JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2009 | Volume:2 | Issue:2|Papers Count:10

To determine the effect of sprayed herbigated Tebothiuron on weeds control and elimination of environmental effects, especially wind power and moving equipments, an experimental design was completed in randomized blocks with 7 treatments in 4 replications in CP57-614 ratoon sugarcane fields. The obtained results showed that there was significant difference in 5 percent-level between treatments about dry weight, number of weeds and yield of Sugarcane. According to mean comparison results, between treatments, Tebothiuron 5 and 4 lit/ha with herbigation method showed the best weed control, in both factors of weeds number and weeds dry weight. In equal dose of herbicide usage, herbigation method was more effective. Spray method only in 5 lit/ha and up to 60 days after application had acceptable result, but 5 lit/ha in herbigation method was better and didn’t have significant difference with 4 lit/ha in herbigation method. Maximum and minimum yield respectively belonged to 5 lit/ha with herbigation and 3 lit/ha with spray method. Also herbigation method was generally more successful in comparison with spray method in weed control and increase of yield and with more resistant time.

In order to assess the deficit irrigation effect on sorghum forage yield, an experiment, was carried out in two years (2006 and 2007) in Khuzestan Agriculture and Natural resources research center, by split plot based on randomized complete block design with three replications. Treatments included four full irrigation levels, 85, 70 and 55 percent in main plot and three sorghum varieties speed feed, KFS2, KFS4 as sub plots. Results of variance analyses of raw numbers showed that there were significant differences at 1 percent level between irrigational treatments for all factors. The reduction of irrigation form full to 85, 70 and 55 percent, caused the plant height to reduce to 49.4 centimeter, till per plant to 1.8 number, 3.8 leaf area index, leaf rate stem to 0.9 percent, even fresh and dry ton per hectare were also reduced. Speed feed variety with 89.5 mean stem elongation and 2.2 percent leaf ratio to stem was the best cultivar in the group and that KFS2 was the next best variety in other group. Irrigation and varieties of interaction also had significant difference, in 5% and 1% level for fresh and dry yield. As soon as irrigation was reduced, the yield was also reduced and in all irrigation levels speed feed variety was superior. Finally speed feed variety with 70 to 85 percent rather than full irrigation was recommended if there were water limitation.

This study was set up to evaluate the effects of drought stress on the growth and development of siliques, oil percentage and yield of the spring rapeseed in agricultural and natural resources research center of East-Azerbaijan during 1386. This experiment was conducted in factorial design as a base of randomized completed block design with three replications. In genotype factor including two hybrid oil rapeseed genotypes (RGS300 and Hayola401), were irrigation factor including four levels as stress (non stress and water stress during stem elongation, flowering and the grain filling stages of oilseed rape) The results showed that the water deficit stress, in all stages impacted the growth of the silique, the area of silique, oil percentage and yield of seed. Water deficit stress decreased seed yield by decreasing of Pod Growth Rate (PGR) and the area of silique. The most drought effect of seed yield decrease was related, to flowering and the grain filling stages. There was a significant difference in genotypes about oil percentage and seed yield. The results indicated that the seed yield of Hayola 401 with a mean of 1622 kg/hec was greater than RGS 300 with a mean of 1388 kg/hec .

In order to study the effect of different weed competition periods on sunflower yield, cv. Allstar, an experiment was conducted in Islamic Azad University of Tabriz, Iran, during 2007 based on randomized complete block design with three replications. The first five treatments were the presence of weeds in the first 2, 4, 6, 8, 10 weeks and their subsequent control during the remaining growth season. The sixth treatment included the preservation of weeds in the whole growth period. The seventh treatment was chosen as a control and the weeds, in the whole period of growth, came under the control. Dominant weeds in experiments were redroot pigweed (Amaranthus retroflexus L.), lambsquarters (Chenopodium album L.), bermuda grass (Cynodon dactylon L.) and small bindweed (Convolvulus arvensis L.). Results showed that the effects of treatments on leaf area index (LAI), anthodium diameter, grain number per anthodium, hollow seed percentage, hundred seeds weight, seed grain yield and seed oil yield were significant. Reduction value in LAI was calculated 54%, when weeds competition with sunflower extended along it' s growth period. Simultaneous growth of weeds and sunflower for more than 8 weeks could reduce grain number per anthodium, significantly. Grain yield of sunflower in full season weeds interference reduced to 27.5%, compared with control. With attention to oil yield reduction of sunflower from 29%, when weed control delayed until 4 weeks after sunflower emergence, to 43% in full season competition of weeds in present weed densities, weed control is recommended, when they grow simultaneously with sunflower more than 2 weeks after sunflower emergence.

