CROP PHYSIOLOGY
Year:2011 | Volume:3 | Issue:9|Papers Count:9

In order to evaluate the best sowing date and its effect on yield and yield components of sunflower cultivars, a field experiment was done as split block design in a randomized pattern of complete block design with three replications in 2009 in Shahinshahr, Isfahan. The sowing date was studied in four intervals: 22 June, 2009, 1 Jul, 2009, 11 Jul, 2009, and 21 Jul 2009. The four factors used were, Alestar, Azargol, Master and Zaria. The results showed that sowing date had a significant effect on the number of seed, weight of thousand seeds, seed yield, LAI, Cap diameter and oil percentage. The higher seed yield (4170 kg/ha) was obtained from the first sowing date (22 June.2009), and the lowest seed yield (2230 kg/ha) was obtained from the last sowing date (21 Jul.2009). The average of seed yield in 1 Jul.2009 and 11 Jul.2009 was 3980 and 2760 kg/ha. The highest number of seed (759.5) and weight of thousand seeds (55 gr) was obtained from 22.June.2009 and the lowest number of seed (619.3) and weight of thousand seeds (36 gr) was obtained from 21.Jul.2009. The cultiver had a significant effect on all studied traits except the number of seeds. The highest and lowest seed yield were related to Azargol (4090 kg/ha) and Alestar (2450 kg/ha). The seed yield of Zaria and Master were 3500 and 2910 kg/ha. The highest and lowest weight of thousand seeds was obtained from Azargol (57 gr) and Alestar (38 gr).

In order to study the effect of foliar application of nitrogen at different dates, residue management methods and planting methods on yield and yield components of Mung bean, a field experiment was carried out in summer, 2009 at Azad University Research field in khoramabad. Treatments were arranged in a strip- split plot using randomized complete block design with three replications. The planting method levels consisted of raised bed plots and no-tillage, wheat residue management consisted of burning straw and straw mulching, and foliar application of nitrogen consisted of four levels: no foliar application, foliar application in the rapid stage growth, foliar application before flowering, and foliar application in the stage growth and flowering. Results showed that Mung bean in no-tillage had higher grain yield, biological yield, number pod per plants, Number of seed per pod and 1000- grain weight. Moreover, grain yield, biological yield, number of pod per plants, number of seed per pod and 1000-grain weight were significantly higher than burning straw. Foliar application in the stage growth and after had higher grain yield (627.1 kg.ha-1), biological yield (1507.1 kg.ha-1), number of pod per plants (31.2), number seed per pod (13.2) and 1000- grain weight (47.2 gr). It can be concluded that planting methods (No- tillage) straw mulching and foliar application in the stage growth and after, was considered superior, by producing 782 kg.ha-1 grain yield.

An experiment was conducted in order to study the effects of sulfur fertilizer and compost organic fertilizer on Bam wheat cultivar in Semnan region during 1388-1389. Factors under investigation at this experiment, sulfur fertilizer at three level of 0, 200 and 400 kg/ha and compost organic fertilizer of urban rubbish at 3 levels of 0, 10 and 20 ton /ha were performed. The design was conducted as factorial and on the basis of randomized complete blocks in three replications. The results indicated that in spite of tiller number in plant and spike number in square meter in other cases simple and reciprocal effect of sulfur fertilizer and compost organic fertilizer on experimental traits was significant. In this research increase in sulfur and compost application increased plant height, 1000 seed weight, seed number in spike, seed yield, biological yield, Leaf Area Index and net assimilation rate. Comparison interaction of experimental factors indicated that 400 Kg/ha sulfur fertilizer and 20 ton/ha compost organic fertilizer gained the maximum amount of seed yield (4262 Kg/ha), 1000 seed weight (38 g), seed number in spike (44.47), Leaf Area Index (5.889). The lowest amounts of traits was observed in non sulfur and compost organic fertilizer application.

Terminal heat and drought stress, are the common results during wheat growth, in subtropical and semi arid climates such as Khuzestan province. This study was carried out in randomized complete block design with three replications and twenty five spring wheat genotypes for evaluating, heat stress , normal and late planting at Ahwaz, and water stress, full irrigation and lost anthesis drought at Behbahan research station during two years 1994-95 and 1995-96. Simple analysis of variance was conducted for seed number per square meter (SN), seed weight (SW), seed yield (SY), and multiple analysis of variance between both environments. Since the comparison of an average of factors may be an unsuitable index in stress condition for tolerance determination, and in order to reciprocate effects between genotype and environment, stability analysis was conducted, and genotype responses in all environments was computed based on regression definition (R), standard deviation (S2d), coefficient of determination (R2), and genotypes means. Results showed that the regression analysis, the stress susceptibility index (SSI), and SY identified the genotypes tolerance to stress. The sever conditions, heat and drought stress, SN, SW, and SY 12, 13, and 28% respectively. The Attila genotype wheat, SSI=0.83, R=1.18, and SY=4807 kg/ha. Superior genotypes for terminal heat and drought stress conditions, and the Fong wheat, SSI=0.45, R=0.68, and SY=4279 kg/ha., compatibility to severe conditions and it’s early maturity were recommended for late planting in Khuzestan.

