فصلنامه پژوهشهای زراعی در حاشیه کویر
سال نهم شماره 2 (تابستان 1391)

In order to investigate effects of different sowing dates and Cycocel application on yield and yield components of barley (Hordeum vulgar) cultivars, an experiment was carried out at split factorial in randomized completely block design with three replications at Mazandaran province in 2009-2010. Main factor was sowing dates in three levels including 7 and 26 November and 11 December and subfactor was three cultivar including Sahra, Prodactive and M12 and Cycocel rates in two levels including 0 and 2.8 litr cycocel ha-1 with factorial. Results showed the maximum andminimum of the fertile spikelet percentage per spike, spikelet per plant, grain yield (293.1 and 259.4 g.m2) and harvest index were obtained on 26 November and 11December, respectively. Sahra and M12 cultivar had to most and least of the spikeletper spike, fertile spikelet percentage per spike, spikelet per plant, grain yield (316.9 and 244.4 g.m2), biological yield (719.4 and 614.2 g.m2) and harvest index,respectively. With application of the cycocel, decreased of the plant height, but increased of the fertile tiller per plant, spikelet per spike, fertile spikelet percentage per spike, spikelet per plant, grain yield, biological yield and harvest index. Maximum and minimum of the spikelet per spike, fertile spikelet percentage per spike, spikelet per plant, grain yield and harvest index were obtained in interaction of the 26 November × sahra cultivar and 11 December × M12 cultivar. Therefore planting date of the 26 November, sahra cultivar and application of the 2.8 litr cycocel ha-1 because of the most of increased the yield components and due to grain yield and harvest index introduced the best of treatment.

Wheat is threatened by the devastating epidemics of yellow rust all over the world. A severe epidemic of yellow rust occurred on wheat in northwest and west of Iran during 2009-2010 cropping season. To study the effect of yellow rust on yield of Sardari, a wheat cultivar grown widely in dryland areas of Iran and to assess the effects of fungicides application on control of disease and yield reduction, an investigation was performed in 214 farmers field with 5150 hectares in a hot spot area of Mianeh, East, Azarbaijan. Two fungicides, Propiconazole and Tebuconazole at different growth stages of wheat were sprayed using three application methods. Disease severity was recorded at the end of growth period and grain yield and percentage of yield reduction were assessed after harvest. The results of analysis of variance for data showed significant differences for time of spry, method of sprying, grain yield and percentage of yield reduction. Average yields of Sardari cultivar in sprayed and non- sprayed fields were 2033 and 885 kgha-1, respectively, indicating 1148 kgha-1 yield reduction by the disease. Early spray of fungicides increased grain yield significantly compared to late sprying. Disease severity in early sprayed fields was 10-20% while in late sprayed or non- sprayed fields disease severity rised upto80-100%. Tebuconazole controlled disease better than propiconazole in many fields. Effects of yellow rust were different on yield of eight wheat advanced lines and two check cultivars Sardari and Azar2. The highest grain yield (3812 kgha-1) was produced by line CIMMYT 82-126 which was resistant to yellow rust. Mean grain yields of Sardari and Azar2 cultivars were 1490 and 2419 kgha-1 respectively. In general, the results of the present study showed that in epidemic years, yellow rust can reduce 55-65% grain yield of Sardari cultivar, but chemical control through on time application of fungicides can decrease disease severity and increase grain yield.

This research was performed with the aim of comparing the impact of Calcium element on the yield of grain, oil, protein and quantity of grain calcium in maize under the condition of low irrigation stress. The experiment was conducted in a field located in Varamin belt in the form of split plot design with random blocks in three replications in 2009. The results showed that highest yield was obtained from control irrigation and sprayed 8 percent Calcium concentration with 14467.1 kg per hectare was the ratio of irrigation treatment and control 88.7 percent showed superiority. the highest percentage of oil and protein were obtained under mutual impacts of irrigation and calcium treatments. the highest and lowest levels of oil were obtained respectively from common irrigation treatment and spraying calcium with 8% concentration respectively by 7.1% and treatment of stopping irrigation in the step of 7-9 leaves up to leaf convolution and control with 4.81%; but stopping the irrigation in step of 7-9 leaves up to leaf convolution and spraying calcium with 8% concentration could deliver the highest percentage of protein with 9.43T and the lowest percentage of protein obtained from common irrigation treatment and control with 8.83%. The findings indicated that the percentages of oil and protein have inverse relationship with each other and an increase in one of them would result in decreasing the other.

In order to investigate the effect of zeolite on oil quality of rapeseed (Brassica napus L.) cultivars in drought stress condition, an experiment was carried out in research farm of Seed and Plant Improvement Institute in 2009 in Karaj-Iran. The experiment was conducted as Randomized Complete Block Design with Factorial split-plot arrangement in three replications. Irrigation factor was chosen at two levels, included complete irrigation and irrigation holding at stem elongation stage. Zeolite was used at two levels, non application and 10 ton per hectare. These treatments were randomized in main plots while, three canola cultivar (Zarfam, Sarigol and Okapi) were randomized in sub plots. Palmitic, stearic and arachidic acids (saturated fatty acids) and palmitoleic, alaidic and linoleic acids (unsaturated fatty acids) were measured. Results showed that drought stress conditions decreased severely fatty acids, but application of zeolite in drought stress increased water holding capacity of soil, resulte in increasing of unsaturated fatty acids and oil quality in rapeseed. Based on the results of present study, due to increasing oil quality and decreasing plant water requirement, application of zeolite is economically recommendable.

