Yield Potential Progress in Short Bread Wheats in Northwest Mexico

Abstract

Germplasm from the spring wheat (Triticum aestivura L.) breeding program at the International Center for Improvement of Maize and Wheat (CIMMYT) has had a major impact on the yield of irrigated spring wheats in most developing countries in the past 30 yr. The rate and nature of yield potential progress in this germplasm was measured comparing eight outstanding short cultivars released in northwest Mexico between 1962 and 1988. They were grown under irrigation and optimal management, including disease and lodging protection, in each of six winter growing seasons (1989-1990 to 1994-1995) at the CIANO (Centro de Investigaciones Agricolas del Noroeste) experiment station in Sonora, Mexico. There were highly significant effects of cultivar on grain yield, and, although cultivar × year interaction was significant, there were few significant crossover interactions between pairs of genotypes and years in the grain yield data set. Yield averaged across the 6 yr increased linearly from 6680 kg ha-~ for the earliest cultivar, Pitic 62, to 8475 kg ha-~ for Bacanora 88, the latest. The rate of progress against year of release was 67 kg ha-~ yr-1 (r = 0.99, P < 0.001), or 0.88% per year. Grain yield progress was correlated with kernel number per square meter (r = 0.84, P < 0.01) and harvest index (r = 0.81, P < 0.02), but not with total biomass production, kernel weight, days to anthesis, spikes per square meter, or kernels per spike. Thus linear progress in yield within short germplasm has continued at least until the late 1980s, and the yield components studied did not indicate any clear direction for future progress, apart from that suggested by the strong relationships between grain yield and harvest index and grain yield and kernels per square meter, as has been seen in most studies of yield progress in cereals.

Genetic Analysis of Relative Cell Injury Percentage and Some Yield Contributing Traits in Wheat Under Nomral and Heat Stress Conditions

“…Wheat varieties with a better genetic potential perform better in conducive and non-conducive environment ecosystems (Calderini and Slafer, 1999;Reynolds and Borlaug, 2006). There is a correlation between yield improvement and increased dry matter, other than grain, but less attention was given to above-ground mass (Sayre et al, 1997). Crop plants have various mechanisms to improve yield (Singh et al, 1998).…”

The International Heat Stress Genotype Experiment for modeling wheat response to heat: field experiments and AgMIP-Wheat multi-model simulations

“…Of the 16 cultivars originally included in the first two-years of the IHSGE, two (Bacanora 88 and Nesser) were selected for the AgMIP-Wheat model intercomparison. Bacanora 88 is a high-yielding Mexican cultivar (Sayre et al, 1997) and Nesser is considered heat and drought tolerant (Okuyama et al, 2005). Both cultivars have low photoperiod sensitivity and low vernalization requirements.…”

Yield potential, potential yield and realized yield at farmer level of cereals with special reference to rice (<em>Oryza sativa</em> L.)

“…Adequate partitioning among plant organs is crucial to ensure that plants with comparatively heavier grain weight have strong enough stems and roots to avoid structural failure (Berry et al, 2007). However, among current elite materials of wheat, HI varies in the range of 0.40-0.55 (Sayre et al, 1997) and lower limit of the range is relatively low so that further increase in HI in combination with other desirable characteristics that determine yield might be feasible. In maize, any marked reduction of crop height or increased HI has contributed little to the increase in yield potential of hybrids Duvik, 1992).…”