of sowing. The genotypes with in-determinate and semi-determinate growth habits produced greater grain yield plant −1 when sown during early and recommended months, respectively. The genotypes, irrespective of their growth habit produced comparable grain yield plant −1 when sown during delayed month. However, across-dates of sowing, the average seed yield and stability of in-determinate genotypes were significantly better than semi-determinate and determinate genotypes. Based on YREM estimates, our study indicated that genotypes with semi-determinate growth habit should be preferred over those with other growth habits even for early or delayed sowing due to low grain yield penalty caused by crossover genotypes × dates of sowing interaction.