To study theeffects of water stress, zeolite and salicylic acid application on oil quantity and quality of safflower, an experiment was performed as split factorial based on randomized complete block designe with four replications in experimental farm of Islamic Azad University, Arak, Iran in 2010. Three levels of water stress, I0: normal irrigation (control), I1: irrigation of 85% water requirement of plant, and I2: irrigation of 70% water requirement of plant were considered as main plots and three levels of zeolite consumption, Z0: no zeolite, Z1: 4 t ha-1 zeolite, Z2: 8 t ha-1zeolite and two levels of salicylic acid consumption, SA0: no salicylic acid and SA1: sprayof 300 ppm salicylic acid were considered as sub plots.The results showed that the effects of different levels of water stress on traits such as plant height, first branch height, branch number, oil percentage, oleic acid, linoleic acid and oil yield were significantat 1% probability level. Effects of zeolite consumption levels on first branch height, branch number, oil percentage, oleic acid, linoleic acid and oil yield were also significant at 1% probability level. Consumption of salicylic acid showed significant effects on oil percentage, oleic acid, linoleic acid and oil yield (p<0.01), but its effect on first branch height and branch number was not significant. None of water stress, zeolite and salicylic acid treatments had significant effect on harvest index.

To study the effects of Nitroxin, levels of nitrogen and animal manure on grain and biological yield and nitrogen of sweet corn cultivar Chase, an experiment was conducted in Research Farm of Islamic Azad University of Arak, in 2010 using a factorial experimental design based on randomized complete block with three replications. The studied factors included two levels of Nitroxin (inoculated and noninoculatedseeds), three levels of nitrogen(0, 50 and 100 kgha-1) and three levels of animal manure (10, 20 and 30 tha-1). The results showed that Nitroxin affected ear weight, number of ear per bush, number of grain per bush, length of non-inoculated part, grain yield per ear and biological yield. Animal manure also affectect ear weight, length of non- inoculated part, ear harvest index, grain yield per ear and biological yield, so that decreased the length of non- inoculated part and increased other characteristics. Effect of nitrogen on length of non- inoculated part, ear harvest index, biological yield and nitrogen content of plant was significant. The highest grain yield per ear (52.92g) was obtained in treatment of inoculation of seed with Nitroxin, 20 tha-1 of animal manure and 50 kg ha-1 of nitrogen application. In addition to reduction of chemical fertilizer, consumption, jointly application of chemical fertilizer, animal manure and biologic fertilizer caused a considerable increase in grain yield of sweet corn.

In order to determine the best planting pattern and optimum plant density of rapeseed, an experiment was carried out in two years 2006 and 2007 at Agricultural Research Station of Varamin. The experiment was a split-plot design on randomized complete block basis with four replications. The main plots included four planting methods (one row on furrow with 60 cm width, two rows on furrow with 60 cm width, two rows on furrow with 50 cm width and one row on furrow with 50 cm width) and the sub plots included three seed rates (6, 8 and 10 kg/ha-1). The results of combined analysis showed that effect of planting pattern was significant on characteristic such as day to flowering, number of pod per plant, number of seed per pod, duration of flowering and oil percent and the effect of seed rates was significant on plant height, 1000 seed weight and seed yield. The effect of interaction between planting pattern and seed rates was significant on day to germination, day to maturity, number of pod per plant and 1000 seed weight. The results of mean comparison analysis indicated that planting method of one row on furrow with 60 cm width produced the highest day to flowering terminate, number of pod per plant, number of seed per pod, duration of flowering and oil percent. Application of 6kgha-1 seed rate produced the highest 1000 seed weight and seed yield. Generally, the resulte of this experiment showed that the highest valuse of most characteristic were obtained from application of 6kgha-1 seed rate and planting method of one row on furrow with 60 cm width.

This study was carried out in order to investigate the chromosomal behavior duringmeiosis, morphological assessments and fibers quantitative and quality traits in herbaceum (Iranian endemic), arboreum, F1 hybrids of two species and Bc4 genotypes. Since the arboreum species used in this study had good fiber quality, so in order to improve the fiber quality of endemic cotton, hybridization between twospecies which followed by several back crossing with endemic cultivars was performed in Cotton Research Department of Varamin, Iran. The endemic cultivars were Garmsar and Qum red-boll (herbaceum) and VTDL (arboreum). Regarding morphological characters, the F1s traits were intermediate and Bc4 showed intermediated and more resembled to endemic parents traits. Cytological investigation showed that in F1s the adjacent and alternative quadrivalents were frequently occurred. In population of Bc4 offspring the quadrivalents were appeared in low frequency. Besides, other abnormalities like univalent, trivalents and triple sets of chromosomes in MII and AII were found which resulted in deviation from Tetrads. The fiber quantitative and quality traits investigation results showed that the hybrid Garmsar x arboreum had fibers with 26.7 millimeter length which caused by transferring the genes from arboreum parents to endemic cotton cultivar.