نشریه بوم شناسی گیاهان زراعی
سال نهم شماره 2 (پیاپی 31، تابستان 1392)

In order to evaluate the effects of foliar application of manganese, zinc and boron on grain quality and quantity characteristics of dryland wheat, a split-split plot experiment was conducted based on a randomized complete block design with three replications. Experiment was carried out in Dryland Agricultural Research Station in Maragheh region, northwest Iran during 2008-2009. Wheat cultivars (Azar2 and Homa) were planted in main plots. Foliar application time in three stages of tillering (GS32), stem elongation (GS37) and flag leaf emerging (GS64) and foliar application of micronutrients (control, pure water, 35g.ha-1 manganese sulfate, 25 g.ha-1 zinc sulfate and 15 g.ha-1 boric acid) were also allocated to subplots and sub subplots, respectively. Results showed that foliar application of microelements significantly affected grain yield, spike number per area unit, dry weight and fresh weight of flag leaf and harvest index. According to the results, application of 35 g.ha-1 manganese sulfate and 25 g.ha-1 zinc sulfates had non significant effect on grain yield. \ Application of 15 g.ha-1 boric acid resulted in the highest yield (1418 kg. ha-1), dry weight and fresh weight of flag leaf. The highest number of spikes per m2 was observed with application of 35 g.ha-1 manganese sulfate. According to these results, tillering stage (GS32) was the best stage for foliar application of micronutrients that produced the highest yield (1630 g.ha-1). Azar2 was better cultivar and produced 32 and 36 percent higer biological and grain yield in comparison to Homa cultivar, respectively.

In order to evaluate the relationship between some morphological and physiological traits of basil (Ocimum basilicum L.)
under effect of super nitro plus and bio super phosphate, an experiment was conducted as a complete randomized design with three replications in Damavand region, north Iran in 2011. Treatments were super nitro plus 2 lit.ha-1, bio super phosphate 4 lit.ha-1, super nitro plus 2 lit.ha-1 + bio super phosphate 4 lit.ha-1 and control (no fertilizer). Characteristics like chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, plant height, root length, shoot diameter, leaf fresh weight, shoot fresh weight, root fresh weight, leaf dry weight, shoot dry weight, root dry weight, dry weight of vegetative parts, fresh weight of vegetative parts
and leaf area were measured. According to the results, fresh weight of vegetative parts had a positive significant correlation with plant height, shoot diameter, leaf fresh and dry weight and shoot fresh and dry weight. The results of stepwise regression analysis showed that leaf fresh weight, shoot fresh weight and chlorophyll a had positive effect on fresh weight of vegetative parts. Also based on the results of path analysis, leaf fresh weight had the greatest direct positive effect on the fresh weight of vegetative parts. Also there were indirect positive effect and plant height, shoot diameter and shoot fresh weight had a positive effect on fresh weight of vegetative parts through leaf fresh weight. Chlorophyll a had a negative effect on fresh weight of vegetative parts through leaf fresh weight. In conclusion, application of bio-fertilizers was useful for vegetative growth of basil and traits of leaf fresh weight, shoot fresh weight, plant height, shoot diameter and chlorophyll a could be recommended for breeding programms.

Fungal soilborne pathogens of tobacco are important phytopathogens distributed worldwide and can cause yield losses in tobacco growing countries. The managment of fungal soilborne pathogens are accomplished using chemical pesticides, crop rotation, resistant varieties, biological control, plant extracts and oils, etc. Application of plant extracts is preferable for management of this disease because chemical pesticides are expensive and pollute the environment. In order to evaluate in vitro inhibitory effects of some medicinal plant extracts on growth of Sclerotinia sclerotiorum, the causal agent of tobacco collar rot, and selection a suitable extract solvent, an experiment was carried out as factorial based on a completely randomized design with five replications in Tirtash Research and Education Center laboratory in 2012. Factors were crude extracts at nine levels (extracts of nine plant species), solvent at five levels (water, acetone, hexzan, ethanol and methanol) and cocentration at three levels (0, 1000 and 2000 ppm). The minimum inhibitory concentration of each extract was determined by agar diffusion method. Results indicated remarkable antifungal activity of crude extracts of tobacco, catmint, thyme, fennel, hyssop and badrashbi on Sclerotinia sclerotiorum. Methanol was the best solvent to extract antifungal compounds. Minimum inhibitory concentration of methanol extract of tobacco, catmint, thyme, fennel, badrashbi and hyssop were equal to 1.5, 1.5, 2, 3, 3, and 2.5 mg.ml-1, respectively.

