Crop Production
Year:2015 | Volume:8 | Issue:1|Papers Count:12

In order to study of the effects of microelements chelate fertilizer (Jadogar) on yield and yield components of sunflower (Helianthus annus L.) at different levels of plant densities, a field experiment was carried out as factorial based on randomized complete block design with 4 replications in Shahrood University of Technology. Factors included plant distance on the row in 5 levels (10, 20, 30, 40, 50 and 60 cm) and microelements chelate fertilizer (Jadogar) at 2 levels (without apply of micronutrient and micronutrient apply). The results showed that increasing of density increased vegetative growth period. Increasing of plant density had positive effect on plant height and negative effect on stem diameter. Plant distance on the row (20 cm) increased grain and biological yield. Using micronutrient through increasing of seed number in anthodium and increasing density through increasing the number of anthodium significantly affected grain yield. Using micronutrient resulted improvement of oil percentage and grain yield. Plant density had no significant effect on oil percentage. Planting density were completely coordinated with grain yield changes so that the major part of the oil yield changes can be defined by grain yield.

To investigate the relationship between the critical period of development (VC-R1 ,R1-R6 and R6-R8) with grain yield and yield components of soybean, a field experiment were conducted with a split plot arrangement in a randomized complete block design in three replications in Gorgan during 2011. Main plot were including five planting dates (April 20, May 13, June 3, June 29 and July 22), and sub plot were including three cultivars (Williams, Sahar and DPX). Photoperiod in each of the developmental stages was calculated by using of the PP-calc program. Then, In Order to eliminate the effects of temperature on growth and development, the number of Cumulative thermal days in each period of development were considered as duration of developmental stages. Decreasing in photoperiod that occurred as a result of the delay in planting, Reduced the duration of VC-R1, R1-R6 and R6-R8 in all three cultivars. Significant positive relationship observed between yield and yield components (except grain weight) and duration periods of VC-R1 and R1-R6. So that the reduce of this developmental duration in the late planting dates, reduced grain yield and yield components. However, The length of R6-R8 no effective on grain yield, because the Duration of this period it may be only effective through grain weight on grain yield. but, no observed a positive significant correlation between seed weight and seed yield. So, the cause of soybean yield losses that occured in delayed planting dates, were due to the reduce of duration of VC-R1 and R1-R6.

Life Cycle Assessment (LCA) is a method that evaluates all environmental effects of a product during its life cycle. The objective of this study was to introduce LCA to Iranian scientific community and to use it in assessment of environmental impact of different production systems of sugar beet in former Khorasan province, west of Iran, compared to Swiss condition. The data were gathered regarding materials and processes from traditional, semi-mechanized and mechanized production systems in 26 regions of 11 geographic areas of Khorasan (current North, Razavi and South Khorasan provinces), the inventory analysis. Then, all the resources (inputs) and environmental emissions (outputs) were quantified under environmental impact category. The results indicated that there is a significant gap between Khorasan and Swiss (optimum situation) in terms of environmental impacts per each ton of sugar beet production (up to 40 times in some of environmental impact category). Moreover this study demonstrated that mechanized sugar beet production system is more environmental friendly regarding to depletion of non-renewable energy sources, global warming, eutrophication, photochemical oxidation, acidification, land use and ozone layer depletion among various systems of sugar beet production in Khorasan. Contribution analysis indicated that irrigation had the greatest role in creating environmental impacts. Climatic condition of this region and the existence of drought led to spend a lot of energy for irrigation. Providing this energy causes high environmental impacts due to the dependence on fossil fuels.

Identification of pattern and classification is one of the most applications of statistical methods in the different sciences. One of the main objectives of modeling and classification is the predications based on variables and available data about a specific topic. In order to determination of the characteristics associated with salinity tolerance, 41 wheat genotypes were evaluated in two conditions (normal and stress) at the research field of the National Salinity Research Center (NSRC). The salinity of water used in irrigation in saline and non-saline conditions was 10 and 2 dS.m-1, respectively. In this study, in order to determination of the characteristics associated with salinity tolerance was used from logistic regression. The dependent variable in this research has the qualitative nature and scale value and other variables in this research were considered as independent variables. The results of the used parameters to goodness of fit logistic regression model indicated that logistic regression model is an appropriate model for determination of the characteristics associated with salinity tolerance in wheat genotypes. The results of logistic regression showed that five variable of number of fertile tillers, number of spikelets per spike, the 100-seed weight, plant height and peduncle length are the most important variables associated with salt tolerance. These variables have the high ability for identification of sensitive and tolerant genotypes under salinity stress in bread wheat. So that the results in study can be used in breeding programs to identify salinity tolerant genotypes.