To evaluate the effects of different levels of iron and Manganese intake as soil and foliar application and their interaction on wheat’s qualitative and quantitative characteristics, a research was done as a factorial experiment in a randomized complete block design with 3 replications at the College of Agriculture, Islamic Azad University Saveh in November 2008. The factors of this research included 3 levels of Soil’s consumption of iron and Manganese and 2 levels of spray of the mentioned elements, in addition to a combination of all of these fertilizers. Results showed that none of the fertilizers had a significant effect on the protein and grain percentage. The Application of iron on soil compared with control significantly increased grain weight, content absorbed iron on seed, concentration of iron on seed, concentration of iron on the shoot and fertile tillers, while application of manganese on soil compared with control caused significant grain weight. Content absorbed manganese on seed, concentration of manganese on seed, concentration of manganese on the shoot. Results showed that spray of iron as compared with control view now significantly increased grain weight, content absorbed iron on seed, concentration of iron on seed, concentration of iron on the shoot; whereas, spray of manganese as compared with control view now significantly increased content absorbed manganese on seed, concentration of manganese on seed, concentration of manganese on the shoot. The results showed that a combination of all these fertilizers as compared with control view now significant increase concentration of iron on seed, concentration of manganese on seed, content absorbed iron on seed, content absorbed of manganese on seed, concentration of iron on the shoot, concentration of manganese on the shoot. It can be concluded that iron and manganese have a negative Interaction on each other.

Rice (Oryza sativa), a salt-sensitive species, has considerable genetic variation for salt tolerance within the cultivated gene pool. To evaluate salinity effects on Na, K and ABA concentration and dry matter of shoot and root, two rice genotypes (IR29 and IR651, sensitive and tolerant respectively identified by IRRI) were grown in a green house experiment, in normal conditions till 6th leaf was fully expanded. Seedlings were exposed to salinity, EC 12 dS m-1 and normal conditions (EC=1.65 dSm-1, Ushida solution base EC) for one week. Samples were taken 0, 4, 12, 24, 48, 96, 168 hrs after starting the treatments for determining ABA concentration in the youngest leaf. In another experiment after four hrs of inserting the treatment of salinity, fluridone in 50 µ M was sprayed only once on leaves, then we used the youngest leaf for measuring Na, K concentration. In this experiment dry matter of root and shoot under salinity in contrast to normal treatment decreased significantly, but this decrease was more in sensitive cultivar. Variation of K was not significant under salinity and salinity cause to accumulate Na in fluridone treatment in a couple of cultivars, but Na concentration in tolerant cultivar was less than half in sensitive cultivar. ABA concentration increased significantly under salinity in tolerant cultivar, however, in sensitive cultivar increase was not significant.

In order to evaluate the effects of different amounts and dates of Nitrogen consumption on the quality and quantity of yield this experiment was carried out in a factorial experiment based on randomized complete block design with three replications in Behbehan. The first factor was Nitrogen five levels of (0, 25, 50, 75 and 100 kg ha) with an Urea source the and second factor was two levels of Nitrogen consumption on different dates. First treatment fertilizer was used in two stages (pre cultivation + pre flowering), and the second treatment in three stages (pre cultivation + pre flowering + pre week before capsule) at equal consumption. The results showed that the best treatment in seed yield and seed oil yield was related to the consumption of 75 kg of pure Nitrogen in the two phases. In some traits such as plant height and number of sub- branch, it was observed that with the increase of Nitrogen quantity a significant increase in these two traits was obtained. The study showed, the higher use of Nitrogen increased the percentage of pollution of sesame plant death and filody. As a result, the most part of pollution was obtained at treatment of 100 kg ha-1 of pure Nitrogen. Since the best choice for fertilizer treatment is a treatment that in addition to a high operation has a high percentage of oil and oil yield, the above results and the fact that the best treatment, is a treatment that obtains best results with the lowest fertilizer consumption. In this research, the best treatment for Nitrogen use regarding traits under evaluation, the treatment that used 75 kg ha Nitrogen in two stages (pre-cultivation + pre-flowering) was introduced.

In order to study the effects of different amounts of irrigation on grain yield and chlorophyl amount of leaves in growth stages of 4 rapeseed cultivares, an experiment was performed in the agriculture research station of Khorramabad in 2009-2010.The design was a split-plot with irrigation treatments as main plot in a randomized complete block design and cultivares as sub plots.4 irrigation periods included normal irrigation (as control), cuting of irrigation from stem stage, irrigation cut from flowering stage and irrigation cut from poding stage.4 cultivars included R.G.S003, sarigol, Option 500 and Hyola 401. The results showed that water deficiency stress had significant decrease on pod number in plant, weight of 1000 grain and decreased grain yield, grain oil yield, biological yield and harvest index of treatments to control consequently. Since limited irrigation water treatments to cause control increased water use efficiency, therefore these treatments can be used to economize water use. The comparison of 4 cultivares showed that in regard to pod number in m2, pod number in plant, grain yield, biological yield, grain oil percent, and grain oil yield. Hyola 401 had relative superior to option 500, R.G.S003 and sarigol. In total, if water was limited, cutting of irrigation from poding stage in comparison to control and use of Hyola401 cultivar was favoured because grain yield and oil yield increased.