نشریه بوم شناسی گیاهان زراعی
سال دوازدهم شماره 3 (پیاپی 45، پاییز 1395)

ABSTRACT  To study the effect of defoliation stress and nitrogen on some quantitative and qualitative characteristics of filed pumpkin an experiment was conducted at Tarbiat Modares University Research Field of Agriculture Faculty. Three levels of defoliation including 0, 50 and 100% and three levels of plant nitrogen fertilizing including 50, 100 and 150 kg/h were studied in a randomized complete block design in three replications with factorial arrangement. Defoliation in the milky stage and of nitrogen fertilizers in two equal split applications were applied at two-leaf and flowering stages. Harvesting was carried out in mid of October. Fruit and grain weight, grain length, width and diameter, oil content, fatty acids linoleic, oleic, palmitic and stearic were evaluated. Grain morphological characteristics were influenced by nitrogen fertilization. Using of excessive nitrogen fertilizer had no positive effect on studied traits. The effect of defoliation stress on fruit and grain weight, grain width and diameter were highly significant (P ≤0.01). Under stress conditions, the highest percentages of linoleic, oleic, palmitic and stearic acid were achieved as 5.44, 3.28, 2.17 and 2.5%, respectively and also the minimum amount of those in complete defoliation were observed as 41, 24.9, 14.5, and 4.25%, respectively. On the whole, removal of photosynthesis unit by reducing production, production disruptions and assimilates allocation, was significantly reduced between different parts of the plant's production. increased levels of fertilizer did not increase yield. Nitrogen fertilizer in 50 kg/ha and no defoliation treatments have been recommended as the most suitable treatments for access to maximum seed yield.

Soil salinity is one of the abiotic stresses and a major problem to have a high yield in wheat. To awareness of relationship between agronomic traits and grain yield in salinity and to determine the traits affecting yield and tolerance to salinity, the Correlations coefficients of different traits and path analysis of grain yield in salinity conditions were investigated. 322 recombinant inbred lines of wheat derived from crosses Roshan and Falat with parents were evaluated in simple lattice design 18 x 18 with two replications. The Experiment was conducted in the 2013-14 crop season at a farm in Ekhteiar Abad in Kerman with EC = 12 ds/m. The simple correlation coefficient among grain yield and the most of evaluated traits had significant positive correlation. The total weight of spikes per plant had the highest positive correlation and significantly with yield. Stepwise multiple regression analysis method showed that the total weight of spikes per plant, harvest index, biological yield and Number of fertile tillers were the most effect on grain yield. Path analysis based on variables in the final stepwise regression analysis showed that biological yield and harvest index had high direct effect on grain yield. Line number 56 having a higher yield than the parents and the other lines was selected as the best genotype in studied conditions.

To determine the allelopathic potential of Ziziphora clinopodioides Lam. on seed germination and seedling growth of chickpea and soybean in laboratory condition, an experiment based on completely randomized design with four replications and six treatments was carried out including distilled water as control, aqueous extract concentrations of Z. clinopodioides by 2.5, 5, 7.5, 10 and 15% (w/v) at Complex Higher Education of Shirvan during 2014. Germination percentage and rate, seedling shoot and root length, dry weight of chickpea and soybean significantly affected by aqueous extract concentrations of Z. clinopodioides in 5% probability levels. Germination percentage and rate of chickpea and soybean significantly decreased by increasing extract concentration. The most inhibitive effect was observed in 15%, that germination percentage of chickpea and soybean decreased by 17.5 and 23.5%, respectively compared to control. Z. clinopodioides extract had more inhibitive on germination rate than germination percentage. Z. clinopodioides aqueous extract significantly delayed the germination of chickpea and soybean. With increasing concentration of aqueous extract of shoot and root inhibition was more impressed than chickpea and soybean. Shoot and root dry weight of soybean showed more reduction than seedling dry weight of chickpea. However, shoot and root dry weight of soybean seedling decreased by 82.2 and 67% respectively, compared to control, while shoot and root dry weight of chickpea seedling decreased by 60 and 53.2%, respectively. According to the inhibitory effect of Z. clinopodioiedes, on growth of chickpea and soybean in farms growing perennial herbs such as Z. clinopodioiedes is not recommended.

To evaluate seed production index of lambsquarters (Chenopodium album L.), leaf appearance rate and yield of fennel (Foeniculum vulgare L.) under inter-specific competition a factorial experiment was conducted in Islamic Azad University, Tabriz Branch, Iran during 2011-2012 growing season based on randomized complete blocks design with three replications. Factors included five weed densities 0, 2, 4, 6 and 8 plants per meter row and its relative emergence times of simultaneously sown 10, 20 and 30 days after fennel emergence. The 8th leaf in fennel appeared after 35.4 days. Time to appearance of the 12th leaf in weed densities of 0-4 plants per meter row was 50 days, while in higher weed densities it was delayed about 11.9 days. Fennel seed and essential oil yields increased with decreasing weed density and delay in its emergence time. Low density and late emergence of lambsquarters caused seed production index to decrease. In simultaneously sown treatments, seeds production index was 9.8% while, in treatments of 10, 20 and 30 days after fennel emergence it was decreased to 5.8, 3.6 and 3.8%, respectively. In this study, treatments with higher biomass production of lambsquarters resulted in greater weed seed production and lower seed yield in fennel, being important for lambsquarters management in fennel fields.

