JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2012 | Volume:4 | Issue:14|Papers Count:14

An experiment in the form of one time chopped plots in the frame of quite randomly block design and in four repetition was done in the investigation field of Islamic Azad university, Chaloos branch, in 2008 to study the most important physiological characteristics which are affecting on rice grain yield, Fajr variety. Three planting dates (May.30th, June 9th, and june.19th) as main factors and four densities (17, 34, 51 and 68 plant per m2). As sub factors were consider. The obtained results showed that with the increase of bush density, the yield of grain in stage unit will increase, so that the high most of grain yield (6403 kg/ha) in the density of 68 bushes per/m2 obtained. With the delay of planting date, the yield of grain in surface unit reduced, so that the high most of grain yield related to planting date of may.30th and june.9th (6264 and 6357 kg/ha) and the least one obtained for planting date june.19th (5576 kg/ha). With the increase of planting density, dried matter of whole plant the speed of crop growth, the index of Leaf surface, and the speed of Relative growth rate increased, but the ratio of Leaf surface decreased. Also, whit the delay of planting dried matter of whole plant, the index of Leaf surface, the speed of crop growth increased, but the speed of relative growth rate and the ratio of Leaf surface decreased.

Drought stress is one of the most important environmental factors that are effective on growth, development and production of plants. This study examined the germination and seedling growth characteristics of 8 wheat genotypes (Sardari 101, Homa, Zarrin, Azar2, Rasad, Gascogene, Sayson and Marten) under four levels of water potentials (0, -2, -6, -10 bar) using a 4×8 in a factorial experiment based on completely randomized design with three replications. Results showed that drought levels had significant effect on all traits, except the radical fresh weight. Reduction in water potential decreased germination percentage, radical and plumule lengths, coleoptile length, seedling fresh weight and plumule fresh weight. The genotypes showed a significant difference in all traits, except radical plumule ratio, radical fresh weight and radical plumule ratio of fresh weight. Results also indicated that variety of drought stress level interaction, except in plumule length, seedling fresh weight and plumule fresh weight, was not significant. Under water stress condition Homa cultivar had longer radical and plumule length, and higher proportion of seedling fresh weight, plumule fresh weight and plumule dry weight as compared to the other cultivars. In conclusion, Homa cultivar proved to be was tolerant to drought stress.

To study the effect of nitrogen foliar application and sowing date on yield and yield components of rapeseed (Brassica napus L.), an experiment was carried out In Agricultural and Natural Resource Research Center of west- Azerbaijan during 2009- 2010. The experimental design was in split plot based on RCBD with three replications. Main factor, foliar application with urea fertilizer in three levels (stage of stem elongation, stage of poding and control) and sub factor, sowing date in four levels (10 Sep, 20 Sep, 30 Sep and 10 Oct) were considered. Experimental Results showed that the effect of nitrogen foliar application and sowing date were significant on yield and yield components. The highest grain yield with mean of 5194 Kg/ha was obtained in primary sowing date (10 Sep) and the nitrogen foliar application in stage of poding.

Safflower (Carthamus tinctorius) is one of the oilseed plants that can influence strongly on oilseed security because it is extremely compatible with environmental conditions. In order to evaluation of safflower genotypes for growth phenology, seed and oil yield and oil percentage in Karaj condition, an experiment was carried out as a randomized complete blocks design with four replications at Seed and Plant Improvement Institute in 2009. Result showed days number to blooming, days number to flowering, day number to 50% flowering, day number to maturity, seed yield, oil percentage and oil yield significant (p£0.01 and p£0.05) at genotypes factor. The maximum days number to blooming, day number to flowering, day number to 50% flowering and day number to maturity were obtain for DK-376 genotype. The most seed yield was obtained for Goldasht genotype and most oil yield was produced for Goldasht and DK-411 genotypes, respectively. Oil yield had been positive correlation with seed yield and oil percentage. Therefore, Goldasht genotype because of the most seed and oil yield observed the best of genotype.

