NEW FINDINGS IN AGRICULTURE
Year:2009 | Volume:3 | Issue:3 (11)|Papers Count:8

This research was done to study the effect of seasonal rainfall on optimization of irrigation water. The study was carried out on cotton crop in east of Mazandaran province. Optimal amounts of water consumption were evaluated for water resources and land limitations conditions. By influencing of rainfall amount on production function, optimized relations of consumed water in limitation of land and water condition were modified. Results showed that modified equation was depending on rainfall. The proposed equation was extended for the next years, with the existing data a relationship was established between the amount of optimum irrigation water and growing season rainfall. Results of calculations shows that, increasing of the growing season rainfall (R) in production function, another production function with different coefficient will be obtained.  Based on this modified equation, the values of Ww for different years decreased nonlinearly with seasonal rainfall increase. By applying seasonal rainfall in optimal amounts of water and its effect on these factors, available water resources can be saved. These savings will increase the cultivation area. By frequency analysis with different return period, the optimum water requirements were obtained. By use of frequency analysis, it can be concluded that, if occurrence probability of growing season rainfall be 80%, the value of Ww for cotton crop should be 180 mm in this area. Thus, with this occurrence probability and available water resources, the crop cultivation area can be estimated.

Determine the most suitable genotype and planting date for Canola, an experiment based on a split plot in randomized complete block design with three replications was conducted during Farm 2005-2006. Four planting dates, 15 and 30 November, 15 and 30 November in the main plots and four genotypes (Hyola401, PP401, R.G.S.003, Option 500) in the subplots were studied. Analysis of variance showed that grain yield, yield components and total dry matter were significantly affected were planting date. Planting date of November 15 was superior characteristics. Genotypes studied also in terms of yield and its components and other traits, significant differences were noted. The highest and lowest yield hybrid Hyola401 respectively with 2.61 tons per hectare and with genotype Option500 1.51 ha belonged. First planting date of all physiological parameters studied compared to other planting date was best. Hybrid Hyola401 due to being more leaf area index (3.51), total dry matter (1249 g/m2), CGR (21 g/m2.day1), NAR (7 g/m2 day1) and RGR (0.064 g/g1.day1) the highest yield (2805 kg/ha1), respectively. The results of this study Hyola401 hybrid planting in semi-November planting date is recommended for the Ahvaz region.

This research was done in order to consider the effects of distances between row, density and cultivation pattern of 704 single crass forage corn (K. Sc 704) which was accomplished with summery dilatory cultivation after harvesting of rice. It was done at Gharakhil research center of Ghaemshahr in 2008.The experiment design was selected as factorial based or RCBD with four replications. Treatments were selected as distances between rows (65, 75, 88 cm), two cultivation pattern (single linear row and two zigzag row) and two cultivation density level 70000 and 80000 bush in hectare. Results showed that distances between rows influenced only on wet forage yield, as wet forage yield in 65 cm distance between rows with 25.38% rate was gained more than 85 cm distance between rows. The yield of wet forage in two zigzag row cultivation patterns was %7 rates more than single row cultivation. Corn diameter and single bush dry weight in 70000 bush density in hectare was more than 80000 bushes in hectare. Stem diameter and wet forage yield in two rows cultivation were more than single linear row cultivation. Maximal of stem wet weight rate to all in 70000 bush density in hectare were gained in two zigzag row cultivation. The largest corn length was gained in 65 cm distance between row and two zigzag row cultivation. Maximal of wet forage yield was gained in 65 cm distance between rows with 80000 bush density in hectare.

This study was done to investigate the effect of water deficit on agronomical characteristics and growth indices of winter rapeseed cultivars in Kermanshah region. The experiment was performed by using a split plot design based on RCBD with 3 replications, in the farm research of Eslamabad in Kermanshah. The treatments were selected as drought stress (D) as the main plot in two levels convectional irrigation or irrigation after 80 mm evaporation from A class pan (D1) and stopping irrigation since flowering stage (D2), and variety (V) as the sub- plot in 9 levels  consist of Opera (V1), ARC-5 (V2), Dexter (V3), SLM046 (V4), Zarfam (V5), Okapi (V6), Talaye (V7), Licord (V8) and Modena (V9). Investigated agronomical characteristics were: the plant weight, stem diameter, the number of secondary branches in the plant, the number of pods in the main stem, the number of pods in the secondary branches, the number of pods in the plant, the number of grains in the pods of main stem, the number of grains in the secondary branches’ pod, the number of grain in plant’s pod, the 1000 grain weight, the percentage of grain’s oil, grain yield, oil yield, biological yield, harvest index, Total Dry Weight (TDW) and Leaf Area Index (LAI). The result showed that stopping of irrigation(drought stress) since flowering stage, had deleterious effect on the growth, yield, yield components and agronomical characters, so that observed difference were 1% and 5% significant. The simple effect of variety on the stem diameter, the number of pods in the secondary branches, the no. of pods in plant, the no. of grain in the secondary branches’ pods, the no. of grain in plant’s pods was not significant, but had considerable effect on the other characters. The interaction effects between irrigation and variety was only significant on the biological yield, harvest index and percentage of oil grain, and was not significant on the other characters. The variety of SLM046 based on the oil yield (1870 kg/ha), grain yield (4187 kg/ha), yield components and the stress tolerance index was put in the best group and Talaye, Zarfam, Licord, Opera, ARC-5, Dexter, Okapi and Modena varieties were put in the other groups. The analysis of the stage of growth showed that drought stress increasing causes the Total Dry Weight and the Leaf Area Index decreasing. The percentage of mentioned factors in SLM046 variety was less than other varieties.