The current study was carried out to determine the most appropriate isolation distance in seed production cottom farms in two cropping years at Moghan agricultural Research Station. Cotton cv. Mehr as conventional cultivar in this region was cosidered as female parent cultivar or pollen receptive and Red leaf and Okra leaf cultivars were considered as male parent or pollinator. The marker genotypes were planted with distances of 80, 160, 240, 320, 400, 800, 1600 and 3040 cm from both side with mathernal parent. Seeds obtained from female parent cultivar were grown in the second year in factorial experiment with randomized complete block design in four replications and after growing in six-leaved stage the total number of plants and out-crossing plants were counted and percentage of outcrossing were calculated for different isolation distances. The out crossing percentage average in isolation different distances and their interactions in both markers showed significant difference. Out-crossing rate in 80cm isolation distance between female parent with Red leaf and red Okra leaf male parents were 11 and 4.5%, respectively. Totally  in both Red and red Okra leaf male parents in 80 cm of isolation distance maximum out-crossing happened but in 80 to 400cm distances it was reduced extremely and teneded to be zero. Results are showing low rate of out-crossing in cotton and giving good idea for researchers in hybrid seed producers to consider maximum 4 cm of isolation distance getting net and standard cotton seed.

One of the main goals of sustainable agriculture projects is poverty reduction, discrimination among different regions in the context of environmental protection. Land capability assessment is the first step in the process of sustainable development. Due to the physiological properties of saffron, its resistance to drought and high temperatures, its role in socio-economic status and considering the vast dry climate area in the country, this analytical study was conducted to determine the land capability for saffron cultivation. For this aim, in the form of fuzzy multi-criteria decision-making methods, Bonissone method was used to determine land capability in every land use. In this method, the required information layers were provided in ArcGIS software. Then the data was fuzzed using Chen and Huang method. Following the procedure fuzzy analysis was performed on data and finally fuzzy data were become to no fuzzy and estimation of potential land capability was conducted. The obtained results showed that that a total of 785 km2, 365 km2 (46.56%), 321 km2 (40.9%) and 98.4 km2 (12.54%) have suitable, average and relatively unsuitable ability for Saffron cultivation respectively. The results showed the efficiency of fuzzy logic to assessment land capability. The results of this study provide better planning to minimize the effects of the destruction caused by culture development projects and can create condition that provide balance among development and environment projects according to the priorities and zonation of land capability.

Broomrape is one of the most important parasitic higher plants imposing annually remarkable damages to crops. Finding a suitable management method to broomrape growth and damage depression had continuously been considered by investigators. In this research, the effect of pot intercropping of three bean varieties including kidney, wax and navy bean was investigated as a method to decrease of Egyptian broomrape damage. The experiment was carried out based on randomized complete block design with seven treatments including of each of bean varieties pots intercropping with and without host and broomrape. After two months, tomato height, dry weight and fruit weight and height and number of broomrape branches were measured. Intercropping of kidney and wax bean with tomato had the most effect on increasing of height, dry weight and fruit weight of tomato. Also, all bean varieties had the same effect on height and number of broomrape branches. Therefore, intercropping of bean with tomato has high potential in tomato growth improvement and broomrape damage decrement. Intercropping of beans with tomato is recommending managing broomrape.

Incurrent research, the aphidicidal effect of essential oils of rosemary, ajwain, yarrow, caraway and lavender on wheat common aphid (Schizaphis graminum) has been studied. Studied plants essential oils were extracted using hydro-distillation method and 2, 4, 6, 8, 10 and 12 per thousand concentrations of essential oils were prepared. Aphids collected from wheat and broomcorn Miyaneh farms, Iran transferred to cultured wheat plants in greenhouse condition. Essential oils concentrations were poured on 10 adult wingless aphids. The mortality percentage was calculated 2, 4, 6, 8, 10, 12 and 24 hours after treatment. Data were analyzed based on completely randomized design.  In concentration of 12 per thousand ajwan and yarrow had highest aphidicidal activity, while rosemary in 2 per thousand was more killer effect than others. Comparison of LC50 of studied plants essential oils after 24 hours showed that ajwain essential oils had more mortality effect on wheat common aphid than others. Alsso essenrial oils of yarrow, caraway and lavender had about same LC50 and rosemary was the weakest one. Essential oils of these plants could be considered as a natural pesticide for chemical pesticides replacement.