CROP PHYSIOLOGY
Year:2010 | Volume:2 | Issue:1|Papers Count:10

In order to study the effects of planting date and cultivar on yield and yield components of Mung bean, an experiment was conducted in a factorial form in a completely randomized block design with four replications in Safi – Abad research center of Dezful, during summer 2009. Four levels of cultivar (Gohar, NM92, VC 3960- 8and CN -9 -3) were used. Biological yield, grain yield, harvest index, yield components, pod length and plant height were evaluated in this study, so that planting date in three levels including june 22th, 6 July and July 21th and genotypes in four levels consisted the evaluated levels of these 2 factors. In this research, traits such as biological yields, economical yield harvest index and yield components were measured. Results indicated that planting date had a significant difference (a=0.01) on biological yield, economical yield, harvest index, and yield components. So that Planting date of june 22th was the most appropriate planting date for all traits. The evaluated cultivars had significant effects for all traits except harvest index. The interaction between cultivar and planting date had a significant effect for all traits in a=0.01 except harvest index. It was significant for harvest index in a=0.05. in general, according to obtained results of planting date, July 22th­ was introduced as the best planting date and cultivar NM92 was the most appropriate cultivar for this experiment.

Drought stress is one of the most important problems in crop production in arid and semiarid regions of the world the application of some materials such as superabsorbent polymers in soil could increase water retention in soil and decrease water use and fertilizer leaching. In order to study the effects of superabsorbant under under droughjt stress condition on yield, yield components and some of physiological traits of corn (Zea mays L.) an experiment was conducted in the form of split plots in a randomized completely block design with three replications in research farm of Islamic Azad University of Birjand in 2008. Irrigation treatments with three levels (100, 70 and 40 prcents of plant water requirements) were chosen as main factors and superabsorbent with four levels (0, 35, 70 and 105 kg/ha) were chosen for subplots. Results indicated that there was a positive significant correlation between mean relative water content of leaf and mean chlorophyll index of leaf.It was a significant positive correlation between mean chlorophyll index of leaf and mean area duration of leaf (r=0.705 and r=0.883) as well. On the other hand there was a positive and significant correlation between leaf area duration and seed yield (r=0.851). It seems that drought stress caused a decrease in seed yield through a decrease in relative water content, chlorophyll index and leaf area duration, and superabsorbent caused an increase in leaf area duration and consequently a higher increase in seed yield with a significant and positive effect on chlorophyll index except 1678 degree growth day.

In order to study the effect of plant density and specie on quantitative variables of forage vetch (vicia sp.) in dryfarming of Khorramabad conditions, an experiment was conducted in the research farm of agriculture campus of Lorestan University on February 10th during 2007-2008. In this experiment three levels of plant density including 100, 150 and 200 seeds per square meter along with three species of vicia sp including vicia narbonesis, vicia sativa and vicia dasycarpa were arranged in a factorial experiment in a randomized completely block design with three replications. Results indicated that the maximum and minimum dry forage yield (3842 and 1578 kg/h) and biological yield (5789 and 2237 kg/h) belonged to broad leaf vetch and hairy vetch at 150 seeds per square meter respectively. In addition, the highest and lowest grain yield belonged to broad leaf vetch and common vetch that were 1948 and 392.1 kg/ha. Besides, the maximum and minimum pod weight (with no seeds) belonged to broad leaf vetch and common vetch in densities of 150 and 200 plants per square meter that were 578.4 and 142.9 kg/h.

In order to determine different amount of seeds on yield and grain yield components in different planting patterns, this experiment was conducted in a split split plot and in a randomized completely block design with three replications. Treatments were two methods of planting, including flat and raised bed planting in main plots, two wheat genotypes including Karkheh and S78-11 in subplots and three different amount of seeds (400, 600, 800, seeds per square meter) in sub subplots. Results indicated that the effect of planting method on plant height, stem diameter, and spike length was significant. The effect of genotype on spike length was significant as well. In addition, the effect of density on thousand seed weight was significant. Accordingly, since the grain yield doesn’t have a significant difference in density, the density of 400 seeds per square meter is preferred, when it is compared to other densities. In regression model of this experiment, harvest index had the most direct effect on grain yield, and biomass yield had a less direct effect on grain yield.Results of path analysis of this experiment indicated that regardless to biomass and harvest index, no grain yield will increase.

In order to determine the best plant density of sunflower, cultivar Master, this research was conducted in a split plot experiment and in a randomized completely block design with four replications with row distances of 50, 60, and 70 cm in main plots and four densities including 6, 7, 8 and 9 plants per square meter in subplots in the agronomic station of Dashte Naz. Results indicated that planting pattern (lines distances of planting) had a significant difference on some traits such as stem height, seed yield and oil yield in a=0.01 and a=0.05, but it wasn’t significant on some traits such as leaf area, thousand seed weight and oil percentage. In addition, the effect of plant density on some studied traits except oil percentage indicated a significant difference in a=0.01 and a=0.05, so that with the increase of density from 6 plants per square meter to 9, the leaf area and thousand seed weight decreased, but stem height, seed yield, and oil yield increased. The highest seed and oil yield was obtained from the planting pattern of 50 cm with a density of 9 plants per square meter with the yield of 3947 kg (seed yield) and 2103 kg (oil percentage). Meanwhile, it should be mentioned that plant distance on planting rows has been varied.