Barley (Hordeum vulgare L.) with wide dispersion and adaptation can be planted in arid unsuitable areas for planting wheat and produces considerable yield. Selecting suitable planting date is an effective factor on yield from phonological point of view because plant does not meet undesirable conditions at all its developmental stages. Regarding to the importance of planting date in obtain maximum yield, the effect of seven different planting dates (24 Nov., 6, 18, 30 Dec., 15, 23 Jan. and 6 Feb.) was evaluated on two barley cultivars (Yousef and Sahra). Experiment was carried out as split plot based on a randomized complete block design. Spike weight, number of spikes per plant, plant height, number of seeds per spike, seed weight per spike, spike length, economic yield, awn length, seed thousand weight, peduncle length and peduncle weight were measured. Based on the results, the effect of planting date was significant on all the studied trait, except for plant height and peduncle length. Results showed that 24 Nov. and 6 Dec. were the best planting dates for barley planting. Also result of regression analysis showed that spike number per m2, peduncle weight, 1000 seed weight and peduncle length had the most effect on seed yield.

In order to investigate the effect of salicylic acid on growth parameters (shoot and root fresh weight) and some biochemical markers including proline, soluble protein and malondialdehyde levels in wheat seedlings under salt stress, a factorial experiment based on a completely randomized design was conducted with
three replications. Factors were salinity at three levels (0, 75 and 150 mM. NaCl) and salicylic acid at three levels (0, 200 and 400 mg.l-1). Eight days after planting and in complete bifoliolate stage, salt stress treatments were applied. Concentration of 75 mM NaCl was applied by concentrations of 25 and 50mM during two times with seven days interval. NaCl 150 mM was also applied by concentrations of 25, 50, 25 and 50 mM during four times with seven days interval. Seven days after exerting the salt stress, leaves were sprayed by concentrations of 0, 200 and 400 mg.l-1 salicylic acid, with three replications, during two times with six days interval. Based on the results, the amount of protein, shoot and root fresh weight reduced with salinity increasing, but proline and malondialdehyde amounts increased. Exogenous salicylic acid application increased
protein, shoot and root fresh weight contents, but reduced proline and malondialdehyde in presence of salinity. However, exogenous salicylic acid application in normal condition stress have not any effect on proline and malondialdehyde contents.

Soil quality assessment is necessary for identifying the effects of different management systems on agriculture and natural resources including rang and forest degradation. Such studies can be useful for identifying sustainable practices in each region with intention of preventing land degradation, providing sustainable crop production and environmental protection. Land use changes play an important role in global change phenomena. Nowadays changing forests and pastures to agricultural land use are a worldwide problem that results in environment degradation and global climate change. This study was conducted to determine some soil properties due to land use changing in Miyaneh region, northwest Iran. The studied properties were soil texture, soil organic carbon, soil pH and soil calcium carbonate in three land use types of pasture, dry farming and irrigated wheat. The results showed that soil texture in top soil changed from silt clay loam in pasture to sandy loam and silt loam in cultivated lands. The values for soil organic carbon were highest in pasture (1.2%) and decreased to 0.9% and 0.5% in dry farming and cultivated land use, respectively. pH values in dry farming soils (7.6) were lower than those of the cultivated soils (7.9). However, soil calcium carbonate percentage was the highest in cultivated (22%) and lowest in pasture (8%). In conclusion, results showed adverse effects of land use change on soil quality.

The current study projective was conservation tillage application necessities study from Jihad-e-Agriculture Agency of Miyaneh county experts’ point of view. Statistical community of the study was 150 agriculture specialists of Miyaneh Jihad -e-Agriculture Agency. Prepared questionnaire forms as research tools were filled in by interview. Questionnaire validity and reliability were confirmed by specialists’stand point and Cronbach's alpha coefficient using SPSS ver. 16 in range of 76.7-91.4%, respectively. R factor analysis method was used for data analysis. The results indicated that research variants including six factors of governmental financial grants, villager's cooperation, religious and believes motivations, mechanization, legislation, agricultural extension and education by media justified about 58.65% of variance of conservative tillage application necessities from Jihad -e-Agriculture Agency of Miyaneh county experts’ point of view. Governmental financial grants factor with Eigen value of 6.89 had the highest ratio in variants expression. Also, villager's cooperation with Eigen value of 4.36, religious and believes motivations with Eigen value of 4.20, agriculture machinery development with Eigen value of 3.88, legislation with Eigen value of 2.30, agricultural extension and media education with Eigen value of 1.83 took the next positions. The current research results can be useful and effective in the future planning of agriculture authorities and beneficiary organization.

In order to investigate diversity between some rice genotypes in cold stress condition, 2 genotypes including 11 native genotypes and 11 foreign genotypes were evaluated. Experiment was carried out as split plot based on a completely randomized design with three replications. The genotypes were evaluated in normal and cold stress (10° C) conditions in an incubator. For evaluating phenotypic variation in rice genotypes, root length, shoot length and root and shoot weight were measured. Result showed the significant differences of the studied traits in cold stress condition. Besides, interaction effect of genotype and cold stress condition was significant for all the studied traits. Correlation coefficients between seedlings traits in normal and stress conditions and sensitivity and tolerance indices were high and significant. Cluster analysis based on seedling traits in cold stress condition grouped the genotypes into three groups that susceptible and tolerant genotype were separated from each other. Cluster analysis based on stress tolerant indices for morphological characteristics also separated sensitive and tolerant genotypes from each other. Significant differences between genotypes demonstrated genetic variation for evaluated traits at seedling stage of rice in cold stress condition.