JOURNAL OF RESEARCH IN CROP SCIENCES
Year:2011 | Volume:4 | Issue:13|Papers Count:10

This experiment was conducted in Tonekabon Rice Research Station to study the effects of different levels of nitrogen and planting densities on rice (Oryza sativa L.), cv. Promissing No.3. The experiment design was split plot (RCBD) with three replications. The treatments in main plots were in three levels (200, 250, 300 kg Urea. ha-1) and the treatments in sub plots were in four levels of planting densities (25×25, 20×20, 30×15, 30×11 cm). The recorded characteristics were yield, number of palmate, length of cluster, number of full plenty seeds, weight of 1000 seeds, and total above ground biomass and harvest index. The statistical analysis had shown that the effects of nitrogen levels on all characteristics were not significant. The planting densities effects were significant on yield (P<0.05), number of palmate (P<0.01) and total biomass (P<0.01). The interaction effects of nitrogen levels × planting densities were significant on yield (P<0.05) and number of full plenty seeds (P<0.01). The most effective palmates and total biomass were obtained by 30×11 cm densities. The mean comparisons with Duncan's method (at P<0.05), had shown that the highest number of full plenty seeds (118.2) were obtained by 20×20 cm densities and 200 kg N. ha-1 treatments. The most yields (7689 kg. ha-1) were obtained by 30×15 cm densities and 300 kg N. ha-1 treatments it had no significant difference with 200 kg N. ha-1 together with 20×20 and 30×11 planting densities with 7596 and 7408 kg. ha-1 yield respectively. They could be applied by economical and sustainable considerations.

Land evaluation is the estimation and determination of land utilization type for several proposed land systems in the region. In this study, ALES software was used for physical and economical evaluation. The area’s extension is about 656 hectares, which is located in West of Qazvin in latitudes of 36o 6’and 36o 11’ N and between longitudes of 49o 35’and 49o 40’ E. The average height of the above-mentioned region is 1428 meters and the climate information of Takestan station with 238 mm precipitation as well as Khorramdareh station with 297 mm precipitation was utilized. In the study area, the lands under rainfed cultivation were determined by using satellite images based on soil maps, topography, and the region’s climate; and seven profiles were excavated in LMUs. Results showed that while the most limiting factor in this land was the plant water requirement, the rooting depth and erosion state as well as soil nitrogen and organic matter fertility were the trivial to moderate restriction factors in some units. The results of the ALES software revealed that the rainfed wheat in land units 1, 2, and 3 had S3 fitness and in land units 4, 5, 6, and 7 had S2 fitness. Moreover, rainfed barley in land units 1, 2, and 3 had N physical fitness and in 4, 5, 6, and 7 had S3 fitness. In this study, the economic fitness classes, obtained by ALES, included S2 and S3 for rainfed wheat and S3 and N for barley. The results obtained from the study of wheat and barley indicated that wheat cultivation had priority over barley due to the fact that barley had more yield reduction than wheat, regarding the planting time for it in the region.

To evaluate the effects of distance between and on the planting rows on yield and yield components of chickpea to determine the best row spacing and distances of seeds over rows on the yield and yield component of chickpea cv, Ghazvin, an experiment was conducted in agricultural research center and natural resources of West Azerbaijan in 2009. The distances between rows included 30, 40, and 50 cm, and intra-row distances included 5, 7.5, 10, and 12.5 cm which were arranged as factorial based on randomized complete block design with three replications. Results showed the significant inter and intra-row distances on plant height, Number of branches per plant, Number of pods per plant, 100-seed weight, grain yield per plant, and grain yield per m2. The maximum grain yield 207.9 gr/m2 was obtained from 30cm inter-row and 12.5 cm intra-row distances.

