M. Golabadi, A. Arzani,
Volume 7, Issue 1 (4-2003)
Abstract
Genetic variation of 300 genotypes of durum wheat comprising CIMMYT/ICARDA and Iranian germplasm was evaluated in 1999-2000 at Researh Farm of College of Agriculture, Isfahan University of Technology located at Lavark, NaJaf-Abad. Days to heading, days to maturity, plant height, spike length, grain weight per spike, number of grain per spike, number of spikes per m2, 1000-grain weight, test weight, grain yield, biological yield, and harvest index were recorded. Coefficients of correlation, step-wise regression, factor analysis and cluster analysis of characters and genotypes were conducted using the studied traits. Results indicated that considerable genetic variations exist for the traits and, in particular for grain yield, harvest index, number of spikes per unit area and number of grain per spike. Grain yield had a positive and significant correlation with days to heading, days to maturity, number of grain per spike and grain weight per spike. Factor analysis for the genotypes detected 6 factors, which explained 76.7 percent of the total variation among data. These factors basically involved potential of assimilate distribution, different aspects of plant storage, source-sink relationships, plant height and tillering potential. Cluster analysis was similar to factor analysis in grouping the characters. According to cluster analysis, the genotypes were calssified into 6 clusters with significant differences among all groups. Mean comparisons of traits in these groups showed that genotypes of groups 5 and 6 were superior in grain yield and harvest index and are beneficial to the local durum breeding objectives.
M. Rabiee, M. Kavoosi, P. Tousi Kehal,
Volume 15, Issue 58 (3-2012)
Abstract
To determine the proper nitrogen fertilizer rates and its application times for achieving high grain and oil yields of rapeseed cultivar, Hyola 401, a research was carried out in paddy fields of Rice Research Institute of Iran in Rasht during two cropping seasons. A factorial experiment was conducted in a completely randomized block design with three replications. The experimental factors were pure nitrogen fertilizer rate at five levels of 0, 60, 120, 180 and 240 Kg ha-1 and fertilizer application times at five levels of all fertilizer at planting 1/3 at planting + 2/3 in stem elongation 1/3 at planting + 1/3 in stem elongation + 1/3 before flowering 1/3 in 3-4 leaf stages + 1/3 in stem elongation +1/3 before flowering 1/4 at planting + 1/4 in 3-4 leaf stages + 1/4 in stem elongation + 1/4 before flowering. The results of statistical analyses showed that from amony nitrogen rates, application of 240 Kg N ha-1 and 180 Kg N ha-1 with average production of 2505 Kg ha-1 and 2596 Kg ha-1 respectively showed the highest grain yield and were in the same group. of Nitrogen application times, application of 1/3 at planting + 1/3 in stem elongation + 1/3 before flowering had the highest grain and oil yields with average of 2155.3 Kg ha-1 and 9865 Kg ha-1, respectively. Maximum oil percentage was observed in control treatment (without N-fertilizer application) and the highest oil yield was obtained for nitrogen rates of 180 and 240 Kg ha-1. Also, the highest growth period was observed for the treatment of 240 Kg nitrogen with 206.3 days. The results showed that nonsignificant difference exists between the nitrogen rates of 180 and 240 Kg ha-1 in grain and oil yields. Therefore, the rate of 180 Kg ha-1 is recomended due to less fertilizer consumption and prevention of destructive effect on the environment