In order to evaluate the growth characteristics, yield components and yield of sweet corn affected by different tillage operations, planting densities and planting patterns, a field experiment was conducted as factorial of 2×3×3 treatments based on a randomized complete block design with three replications at university Putra Selangor, Malaysia during growing season of 2007-2008. The factors were three tillage methods including, (moldboard plow and disk harrow (T1), disk plow and disk harrow (T2), and rotary cultivator (T3) only as control), three plant densities (of 63000 (D1), 41600 (D2), and 31500 (D3) plants ha-1 only as control) and single row as control (P1) and double row (P2) planting patterns. The traits of dry weight of root, plant height, ear corn height, cob corn dia, stem dia, ear dia, kernel depth, fresh weight husked, row length of kernel, number of kernel per row, number of row, fresh weight husked, ear dia dehusked and yield were investigated. The results revealed that the main effect of tillage operation was significant (p≤0.01) on growth characteristics and yield of sweet corn. Interaction effects of plant densities × planting pattern were significant on yield at 5 percent level. The maximum corn yield attributed to the plots plowed with disk plow followed by disk harrow (T2) with 12503.3 kg.ha-1. Corn yield in P2 was 41% greater than P1 planting pattern. With decreasing plant densities of 63000 to 41600 and 31500, the average corn yield decreased to 36% and 76%, repectively. Maximum and minimum of corn yield obtained to 1443.87 and 7268.89 kg ha-1 from P1D2 and P1D3, respectively. In overal, in order to improve the production and yield of sweet corn as a valuable cereal under Malaysia climatic conditions, disk plow, two-row planting pattern and density of 63,000 plants ha-1 could be recommended.

In order to investigate the response of grain and green pod yield and grain yield component of three faba bean cultivars to six sowing dates, a study was carried out as factorial in randomized complete design with four replications during growing season of 2012-2013 crop year in Gorgan agricultural research station. Analysis of variance showed that a significant effect of sowing date on the all traits, included: plant hight, number of lateral branches per plant, number of node on the main stem, number of pod per plant, number of grain per pod, 100 seed weight, grain yield and green pod yield, biological yield, harvest index, and the cultivar had significant effect on plant height, number of node on the main stem, 100-seed weight, biological yield of faba bean; also interaction between cultivar and sowing date had significant effect on the number of pod per plant, number of grain per pod, biological yield and plant height. Regression results indicated error disintegration of dry grain yield, green pod and biological yield with delay in planting. Based on these results, dry grain yield declined at a rate of 48 kg.ha-1 in distance between first and last sowing date for each day by delay in planting. the results of regression analysis indicated that green pod yield was decreased with 265 kg.ha-1 with each day of delay in cropping from 18 October sowing date. Based on these findings can be introduced 18 October sowing date as critical sowing date for faba bean at in experiment.

In order to study the effect of Mn and Zn micronutrients foliar application on quality and quantity characteristics of mung bean under water stress a field experiment was conducted at the University of Zabol in 2011-2012. The experiment was conducted in split plot design with three replications. Main plots were different levels of drought stress included: optimum irrigation, withholding irrigation in vegetative growth stage, and with holding irrigation in flowering stage. Sub plots were of four levels of micronutrients foliar application included: no foliar application, 3000 ppm foliar application of zinc, 3000 ppm foliar application of manganese, and foliar application of zinc+manganese. The results showed that the highest plant height, No. capsule in plant, No. seed in capsule, 1000 seeds-weight and biological yield and harvest index obtained from optimum irrigation treatment. The highest grain yield was achieved from optimum irrigation treatment and foliar application of zinc+manganese. The most amounts of carbohydrate percentage, zinc and manganese was achieved from treatments of micronutrients foliar application. But micronutrients application led to decreasing phosphorous uptake in plant. The results showed that interaction between irrigation treatments and micronutrients foliar significantly increased plant height, grain yield and biological yield. The highest grain yield (451 Kg ha-1) was achieved from optimum irrigation and foliar application of zinc+manganese. It can be concluded that water stress at the flowering stage had the most effect on reducing grain yield of mung bean. Although the highest concentrations of carbohydrates and proteine were found in water stress at the vegetative growth stage, Since reduction during seeds filling period and the lack of adequate absorption of micronutrients, the effects of the drought in was more pronounced at the vegetative growth stage than water stress the flowering stage, and drought stress in this stage decreased grain yield.

Effect of nitrogen (0, 40, 80, 120 and 160 kg N ha-1) and plant density (40, 60 and 80 plant m-2) on yield, yield components, grain quality and chlorophyll index of rapeseed was investigated as a factorial experiment based on randomized complete block design with three replications. The effect of nitrogen and density on all traits was significant. Maximum 1000-seeds weight, chlorophyll index and grain yield were obtained at 120 kg N but maximum oil percentage (46.63%) was revealed at 40 kg N. Mean comparison for density indicated that maximum 1000-seeds weight and chlorophyll index belonged to 40 plants density. Maximum oil percentage (45%) and grain yield (280 g m-2) were achieved at 60 plants density but there wasn’t significant difference between this treatment and 80 plants density for oil percentage and grain yield. Effect of treatments interaction on number of pods/m2, number of seeds/pod, biological yield and oil yield was significant. The highest biological yield (1320 g m-2) was obtained at 160 kg N and density of 80 plants. Maximum oil yield (158 g m-2) was also belonged to 120 kg N and density of 80 plants. It should be mentioned that this treatment had no significant difference with treatments of 120 kg N and density of 60 plants and 160 kg N and density of 60 plants. Therefore, it seems that density of 60 plants with consumption of 120 kg N ha-1 is suitable for producing maximum grain and oil yields of winter rapeseed.