To evaluate the effect of competition in golden wheat and wild oat in different densities, a study was conducted in split plot randomized block in agricultural and natural resources research center of W. Azerbaijan in 2007. Factors studied included three levels of crop density plants, including 300, 400 and 500 per square meters and four wild oat densities, including zero, 30, 50 and 70 plants per square meter which were the number zero wild oat per square meter as a control plot for wheat. The sown number of rows in each plot was six of which one was not sown. Research results showed that plant height, number of leaves per plant, flag leaf area, flag leaf chlorophyll content, yield, harvest index, spike length had significant difference. Increased density of wheat and wild oat decreased leaf number significantly and the highest number of leaves to the relative density of 300 plants per square meter of wheat and zero wild oat plant per meter square (wheat, oat) with a mean of 20.10 and the lowest Relative density of 500 plants per square of wheat and 70 wild oat in meter squares with mean 0.73 (wheat, oat) is concerned. With increase in wild oat Density, wheat flag leaf chlorophyll content was significantly decreased maximum chlorophyll content obtained in 300 wheat per square meter and zero wild oat with mean (Spad) 53.7 and the lowest content was related to the density of 400 plants per square meter of wheat and 70 wild oat plants per square meter with a mean (Spad) 28.93. However, the treatments of wheat density (300, 400 and 500) respectively with 50, 30 and zero plant density in meter square of wild oat were statistically in a same level.

The evaluation of energy efficiency and determining types and amounts of consumed energy could be assumed as a scientific method for stability and constancy of production in an agricultural ecosystem. In this paper we estimate and evaluate the consumed energy for agricultural ecosystem in Astan-E-Ghods-Razavi’s farms in Mashhad. The research was done according to the results of step by step operational and theoretical measurements of tillage, planting, cultivating and harvesting. To do this, we converted results (related to inputs and outputs) to equivalent consumed and generated energies to be able to calculate the efficiency of energy. The amount of consumed input energy and generated output energy (wheat seed) in irrigated farming was 7731553 (Kcal/ha) and 20517800 (Kcal/ha) in average. So energy efficiency (output/input) for seed, chaff and biological yield (seed + chaff) was 2.65, 2.14, and 4.8 in average. The evaluation of input energy showed that most of energy consumption was related to electricity energy consumption for irrigating that was about 41.5% of total consumed energy. After that, net consumed nitrogen by 17.75% and consumed fuel by 15.15% had second and third place in this ranking. In addition, human labor (biological energy) by 0.7%, herbicide by 0.49% and pesticide by 0.29% were the least energy consumer parts that with agronomic suitable management can reduce the consumption of other energies, so increasing in efficiency per unit area, generated energy or products without decreasing in quality of operations.

To evaluate the herbal genetic resources to drought tolerance, an experiment with 15 spring barley genotypes was conducted in Khoy research station in 2009 in the irrigated (only one irrigation after planting) and drought conditions. Experimental design was RCB with three replications. Different traits including 1000 kernel weight and grain yield were measured and recorded. Simple analysis of variance for each experiment and combined analysis of variance showed significant differences among all traits except awn length and days to seedling emergence. Genotype x environment effect was significant for all traits except for awn length, spike length, number of grain per spike, fertile tillers and plant height. Results of mean comparisons of grain yield showed that genotypes no. 15 and 14 (native to Khoy) and 3 (Rihane/Alger-union) proved to be were better than the others. Genotype 12 (Karoon/California) was the poorest in both experiments. Relationship between grain yield in irrigated and drought conditions and STI, GMP and MP showed that genotype no. 15 (native to Khoy) was better than the other genotypes in grain yield in both conditions (irrigated and drought) and also in drought tolerance indices.

To analyze the effects of nitrogen fertilizer on yield, yield component, morphological characteristics and protein of maize hybrids in climatic conditions of Dezful an experiment was conducted on the field of Islamic Azad University of Dezful Branch in arable year of 2009 in order to choose proper hybrid (s) compatible with the region, to remove harvest problem, to encounter hazards of the late season, and to use nitrogen fertilizer optimally. This experiment was performed in the form of split plots in randomized complete block design in three replications. Treatments included three different levels of nitrogen fertilizer (200, 240 and 280 kg/ha in the form of urea as main plots and five hybrid consisting of S.C.704 (control), S.C.700 and B.C.666 (foreign hybrid) and KLM and K47 (the group ripening earlier than the control) were in sub plots. The results obtained from this experiment showed that there was no significant statistical difference for grain yield at different levels of nitrogen fertilizer. For different hybrids, significant statistical difference was observed such that the maximum and minimum amount of grain yields with 10160 and 7447 kg/ha was associated with treatment KLM and K47 respectively. The results obtained for yield component indicated that the seed number per row, row number per ear and 1000 grain weight and also some morphological characteristics such as plant height, ear height from surface of the ground, ear diameter and era length no significant difference at various levels of nitrogen fertilizer; however, a very significant difference was observed between hybrids. For the features of biological yield and harvest index there was a significant statistical difference between hybrids only. According to the results obtained from this study, the amount of 200 kg/ha nitrogen was suggestible and the hybrid K47 made it possible to use environment (especially light and heat) and nutrition factors optimally.

