JWSS - Journal of Water and Soil Science

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It is believed that various types of field bean, including pinto, white and red, differ in adaptability to high temperatures and may, thus, differ in response to delay in planting. In order to evaluate this response, an experiment was conducted during 1996 at the Agricultural Research Station, Isfahan University of Technology, using a randomized complete block design with split-plot layout. Main plots consisted of four planting dates (April 28, May 13 and 28 and June 13) and sub-plots included four genotypes of common bean (red bean, c.v. Naz pinto beans, experimental lines 11816 and 16157 and a white bean, experimental line 11805).

 Number of branches per plant, number of pods per branch and per unit area, number of seeds per pod of main stem and branch, number of seeds per main stem, per branch and per unit area, 100-seed weight and seed yield significantly reduced, while harvest index significantly increased by delay in planting and consequent increases in temperature and reduction in time for growth. The lower harvest index obtained with early planting was the result of the lower efficiency of the produced vegetative growth due to the coincidence of seed filling period with high temperatures. Pinto bean line 11816 ranked the highest for number of branches per plant and harvest index among the genotypes evaluated and produced the highest seed yield (3030 kg ha^-1). Although red bean Naz ranked the highest for number of pods and seed per main stem and per unit area, it had the lowest harvest index and 100-seed weight and, consequently, produced the least seed yield (2254 kg ha^-1). The results obtained indicate that delay in planting adversely affects bean seed yield. Pinto bean line 11816 may have higher yield potential among the genotypes studied at all planting dates under conditions similar to the present experiment. No specific relationship was observed between apparent seed characteristics and plant tolerance to heat.

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A field experiment was conducted in 2000 at the Agricultural Research Station, Isfahan University of Technology, to model the response of four safflower genotypes to day length and temperature changes under field conditions. Five planting dates (March 12, April 12, May 10, June 8, and July 12) and four safflower genotypes (Arak 2811, local variety Koseh, Nebraska 10 and Varamin 295) were evaluated using a randomized complete block design with split-plot layout in three replications. Date of planting was considered as the main plot and cultivars were randomized in the sub-plots. Number of days from planting (P) to emergence (E), stem elongation (SE) to head visible (HV), and HV to flowering initiation (FI) significantly reduced with delay in planting as the result of increase in temperature during these periods. Number of days from P to SE, duration of flowering (DF) and termination of flowering (TF) to physiological maturity (PM) were significantly affected by planting date and reduced as day length increased. The same was observed in the case of number of days from P to 50% flowering (MF) and to PM. Large co-variation of day length with temperature may explain a portion of day length contribution to the variation in the above periods. Varamin 295 was later than other genotypes with respect to the duration from P to HV, and specially, for rosette duration. In addition and for unknown reasons, the rate of development (RD) of Varamin 295 at all developmental periods could not be explained by day length and/or temperature variables. Among other genotypes, Koseh with 125 days, and Nebrska 10 with 118 days from P to PM were the latest and the earliest genotypes, respectively. The response of Koseh to planting dates, as measured by the duration of various developmental stages, differed from Arak 2811 and Nebraska 10. This was attributed to the probable response of Koseh to day length. RD of Koseh, Arak 2811, and Nebraska 10 during P to MF was explained by a linear regression and RD of Koseh during P to PM by a polynomial regression with day length by mean temperature as an independent variable. RD of Arak 2811 and Nebraska 10 during P to PM was explained by minimum temperature. It seems that partial sensitivity of Koseh to day length has a considerable significance in its adaptation to environmental conditions prevailing in the summer under Isfahan climatic conditions.

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Although safflower is known to be a cool-season crop, it is usually planted as a summer crop in Isfahan. Thus, an experiment was conducted in 2000 at the Agricultural Research Station, Isfahan University of Technology, to study the effects of date of planting on growth, yield components, and seed yield of safflower. Five planting dates (March 12, April 12, May 10, June 8, and July 12) and four safflower genotypes (Arak 2811, local variety Koseh, Nebraska 10, and Veramin 295) were evaluated using a randomized complete block design with split-plot layout in three replications. Date of planting was considered as the main plot and cultivars were randomized in sub-plots. Delay in planting from March 12 to may 10 reduced plant dry weight per unit area, number of heads per plant, number of seeds per head, seed yield per unit area, harvest index and petal yield. The above traits increased as planting was further delayed from May 10 to June 8. Highest seed oil and lowest seed protein contents were also obtained for this planting date. Plants of July 12 planting date did not reach physiological maturity. Among the genotypes evaluated and over planting dates, the highest and lowest number of heads per plant, 1000-seed weight, and seed yield were produced byArak 2811 and Veramin 295 (mean of the first and second planting dates), respectively. Highest seed yield (4512 kg ha

^-1) was produced by local variety Koseh in June 8 planting date. It might be concluded that this variety has adapted to the summer planting conditions of Isfahan by natural selection.