In order to study the effect of irrigation method and weed interference on sorghum yield, in Khorramabad conditions, an experiment was conducted in a split plot form and in a randomized completely block design with four replications in Kamalvand research station of Islamic Azad University, Khorramabad branch, during 2009. Utilized factors of this experiment were irrigation method in three levels included the irrigation of all furrows, every other fixed irrigation, and every other varied irrigation in the main plots and weeds control factor included no weed eradication, thorough weed eradication during the growth season and one eradication in 7-8 leaf stage of sorghum in subplots. Results indicated that with the change of common irrigation method to the every other fix irrigation, water consumption decreased significantly, but the reduction of dry matter yield wasn’t significant. In this case, the most water use efficiency was obtained. Besides, the maximum seed and biological yield were obtained from thorough weed eradication. On the whole, the irrigation of all furrows with thorough weed eradication indicated the maximum forage yield (114750 kg/h) and every other fixed irrigation with thorough weed eradication indicated the maximum water use efficiency (15.3 kg/cubic meter) along with optimum forage yield as well.

In order to study the relative tolerance of 12 canola varieties, this experiment was carried out in a randomized completely block design with three replications including recommended condition planting time in November 6th, recommended planting time, and spring irrigation interruption and late planting time in two years of 2005 and 2006 in Ahvaz research station. Results of two year compound analysis indicated that there are significant differences among agronomic traits in different conditions. The means comparison indicated that a delay in planting caused a 4 day delay in seed germination, 5.6 percent emergence reduction and a reduction of 5.4 days for flowering, compared to recommended conditions. The average maturity duration of genotypes was 158.4 days in recommended conditions and decreased to 155 and 141.9 days in drought and late planting conditions respectively. Late planting date of genotypes caused a reduction of 11.1 pods per plant compared to recommended conditions. The average number of seeds per pod of genotypes in recommended, irrigation interruption and late planting date were 20, 18.4, and 17.3 respectively. The highest and lowest thousand seed weight was 2.9 and 2.6 gr produced in recommended and late planting conditions respectively. The average of seed yield of genotypes decreased to 1705 and 33.1 percent in drought and late planting date compared to recommended conditions. The drought sensitive index indicated a significant difference among genotypes, so that Hyola 401 was better than other genotypes according to seed yield, early maturity and avoiding from seasonal late stress.

The Present study has been performed to survey the effects of different planting dates on yield and grain yield components of early soybean cultivars planted in the split block based on RCBD, repeated three times in Dezful region. Used cultivars were: Williams, L504, L14, 032 and DPX and the dates of planting were 15 June, 1 July and 16 July 2009. The results showed that the date of planting has no significant effect on some plant’s specifications such as plant height, plant dry weight, harvest index, percentages of oil and protein content, seed yield in unit area and yield components including weight of one thousand seeds, number of seeds in a pod and number of pods in the plant and the only significant variance was observed in the duration of growth period with the exact probability of 1%. In this study, the cultivars under analysis have not shown significant variance in some specifications such as plant dry weight, harvest index, percentage of seed’s protein content and percentage of seed’s oil content and showed just 5% variance in relation with the number of plant’s pods and the number of seeds in a pod and in some specifications such as seed yield, weight of one thousand seeds, plant height and duration of growth period showed the significant variance of probability 1%. However, in observing the reciprocal actions, only duration of growth period showed the significant variance of probability 1% and plant height showed the significant variance of probability 5%, and in other specifications, no significant variance was noticed. Among the cultivars under analysis, 032 with the average yield of 7068 kg/hectare dedicated the highest and DPX with the average yield of 4078 kg/hectare dedicated the lowest yield per hectare to themselves. Also, the date of 15 June with the average yield of 5661 kg/hectare and the date of 16 July with the average yield of 5320 kg/hectare, respectively, had the most and the least yield per hectare.

In order to study of sugarcane (Saccharum officinarum L.) aniuploidy in vitro culture, disinfection of initial leaves of sugarcane variety CP69-1062 was studied using six treatments in a completely randomized design (CRD) with five replications. Sequential applications of 20% sodium hypochlorite for 10 minutes and 0.1% mercuric chloride for 3 minutes and 30 seconds had the best results on disinfection of initial leaves. Six callus induction treatments were evaluated through completely randomized design with four replications. Murashig and skoog (MS) based medium supplemented with 2.5 mgl-1 2, 4-D had the best results for callus induction of initial leaves. Regeneration of calli was studied using five treatments in a completely randomized design with five replications. MS medium supplemented with 1 mgl-1 BAP and 0.5 mgl-1 IBA and also 2 mgl-1 BAP and 0.5 mgl-1 NAA were more efficient on regeneration.Root formation was studied using five treatments in a completely randomized design with four replications. MS medium supplemented with 3.5 mgl-1 NAA was found as the best for root induction treatment. Cytogenetics studies were performed 45 days after transmission of regenerants to the soil (71% acclimatization).32.5% of selected plantlets demonstrated aniuploidy in their root meristemic cells.