To determine the most precise possible manner of the cause and effect relations between yield and yield components, a simple correlation method in the path of coefficient analysis was used in 10 line of barley. During the growth season and after yield harvesting, 14 character Istic data were recorded. Results of analysis of variance showed significant differences among lines in terms of traits under 5% and 1% probability of levels, which indicated the existence of genetic variation. Yield of lines showed the significant difference, just 1% and the first line had the most yields. Using stepwise regression was formed the best suitable model at yield. Using path analysis, correlation between characters, which remainded into the model was broken to direct and indirect effects. The highest positive correlation (0.75) was obtained between harvest index and grain yield which resulted in high direct effect of harvest index on grain yield (0.9561). Also biological yield direct effect was obtained high and positive on grain yield and had positive correlation with grain yield. Grain number per spike was also found to be positively insignificant direct effect on yield, but indirect effects through biological yield and harvest index were fairly high.

To study the effects of Irrigation cycle on agronomic characteristics of four varieties of castor in Damghan climatic conditions, on experiment was done in agricultural farm of Damghan Islamic Azad University (Iran) during 2010-11 as split plots in a randomized complete block design with three replications. The main plot was irrigation intervals (5, 10 and 15 days) and the sub plot four castor varieties (mono-flower, bi-flower, local and red-flower) that were performed in stable density of five bushes per cultured square meter. After germination, the amount of irrigation water in each treatment was recorded using volumetric devices. Plant traits evaluated included the inflorescent elongation, the number of seed in bush, dry weight and the weight of thousand seed, oil percentage, seed protein percentage and seed yield. Then they were related to whole statistical population; all examined traits indicated a significant difference for irrigation period. Therefore, bi-flower variety with 1241 kg per hectare on 5-day irrigation period had most grain yield. Most oil percentage was observed in local variety on 15-day irrigation period with 50% and least oil amount was seen in local variety on 5-day irrigation period with 37%. In this experiment local variety produced more oil amount in 15-day irrigation period. The Best irrigation level for all studied traits except for oil and protein seeds was 5-day irrigation period.

In the course of constant materialized agriculture, an experiment was conducted in Majid Abad region -Khoy- during 2010, to study the effect of intercropping corn and pinto bean in replacement and additive methods. The experiment was carried out by using randomized complete block design with three replications and 10 treatments. They included: three treatments of replacement intercropping with 1:1, 2:1 and 3:1 proportions of corn and pinto bean (with densities of 7 plants m-2 for corn and 40 plants m-2 for pinto bean); five treatments of additive intercropping (with densities of 7 plants m-2 for corn and 4, 8, 12, 16 and 20 plants m-2 for pinto bean), one sole cropping of corn (7 plants m-2) and one sole cropping of pinto bean (40 plants m-2). The results showed that in corn, the effect of intercropping on number of seed per row in ear, 100 seed weight, seed yield per plant and seed yield per hectare was significant. The maximum number of seed per row in ear, 100 seed weight, seed yield per plant was obtained from replacement treatment with 1:1 proportion and maximum seed yield per hectare was obtained from sole cropping of corn. For pinto bean, effect of intercropping it was significant for plant height, branch number, number of pods per plant, seed yield per plant and seed yield per m2. The maximum 100 seed weight, number of pods per plant, and seed yield per plant belonged to treatment of additive intercropping T6 (with densities of 7 plants m-2 for corn and 4 plants m-2 for pinto bean) and maximum seed yield per hectare was obtained from sole cropping of pinto bean. In order to evaluate the beneficial effect of intercropping, land equivalent ratio (LER) was more than one, and the maximum amount (1.26) was obtained from T9 treatment (with densities of 7 plants m-2 for corn and 16 plants m-2 for pinto bean). This treatment was, therefore recommended at the best intercropping pattern in this experiment.