Crop Production
Year:2009 | Volume:1 | Issue:4|Papers Count:7

In order to evaluate the utilization ability of drought resistance indices such as: yield index (YI), yield stability index (YSI), stress susceptibility index (SSI), tolerance (TOL), mean productivity (MP), geometric mean productivity (GMP) and stress tolerance index (STI) in sunflower hybrids, three separate experiments were conducted as randomized complete block design at the research field of Seed and Plant Improvement Institute in Iran-Karaj, in 2006. The first experiment was conducted at optimum conditions where plants were irrigated after 60 mm evaporation from evaporation pan, class A, whereas the second and third experiments were irrigated after 120 (mild drought stress) and 180 (sever drought stress) mm evaporation, respectively. The results showed that under mild and sever drought stresses only STI by having positive and significant correlation with seed yield under non-stress and stress conditions was more effective in identifying the high yielding hybrids. The evaluation of hybrids using drought resistance indices indicated that Allstar hybrid had maximum leaf area index (LAI) and seed yield under mild and sever drought stress as 1671 and 701 kg.ha-1, respectively, and was superior to others.

Almost half of agricultural lands in Iran are saline and it is one of the most important constraints in cultivated lands. Wheat is the most important crop in saline lands in rotation of Golestan province. Since saline soils amelioration is so expensive, achievement of genotypes with tolerant and high yield potential is essential. 22 genotypes of selective wheat of recent experiments with three local check (Zagros, Kavir and promising line of no. 4) were cultivated in two location contain saline research station of Ag-Gallah (saline condition) and Gorgan research station (non saline condition) in 2007 with three replications in latis experiment. The results of simple and combined analysis in two locations showed significant difference between genotypes. Significant correlation between harvest index and 1000 kernel weight with yield in saline condition was recognizable. In non saline condition the correlation of between yield and harvest index was significant also. Genetic variance in saline condition was less than non saline condition and then as a result selective genotypes must have been high yield potential in both of locations. For example genotype no. 26 had high yield but with low yield stability. In all, genotypes yield in each of two conditions, the stability of genotypes in saline condition and disease situation screened genotypes no. 62, 56, 44, 80, 23, 81, 78 and 7.

In order to study of yield, yield component, plant height, total dry matter and radiation use efficiency with 13 spring varieties of rapeseed ,an experiment was carried out in 2007 growing season at Agriculture and Natural Resources Research Station of Torogh,Mashhad. These cultivars were from three rapeseed species belonged to Brassica napus, Brassica rapa and Brassica juncea. Experimental design was Randomized Complete Block with 4 replication. Result showed that a significant difference was existed among cultivars for yield, yield component, plant height and total dry matter. With exception of number of pod, Hyolla Hybrids had more yield components than other cultivars. Meanwhile cultivars of B.napus had more yield components than cultivars of B.rapa. Hyolla 330 with average of 1475 Kg.ha-1, BP18 with average of 1277Kg.ha-1 and Hyolla 401 with average of 1274 Kg.ha-1 had the most yields in this experiment respectively. We concluded that cultivars of B.napus had more yield than varieties of B.rapa. Cultivars in this trial presented considerable difference regarding radiation use efficiency. The value of radiation use efficiency under this investigation ranged from 0.4487±0.201 DM. MJ-1 to 1.8355±0.07 DM. MJ-1. Hyolla 330 with average of 1.8355+0.07 DM. MJ-1 and Zarfam with average of 1.32+0.725 DM. MJ-1 had the most radiation use efficiency. At this experimental condition, generally cultivars of B.nupus had greater slope of dry matter expansion in unit of cumulative received radiation than both B.rapa and B.juncea cultivars.

This study was conducted to evaluate genetic diversity of durum wheat cultivars using multivariate analyses on agronomic and morphological traits. Thirty genotypes were planted in a randomized complete block design with three replications in 2003. Agronomic and morphological characteristics including days to flowering, days to pollination, days to maturity, plant height, spike length, grain weight per spike, number of grain per spike, number of spike per m2, grain yield, biological yield, 1000 grain weight, kernel weight and harvest index were assessed in the studied genotypes. Multivariate statistical analyses including principal components analysis (PCA), principal co-ordinate analysis (PCO) and cluster analysis were used to assess the pattern of morphological variations and to group the genotypes. The obtained results from grouping 30 cultivars of durum wheat with 3 studied methods indicated that in the most cases the applied methods produced almost similar grouping among cultivars. Cluster analysis, however, used both genetic variations between genotypes and traits, and hence is considered as a superior method for grouping the genotypes.

