AGRICULTURAL RESEARCH
Year:2006 | Volume:6 | Issue:4|Papers Count:6

In this study investigates the resistance of twrolive cultivars of Baghmalek and Zard to water stress and different potassium levels. Different irrigation treatments were performed: I1) watering when 0-33 % of the plants available water is used; I2) watering when 34-66 % of the plants available water is used; and I3) watering when 67-100 % of the plants available water is used. Additionally, fore each plant, three potassium levels of zero, 50 and 100 g sulphate were added during the planting period. The experiment was carried out in a completely randomized design with factorial arrangements and four replications. Further, vegetative characteristics such as: dry and fresh weights of leaf, stem, and leaf and root areas were measured. It was found thtat vegetative characteristics of cv. Baghmalek were better than Zard olive. In both cultivars, dry and fresh weights of leaf, stem and root and leaf area reduced with decreasing irrigation. Plants in I3 had lower vegetative growth and showed leaf abscission. As irrigation was reduced, the ratio of root to shoot increased and the I3 caused the highest root/shoot ratio.Adding potassium led to increasing dry and fresh weights of leaf and stem and leaf area. Plants subjected to K1 and K2 treatments showed more vegetative growth than K3 treatment, but in the most cases no significant differences were found between K2 and K3 treatments. Use of potassium sulphate for plants under water stress, resulted in more vegetative growth than control.

Study of soil erosion process and evaluation of its controlling factors, are supposed to be important prerequisites for proper management of soil and water resources in watersheds. In addition, comparative assessment of the impacts of human controllable interferes through "land use change is very important. The present study was conducted in experimental plots installed in the two rainfed and poor rangeland, land uses of Gargak watershed, Chaharmahal-e Bakhtiari Province, Iran. The study was performed using a rainfall simulator during summer and winter seasons. Using a rainfall of 34 mm per hour, the runoff and sediment were collected and measured within 5 minutes time intervals. The results of the ANOVA and t-Test showed that the runoff and sediment yield in summer for the poor rangeland are more than those of rainfed area at 99% level of confidence. In winter, at the same level of confidence, the runoff and sediment yield were more than those of rangeland.

Land use and soil separability were investigated by the means of LISS-III remotely sensed data in Aran-Bidgol. After geometric correction and radiometry, the DEM was employed to combine the data and derive the useful outputs. The manipulated data bonds in LISS-III were used to examine the separability of the soils. The train samples were chosen upon directing homogeneus units on the color maps using using field studies and other information. In order to evaluate soil separability, mean, standard deviation and variance of the train sampels were calculated and assessed. The images were classified by the use of supervised method and maximum likelihood algorithm. Then, the outputs were compared with the real ground maps. The results showed that LISS-III sensor could not discriminate Typic Haplosalids from Typic Aquisalids. Gypsic Aquisalids and Typic Aquisalids had the highest and the lowest reflections, respectively. Typic Aquisalids had spectral interferences with Typic Torriorthents formed on gravelly colluvial fans. The surface of Gypsic Aquisalids was covered by salt and gypsum, whereas, the surface of Typic Aquisalids was sealed with sponge- and polygon-like crusts which were moist at the lower layer. Na and Mg salts were predominant in the two soils. The finding sdemonstrated that salty soils with smooth polish and puffy surfaces; smooth and dark surfaces with low to moderate salt accumulation; and spong- and polygon-like crusts were classified in a similar class. Overall, when it is intended to identify and separate the aridic soils at the level of sub-group, the data from Indian satellite are suitable due to easy-to-access and low cost for digital processing.

Indirect regeneration of chickpea is difficult due to low producing of callus and genetic instability. In this study, direct regeneration through multiple shoot from embryo axes of five chickpea genotypes (Hashem, Arman, Piruz, MCC505 and MCC426) in MB media (including MS salts and Bs vitamins) with different levels of cytokinin hormones (BAP: 1,2,3 mg/L; TDZ: 0.2,0.4, 1,3 mg/L; Zeatin: 0.5, 1,2 mg/L and Kin: 1,2,3 mg/L) were reviewed and then rooting of regenerated shoots in MB and 1/2 MB media with IBA (1 and 2 mg/L)have been studied. For regeneration of roots, MB and ½ MB media with IBA (1 and 2 mg/L) were allied. The results showed that the best medium for shooting of embryo axes was genotype dependent. In overall, the MB media containing BAP produces more and better shoots (1 mg/L in MCC505 and 3 mg/L in other genotypes) and shoots had normal growth. The medium containing ½ MB and IBA (1 and 2 mg/L) was found to be suitable for rooting of regenerated shoots. The number and the length of obtained roots were appropriate for acclimation step.

The desert area of Rudasht, located in east of Esfahan province, due to low precipitation and high evapotranspiration (average annual precipitation of less than 100 mm and potential annual evapotranspiration of about 2400 mm), especially during the summer season, faces with insufficient and low quality water resources. To study the effect of deficit irrigation on cantaloupe, using drip irrigation system, a field experiment was conducted in Rudasht Drainage and Salinity Research Station located at 65 km east of Esfahan city, in central part of Iran. The applied irrigation water treatments were 65%, 80% and 95% of the cumulative evaporation from class A pan. In this study, the statistical split plot design was used. The applied water treatment during the irrigation season was equal to 300, 342 and 384 mm, respectively. The results showed, as the irrigation water increases, the yield of fresh fruit, yield per unit area, number of fruits per plot, weight of fruit per plant, and irrigation water use efficiency increases. The production function which shows the relationship between yield and applied water, showed a second order polynomial with high coefficient of determination (R2 = 0.99). Furthermore, the relation between irrigation water use efficiency and amount of applied irrigation water, showed a second order polynomial with high coefficient of determination (R2 = 0.97). The results showed that the cantaloupe is very sensitive to deficit irrigation.

In order to study the response of potato growth indices in the seed production and commercial crop plant densities to weed infestation period an experiment was conducted in Agricultural faculty of Bu-Ali Sina University in 2006. This experiment was a factorial experiment based on a randomized complete block design with three replications. Experimental treatments were potato plant density at two levels, 5.33 (optimum plant density of commercial fields) and 6.66 (optimum plant density of seed production fields) plant m-2 and weed infestation periods at seven levels, in which at the five levels, weeds were allowed to grow for 10, 20, 30, 40 and 50 days after crop emergence and then weeds were removed manually until harvest, In addition two control treatments (full- season weeded and full season infested) were taken. Each plot consisted of four rows (eight meter per rows) with a row spacing of 75 cm. In order to calculate the growth indices of crop sampling started from 10 days after crop emergence, and repeated in 10 days interval, for 11 times. The results showed that until 40 days after crop emergence, total dry matter accumulation was not affected by weed infestation period and about 90 days after crop emergence weed infestation had maximum effect of total dry matter. In the low plant density, the effect of weed infestation period on leaf area index, crop growth rate and tuber growth rate was more than those of high plant density. So that full- season weed competition led to a 44.4%, 36.5%, 42.3% and 40.0% reduction in above mentioned potato growth indices (at their maximum amount), respectively, in compared to weed- free treatment, at the low plant density. However, the reduction in the high plant density was 40.0%, 34.8%, 39.7% and 35.1 %, respectively. The effect of weed infestation on tuber yield in commercial plant density was more than those of seed production plant density.