مجله دانش زراعت
پیاپی 9 (1392)

To evaluate the advantage of chickpea-barley intercropping systems under weed interference conditions، an experiment was conducted at the Agricultural Research Station، Faculty of Agriculture، University of Bu-Ali Sina، during 2010 growing season. Experiment was conducted as split plot base on randomized complete block design with three replications. Weed control treatment at two levels of weed free (WF) and weed infested (WI) as main factor and nine different planting patterns including pure stand of chickpea (PP1)، pure stand of barley (PP2)، additive intercropping of 25 (PP3)، 50 (PP4)، 75 (PP5) and 100% of barley (PP6) with chickpea، and replacement intercropping of 25 (PP7)، 50 (PP8) and 75% of barley (PP9) with chickpea were considered as sub-plots. Intercropping systems were evaluated by using indices of land equivalent ratio (LER)، total relative yield (RYT)، aggressively index (AI)، competition index (CI) and relative crowding coefficient (RCC). Results showed that in all intercropping treatments LER was more than one. Maximum value of LER (2. 40) was achieved at WI × PP6 treatment. Also، CI at the treatments of intercropping was less than one 1. Minimum (0. 01) and maximum (0. 99) values of CI were achieved at WI × PP8 and WF × PP3 treatments، respectively. Based on aggressively index، barley plant was aggressive than chickpea. In general، under both weed control and weed interference conditions، barley and chickpea intercropping systems were better than sole cropping of each of them

Drought stress in germination stage is one of most important factor that limit yield and growth of lentil in Iran. The heterotrophic seedling growth can be considered as the product of three components: initial seed weight، the fraction of seed reserves which are mobilized، and the conversion efficiency of mobilized seed reserves to seedling tissues. In order to investigate the effect of drought stress on percentage and rate of germination and seedling growth components، a factorial experiment was conducted based on randomized completely design (RCD) with three replications. The experimental factors were included three lentil cultivars (Robat، Kimia، Gachsaran) and five levels of drought stress (0، -3، -6، -9، -12 bar of polyethylene glycol 6000). The results showed that with increasing drought stress، percentage and rate of germination percentage was decreased to zero in the osmotic potential of -12 bar. Although significant difference was not observed in germination percentage in drought stress levels between different cultivars، but difference in germination rate was significant. The rank of cultivars was Robat> Gachsaran> Kimia in germination rate. The inverse linear relationship was made between drought stress levels and seedling growth components. More seed reserve depletion in Robat and Gachsaran lead to more seedling dry weight of two cultivars in compare to Kimia cultivar that had more conversion efficiency. Thus efforts to improve germination and seedling growth in lentil breeding programs should focus on improvement of component of mobilized seed reserves.

The aim of this research was to investigate the root colonization percentage of grain sorghum cultivars by two species of mycorrhizal fungi and its effect on some of morphological and agronomic traits. Experiment was laid out as factorial based on randomized complete block design with three replications. Experimental treatments included three levels of fungi (F1: control without inoculation، F2: inoculation with Glomus mossea and F3: inoculation with G. intraradices) and three sorghum cultivars (V1: Payam، V2: Kimia and V3: Sepideh). Traits of root dry weight، root colonization percentage، plant height، panicle length، panicle diameter، stem diameter and flag leaf area were evaluated. The ANOVA results showed that mycorrhizal fungi and cultivar had significant effects on all traits. The effect of fungi × cultivar interaction was also significant for all traits except plant height، panicle length and flag leaf area. Based on means comparison، maximum values of evaluated traits were belonged to Kimia cultivar. Also، between fungi treatments، the highest values of flag leaf area and plant height were revealed at G. mossea، so that in this species in compawither to control treatment (without inoculation)، flag leaf area and plant height traits wered increased by 7. 53 and 9. 74 percent، respectively. Means comparison of fungi × cultivar interaction for root dry weight indicated that maximum value of this trait (20. 7 g plant-1) achieved at V3F3 treatment. In this treatment in comparison to V1F1 treatment root dry weight was increased by 40. 5 percent. In general، it seems that application of mycorrhiza by increasing nutrient uptake، can improve morphological and agronomic characteristics of sorghum.

In order to investigate genetic diversity and heritability of some morphological traits in five bread wheat (Triticum aestivum L.) cultivars، two separate experiments were conducted based on randomized compeletly blocks design (RCBD) with 3 replications under stress and normal conditions. The results showed that differences between cultivars were significant for the majority of traits in both conditions، that this indicated a high diversity among the cultivars for the above-mentioned traits. The mean compression results showed that tolerant cultivar of Pishgam had the most root length and root dry weight in both conditions. Phenotypic correlation indicated that root length had significant correlation with root fresh weight under normal condition and it showed a positive and significant correlation with leaf length، root number، root fresh weight and root dry weight under stress condition. Stepwise regression showed that، root dry weight، root number and above ground fresh weight to root fresh weight ratio were the main effective traits on root length under stress condition. Furthermore، above ground dry weight to root dry weight ratio and flag leaf area traits had the maximum and the minimum genetic diversity under stress condition، respectively. In addition، root dry weight and root dry weight to root fresh weight ratio traits had the maximum and the minimum heritability، respectively.