A growth chamber study was carried out to evaluate the allelopahtic effects of shoot and root water extract of Hoary cress (Cardaria draba) on seed germination and seedling characteristic of sorghum (Sorghum bicolor). The study was conducted based on completely randomized design with four replications in research laboratory of faculty of agriculture, University of Birjand in 2008. Treatments were four levels (25, 50, 75 and 100%) of shoot, root and their mixed water extracts of Cardaria draba with distilled water as control. Results showed when concentration of shoot and root extracts increased, germination percentage, germination rate, root length, stem length, root fresh weight, stem fresh weight, seedling fresh weight, root/stem fresh weight ratio and root/stem length ratio decreased significantly. In the concentrations of 75 and 100 percent of allelopahtic extract no germination was recorded. The functional three-parameter logistic model provided a successful estimation of the relationship between water extract levels and germination response of sorghum. The fitted model showed that the 50% concentrations of all organs extract caused 50% reduction in maximum germination percentage of sorghum. The highest and lowest slope of the model was observed in shoot and root tissues water extract, respectively. There was not significant difference between the 25% concentration of all organs extract, the 50% concentration of root extract and control when studied the time to 50% of maximum germination percentage. Based on orthogonal comparisons, shoot, mixture and root water extract had the most inhibition on germination percentage, root and stem length, respectively.

The present research was conducted under laboratory and field condition to determine seed priming effects on maize inbred line's germination, emergence, and grain yield. Seeds of two maize inbred lines include of Mo17 (as paternal line) and B73 (as maternal line with cytoplasmic sterility) in the laboratory conditions were subjected to hydropriming for 12, 24, 36 and 48 h, or osmoticpriming with solution of polyethylene glycol-6000 and urea solution for 96 h (with osmotic potential -1.2 MPa), then germination performance was considered. Results of laboratory experiment showed that both inbred lines responded to priming treatments approximately similar. Maximum invigoration was observed in seeds hydroprimed for 36 h as indicated by lower mean germination time and higher values of radical and coleoptile length. However, osmoprimed seeds behaved similar to or even poor than that of control. The most promising laboratory seed treatment with 3 sowing dates of paternal line were advanced to field experiment where seedling emergence, phenological growth trend, and yield components were assessed. The experimental design was spilt plot on a randomized complete block design with 4 replications that main plots were assigned to pre-sowing seed treatments (control and hydropriming for 36 h) and sub-plots were assigned to 3 sowing date of paternal line (b1=same sowing date for both parental lines, b2= sowing of paternal line basis on 2cm radicle emergence of maternal line, b3= sowing of paternal line basis on 4cm radicle emergence of maternal line). Result showed that extent of seedling emergence was greater for hydroprimed seeds. On the other hand, sowing of paternal line basis on 2cm radicle emergence of maternal line was the most effective to achieve of high synchronization between silking and anthesis of parental lines; also this treatment significantly improved the yield components.

An experiment was carried out in 2008 to investigate the effects of different irrigation regimes, and Chickpea cultivars on chickpea production in the Khorramabad Lorestan. The experiment was split–plot in a randomized complete block design with 3 replications. Supplementary irrigation AT 8 levels (1-rainfed without irrigation, 2-Irrigation after Sowing, 3-Irrigation at flowering, 4-Irrigation at pod fill, 5-Irrigation at Sowing+flowering, 6-rrigation at Sowing+pod fill, 7- Irrigation at flowering+pod fill, 8-Irrigation at Sowing+flowering+pod fill) was allocated to main plots, and the genotypes (Filip 93-93, Hashem, and Greet) was allotted to sub plots. Chickpea yield components was measured base on the 10 randomly selected plants from each plot, and grain yield was determined base on the middle rows of each plot. Among irrigation treatment the highest grain yield per area (762.2 kg/ha) was belonged to irrigation at sowing+flowering+pod fill. Three times irrigation treatment in comparison to rainfed increased grain yield per area by 251.7%. This is show the importance of supplementary irrigation for increase of chickpea yield. Among chickpea cultivars the highest level of grain yield per area (701.8 kg/ha) was achieved for Greet mass. Grain yield for Hashem cultivar was very low. In conclusion, Hasher cultivar dose not recommended for spring crop in regions with climatic condition like Lorestan, but Filip had appropriate compatibility.