In order to study effects of water deficit stress on agrophysiological traits of Maize cultivars, an experiment was conducted in the farm research station of Arak Islamic Azad University, Iran in 2009. The experimental design was split plot based on RCBD with three replications. The treats were considered as irrigation in three levels: 100% (control) , 75% and %50 (water deficit stress) crop water requirement plant and maize hybrids consisted of KSC500, KSC524, KSC700, KSC704 and DSC370. Results showed that water deficit stress reduced relatively water content, cell membrane stability and grain yield. About hybrids, the highest grain yield obtained from early and medium maturity hybrids. Also the highest cell membrane stability and relatively water content belonged to medium maturity hybrids. Interactions effects of treatments showed that, in condition of moisture optimum(100% crop water requirement) and water deficit stress (75% and 50% crop water requirement plant), grain yield in KSC524 and 500 was high compared to other hybrids. The highest grain yield equal 8624.22 Kg/ha by treatment KSC524 with 100% crop water requirement plant and lowest grain yield equal 4072.32 obtained from treatment KSC700 with 50% crop water requirement.

In order to study of planting date and nitrogen rates on agronomical traits of potato Var Markiz, an experiment was conducted in the farm research station’s of Arak Islamic Azad University, Iran in 2008. The experiment was factorial based on RCBD with four replications. The treatments composed of planting dates in three time, 21 June, 8 July and 22 July and nitrogen rates in four levels: 46, 80, 115 and 150 kg/ha. Results showed that, that effect of planting dates on tuber yield was significant. The maximum yield by 19.5 t ha-1 was obtained from 21 June planting date. Interaction of planting date and nitrogen rates on tuber fresh weight, tuber dry weight, number of tubers per plant, number of small and large tubers per plant, diameter size of tuber and tuber yield were significant. The highest yield by 24 t/ha was related to 21 June planting date with 150 kg/ha nitrogen.

This research was don to investigate the effect of mycorrhiza and vermicompost as the biological fertilizers to compare with chemical fertilizer phosphorous and nitrogen on yield and yield component of corn. It was based on factorial in a RCBD with 3 replications when soil control condition was some in 2010. Treatment were considered as using chemical fertilizer (F) in three levels of fertilizer's sources, urea, triple super phosphate and potassium include: F0 (N=0, P=0, K=0), F1 (N=70, P=50, K=30) and F2 (N=150, P=100 and K=50) kg/ha, vermicompost treatment in two levels (using V1 and non-using V0) and mycorrhiza treatment in two levels (using M­ and non-using M0) (population 105 g/spore). Results of variance analysis showed there was significant different between different levels’ interaction of vermicompost, chemical fertilizer and mycorrhiza on grain yield p=1% and there isn’t any significant difference between the kernel number and 1000 kernel weight. Comparing the average of interaction of vermicompost, mycorrhiza and chemical fertilizer showed significant difference on grain yield, that treatment V1F0M1 and V1F1M1 with averages 119.33 and 113.00 g/pot have higher amount of grain yield than treatment V1F2M1 with average 106.33 g/plant, and treatment V1F0M0 with average 87.00 g/plant has lowest amount of grain yield. Comparing the average of vermicompost interaction, fertilizer’s level and myeorrhiza showed significant difference on the 1000 kernel weight and treatment V1F0M1 with average 168.33 g has highest weight of 1000 kernel weight and treatment V1F1M1 with average 134.67 g has lowest weight of 1000 grains. Use of mycorrhiza and vermicompost in low levels of chemical fertilizer could cause increase of yield and grain yield component but in high levels of chemical fertilizer their activity became hampered.

In ordsr to study yield and some physiologic characteristics of sunflower (cv. Euroflor) in reaction to water and potassium applying, a RCBD base split plot experiment was conducted in 2009 at Islamic Azad University- Tabriz branch research farm. Water deficite stress at four levels (50, 90, 130 and 170 mm evaporate from class A pan) arranged in main plots and five K2SO4 levels (0, 50, 100, 150 and 200 kg/ha) in sub plots. The results of variance analyzing of date showed that interaction of stress and K was highly significant on height of stem, leaf dry weight, number of grain in anthodium, weight of grain in anthodium, biomass, yield, harvest index and 100 kernel weight, effective filling period was significant. Result showed that the interaction effects of treatments had significant different in these traits. Rate of a traits under study increased when 200 kg/ha of potassium sulphate was used and field irrigated after 50 mm evaporation from pan. Application of potassium decrease drought stress damage. Irrigating after 50 to 90, 130 and 170 mm evaporation from pan decreased yield by 10.36, 24.43 and 59.46 percent. But yield reduction by application 200 kg/ha potassium sulfate fertilizer was only 32.48 percent. This indicates that by applying potassium fertilize yield reduction will be decreased under drought stress.