Hulless Barley Seeding Rate Effects on Grain Yield and Yield Components

Abstract

Recent efforts to expand markets for winter barley (Hordeum vulgare L.) in the mid‐Atlantic have focused on hulless types due to higher energy density. The exposed endosperm of hulless barley makes damage more likely than with hulled barley, and emergence is typically lower. Information to determine the optimum seeding rate for winter hulless barley is presently unavailable. Experiments were conducted over six site‐years in Virginia to evaluate seeding rate effects on grain yield and yield components of six hulless and three hulled barley lines. Seeding rates ranged from 278 to 742 viable seeds m−2. At similar seeding rates, final plant stands for hulless lines were 75% of that for hulled varieties. At equivalent plant density of 320 plants m−2, average grain yield for hulled lines was 6000 kg ha−1 and 4500 kg ha−1 for hulless lines. Yield of the best hulless barley line was 80% that of the hulled lines. A large portion of this is attributable to lower individual kernel weight, due to the absence of the hull weight. Hulless barley lines also had 5% fewer heads per square meter and 29% fewer grains per head. Seeding rates for hulless barley in a conventional, tilled seedbed should be at least 400 seeds m−2 to approach optimum yields. These results also support the conclusion that seeding at 480 to 520 seeds m−2 is appropriate for sites with high yield (5000 kg ha−1) potential.

Effect of the nud gene on grain yield in barley

“…In Foggia autumn, naked DHs differed from hulled ones also in terms of PH and HD. In this case, the association with a lower PH in the naked DH group is in agreement with the observations of Choo et al (2001) for naked and hulled doubled haploid (DH) lines (like in our case derived from a single hulled × hulless cross), and of Thomason et al (2009) in naked and hulled breeding lines. It could also suggest the existence of either pleiotropic or linked effects of the nud gene.…”

“…Nevertheless, the naked genotypes still have lower grain yields compared to the hulled varieties, and it has not yet been clearly demonstrated whether it is only a matter of lacking glumes or whether it also depends on other associated traits/factors. Thomason et al (2009) studying the yield performances of hulless and hulled breeding lines found that a large part of the difference in grain yield in naked lines was due to the absence of the hull weight, although naked lines also had fewer heads per square meter and fewer grains per head.…”

“…After the two experiments, the use of such advanced backcross materials strongly suggests that the nud gene per se, when properly introgressed into a hulled background, only leads to irrelevant differences in yield, together with a reduction in grain size, as observed by Choo et al (2001) and Thomason et al (2009). This in turn leads to a HI reduction, exclusively due to the absence of the glume weight.…”

“…This could mean that the associations observed for example by Thomason et al (2009) and Choo et al (2001) with fewer heads/plants per m 2 , and by Thomason et al (2009) with fewer grains per spike were rather due to different, non-isogenic, hulless genotypes used, and/or to environmental factors, or to grain damage conditions that reduced the emergence of hulless barley, than to the direct or even pleiotropic effects of the nud gene.…”

Influence of wheat populations arrangement on growth characteristics and grain yield

“…Some authors have seen absence on yield change due to plant density variation (Thomason et al, 2009), a result that might be related with wheat capability in sprouting, compensating the absence of plants, as well the yield components, which end up maintaining the same yield index (Holen et al, 2001). In this study, a yield component that had a positive influence on maintaining productivity was the thousand grain weight (Tables 6 and 7) which was higher in paired spacing and at low plant densities.…”