Iranian Journal of Field Crop Science
Year:2019 | Volume:50 | Issue:2|Papers Count:10

To evaluate and select drought tolerance genotypes in common bean and identify the best indices for drought tolerance, an experiment was conducted at research field University of Tehran, Karaj, Iran, during 2015-2016 growing season. In this study, 102 common bean genotype were evaluated in an augment design under normal irrigated and drought stress (non-irrigated from flowering stage until the end of growing season) conditions. Average values of grain yield and drought tolerance indexes and simple correlation coefficients of indexes with irrigation and dry farm yield showed that indices including MP, GMP and STI were the most suitable criteria for screening bean’ s genotypes. In 3-dimensional graphs, referring to MP, STI, and GMP indexes and grain yield under dry farming and irrigation condition, 100, 63, 47, 88 and 76 genotypes were identified as genotypes with high production and tolerant to intensive drought in A group. Actually, these genotypes had the highest yieldunder both irrigation and dry farming conditions. Cluster analysis based on investigating indices and yield under drought stress and non-stress conditions showed that genotypes was grouped in three clusters and most of drought tolerant genotypes with high yield were grouped in third cluster, while most of sensitive genotypes to drought stress were grouped in the second cluster.

Sustainable agriculture is one of the desired principles for scientists at current period, and intercropping that ensures the stability of the production factors and resources and it can fertilize the future of agricultural production. This experiment was conducted based on randomized complete block design with four replicates at the Agricultural Research Station of the College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran, during the growing season of 2014-2015. The intercropping system was as replacement. The considered cultivars were fodder sorghum (Pegah cultivar) and corn (ksc600). Treatments included pure maize, 75% corn + 25% sorghum, 50% corn + 50% sorghum, 75% corn sorghum + 25% corn and pure sorghum culture. The results showed that the single cropping sorghum, 75% sorghum + 25% corn and 50% sorghum + 50% corn treatments with 61, 60 and 45 t/ ha yield, respectively, produced greatest sorghum forage yield., and in corn, the single cropping of corn, 75% corn + 25% sorghum and 50% corn + 50% sorghum treatments had the highest grain yield with 8. 7, 8. 6 and 8. 4 t/ ha yield, respectively, but decreased the number of plants per hectare does not follow yield reduction and the yield (gram per plant) reveals this share.

In order to evaluate freezing tolerance of some clover species as well as planting date and acclimation period effects on plant tolerance, an experiment was conducted in 2012-13 in Faculty of agriculture, Ferdowsi University of Mashhad in completely Randomized Design with factorial arrangement and four replications. Experimental factors included two planting dates (late September and late October), four clover species (red clover T. pratense, white clover T. repense, Persian clover T. resupinatum (autumn species) and crimson clover T. incarnatum (spring spieces) and eight freezing temperatures (0 (control),-3,-6,-9,-12,-15,-18,-21º C). Electrolyte leakage percentage of leaf and crown was measured and used to determine lethal temperature for 50% of plants (LT50el(l) and LT50el(c) for leaf and crown, respectively). Results indicated that interaction of planting dates, species and freezing temperatures on electrolyte leakage of leaf was significant in a way that a lower mean of this parameter was observed in autumn species in first planting date compared to the second planting date but the reverse was found in spring species. Decreasing temperature to less than-12 and-15 ˚ C resulted in an increase in electrolyte leakage of crown in red and Persian clovers, and white and crimson clovers, respectively). The least LT50el(l) in first planting date was found in red and Persian species and the highest in crimson species while in the second planting date, the lowest mean was observed in Persian and crimson and the highest in red species. Also, plant dry weight decreased as freezing temperature dropped to-9 ˚ C.

