JOURNAL OF CROP SCIENCE RESEARCH IN ARID REGIONS
Year:2017 | Volume:1 | Issue:1|Papers Count:10

In order to evaluate the seed and essential oil yield and harvest index of cumin, a factorial experiment based on randomized complete blocks design was conducted with three replications, at the research farm of the faculty of agriculture of Urmia University in 2010. Treatments were four irrigation regimes (irrigation after 50, 100, 150 and 200 mm of evaporation from a class A pan) and different amounts of superabsorbent polymer (0, 60, 120, 180, 240 and 300 kg/ha). The highest biomass yield (3640 kg/ha), seed yield (1226 kg/ha) and essential oil (36. 5 kg/ha) belonged to irrigation after 50 mm of evaporation and 60 kg/ha superabsorbent polymer application. Increasing in irrigation distances to 100, 150 and 200 mm of evaporation needs to 180 and 120 kg/ha polymer to produce maximum yield (biomass and seed), but they were 60 and 300 kg/ha polymer for essential oil yield and harvest index, respectively. The maximum harvest index of seed for irrigation after 100, 150 and 200 mm of evaporation belonged to 180 kg/ha superabsorbent treatment. Application of superabsorbent at irrigation after 50 mm of evaporation (non-stress condition) does not have efficiency for essential oil production compared with the control (without polymer in this irrigation). In conclusion, increasing irrigation intervals from 50 to 200 mm of evaporation from pan lead to reduce the yield (biomass, seed and essential oil), that application of superabsorbent polymer A200 compensate part of this reduction.

Excessive use of chemical fertilizers causes imbalance of nutrients, especially micronutrients, in soil and leads to decreased absorption of iron, zinc and manganese by plants. The prevalent calcareous and alkali conditions of agricultural soils in East Azerbaijan have resulted in restricted absorption and uptake of soil micronutrients by crops in the province. In order to investigate the effects of micronutrients and organic fertilizers on some properties of wheat Cv. Sardari, a field experiment based on randomized complete block design (RCBD) with 12 treatments and three replications was performed at the research farm of Maragheh University during 2013-2014. Treatments included FeSO4, ZnSO4, FeSO4+ ZnSO4, FeSO4+ MnSO4, ZnSO4+MnSO4, poultry manure, poultry manure+FeSO4, poultry manure+ ZnSO4, poultry manure+MnSO4, poultry manure+FeSO4+ ZnSO4+MnSO4. Concentrations of Fe, Zn and Mn were 1000, 3000 and 1000 ppm, respectively. Results showed that integrated application of micronutrients and organic fertilizers increased nitrogen percentage and grain protein content. Combined application of poultry manure+FeSO4+ ZnSO4+MnSO4 increased grain yield, protein yield, protein content and potassium content by 44. 86, 54. 24, 6. 38 and 41. 86 percent, respectively over the control. The highest phosphorous content was achieved by application of FeSO4, followed by poultry manure + FeSO4. In general, micronutrients and organic fertilizer enhanced wheat grain yield and quality by influencing the soil macronutrients uptake.

The effects of sowing date and plant density on yield and yield components of mung bean cv were studied in a split-plot experiment, based on a randomized complete block design in three replications, which was performed at the research farm of Islamic Azad University of Jiroft in 2010-2011. The main-plots were devoted to sowing date at four levels (June 29, July 6, July 12 and July 20) and the sub-plots were devoted to density at three levels (10, 20 and 30 plants m-2). Analysis of variance revealed that sowing date significantly influenced plant height at the 1% level of probability and the number of pods per plant, the number of grains per pod, grain yield and biomass at the 5% level of probability. The effect of plant density was significant on the number of pods per plant and biomass at the 5 and 1% probability levels, respectively. The interaction of sowing date and plant density was significant only for plant height and biomass yield. The highest grain yield (1001 kg ha-1) was obtained from July 6 and the lowest one (714. 3 kg ha-1) from July 20. Although the effect of plant density was not statistically significant on grain yield, the highest grain yield (907. 98 kg ha-1) was related to the density of 30 plants m-2. Considering the oneyear results, the best sowing date can be regarded as to be July 6 with the density of 10 plants m-2 under the regional conditions of Jiroft.

