Crop Production
Year:2009 | Volume:2 | Issue:2|Papers Count:11

Yield, harvest index and morphological characters of 13 spring cultivars of rapeseed were evaluated 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 Compelet Block with four replication. Result showed that significant difference occurred within cultivars for yield and harvest index. Hyolla 330 with average of 1475 Kg.ha-1, BP18 with average of 1277 Kg.ha-1 and  hyolla 401 with average of 1274 Kg.ha-1 had respectively most yield in this trial. Obviously hyolla hybrids had more relative superiority than other cultivars regarding harvest index. Cultivars of B.napus had more both yield and harvest index than B.rapa cultivars. The examination of morphological characters, including chlorophyll content and stomata density and height, showed that considerable difference existed among cultivars. Rate of chlorophyll enhanced increasingly at tow intervals of sampling because of leaves development. Strongly positive correlation observed between yield and harvest index (r=0.75**). Among morphological characters positive correlation was obtained between yield and height (0.34*). Considrable correlation which was between chlorophyll content and yield, was'nt very noticeable (r=0.27*).

In order to investigate effects of determine the best equidistance arrangement with different densities Chickpea (Cicer arientinum var. Philip). Design of experiment was randomized complete block with four replications. Treatments were control (50*7) (cm) and different of row spacing and plant to plant (cm) distance (10*10, 12*12, 14*14, 16*16, 18*18, 20*20, 22*22, 24*24, 26*26 and 28*28). Experiment was conducted in 2006-2007 year in on the Research Farm of Gonbad Agricultural Faculty (Iran). Equidistance arrangement showed no significant effect on seed yield, seed number per pod but it had significant effect on pod number per plant, seed weight, number of deaf pods and number lateral branches. The results indicated the highest seed yield was obtained from treatment row spacing and plant to plant 18* 18 (cm) that was 4665 Kg/ha and was 36.1 percentages more than control.

In order to study the effects of nitrogen fertilizer on yield and growth of soybean (Glycine max L.) an experiment as factorial in RCB design with three replications was conducted during 2006 and 2007 years at North Khorasan. Factors were cultivar (Hobbit, L.W.K., and Williams), and nitrogen fertilizer (0, 50, 100, and 150 Kg N/ha from urea source). Results indicated that cultivar and N fertilizer significantly effected on seed yield. Williams showed the highest seed yield among cultivars. With increasing N fertilizer application, seed yield increased significantly. Among yield components, number of pod per node, significantly affected by N fertilizer; Nitrogen application caused that number of pod increased. Growth analysis indicated that, nitrogen fertilizer caused the increment of dry matter accumulation, crop growth rate, and leaf area index. Also, williams and L.W.K. showed higher growth indices rather than hobbit.

Emergence of crops is affected by environmental factors such as soil water, salinity and sowing and seed quality. The present study was conducted to evaluate the effect of seed aging (seed quality) on emergence of wheat under optimum (control) and stressful conditions including salinity (2 levels), drought (2 levels) and deep sowing depth (physical stress). Seeds (cv. ‘Zagros’) were kept at a high temperature (43°C) and high relative humidity (90-95%) to create different classes of seed aging. Factorial combinations of 5 seed aging treatments (0, 48, 72, 96 and 144 h accelerated aging periods) and 6 levels of environmental factor were treatments of the experiment. Results indicated that maximum and rate of emergence reduced significantly with increase in the duration of accelerated aging in all environmental factors. Decreasing slope of maximum emergence for control, medium drought, severe drought, sowing depth, medium salinity, severe salinity were 0.192, 0.304, 0.152, 0.296, 0.221 and 0.184, respectively. Decreased percent of emergence in 0 h compared with 48, 72, 96 and 144 h at control environment condition were 9.10, 5.68, 21.59 and 27.27 respectively. But, this decreased percent of emergence increased in stress conditions. Overall, seeds of high vigor had better emergence than low vigor seeds in stress and they had higher maximum emergence and rate.

In order to determine the effects of zinc foliar application on yield and its components single cross 704 under water stress condition, experiment was carried out at Agricultural Research Center of Varamin, in Southeast of Tehran, during 2007-2008. Field experiment was conducted in split plot design based on randomized completely block at three replications. Main plots included water stress at three levels of irrigation, about %50 field capacity (without stress), irrigation stress based on %60 field capacity and irrigation stress based on %70 field capacity and sub plots were treatments of foliar application at four levels, zinc sulfate, zinc chelate, foliar application with water and non foliar application. Results showed that maximum quantities were in irrigation about %50 field capacity (without stress) on traits such as seed yield, 1000 kernel weight, stalk diameter, percentage of seed protein, diameter of ear, number leaves of ear, ratio of grain weight, ear weight and minimum quantities were in irrigation stress based on %70 field capacity. In foliar application, maximum quantities were on 1000 kernel weight, seeds per row, total number of seeds in ear, percentage of seed protein, percentage of seed oil, foliar application zinc sulfate and maximum quantities foliar application chelate was for traits seed yield, stalk diameter, percentage of seed humidity. Therefore, Interaction, foliar application zinc sulfate and irrigation about %50 field capacity (without stress), were better than others. Means comparisons effect of foliar application at this test showed that, foliar application ZnSo4 and zinc chelate were better, respectively.

