JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2015 | Volume:7 | Issue:26 |Papers Count:9

In order to study the effects of increasing corn plant density on competitive ability of corn with natural weed population in Khuzestan climate, a Randomized Complete Block design with four replications was conducted in the experimental field station at Ramin Agricultural and Natural resources, Mollasani university of Ahwaz. Treatments included pure stands of corn at three density (40000, 70000 and 100000 plants ha) and weed interference period to v9 and v13 in any of plant density (40000, 70000 and 100000 plant ha). Also another additional treatment was adopted as weed-interference during the growth season with density of 70000 plant ha.Results showed that there was significant difference between the studied characters, biological yield, grain yield, harvest index, grain number per ear, and row number per ear, grain number per row and 1000-kernel weight among treatments. The studied characters were severely reduced by increasing the duration of weed interference after corn emergence. In addition, results showed that with corn plant increasing density, corn plants tolerated the presence of weeds until v9 stage with approximately 6-15% in yield loss.

In order to study the effect of plant density on quantitative and qualitative yield of sunflower var. Hayson, a field experiment was conducted as a randomized complete block design with four replications in Agricultural and Natural Resources Research in Mazandaran province (Sari – Dashte Naz) in crop year of 2009. In this experiment, four density levels 55, 63, 83, 111 thousand plants per hectare) were considered as the main factor and three levels of potassium as (0, 50, 100kg per hectare) as the sub factor. Analysis of variance showed that the density had significant effect on seed protein and the percentage of oil, but the number of rows of seeds, the number of filled seeds and seed yield were not significantly affected by the density. The results showed that the density of 83 thousand plants per hectare with 100kg potassium fertilizer had the greatest impact on increasing of the number of rows of sees, number of filled grain and seed yield. Density and potassium levels did not have significant effect on seed protein but the greatest oil percentage belonged to 83 thousand plants per hectare. On the basis of results, it is defined that increasing density on the optimum level, caused to increase yield components, oil percentage and seed yield.

A study of some phonological, morphological traits with yield and yield components of chickpea genotypes in Fall planting under dry farming condition was carried out through an experiment at Agricultural and Natural Research station of Ardabil in 2010-2011.The experiment was carried out in a randomized complete block design with 15 chickpea genotypes with four replications. Characteristics were days of anthesis, poding, maturity, plant height, number of branches, number of fertile and non-fertile pod, number of seed per plant, 100-seed weight, biomass yield, harvest index and seed yield per plant. The results of variance analysis showed that all of studying traits except non-fertile pod per plant were significantly affected by experiment treatments. (Flip 98-138C*Se 199 TER 85074) *SEL99TH15039 and CA9738007*SEL99TER85534 genotypes had maximum and minimum days to anthesis, respectively. The highest plant height belonged to Flip97-118C genotype and Local variety had the lowest value. This genotype had the highest branches per plant. CA9783007*SeL99TER 85534 genotype had the highest fertile pod and seed per plant, although the lowest seed number per plant belonged to Djam genotype. The highest 100-seed weight was obtained from (ILC4291*Flip98-129C) *S98008 and S99326*SEL99TH15042 genotypes. This genotype had the highest biomass per plant and harvest index, too. There were positive and significant correlations between number of fertile pod and seed per plant, 100-seed weight, biomass and HI with seed yield.

In order to determine the effects of yield and yield components on corn planting and defoliation, an experiment was carried out in a randomized complete block design with three replications in Agricultural Resource Research Station of Khoy. In this experiment, planting pattern in four (20×75, 20×51, 14×75 and 17× 60) as the main plot and defoliation at three levels (no cutting the leaves, cutting the leaves off the top third, cutting alternating leaves) were considered as sub plots. According to the test results, pattern significantly affected on all traits except grain weight and harvest index. The highest yield of planting patterns 20×51 which had the lowest planting density (66000 plants per hectare) was obtained. 20×51 and 17×60 inter-planting statistically showed significant difference. The highest seed weight with an average of 6/301g belonged to non-cutting treatment of the leaves. Of course, the treatment of non cutting leave and cutting off the top third of vegetation was not significantly different. interactive planting and cutting leaves, the highest seed weight of 319g of planting 20×75 with treatment continuation of the leaves and the highest grain yield of 15000kg per hectare of planting 20×51 cell treatments belonged to cutting off the top third of the canopy.

