فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 23 (پاییز 1391)

This study was conducted to determine the application of biofertilizers¡ instead of chemical fertilizer¡ for optimal cowpea nutrition. It was performed in a factorial experiment based on Randomized Complete Block Design with three replications at Agricultural Research Center of West Azarbaijan¡ Iran during growing season of 2008-2009. Experimental treatments consisted of 4 rates of biofertilizers (without fertilizer ¡ Yashil chemical fertilizer¡ Nitragine biofertilizer¡ Yashil㘫歪ࢧ) as factor A and 4 rates of nitrogenous chemical fertilizer( 0¡ 26.25¡ 52.5 and 75 kg/ha urea) as factor B. Analysis of the results showed that there were significant differences between rates of factor A (Nitragin biofertilizers Yashil chemical fertilizer) and rates of chemical fertilizers and interaction between different levels of factor(A and B) for grain yield¡ number of grain per pod¡ number of grain per plant¡ number of pod per plant¡ 1000- grain weight and harvest index at 5% level of probability. It was also revealed that the effect of Yashil㘫歪ࢧ treatment was highly positive. The results showed that application 52.5 kg/ha urea highly increased on traits. The results obtained from interaction of different levels of factor AÍB indicated that application of 52.5 kg/ha urea and Yashil Nitragin combination had the highest effects on all traits. With regard to this results¡ it can be said that application of biofertilizers with chemical fertilizers had maximum increase in all traits under study.

This study was conducted to determine the application of biofertilizers, instead of chemical fertilizer, for optimal cowpea nutrition. It was performed in a factorial experiment based on Randomized Complete Block Design with three replications at Agricultural Research Center of West Azarbaijan, Iran during growing season of 2008-2009. Experimental treatments consisted of 4 rates of biofertilizers (without fertilizer , Yashil chemical fertilizer, Nitragine biofertilizer, Yashil㘫歪ࢧ) as factor A and 4 rates of nitrogenous chemical fertilizer( 0, 26.25, 52.5 and 75 kg/ha urea) as factor B. Analysis of the results showed that there were significant differences between rates of factor A (Nitragin biofertilizers Yashil chemical fertilizer) and rates of chemical fertilizers and interaction between different levels of factor(A and B) for grain yield, number of grain per pod, number of grain per plant, number of pod per plant, 1000- grain weight and harvest index at 5% level of probability. It was also revealed that the effect of Yashil㘫歪ࢧ treatment was highly positive. The results showed that application 52.5 kg/ha urea highly increased on traits. The results obtained from interaction of different levels of factor AÍB indicated that application of 52.5 kg/ha urea and Yashil Nitragin combination had the highest effects on all traits. With regard to this results, it can be said that application of biofertilizers with chemical fertilizers had maximum increase in all traits under study.

To evaluate the influence of vesicular arbuscular mycorrhizal (VAM) on yield and yield components of three sorghum cultivars, a factorial experiment based randomized complete block design with four replications was carried out in 2007, at the Agricultural Research Center of Zahak, Iran. The treatments were different mycorrhiza species in three levels: without mycorrhiza (M1), Glomus etanicatum (M2) and G. mosseae(M3) and three cultivars of sorghum: local cultivars (C1), KGS25 (C2) and KGS29 (C3). The results showed that all of the traits measured were increased by inoculation of cultivars with mycorrhiza. The highest plant height (165.1 cm), stem diameter (1.61 cm), flag leaf length (27.22 cm), flag leaf width (3.67 cm) and ear width (5.00 cm) was obtained by inoculation of seed with Glumus etanicatum, and highest ear length (19.21 cm), ear number (2.51), seed number per ear (10252.11), 1000-seed weight (17.56 g) and grain yield (1967.32 kg/ha) by using Glumus mossea. The highest leaf width and length belonged to local cultivar, and the highest seed yield to KGS 29 cultivar. However, differences of other traits among sorghum cultivars were not significant. Based on the experimental results it can be concluded that highest grain yield may be obtained by inoculating seeds of KGS 29 with Glumus mossea.

To study the effects of different levels of irrigation cuttings and plant densities on yield , and yield components of corn (SC 704), an split plot experiment based randomized complete block design, with three replication was conducted in Damghan, Iran. Main plots were 4 cuttings of irrigation: (jointing, tasseling, milking and seed hardening stages) and sub plots consisted of four plant density: 45000, 60000, 75000 and 90000 plants per hectare). Result showed that corn tolerated the last of irrigation cutting as corn pared to its cutting at other stages and has increased yield. Cutting of irrigation at seed hardening stage, increased number of seeds per ear row, number of rows per ear, and 100 kernel weight. While when plant density increased seed yield, number of seeds per row, number of rows on ear, and 100 kernel weight decrease.