This research was conducted to investigate genotyp×environment interaction for grain yield of ten wheat cultivars in 8 environments (combinations of two nitrogen fertilizer treatment and four irrigation regimes). Analysis of additive main effects (analysis of variance) and multiplicative interaction effects (principal component analysis) revealed that the effects of genotype, environment and genotype × environment interaction were highly significant. Three first principal components explained 89% of the interaction sum squares. Biplot of the first principal component and mean grain yields for genotypes and environments revealed that high yielding genotypes of Pishtaz and Moghan1 were more stable cultivars. Pattern analysis of two first significant principal components for genotypes and environments and also cluster analysis based on stability statistics of AMMI3 model (SIPC3 and EV3) showed that Pishtaz genotype had general stability. The grain yield of this cultivar was higher than the average of all genotypes, it was implied that this cultivar had general adaptability. Khazar cultivar was ranked as the second stable cultivar with having grain yield of approximately as much as the average of all genotypes; thus it was considered as a genotype with moderate general adaptability. Cultivars of Alvand, Sabalan, Moghan1, Darab and Falat showed very low stability. Sardary and Omid with lower yield were recognized as unstable cultivars. Also, it was found that all environments had contribution in the interaction effects.

In order to study of effects of deficit irrigation on morphological traits and growth indices variation of corn forage (SC. 704) in Rasht region, an experiment based on randomized complete design with four treatments and three replication was conducted in 2007 growing season, at research farm of faculty of agriculture, University of Guilan. Experimental treatments consisted of: no-irrigation, 100%, 75% and 50% (full irrigation) available water depletion from soil. Results showed that irrigation based on 75% available water depletion from soil caused significant reduction in leaf dry matter, crop growth rate and leaf area index. In comparison with full irrigation and 75% available water depletion from soil, 100% available water depletion from soil caused significant reduction in total dry matter, ear, stem and leaf dry weight, leaf area index, crop growth rate, leaf number and plant height. In the non-irrigation and 100% available water depletion treatments the total dry matter, stem dry weight, ear dry weight, leaf number, flowering duration and plant height significant difference not seen. With reduction in irrigation water, silking and ear formation delayed and stem diameter increased. Deficit irrigation increased water productivity and 75% available water treatment was showed a better performance (6.07kg.m-3). Forage dry matter in 50%, 75% and 100% available water depletion and non-irrigation was 16191.25, 14563.56, 11479.51 and 10879.83 kg.ha-1, respectively. According to the results, in Rasht region climate, after 75% available water depletion from soil, growth indices significantly varied. Thus, in this region, irrigation based on 75% available water depletion from soil may cause improvement in corn forage.

Evaluation of weed population and their interference on lentil varieties at different sowing date was investigated in a field experiment in Khorramabad during 2005-06 growing season. The experimental design was a randomized complete block in factorial arrangement with 4 replications. The experiment had 3 factors including: planting date at three levels (autumn, winter, and spring) weed interference at two levels (weed free, and weed infested throughout the total growing season), and three lentil varieties (Gachsaran, Flip93-93, and Lorestan landrace). Broad leaf weed species relative frequency for autumn lentil was more than winter and spring lentil 77.8 and 345.7% respectively. The highest level of relative frequency, and importance value in all sowing dates was belonged to safflower (Carthamus oxyacantha) and bedstraw (Galium tricornutum). Weed population severely decreased as sowing date delayed, so that average weed density for winter and spring lentil was only 40.5 and 4.3% of weed density in autumn lentil. There were not significant differences between autumn and winter lentil from the viewpoint of weed biomass. Spring lentil weed biomass was lower than 1/5 averaged over winter and autumn lentil. In autumn and winter lentil weed interference caused yield loss by 32.6 and 33.5% respectively. Yield loss due to weed interference for spring crop (22.3%) was significantly lower than for two other sowing dates. Lentil variety effect and its interaction with sowing date on weed population characteristics were not significant.

To evaluate tolerance of rice genotypes (Oryza sativa L.) to soil/water salinity and to utilize selected tolerant genotypes in rice breeding program and further agronomy and physilogical studies 56 rice genotypes have been evaluated. Of which 40 rice genotypes from International Rice Research Institute (IRRI) together with 16 selected tolerant rice genotypes have been tested in two separate experiments in locations with coastal and in-land salinity sources in Sari and Amol, Mazandaran, Iran, respectively during 2006-7. Experiments were set in Randomized Complete Block Design (RCBD) with 3 replications in each site. Genotypes were evaluated for salinity code, plant height, tiller number, panicle sterility, 100-grain weight, grain yield/plant. Due to photoperiod sensitivity of some rice genotypes in experiment 1, data only for salinity code, plant height and tiller number has been analysed. Results of analysis of variance showed presence of significantly difference for all evaluated traits. Based on results of the experiments and farmers preference 4 rice genotypes including Binam, Hashemi, IR67075-2B-5-2 and IR67075-2B-18-2 showed better performance and has been selected for rice breeding program and further agronomy and physiological tests.

This experiment was conducted to evaluate the effect of nursery establishment under plastic cover on yield of some rice cultivars at Lordegan region in 2007. Experimental design was a split plot with a randomized complete block with three replications. Four rice cultivars (Hashemi, Hasani, Saleh and Native) were seeded at three seedling date (14 April, 5 May and 15 May). Two first planting dates was under plastic cover and third planting date was under free plastic cover. Results showed that delay in seedling date significantly decreased grain yield, biological yield and harvest index. The maximum grain yield was obtained in Hashemi cultivar. Interaction between seedling date and cultivar on grain yield were significant. Saleh cultivar produced maximum yield at 14 April seedling date and Saleh cultivar in 15 May seedling date had minimum grain yield.