In order to evaluate the intercropping of Sweet corn and Okra affected by vermicompost and urea fertilizer a field experiment was conducted at research field of Tarbiat Modares University during 2015 spring and summer. In this research effect of five mixing ratio of sweet corn/okra including: 100: 0 (sweet corn monoculture), 75: 25, 50: 50, 25: 75 and 0: 100 (okra monoculture) and two nutrition systems consisted of chemical (urea) and organic (vermicompost) were investigated with factorial arrangement of treatments based on randomized complete block design with three replications. The results showed that factors interaction on the number of desirable ear, sweet corn yield and okra seed yield were significant (P≤ 0. 01). Also mixing ratio effect on sweet corn 100 kernel weight (P≤ 0. 05), okra 1000 kernel weight and the number of fruits square meter (P≤ 0. 01) was significant. According to mean comparisons the highest sweet corn yields (9614. 58 kg. ha-1) and okra (2848. 65 kg. ha-1) was obtained in their monoculture receiving the chemical fertilizer. The highest LER (2. 10) was obtained in 50: 50 treatment under vermicompost nutrition system followed by 75: 25 under same nutrition system (LER=1. 93). Also competition index evaluation in the different treatment confirmed the rating of superior treatments.

Innovative strategies are needed to improve water and nitrogen use efficiencies in sandy soils. The objectives of this study were to quantify the amount of nitrate leaching losses under conventional and integrated nutrient management of canola and wheat. The experiment was carried out using a randomized complete-block design, with three replications. Fertilization treatments including: urea (CF), urea + zeolite (CF-Z), urea + composted manure (IF), urea + composted manure + zeolite (IF-Z) and control (CK). The maximum water deep percolation was occurred after irrigation in November and May. The average of annual nitrate leaching losses for CF, CF-Z, IF, IF-Z and CK were 53. 64, 41. 21, 33. 16, 25. 59 and 9. 23 kg. ha-1, respectively. The maximum and minimum annual nitrate leaching factor were achieved with the CF (47%) and IF-Z (10%) treatments, respectively. Annual nitrate leaching losses and annual nitrate leaching factor showed positive and significant correlations with the amount of water inputs in the months. The IF-Z fertilizer treatment produced the highest grain yield for canola (3661. 5 kg. ha-1) and wheat (4058. 9 kg. ha-1). The results showed that application of manure compost and zeolite could be a useful methods for decreasing chemical fertilizer application rates and improving the sustainability of agricultural systems.

The Cultivation of medicinal plants such as Lamiaceae family has been increasing throughout the world, considerably. Peppermint known as an important species in this family which it’ s important is due to menthol in the essential oil. In current study the physiological and biochemical responses of peppermint investigated under different levels of irrigation including 100 (as control), 75, 50 and 25 % field capacity (FC) in CRD design with three replications in research greenhouse of Agronomy Department of University of Tehran in 2013 year. The results indicated that, irrigation levels had a high significant effect on hydrogen peroxide (H2O2), malondialdehyde (MDA), catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX) and superoxide dismutase (SOD) (P≤ 0. 01). While, the effect of irrigation levels was not considerable on soluble sugar content. The highest content of soluble sugar and soluble protein observed at 50 and 75 % FC, respectively. The highest H2O2 and MDA (59. 63 and 16. 25 μ mol/g) recorded at 25% FC with significant difference in respect to the other treatments. The highest activity of antioxidant enzymes CAT, APX and GPX detected at 50 % FC, then reduced with increasing of drought stress up to 25 % FC. The activity of SOD increased with increasing of the drought stress and peaked at 25 % FC. These results suggest that peppermint is a drought sensitive plant which is unable to increase its enzymatic antioxidant capacity in intense drought stress conditions.

In order to evaluate of nitrogen use efficiency and agronomic characteristics of winter wheat to rate, time and method of nitrogen application, this study was carried out in the field of Payaam Nour Arak University in Markazi province in 2011. A factorial arrangement of treatment in a randomized complete block design with three replications was used. Factors were included 1-time of nitrogen application (T1= 50% of nitrogen in sowing date + 50% of nitrogen in tillering stage, T2= 50% of nitrogen in tillering stage + 50% of nitrogen in stem elongation, T3= 50% of nitrogen in stem elongation + 50% of nitrogen in heading stage), 2-rate of nitrogen application (R1= 150 kg ha-1 urea, R2= 300 kg ha-1 urea) and 3-method of nitrogen application (M1= mix with soil, M2= using by irrigation, M3= foliar application). Each plot consisted of 4 rows, 5 m long. Results indicated that the using time affected on the characteristics such as: stem height, peduncle and spike length, number of spike per m-2, number of grain per m-2, spike biological yield, economical yield of spike, and nitrogen use efficiency significantly. The effect of nitrogen rate was significant on stem height, peduncle and spike length, number of grain per m-2, spike biological yield and nitrogen use efficiency, too. Results indicated that the nitrogen use efficiency was significantly higher than of other treatments in foliar application of urea fertilizer (150. 4 %) and using nitrogen by irrigation (14. 07 %).