The main objective of this study was to describe emergence rate response to temperature and estimate cardinal temperatures (base, optimum and ceiling temperatures) and biological days requirement for safflower emergence. To do this, four safflower cultivars (Esfahan, Goldasht, Padideh and Sofeh) were sown at 12 sowing dates (every month) and the emergence rate (inverse of time to 50% emerged seeds) was calculated for each sowing date. The segmented, dent-like and beta functions were used to describe the relationship between emergence rate and temperature. Root mean square of deviation (RMSD), coefficient of variation (CV), correlation coefficient (r) and linear regression coefficients (a, b) between predicted and observed days to emergence were used to select the superior function. Results indicated that the compared to the dent-like and beta functions, the segmented function described well the response of safflower emergence to temperature due to the higher r (0.90-0.97), and lower RMSD (2.17- 4.06) and CV (12.3-22.4). Fit of the segmented function on data of emergence rate to temperature showed cardinal temperatures (base, optimum and ceiling temperatures) among cultivars ranged from 2.30-3.44, 20.56-23.28 and 35oC, respectively. There was no significant difference among the cultivars in terms of cardinal temperatures. The biological days requirement for emergence among cultivars ranged from 8.05 to 9.78 which were not different significantly. The quantitative information provided by this study can be used in the crop models to predict the emergence time courses under diverse temperature conditions.

In regions of Iran with Mediteranean climate, drought stress generally occurs in terminal wheat growth stages. Using tolerant varieties and some agronomic operations may decrease the damage of this stress. In order to study the reaction of 11 wheat genotypes to terminal drought stress under two zinc consumption conditions, the study conducted during 2011-2013 crop season at Isfahan. Genotypes were WS-82-9, Sirvan, WS-86-14, Pishtaz, Parsi, Back-cross-Roshan, Arg, Roshan, Pishgam, Alvand and Mahdavi were evaluated under three treatments, normal irrigation, no irrigation after heading and also no zinc application, and no irrigation after heading and two times foliar application of zinc at vegetative growth stages. Results showed that all studied traits except no. of spikes per m2 and days to anthesis decreased under terminal drought stress. Drought stress decreased grain yield of genotypes between 36.2-59%. Among the yield components, the most reduction occurred in thousand kernel weight. Grain yield increased by an average of 7.3% under zinc foliar application. But the reaction of genotypes varied between 5.2% to 9.8%. Zinc application caused significant increase in grain weight via improved grain filling rate, so thousand kernel weight and grain filling rate were 2.4 gr and 0.091 mg grain-1day-1 greater than no-zinc application. Varieties Pishgam and Sirvan can be recommended for cultivation in areas with probability of terminal drought strees.

Competitive relationships of watergrass (Echinochloa oryzoides) and barnyardgrass (Echinochloa crusgalli) with rice in different plant proportions of 0:4, 1:3, 2:2, 3:1, and 4:0, weed:rice in each hill were investigated in a field experiment. Weed biological and grain yield (both Echinochloa species) were higher than rice; however, the harvest index was higher for rice compared to weed species. Relative yields (based on number of tillers, biological yield, and grain yield), replacement series diagrams, rice aggressivity index, and relative crowding coefficient exhibited higher competitiveness for weed than rice. Rising in the ratio of each species at the planting proportion increased the biological, grain and relative yield and harvest index in both rice and weed. Furthermore, it caused an increase in rice aggressivity index. In all tested plant proportions, weeds were superior to rice regarding biological and grain yield, except for 1:3 weed:crop in which both species were similar for grain yield. Comparing two Echinochloa species, watergrass, had lower biological yield, but higher harvest index. Grain and relative yields, and relative crowding coefficient were not significantly different for two weed species; however watergrass led to more reduction in grain yield, harvest index, relative yield and aggressivity index of rice.

Use potentioal of bifertilizer has been considered worldwide for years. This study evaluated the effects of Piriformospora indica, Sebacina vermifera and Glomus intraradices on grain yield and yield components of rice plants grown as flooded, under sterilized field condition, in condition Ilam province. Seedlings were grown on sterilized paddy soil in two types of nurseries, semi-wet nursery and wet nursery, with or without mycorrhizal fungi inoculation. 30-day old seedlings were transferred to sterilized field with well puddled soil flooded with 3-5 cm of standing water. Three controls included (1) non-fertilizer/non-AMF/non-EF (F0), (2) F0/non- sterilized soil (I), and (3) non-AMF/non-EF/Fertilized as recommended (F). In CF, the plant recorded a significantly higher total biomass and grain yield. Grain yield were not significantly influenced by AMF/EF colonization but shoot biomass, tillering, number seed in panicle and length panicle were significantly influenced by EF colonization. For plants originating from the semi-wet nursery, shoot biomass, grain yield of field-grown plants at harvest were significantly increased. Of the AM/EF used in the present research Sebacina vermifera gave the best performance in all the growth parameters in study.