In order to study grain yield and yield components of 16 advanced wheat lines under rainfed and supplementary irrigation conditions, this research was conducted in randomized block design with 3 replications at Maragheh Research Station during 2008-09 seasons. Analysis of variance revealed significant differences for date to heading, plant height, 1000 kernel weight, tiller number, spike length, seed number per spike, spikelet number per spike, peduncle length, harvest index, leaf, sheath length and grain yield. Results also showed that the lines No. 4 (91-142 a 61/3/F35.70/MO73//1D13.1/MLT) and 16 (Azar2) with 1895 and 1878 Kg/ha, lines No. 4 and 7 (YUMAI13/5/NAI60/3/14.53/ODIN//CI13441) with 2132 and 2285 Kg/ha had highest grain yield under rainfed and supplementary irrigated conditions respectively. Based on results these 16 lines and cultivars were grouped in 4 and 3 distinct classes using Ward’s Method of cluster analysis under rainfed and irrigated conditions. Path analysis indicated that vigor at shooting stage, seed number per spike and HI were positive important traits to select lines for high yielding potential in this study. HI and TKW had also positive effects on grain under supplementary irrigation.

Due to the large diversity of weeds in irrigated and rain fed wheat fields in East Azerbaijan province, Determining dominant specific weeds and prepare their distribution map, wheat fields were survey based on identical approach. During 9 years (from 2000 to 2009), in 231 wheat fields based on their sizes from 19 counties were selected and abundance of weed species were studied. The results showed that there were more than 112 and 137 species of weeds in irrigated and rain fed field belonging to 101 genera of 28 families. The most important dominant broad leaf weeds in rain fed and irrigated fields were: Galium tricornatum, Chenopodium album, Descurania Sophia, Polygonium aviculare, Geranium tuberosum, Goldbachia laevigata. Grass leaves weeds are Eremopyrum bonaepartis, Alopecurus myosuroides, Bromus tectorum. In addition weed genuses like Acroptilon repens, convolvulus arvensis, Salsola kali, cardaria draba, Lactuca serriola, arethemost prevalent weeds at harvesting time in the wheat fields of province. The results also showed that controlling measures of weeds in wheat fields of province is not satisfactory and their management methods prior to harvesting are even worse.

To evaluate tolerance of rapeseed cultivars under drought stress conditions, a split plot experiment based on RCBD with four replications was carried out for two years at Karaj, Iran. In this experiment, the effects of irrigation treatments in two levels as main plot such as normal irrigation and cutting irrigation from silique formation till end of growth and on varieties as sub plots in 12 levels including of Licord, Okapi, SLM 046, RGS 003, Hyola420, Option500, Zarfam, Orient, Opera, Talaye, Sarigol and Hyola401 were studied. The results showed that drought stress decreased plant height, branch per plant, siliques per plant, grains per siliques, 1000 seed weight and seed content; while it increased harvest index. Drought effect on seed oil percentage was not significant. Experimental results indicated that there is significant variation in all evaluated traits. SLM 046 and Zarfam produced highest yields under normal irrigation (3771 kg/ha and 3727 kg/ha) respectively and under drought stress condition (2705 and 2663 kg/ha) respectively. Also named cultivars in two irrigation treatments had the highest oil yield. Therefore, Zarfam and SLM046 can be reported as varieties with stable yields under both normal irrigation and stress conditions at silique stage of rapeseed varieties studied.

This experiment was conducted to study the effects of water deficit stress on yield and yield components of four corn hybrids. The experiment was laid out in split plot using randomized complete block design with three replications. This experiment was carried out at east Azarbayjan Agriculture and Natural Resources Research Center in 2008. Treatments consisted of four irrigation levels (without stress, water stress at 6-7 leaves stage, stress at anthesis stage and stress at kernel filling stage) as main plots, and four corn hybrids (single crosses 704, 604, 500 and double cross 370) as sub-plots. Results of data analysis revealed that in general, most of the traits under stress conditions had negative and significant correlation whit grain yield. Results of stepwise regression and path analysis showed that under average conditions, selection for higher ear weight may improve yielding ability of selected genotypes. Under average conditions ear weight had greatest positive direct effect on grain yield, and positive indirect effects through ear diameter, plant high, mean stem diameter and cob weight on grain yield. Water deficit stress at 6-7 leaves stage, ear weight had greatest positive direct effect on grain yield and indirect effects through plant height, length of tassel and ear length on grain yield. Water deficit at kernel filling stage 300-kernel weight had greatest positive direct effect on grain yield, and positive in direct effects through number of grain and kernel depth on grain yield.