To study the effect of drought stress, potassium application and, soil and foliar application of micronutrient on yield and yield components of hybrid grain – maize S.C.704, this study was conducted in split-split-plot experiment based on RCBD with three replications in 2009 in Uremia. The factors were: drought stress as a main plot with two levels (normal irrigation and drought stress), potassium as a sub-plot with two levels (non-application and 200kg/ha application) and micronutrients as sub-sub-plot with three levels (non-application, soil and foliar application). Plant height, fresh forage, stalk biomass, leaf biomass, plant biomass, flag leaf area, maize length, maize diameter, proline and RWC were measured.Result showed that drought stress had significant effect on proline, plant height, flag leaf area, maize length, fresh forage, stalk and leaf biomass. Potassium had significant effect on plant height, plant biomass, maize diameter, maize length proline and stalk biomass.Also interaction of drought stress, potassium and soil application of micronutrients increased leaf biomass 20% and praline 0.34% significantly, but Interaction of drought stress, potassium and non-application of micronutrients increased RWC 8% as compare with foliar application of micronutrients. It can be concluded that in drought stress, potassium application with micronutrients caused by the improvement of growth indeces, therefore the usage of these nutrients is recommended in Uremia.

To investigate the effect of irrigation management and nitrogen application on yield and yield components of sahar cultivar of soybean, an experiment was arranged as split plot based on randomized complete block design with four replications in Ramian, Golestan province during summer 2010. Treatments were irrigation managements (7, 14 and 21 days) and nitrogen application rate in growth stages (0, 35, 70, and 105 kg per hectare). Nitrogen was used in vegetative stage (with first irrigation of all plots) and reproductive stage (with irrigation of all plots). Results showed that number of filled and empty pod, number of seed per plant, 100-seed weight, seed yield and number of node per plant were affected by irrigation management. Effect of nitrogen amounts on number of filled and empty pod per plant, number of seed per plant, 100-seed weight, seed yield and number of node per plant were significant. Interaction between irrigation management and nitrogen application except number of empty pod was not significant. Number of filled pod, number of seed per plant, 100-seed weight and seed yield (with 72/59, 159/5 and 13/82g respectively) in 14- days regime was maximum. Maximum seed yield in 14- day regime was 4360 kg ha-1. Minimum amounts of all traits belonged to 21- days' regime. Minimum seed yield in 21- day regime was 3485 kg ha-1. Maximum and minimum amounts of all traits belonged to 150 and 0 kg nitrogen respectively. Seed yield in application of 150 and 0 kg nitrogen was 4430 and 3368 kg ha-1.Number of seed per plant, number of filled pod and 100-seed weight (with 0/97, 0/94 and 0/78 respectively) had positive correlation seed yield.

The purpose of the present investigation was to compare the influence of different biofertilizers to optimize the effect of chemical fertilizers that are requisite for organic farming. The experimental design was in randomized complete block with three replications and 16 treatments (48 plots). The study was conducted during growing seasons of 2007- 2008 (in two years) at agricultural research station of Islamic Azad University, Tabriz, Iran.Treatments were: first factor (A) in 4 levels of phosphate fertilizers and secondary factor (B) in 4 levels of nitrogen fertilizer (Urea). Analysis of variance showed that there were significant differences between phosphate treatments in yield traits at 1 percent probability levels and yield index and number of seed at 5 percent probability levels. In all traits there were significant differences at 5 percent. In comparison effects of P and N treatments in all traits were significant at 5 and 1 percent in yield. Maximum yield was attained in phosphate treatments (a3) and nitrogen treatments (b4). The results also revealed that A3B3 treatment with mean yield (19150.9 kg/ha) produced highest one and A4B2 treatment with mean yield (10650.9 kg/ha) the lowest.