To evaluate the effect of soil salinity stress on some vegetative and reproductive traits of sunflower (Helianthus annus L.) oil varieties in Mahabad conditions، a factorial experiment was conducted in greenhouse condition based on randomized complete block design with five replications in 2009. Treatments were included five levels of soil salinity (EC: 0. 5 (as control)، 2، 4، 6 and 8 ds /m) and 4 cultivars (Zarya، Armavirisky، Master and Record). Results showed the significant effect of soil salinity and cultivars on stem diameter، leaf chlorophyll، number of leaflets around the head and grain/shell ratio was significant. Interactions between soil salinity and cultivars was also significant on 1000 seed weight، oil percentage and oil yield per plant. Means comparison showed that with increasing soil salinity، trends of all traits was decreased، except 0 grain/shell ratio. The highest stem diameter was observed at control treatment (1. 14 cm) and Armavirisky cultivar (1. 15 cm)، the highest leaf chlorophyll was obtained from 8 ds/m of soil salinity (1. 29) and in Armavirisky and Zarya cultivars (1. 17)، the highest number of leaflets around the head was observed at control treatment (7. 18) and in Record cultivar (7. 76) and the highest grain/shell ratio was obtained from 8 ds/m of soil salinity (47%) and in Master cultivar (42%). In addition، the 1000 seed weight (36. 91 g) was belonged to the control soil (EC: 0. 5 ds/m) and Armavirisky cultivar. The highest oil percentage (48. 47 %) and the highest oil yield per plant (1. 43 g) were belonged to the control soil and Armavirisky cultivar. In general results showed that Armavirisky and Record cultivars having the highest 1000 seed weight، oil content and oil yield in the salinity conditions were better than Zarya and Master.

In order to investigate the effects of plant density، time and number of weed control on yield and yield components on corn hybrids، a factorial experiment in completely randomized blocks design with 3 replications was conducted in 2011 growth season at Research farm of College of Agriculture، University of Shahid Bahonar، Kerman. Weed control treatments were including: weed control during corn growth season (W1)، weed control in 2، 4 and 8 weeks after planting (W2)، weed control in 4 and 8 weeks after planting (W3)، no weed control during corn growth season (W4). Corn varieties were Single cross 704 (C1) and Maxima from FAO580 (C2) that were planted in two densities of 70. 000 (D1) and 90. 000 plants per hectare (D2). The results showed that corn weed competition caused a significant decrease in W4 treatment. Grain yield increased with increasing density، but the number of grains per ear، 100-grain weight، ear length and shoot dry weight were reduced. Maxima variety showed increase in grain yield، 100 seed weight، number of ears per plant and ear length compared to single cross 704. Results of this survey indicated that weed control in two stages after planting stage was suitable to achieve favorable results in Kerman environmental condition.

In order to evaluate the effect of terminal moisture stress on 20 barley promising lines (Hordeum vulgare) and for determination of their relative tolerance، an experiment was conducted based on randomized complete blocks design with three replications in growing season of 2010-2011. In this research some old indices such as، stress susceptibility index (SSI)، tolerance index (TOL)، mean product (MP)، geometric mean product (GMP)، stress tolerance index (STI)، relative drought index (RDI) and two new indices namely، stress susceptibility percentage index (SSPI) and stress non-stress productivity index (SNPI) were used. The lines differences were significant for yield under both non-stress and stress conditions. The results also showed that the indices of MP، GMP، STI and SNPI were significantly correlated to Yp and Ys. Therefore، the above-mentioned indices are the best ones for selection of lines with high yield under non- stress and moisture stress conditions. The results of principal component analysis indicated that the lines number of 10، 4 and 6 were the most resistant lines and the lines number of 13، 16 and 17 were the most sensitive lines. In addition، bi-plot results indicated that MP، GMP، STI and SNPI indices had the most alignment with the yield of lines under stress conditions (Ys). Therefore، theses indices are the best ones for resistant lines with high yield under moisture stress conditions. In cluster analysis، examined lines were generally grouped in two clusters، so that susceptible and relatively susceptible lines underwent in the first cluster and resistant and relatively resistant lines underwent in the second cluster. Finally، SNPI، STI، GMP and MP indices were the best ones and the line of number 10، 4 and 6 were the most resistant lines، respectively.

Genetic diversity of 13 new cereals، primary tritipyrum lines، five triticale lines and nine Iranian bread wheat varieties was studied under the randomized completely blocks design in terms of agronomic and morphological traits. The highley significant difference was observed between genotypes for all traits except in the filamental leaf length، main leaf length and main leaf width. The highest coefficients of phenotypic and genotypic diversity were belonged to awn length، grain yield، harvest index، spicke weight mean traits، respectively. The positive and significant phenotypic and genotypic correlation between harvest index، 1000-grain weight، grain number per spike and spiklet number per spike traits with grain yield can be used in breeding programs of bread wheat and tritipyrum. Factor analysis with varimax rotation extracted 6 factors which described almost 87 percent of total variance. Cluster analysis by Ward method established all genotypes in four groups.