Despite the importance of drought stresses in the early stages of plant growth and establishment, it has usually been neglected as a selection criterion in breeding programs. Therefore, an experiment was carried out at Zabol University Research Laboratory in a factorial experiment, based on randomized complete block design with three replications, in 2013. Experimental factors were six osmotic stress conditions (control,-1. 5,-1. 9,-3. 5,-4. 8 and-6. 5 bar) and two genotypes, fennel and ajowan. The interaction of genotype and drought stress treatments was significant at the 1% probability level for all studied traits, except for seedling dry weight that was significant at the 5% probability level. Fennel than ajowan for germination percentage, speed of germination, seedling length, seedling dry weight and seedling fresh weight had greater values and ajowan than fenel had greater mean germination period. The greatest and lowest values of attribute, except for the mean of germination period (in the-6. 5 bar osmotic stress and conrol, respectively), were obtained in the absence of stress (control) and the-6. 5 bar osmotic stress treatment, respectively. Osmotic stress and genotype interaction showed that the highest amount of germination percentage (94. 67), root length (7. 10 mm), seedling length (10. 36 mm), seedling dry and fresh weight (0. 64 and 0. 0320 gr) was achieved in the absence of stress (control) for fennel and for seed germination rate (10. 31) in ajowan genotype. The highest mean germination period (9. 81) was achieved for ajowan in-6. 5 bar osmotic stress. Generally, fennel than ajowan had higher ability to germinate in the osmotic stress. Seed germination percentage seems to be the most important traits related to germination.

Chitosan is a glucosamine polysaccharide deacetylated form of chitin species and could be used as a biotic elicitor to improve secondary metabolites. In order to study the effect of chitosan on malondialdehyde (MDA), antioxidant enzymes activity such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), phenol compounds, chlorophyl a, b, carbohydrate and proline in ajowan, this study was conducted as a randomized complete block design (RCBD) with three replications at Biocenter of University of Zabol. Chitosan had four levels (0, 100, 150 and 200 ppm). In comparison with the control, the results showed that malondialdehyde (MDA), antioxidant enzymes activity such as catalase (CAT), superoxide dismutase (SOD) and ascorbate peroxidase (APX), phenol compounds, chlorophyl a, b, carbohydrate and proline increased to 72. 96, 92. 22, 91. 74, 92. 61, 86. 35, 73. 52, 81. 16, 94. 6 and 91. 4% respectively, while increasing the amount of chitosan to 200 ppm. It seems that in concentrations higher than 100 ppm, chitosan, as a biotic elicitor, increases antioxidant enzyme activity and secondary metabolites production in four stages of ajowan.

An experiment was conducted to examine the effects of drought stress on two cultivars of sunflower as split plot randomized complete block design at Agricultural Research Center of Khorramabad during 2013 with three replications. Treatments were irrigation at depletion of 25, 50, 75 and 100 available soil water comprising main-plots and two cultivars of sunflower (Record and Alster) as subplots. Drought affected head diameter, grain number per head, 1000 grain weight, core percentage of grain, grain and oil yield and harvest index. Grain yield of Record and Alster at no stress condition were 3359. 10 and 3869. 35 Kg/ha, respectively and oil yield was 1685. 88 and 1818. 10 Kg/ha, respectively. Grain yield of Record and Alster at the strongest drought decreased by 45. 31 and 62. 35%, respectively and oil yield decreased by 49. 50 and 60. 88 %, respectively. In addition to head diameter, 1000 grain weight and grain number per head significantly decreased at stress condition, led to grain yield decreasing. This results suggested that Alster at stress free condition and Record at stress condition has greater grain yield and drought resistance.

An experiment was conducted to evaluate the effects of time and integrated application of urea and humic acid on yield and yield components of chickpea (Cicer arietinum) in rain-fed condition in 2013 at Joghatai, Khorasan-e-Razavi province, Iran. Treatment was arranged as factorial experiment based on completely randomized block design with three replications. Factors were fives combination of urea and humic acid (100% urea, 25% urea+75%humic acid, 50%urea +50%humic acid, 75%urea+25%humic acid and 100% humic acid) and times of foliar application (vegetative and vegetative+flowering). Urea 1% and humic acid (2 lit. ha-1) was used for foliar application. Result showed that interaction between time and integrated application had significant effect on number of lateral branches, number of pods per plant, number of seeds per plant, plant height, economic and biological yield. The greatest economic yield was achieved in combination of 75% Urea+25% humic acid at vegetative stage and combination of 25% Urea+75% humic acid at vegetative+flowering stage. Increasing of urea fertilizer at combination in vegetative stage increased number of pods per plant, number of seeds per plant, plant height, seed weight and number of lateral branches while it decreased these traits on vegetative+flowering stage. In both times, integrated application of humic acid and urea fertilizer had greater yield and yield components compared with two fertilizers alone. Overall results indicated that once spraying with the mixture of 75% nitrogen and 25% humic acid is better than other treatments to achieve good economic yield in dry conditions.