Sugar beet is one of the most important industrial plants and the main resource of sugar production. However, root disease decreases the crop yield. Thus, using the resistant varieties is the safest bioenvironmental safe method to manage the soil-bearing diseases. In this study, resistance of four sugar beet lines along with one sensitive and one resistant genotype were evaluated against Pythium aphanidermatum, root decay factor, under greenhouse conditions.Plants were inoculated in two growing stages, seedling and mature (adulthood) periods. The 3 to 5 day cultured P. aphanidermatum on the CMA medium was used as the inoculum to infected plants. Experiments were carried out randomly as triplicate trials. After a month, disease severity index was measured grades 1 to 7. The results demonstrated that in the seedling stage, genotypes 16 and 44 showed resistance to the pathogen, by contrast to adult plants, genotypes 16, 44, and 78 possess a lesser index than the resistant genotype. We conclude that the reciprocal effects of age and genotype cause disease severity and resistance, and that are positively regulated by each other.

To examine the response of spring barley genotypes to terminal drought stress a randomized complete block experiment with 17 lines and two control varieties in stress conditions (after heading) and non-drought stress as separate four replicates in cropping year of 89-1388 was conducted in Mahabad region. The results from the combined analyses showed that the interaction between test conditions and the cultivars for all characters except the period of grain filling and 1000-kernel weight was insignificant. There was also a meaningful difference among the whole cultivars, from traits point of view, except 1000-kernel weight. The results showed that drought in the ending period of the season, plant height (5/8%), time of maturity (6/6%), peduncle length (25/2%), number of grains per spike (18/2%), spike unit area (11/5%), yield (21%) and their biological functions (22/5%) reduced.Lines SLB39, Matnan-01 and Birlik-1/4 with an average yield of two terms, respectively, with 04/4, 9/3 and 3/4 tons per hectare demonstrated superiority over other lines. Line Birlik-1/4 in both normal and stress conditions was the highest figure compared to the first control (Sayed tajaddin) (29/7%) than the second control varieties (Chaldoran) (40/6%) had a boosting performance. Positive and significant correlation index arithmetic mean, geometric mean, harmonic mean, stress tolerance and grain yield in both normal and stress conditions showed that these indices could identify drought tolerant genotypes and environmental conditions applied to both products so that the lines of these indices were superior. Using cluster analysis method based on stress indices in two groups of lines the lines, were sensitive to drought tolerant SLB39, Matnan-01 and Birlik-1/4 in the drought tolerant lines.

To evaluate the yield, yield components, nitrogen use efficiency and nitrogen uptake on wheat cultivars, a split plot experiment was carried out in 2007-2008 at Moghan Agricultural Research Center, with 2 main plots of nitrogen levels (0 and 200 kg/ha) and 20 genotypes as sub plots with 3 replications. Results of analysis of variance in nitrogen effects showed significant difference for harvest index, grain nitrogen yield, and stable nitrogen yield and nitrogen uptake efficiency. Results showed that in grain yield, biological yield, thousand kernel weight, grain nitrogen yield, stable nitrogen yield, nitrogen use efficiency and nitrogen uptake efficiency were influenced by genotypes. Genotype×nitrogen interaction influenced on grain yield, thousand-kernel weight, tiller number and nitrogen use efficiency at (P<0.05) and for nitrogen uptake efficiency, grain nitrogen yield and stable nitrogen yield at (P<0.01).Mean comparison for grain yield showed cultivars Gobustan, Girmizigul-1 from Azerbaijan and Koohdasht and Chamran from Iran as the highest grain yield. Mean nitrogen uptake efficiency and use efficiency were 47.5% and 17% respectively. The highest nitrogen use efficiency observed to Gobustan and Koohdasht and Moghan-3 and Gobustan had maximum nitrogen uptake efficiency. Cluster analysis for nitrogen use and uptake efficiency, nitrogen responsible, grain and stable nitrogen yield grouped genotypes 3 clusters with different separate characters. The high, low and medium nitrogen use and uptake clusters. Selection of parents from cluster one, same as Koohdasht (high nitrogen use and uptake efficiency) and cluster three same as Nurlu-99 (low nitrogen use and uptake efficiency) will be beneficial for a crossing block design. In order to create new high nitrogen uptake, existing genetic diversity between cultivars of different and far clusters, in a hybrid program will be useful.