The parameters of grain filling and yield components in common wheat (Triticum aestivum L.) and durum wheat (Triticum turgidum L. var. durum)
Final grain dry weight, a component of yield in wheat, is dependent on the duration and the rate of grain filling. The purpose of the study was to compare the grain filling patterns between common wheat, (Triticum aestivum L.), and durum wheat, (Triticum turgidum L. var. durum), and investigate relationships among grain filling parameters, yield components and the yield itself. The most important variables in differentiating among grain filling curves were final grain dry weight (W) for common wheat genotypes and grain filling rate (R) for durum wheat genotypes; however, in all cases the sets of variables important in differentiating among grain filling curves were extended to either two or all three parameters. Furthermore, in one out of three environmental conditions and for both groups of genotypes, the most important parameter in the set was grain filling duration (T). It indicates significant impact of environmental conditions on dry matter accumulation and the mutual effect of grain filling duration and its rate on the final grain dry weight. The medium early anthesis date could be associated with further grain weight and yield improvements in wheat. Grain filling of earlier genotypes occurs in more temperate environments, which provides enough time for gradual grain fill and avoids the extremes of temperature and the stress of dry conditions.
Wheat Cultivars Adapted to Post‐Heading High Temperature Stress
The existence of genetic variation in wheat for tolerance to high temperature stress has been reported but cultivars released for a particular production system often are not characterized. The objective of this study was to identify and describe the characteristics of wheat cultivars adapted to production systems with risks of high temperature during the post-heading period. Fifteen diverse wheat cultivars and one unreleased genotype were evaluated at the Texas A&M University Agricultural Research and Extension Center, Uvalde, TX, during two seasons characterized by daily maximum temperatures as high as 36 � C. Measurements during both seasons included days to heading, days to physiological maturity and grain yield. Large and significant (P < 0.05) grain yield differences were measured among cultivars within each season. Yield varied between 2979 and 4671 kg ha )1 in the first season and between 1916 and 5200 kg ha )1 in the second season. Late planting in the second season delayed heading date resulting in the post-heading period to coincide with periods of high temperatures. Cultivars that headed early, in general, yielded better than cultivars that headed later within each season with yield reduction of 35.3 kg ha )1 in the first season and 91.0 kg ha )1 in the second season for every 1 day delay in heading after mid-March. Earlyheading cultivars outperformed later-heading cultivars because of two distinct advantages: the early-heading cultivars had longer post-heading and, therefore, longer grain filling period than the later-heading cultivars. In addition, early-heading cultivars completed a greater fraction of the grain filling earlier in the season when air temperatures were lower and generally more favourable. The advantage of earlier-heading cultivars was also manifested in the amount of green leaves retained to anthesis. Earlier-heading cultivars produced fewer total leaves per tiller but retained more green leaves and lost fewer leaves to senescence at anthesis than later-heading cultivars. The results suggest that early heading is an important and effective single trait defining wheat cultivars adapted to production systems prone to high temperature stress during the post-heading period.
The Law of Failure
If a broker-dealer liquidates in federal bankruptcy court, why does an insurance company liquidate in state court, and a bank outside of court altogether? Why do some businesses re-organize under state law 'assignments', rather than the more well-known Chapter 11 of the Bankruptcy Code? Why do some laws use the language of bankruptcy but without advancing policy goals of the Bankruptcy Code? In this illuminating work, Stephen J. Lubben tackles these questions and many others related to the collective law of business insolvency in the United States. In the first book of its kind, Lubben notes the broad similarities between the many insolvency systems in the United States while describing the fundamental differences lurking therein. By considering the whole sweep of these laws - running the gamut from Chapter 11 to obscure receivership provisions of the National Bank Act - readers will acquire a fundamental understanding of the 'law of failure'.