Drought stress is one of the important abiotic stresses in plants and leads to major damage in grain yield as well as plant growing, plant structure, and plant metabolism. Sesame is one of important oilseed plants in warm and semi warm region of Iran and regularly faces with drought stress in planting season. In order to investigate genetic variations of sesame lines for their response against water limitation and role of morphologic traits in such condition as screening markers, this two year experiment was conducted during 2007-2008 in Moghan region of North West of Iran. During the first year, quantitative drought tolerance indices were measured with respect to yield values under normal and drought stress conditions. Indices such as SSI, STI, TOL, and MP were evaluated for 22 genotypes originated from different regions in the world and finally first year results showed that STI and MP were designated as the most efficient indices for drought tolerance evaluation of genotypes. In the second year according to STI, 10 genotypes selected, 5 of which had highest, 3 had medium and 2 had lowest STI values, which were used to assess morphological traits with a Split Plot in the form of Complete Randomized Blocks (CRB) design with three replications. Results indicated that irrigation levels as well as the genotypes differed significantly for all studied traits in both normal and two stress conditions. Likewise, there was a positive significant relation between morphologic traits and grain yield. Also results showed that correlations between STI and morphological traits was positive. In other words results revealed that studied traits react to stress condition therefor these traits could be useful and effective for screening sesame tolerant genotypes. Interestingly, the superior genotypes in this study were all of Iranian origin (Karaj-1 and Oltan) which are recommended as the best genotypes for regions suffering from water limitation as geemplasm for breeding program

In order to evaluate the effects of planting depth and irrigation disruption on the yield and yield components of potato, an experiment was conducted in Chaldoran West Azerbaijan Province Iran, during 2013. The experiment was carried out using factorial experiment based on randomized complete block design with three replications and two factors. The first factor was planting depth in three levels (7, 14 and 21 cm) and the second factor was considered as irrigation disruption in four levels (control, two weeks after emergence, tuber initiation and tuber bulking). The results showed that the effects of planting depth and irrigation disruption on number of tuber per plant, plant height, number of branches per plant, tuber size, mean tuber weight, and tuber yield were significant. The maximum tuber yield (30. 22 ton/ha) was obtained from planting in the depth of 14 centimeter. For irrigation cut the maximum tuber yield (30. 89 ton/ha) was obtained from control treatment (full irrigation) and the minimum tuber yield (17. 72 ton/ha) was obtained from irrigation disruption in the stage of tuber initiation, which caused about 50%reduction of potato yield. Therefore, the stage of tuber initiation is the most sensitive stage to the drought stress. As to irrigation disruption in two weeks after emergence, potato yield reduced about 8%. Therefore, an arid area with irrigation disruption at this stage of growth can store much water for the most sensitive stage of growth to the drought stress.

Drought stress is one of the most important limiting factors which can affect crop production in semi-arid regions. To investigate the effects of water stress on some of the morphological characteristics of fenugreek and to identify the best landraces, a factorial experiment was conducted in a completely randomized design with three replicates as potted in the Ferdowsi University of Mashhad in 2014. Experimental treatments were combination of eight fenugreek landraces of Isfahan, Tabriz, Hamedan, Sari, Challous, Amol, Mashhad and Yasooj with four levels of moisture stress (1-no stress (100% of field capacity), 2-mild stress (75% of field capacity), 3-moderate stress (50% field capacity) and 4-severe stress (25% field capacity). The results showed that the main effect of drought stress was significant for all traits studied. The comparison of means revealed that the number of days till flowering, till maturity, plant height, root length and yield components (number of pods per plant, seeds per pod and seed weight) in the highest level of drought compared to control decreased 45. 20, 9. 08, 14. 82, 32. 39, 29. 96, 27. 13, 4. 69, 30. 36 %, respectively. Comparison of landraces also showed that the highest performance belonged to the landraces of Challous and Mashhad. Following the results of the current study, these two landraces could be utilized for modifying landraces with high potential yield in context of water stress.