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Under irrigation and in double-cropping system, a large amount of plant residue remains after harvest that along with the limited time for residue decomposition and complete seedbed preparation, necessitates reduced tillage and special residue management. In the present study, the effects of various seedbed preparation methods on vegetative growth, yield components and seed and oil yields of sunflower (Euroflor hybrid) were studied in a barley-sunflower cropping system during 2001 at the Agricultural Research Station, Isfahan University of Technology. Three residue management treatments (standing, partly removed and burned) along with five tillage systems (moldboard + disk chisel + disk disk moldboard and furrower as the minimum tillage) were laid out in a split-block design with three replications. Burning residue treatment significantly increased plant dry weight at various developmental stages and also head diameter. Number of seeds per head, 1000 seed weight, harvest index, and oil yield were non-significantly higher in the burned residue treatment. Seed yield was significantly higher in the burned and partly removed residue treatments. Moldboard + disk and chisel + disk treatments significantly produced higher plant dry weight at various developmental stages, head diameter and seed yield. Number of seeds per head, 1000 seed weight, harvest index, and oil yield were non-significantly higher in these treatments. Minimum tillage ranked the lowest for these traits. The results of this experiment indicate that chisel + disk treatment with the partly removed residues might be an appropriate seedbed preparation method in a barley-sunflower double planting under conditions similar to this experiment.

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To investigate drought tolerant isolates of rhizobial symbioant of lentil (Lens culinaris L.), 12 soil samples were collected from cultivated and non-cultivated area of Golestan, Chaharmahal-O-Bakhtiari and Isfahan provinces. Local cultivars of lentil including Binam Dorosht, Ghazvini and Faridani were planted in each soil sample. After 10 weeks, a total of 324 rhizobial isolates were recovered from root nodules of the lentil plants. Evaluation of the ability of the isolates to grow at different concentration of salt showed that all isolates grew normally on 200 mM NaCl and only 20% was determined as salt tolerant isolats(>400mM). Among the isolates RL249 was classified as superior salt tolerant strain due to growing on 600 mM salt. The drought tolerance of the isolates was also examined, using PEG6000. In general, the salt tolerant isolates were also drought tolerant, however their tolerance to salinity and drought is not related to their geographical origin. In a randomized split factorial design with three replications, the effectiveness of tolerant isolates(RL249 and RL211) and a sensitive strain (RL 77) was compared on two cultivars of lentil (Binam Dorosht and Faridani) under water stress treatments with the consumptions of 50, 75,90 and 98% of soil available water. Although nodulation rate was reduced in both cultivars as the consequence of drought stresses, plants of Binam Dorosht cultivar showed high nodulation rate due to the increased fresh weight of the roots. Despite the fact that RL249 was identified as a superior nodulating and salt/drought isolate, however nodulation efficiency was decreased significantly under water stress treatments with more than 50 % of soil available water.

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It is necessary to use organic fertilizers and decrease chemical fertilizers consumption to reach sustainable agriculture. Thus, to study the effects of manure incorporation methods, and integrated effects of poultry manure with chemical fertilizers on the grain yield and yield components of maize, an experiment was conducted in 2004 at the Agricultural Research Farm of Lorestan Weather Department, 30 kms northeast of Khorramabad. The treatments were arranged in a split plot layout based on randomized complete block design with four replications. The main plots consisted of incorporation of fertilizer with soil by furrower or disk. The subplots included T0: control (no consumption of fertilizer and poultry manure) T1: 200, 100, and 100 kg ha^-1 of nitrogen, phosphorus, and potassium, respectively T2: 80% of T1+ 4 ton ha^-1 of poultry manure T3: 60% of T1+ 8 ton ha^-1 of poultry manure T4: 40% of T1+ 12 ton ha^-1 of poultry manure T5: 20% of T1+ 16 ton ha^-1 of poultry manure and T6: 20 ton ha^-1 of poultry manure. The results showed that incorporation of fertilizer by furrower, compared with disk, led to significant increase in plant height, 1000 seed weight and grain and biological yields. However, there were not significant differences in the number of seed per ear and harvest index between the two fertilizer incorporation methods. Fertilizer treatments caused significant increase of the treats mentioned except for the harvest index. The interaction effects were not significant for any traits. T5 treatment produced the highest grain yield, and was significantly different from T0, T1, T3 and T6 treatments. The differences between T1 (chemical nutrition system) and T6 (organic nutrition system) were not significant either. Effectiveness of integrated poultry manure and chemical fertilizers on maize yield components was higher than either poultry manure or chemical fertilizer. The results of this experiment indicated that incorporation of 16 ton poultry manure + 40, 20 and 20 kg ha^-1 N, P and K with furrower might be appropriate for maize prodution under conditions similar to this experiment.