To evaluate the dimension of nitrogen fixation in annual medics (M. rigidula and M. truncatula) an experiment was carried out by Factorial design by factor 2 in CRD at 3 replications to determine nodulation and biological nitrogen fixation in greenhouse in Islamic Azad University of Mahabad branch in 2008. The rhizobium strains were chosen from Khake marz of Piranshahr, Jaldian and Soghanlou of piranshar and Bioran, Nalas and Rabat of Sardasht and Borhan and Bitas of Mahabad. In conclusion Soganlu rhizobium strain of Piranshahr and Bioran rhizobium strain of Sardasht had the best effect on nitrogen fixation in M. truncatula, and Nalas rhizobium strain of Sardasht had the best effect on nitrogen fixation in M. rigidula.

One of the major priorities in agriculture is proper use of water and soil sources. Limitation of cultivable land and increasingly population as well as the need of man to more suitable use of natural resources made the exploitation of the soil in a way that in addition to the access of maximum products has kept this source for the maintaing itself and the next generations. In this case, the land evaluation studies have been considered necessary. This study was carried out with the aim of the possibility of the evaluation of barley and alfalfa cultivation in Gargar plain with an area of 15831 ha located in left side of Gargar River. Land evaluation for irrigated cultivation was done with parametric method (square root) and finally relevant maps were prepared with GIS. Results showed that limitation factor of products in the area are not considered climatic variable parameter and the main limiting factor was soil physical condition specially calcium carbonate. Other limitations consist of salinity and alkalinity, drainage and topography.

The use of the energy flow method is one of ways to estimate agricultural development and product stability in agricultural areas. In this research, in the farming years of 2006- 2007 the farms of nuts and oil sunflower in Khoy have been studied from energy efficiency point of view. For the evaluation of energy efficiency on these farms, all data including inputs and outputs were transformed by the use of formula and particular coefficiency in quantity equivalent of production energy and utilized energy and then energy efficiency was calculated. Amount of input energy used on these farms for nuts and oil sunflower 8440.200 Kcal/ha and 8466.700 Kcal/ha respectively and amount of output or production energy yield of seed were separately calculated respectively as 17184000, and 8760000 Kcal/ha. Energy efficiency (output: input ratio) for yield seed was 2.04 and 1.03 respectively. Data showed much of the consumptions of energy were, irrigation, nitrogen, machinery and oil. Also the expenditure for nuts and oil sunflower were 10193.2 and 11223.61 Rials. and net income value, were 53806.8 and 36776.4 thousands Rials (9000 Rials=1$) per hectare, respectively. Income cost ratio were 5.28 and 3.28 respectively, they can be increased by applying appropriate cultivation management. The result of this research shows that because of wide economic efficiency in nuts sunflower farms, in spite of low energy efficiency in the farms, farmers' tendency for cultivating this type is more than the others. Whereas, continuance of present conditions of rigorous waste of energy, especially inputs of irrigation and nitrogen that have the most relation to input energy, will lead to pollution of above mentioned farms and regional ecosystem which will in return be in the risk of the reduction of sub ground waters.

Delay in Planting and low precipitation are the major problems in wheat (Triticum aestivum L.) farming in Iran. To evaluate the effects of inducing of drought tolerance under field conditions, two experiments were done in Agricultural Research Center in western Azerbaijan under well-water and drought stress. The experiment was factorial in complete randomized blocks design with five replications in which factor A includes four cultivars (Zarrin, Shahriar, Sardary and Azar) and factor B (Hydropriming, osmotic solutions (10% polyethylene glycol (8000), 2.5% KCL, 2/5% unic fertilizer) and plant growth regulators (1000 P.P.M Cycocel and 10 P.P.M (IAA). Drought stress was exerted by the interruption irrigation from rapid stem development stage. Result of simple and combined analyses of variance in normal and drought stress showed that traits of grain yield, spike per square meter, grain per spike, spikelet per spike, total dry mater, 1000-kernel weight, flag leaf area, R.W.C area, Plant height and leaf chlorophyll content were significantly different at 5% level. Cycocel and Auxin treatments had highest positive effect on evaluated qualities and KCl showed most Inducting of drought tolerance on wheat cultivar.