Effect of four levels of biochar (0, 25, 50 and 75 ton ha-1) produced from wheat straw and three levels of irrigation (100, 75 and 50 % of crop water requirement) on growth and yield of faba bean was determined in completely randomized design in the greenhouse. The result showed that after faba bean reached maturity, the maximum plant height and leaf area index obtained in 25 ton ha-1 biochar treatment. Also, maximum faba bean yield was also obtained in 25 ton ha-1 biochar. The result of irrigation regimes treatments showed that the crop height and leaf area index decreased by application of deficit irrigation. Faba bean growth and yield were also significantly declined under deficit irrigation. Therefore, it can be concluded that application of biochar (as a soil amendment) in low levels may have a positive effect on crop yield and its components. Further, under biochar application of 25 ton ha-1, the use of deficit irrigation in 75% of crop water requirement is recommended as it did not cause any significant decline in crop yield.

Field experiment was carried out as split-plot based on randomized complete block design with three replications in 2017, to evaluate physiological and morphological performance and oil yield of coriander, in response to water limitation and foliar application of zinc. Treatments were four levels of water supply (irrigation after 70, 100, 130 and 160 mm evaporation from class A pan) and three levels of zinc foliar application (control (foliar application of water), foliar application of zinc with 3 g ZnSO4/L (Zn1) and foliar application of zinc with 6 g ZnSO4/L (Zn2)). Irrigation and foliar application treatments were allocated to main and sub plots, respectively. Decreasing water availability resulted in decreasing leaf relative water content and chlorophyll content. However, proline content of leaves enhanced under limited irrigation conditions. Mean leaf chlorophyll content significantly enhanced by exogenous spray of zinc with 6 g ZnSO4/L, compared with control. Decreasing water supply led to reduction in plant height, stem diameter, number of leaves per plant and grain yield. Foliar application of zinc with 6 g ZnSo4/L caused significant increase in plant height and grain yield. Oil percentage in the grains of coriander increased as a result of water deficit, but grain oil yield decreased with increasing irrigation intervals. Oil yield significantly enhanced by foliar application of zinc with 6 g ZnSO4/L. There was no significant difference between 3 and 6 g ZnSO4/L foliar application of zinc. Therefore, regarding to beneficial effects of zinc on grain and oil yield of coriander, foliar application of 3 g ZnSO4/L recommended for the study area and the similar regions. This would become more important under conditions where water availability is limited.

Varamin is a migratory region due to its close proximity to Tehran's metropolis. This trend has led to increase population and land use change. Conversely, having favorable physiographic conditions and favorable water and soil potential, this region has a high capacity for agricultural development. In this study, the ecological capability were evaluated using Iran's agricultural and rangeland applications model. First, a specific model based on Iran's agricultural and rangeland applications model, for regional studies has been prepared. Then, various maps of elevation, gradient, geographic directions, soil, vegetation type and vegetation density of the studied area prepared in ArcGIS 10. 4 software and then the maps integrated into final plan of the environmental units with 863 units. In the last step, with comparison of applications requirement with properties of units optimal usage of each unit was determined. The results showed that from the total area of the region, 33. 12% were suitable for agriculture with grade of 3; 0. 45 percent with grade of 5; 0. 19 percent for range management with grade of 1; 0. 54 percent with grade of 2; 9. 42 percent with grade of 3 and 54. 93 percent were suitable for protection (1. 35% of the area were allocated to settlements).