Iran Agricultural Research
Volume:31 Issue: 2, Winter and Spring 2012

Little information is available on the effects of applying compost tea to species in dry regions. Compost from agricultural waste can promote drought resistance in plants and increase their growth by improving soil structure and providing nutrients and enhancing the capacity of the soil to store moisture. In order to examine these effects, compost tea was tested on two species growing in dry regions (mountain sagebrush, Artemisia aucheri and Salsola, Salsola tomentosa) at 5 various concentrations; 0, 10, 20, 30 and 40 (m3/ha). This research was conducted as a field study at Neiriz (29o 36''N, 53o 59''E, altitude 1776 m) in Fars province, Iran, during the 2009-2010 growth season. The experiment was factorial, based on a randomized complete block design with 10 treatments and 3 replications. The results showed that compost application increased plant height (25.1%), crown diameter (10.5%), and fresh (7.0%) and dry (5.9%) weights up to a concentration of 40 m3/ha, compared with the control (without compost). It was also found that bulk density, electrical conductivity and soil organic matter all increased after the application of compost. In some cases (e.g. crown diameter and fresh and dry weight), a high concentration of compost had negative effects, which might have been due to osmotic potential. Salsola responded better to compost application than Artemisia. Overall, 30 m3/ha was the most effective concentration of compost tea to stimulate growth increase of Salsola and Artemisia in dryland conditions.

In order to investigate the effects of nitrogen fertilizer levels and intercropping ratios on yield and other morphological traits of two crops, field experiments were conducted during two years (2010-2011) in the research field of the school of Agriculture, Shiraz University, Shiraz, Iran. The study was carried out in a factorial experiment laid out based on a completely randomized block design (RCBD) with three replications where the factors were intercropping in seven different ratios of green bean (B) and safflower (S) (including green bean sole cropping, safflower sole cropping, intercropping of green bean/safflower with 1/1, 1/3, 2/3, 3/1 and 3/2 proportions) and nitrogen fertilizer rates (0, 75 and 150 kg per ha). Overall results indicated that different intercropping systems and N-fertilizer levels significantly affected the yield and other traits measured in both green bean and safflower. Optimal treatments in terms of economic importance for the farmers were intercropping B2S3 or B3S2 with 75 kg N/ha for safflower and B2S3 or B3S1 intercropping ratios under any or 75 kg N per ha for green bean (17.82g/plant) and the highest total LER (3.1). In order to obtain the highest total product amount, which is of prime importance to the farmers, B2S3 intercropping with no N-fertilizer application is recommended. Based on the results of this study, green bean and safflower are compatible and profitable crops and can be recommended to farmers for intercropping.

The present research designed to evaluate the effects of foliar application of methyl jasmonate (MeJA), salicylic acid (SA) and potassium sulfate on improving fruit quality and photosynthesis system. Ten treatments include: SA (0.3, 0.6 and 0.9 mM), MeJA (0.5, 1 and 2 mM), potassium sulfate (0.5, 1 and 1.5%) and distilled water (control) were sprayed on pomegranate trees 2 and 7 weeks after full bloom early in the morning. Results indicated that SA, MeJA and potassium sulfate increased phenolic compound and 1.5% of potassium sulfate and 0.5 mM of MeJA significantly increased the antioxidant activity of pomegranate fruit. Application of SA at 0.6 mM increased significantly hue angle of fruit peel. Foliar application of potassium significantly increased Fv/Fm and Pi parameter. Furthermore, total chlorophyll, b chlorophyll and cartenoids increased by 0.5 % of potassium sulfate, however, the differences were not significant. Besides, 1% and 1.5% of potassium sulfate significantly increased the pH of fruit juice.

This study was conducted to evaluate changes in antioxidants, free proline, relative water content and determination of root colonization of four commercial wheat (Triticum aestivum L.) cultivars (Azar2, Darab2, Shiraz, and Falat) inoculated with the fungus Glomus intraradices, under four water regimes of 100, 75, 50, and 25% of field capacity in the year 2010 at the School of Agriculture, Shiraz University. The means for leaf area, shoot fresh weight, root fresh weight, shoot dry weight and root/shoot ratio were 6.0, 10.2, 15.6, 25.2, and 10.31% respectively higher in the mycorrhizal as compared to non-mycorrhizal cultivars. Water deficit stress reduced root colonization percentage and the highest root colonization (28.10%) was observed in the cultivar Azar2. Compared to the non-mycorrhizal plants, inoculation increased the average values for relative water content, proline content, total chlorophyll content, total protein, superoxide dismutase, peroxidase, and catalase activities of mycorrhizal plants by 5.5, 35.6, 13.8, 21.6, 22.5, 22.7, and 15.5%, respectively. The highest peroxidase (9.77 U mg-1), catalase (9.82 U mg-1), and super oxide dismutase (19.80 U mg-1) activities were obtained by Azar2. The results indicated that inoculation with Glomus intraradices alleviated the deleterious effects of water deficit stress on wheat cultivars via proline accumulation and increased antioxidant activities. The cultivars Azar2 and Darab2 had higher values for most of the antioxidants and root colonization. Consequently, these cultivars could be used in wheat breeding programs for better symbiosis and drought tolerance.

Evaporation, as a major component of the hydrologic cycle, plays a key role in water resources development and management in arid and semi-arid climatic regions. Although there are empirical formulas available, their performances are not all satisfactory due to the complicated nature of the evaporation process and the data availability. This paper explores evaporation estimation methods based on nonlinear dynamic neural network model (NNARX) and adaptive neuro-fuzzy inference system (ANFIS) techniques. It has been found that NNARX and ANFIS techniques have much better performances than the empirical formulas (for the test data set, NNARX R2 = 0.95, ANFIS R2 = 0.94, Meyer R2 = 0.81 and Marciano R2 = 0.68). ANFIS and NNARX models are slightly better albeit the small difference. Although NNARX and ANFIS techniques seem to be powerful, their data input selection process is quite complicated. More studies are needed to gain wider experience about this data selection tool and how it could be used in assessing the validation data.

Euphorbia is a genus of flowering plants belonging to the family Euphorbiaceae. Consisting of 2008 species. The genus Euphorbia produces an irritant, which constitute a health hazard to humans and livestock. The genus Euphorbia is one of the largest and most complex genera of flowering plants, however, several botanists have made unsuccessful attempts to subdivide it to smaller genera. Many Euphorbias are used for medicinal and other purposes. But it is interesting to note that the plant can be both helpful and toxic. In this study, the toxicity of Euphorbia. sp. was examined. The toxic effects of some suspected poisonous plants of the genus Euphorbia (Euphorbia balsamifera Aiton, E. heterophylla L., E. hirta L., E. hyssopifolia L., and E. lateriflora Schum and Thonn), commonly found in the Iran pastures. Changes in haematological as well as biochemical parameters were used as indices of toxicosis. Experiment showed the important constituents of the aerial parts are terpenoids, including triterpenes: α-amyrin and β-amyrin.