Flag Leaf and Peduncle Area Duration in Relation to Winter Wheat Grain Yield1
- S. H. Mohiuddin and
- L. I. Croy2
Information on the photosynthetic area duration in winter wheat (Triticum aestivum L. em Thell.) is important in breeding programs for yield advancement and large numbers of data must be taken for the data to be meaningful. A 2-year field study (1973 and 1974) was conducted at the Agricultural Experiment Station, Oklahoma State Univ., Stillwater, Okla. It was conducted to obtain information on flag leaf and peduncle area duration as selection indexes in relation to yield, tiller number, kernels/spike, and kernel weight in winter wheat and to investigate the response of five winter wheat cultivars to selected N levels and seeding rates higher than presently used for grain production. A split plot design with four replications was used for the study. Nitrogen levels comprised main plots, cultivars were sub-plots, and seeding rates were sub-sub plots. The levels of N were 67, 134, and 202 kg N/ha, and the seeding rates were 67, 100, and 134 kg/ha. The five hard red winter wheat cultivars were ‘Tam W 101,’ ‘Palo Duro,’ ‘Danne,’ ‘Centurk,’ and ‘Caprock.’
All the traits measured differed between the two crop seasons, and a significant year by cultivar interaction suggested the presence of genotype by environment interaction. Differences among N levels were not significant probably because of the high residual amounts of available nitrogen at the experimental site, the lowest level of applied N was adequate for crop growth. The highest seeding rate (134 kg/ha) reduced grain yield, kernels per spike, and flag leaf area duration. Even though the growing conditions differed between the 2 years of the study, peduncle area duration and flag leaf area duration showed a positive correlation with grain yield, kernel weight, and a negative relationship with kernels per spike. These data suggested the use of peduncle area duration and/or flag leaf area duration as selection criteria in breeding for increased grain yield potential. These readings would be more rapid than total leaf area duration; and using selected photosynthetic leaf area indexes in a breeding program for yield, data could be obtained on many more genotypes. The data also support the use of kernel weight as a selection factor for increasing grain yield.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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