To study the effect of nitrogen and boron on yield and sugar content of two varieties of sugar beet, an experiment was carried out in split-split plots at RCBD in three replications with three factors in the personal field of Khoy area.1st factor with two levels of variety, Flores (a1) and Iranian variety of 004 ( a2), 2nd factor with two levels of nitrogen which consisted of soil testing (b1) and 1.5-time soil testing (b2) and 3rd factor with three levels of boron which consisted of no-use (b1), foliar (b2) and soil (b3) application. The result showed that variety had meaningful effect on root length; the highest root length was 32.25 cm in 004 (a2) variety. The effect of nitrogen was meaningful in diameter, length and dry weight of root.The highest content of this factor was in 1.5 time of soil testing of nitrogen usage. The effect of boron on root dry weight, root yield, sugar and molasses content were meaningful. The different methods of boron application showed that maximum rate in all traits was attained with the soil usage of this element.

In order to determine the high yielding, the grain yielding stability, 24 promising barley lines and cultivars, a study was carried out based on RCB – design with four replications in three years (2011 to 2014) in 6 cold and moderate cold rainfed regions of Maragheh, Kurdestan, Zanjan, Urmia, Sararud and Ardabil.After testing of error uniformity, a combined analysis was carried out in three years for each location. Also, final combination of ANOVA was performed for all environments (3 years and 6 locations). Results of combined ANOVA analysis showed that locationgenotype and year×location×genotype were significant. The highest average green yield belonged to Sararud with (2893kg/ha) and the lowest one belonged to Ardabil satation (1524kg/ha. Lines number 12 with with (2471kg/ha) and 22 with 2499kg/ha) had the highest average grain yield among genotypes in 3 3 years and 6 locations. Results of stability analysis using Lin and Binns, CV% and rank methods showed that line number 14 (Schuyler //Alpha/ Durra/3/…) had the highest stability and lines number 11 and 12 showed relatively stable genotypes in comparison with other ones.

According to the statistics, surface irrigation system covers more than 95% of the country' s lands and current efficiency of the system is estimated as less than 35%.Hence, the need for detailed understanding of surface irrigation efficiencies in the irrigated lands and presenting appropriate solutions to increase such factors are too important to measure and should be taken in line with optimal consumption of agricultural water which covers more than 70% of the country' s available water. Hence, a farm was selected in Malajnood village area which was irrigated in furrow method and then was evaluated during the two phases of irrigation. The underlying tests were conducted using partial Parshall with input water flow of 3.66, 1.97L? S. Elliot7Wlker's two-point method was used to determine infiltration equation coefficients. The relationship between needed water and exact moisture distribution which was equal to 2 samples of irrigation indicated two cases of incomplete irrigation. Findings of the study indicated that deep percolation ratio was 23.33 and 45.63 and the irrigation adequacy was 100% that showed the high water losses and low water efficiency, but the full supply of plant water needed.

In order to evaluate the plant density and foliar application of urea fertilizer impact on yield and yield components of Durum wheat var. Arya, an experiment was carried out in 20km north east of Khoy during 2010=11. The fist factor plant density was in three levels (300, 400, 500 grain in m2), the second factor, foliar application of urea fertilizer in four levels (control, stage of tillering, stage of stem extension and stage of flowering) were considered. The result of variation analysis showed that the effect of plant density on number of spike in m2, number of grain in spike, weight of 1000 grains, number of spiklet in spike, protein percentage, grain yield and harvest index were significant. The highest grain yield (6.9 ton/ha) obtained from density of 300 grain in m2. And the minimum grain yield (5.19 ton/ha) was attained from density of 300 grain in m2.The effect of foliar application of urea fertilizer on traits except to weight of 1000 grains was important. The highest grain yield (6.74 ton/ha) was obtained from foliar applications of nitrogen fertilizer in the stage of tillering and grain yield increased about 10% compared with control. In addition to this experiment the maximum grain protein percentage was attained from plant density of 500 grain in m2 and foliar application of urea fertilizer in the stage of flowering.