فصلنامه اکوفیزیولوژی گیاهان زراعی
پیاپی 26 (تابستان 1392)

To evaluate the response of 13 millet accessions to skip irrigation at terminal growth stage¡ two separate experiments based on randomized complete block design with three replications conducted at the Agricultural Research Center of Birjand¡ Iran¡ in 2005 and 2006. Irrigation was stopped in the first experiment at 10% flowering while irrigation was conducted as usual¡ in the second experiment once every 7 days. Combined analysis of variance showed that stopping at flowering time irrigation leads to reduction in all investigated traits¡ especially dry forage and grain yield. Accession numbers 15-143 (Southern Khorasan accession) and 15-24 (Yazd) produced highest grain and dry forage yield in both years and accession number 15-132 (Hamadan) had the lowest yield against all the others. According to the results of this study and considering the severe reduction of grain and dry forage yield recommending deficit irrigation treatment¡ at flowering would not be feasible at Birjand region. Also¡ number 15-131 (Southern Khorasan) accession had an acceptable grain yield and dry forage on both irrigation regimes.

To study the effect of plant growth promoting bacteria (PGPR) and mineral nitrogen fertilizer on yield and yield components of three durum wheat cultivars, an experiment was conducted as a split factorial based on randomized complete block design with three replications in Dehloran Research Station in Ilam, Iran in 2011-2012 cropping season. Experimental factors consisted of durum wheat (Yavaroosm, Kharkheh and Simareh) was assigned to main plot and nitrogen fertilizers at 3 levels (40, 80 and 120 kg.ha-1) and bio-fertilizer (non-inoculation, inoculating with Azotobacter chroococcum, Azospirillum brasilense) to sub plot. Results of analysis of variance showed that among cultivars studied there were significantly differences at traits under study. Yavaroos had the highest plant height, 1000- grain weight, and biological yield. The highest plant height, 1000- grain weight, biological yield and protein content was obtained by application of 120 kg/ha nitrogen fertilizer, but there were not different effect between 80 and 120 kg/ha nitrogen fertilizer. Traits under study were affected by using bio-fertilizer. The highest plant height, number grain per spike, 1000- grain weight, grain yield were obtained from inoculation plants with bio-fertilizer. The effect of cultivar by nitrogen chemical fertilizer interaction had significant effect on plant height, number of grain per spike, 1000-grain weight, and spike per meter squared and grain yield. The highest grain yield was obtained from Yavaroos using 120 kg/ha and the lowest grain was observed from Simareh cultivar and 40 kg/ha. Interaction effect of cultivar and bio- fertilizer had significant effect on harvest index only. Nitrogen fertilizer by bio- fertilizer interaction had significant effect on only grain yield, spike/m-2 and grain yield. The highest grain yield was obtained from Yavaroos cultivar when it were inoculation with Azospirillum 120 kg/ha and the lowest grain yield observed Simareh cultivar when it was treated with 40 kg/ha.

This research was conducted to evaluate the effects of foliar application of methanol on certain kernel related traits at different growth stages of pea var. ILC482 at the Research Station of Faculty of Agriculture in Islamic Azad University, Tabriz Branch in 2011. The study was conducted in split plot experiment based on Randomized Complete Block Design with three replications. Treatments were three levels methanol foliar application at different growth stages (vegetative, reproductive and foliar application at both two stages) which considered as main factor, six levels of foliar application of methanol concentrations: (0 [control], 5, 10, 15, 20, 25, 30%) as sub factor. Results showed that the interactions of methanol applications growth stages and its concentrations on grain number per plant, 100 kernel weight, grain yield, grain filing rate and harvest index were significantly different. Foliar application of methanol at reproductive stage decrease kernel related traits, but this application at both growth stages had positive effect on grain production and kernel related traits. This positive effect on number and 100 kernel weight were significant. The highest grain yield (2460 kg/ha) was obtained by 20% concentration of methanol at both growth stages that increased grain yield above 13.5% compared to the control condition.

In order to identify the density and abundance of weeds in irrigated wheat fields of Ardabil Province, 76 samples of irrigated wheat fields based on cultivation area from all counties of Ardabil province for six years (2001-2006) were selected. The genus and species of weeds from each sampling fields and their population indices density, frequency and uniformity of each species were calculated by using Thomas method. Geographic coordinates of field (Latitude, Altitude and Elevation) were the main coverage and were determined by using GPS. These data were used for producing weed maps using GIS in irrigated wheat fields of Ardabil province. Results showed that bedstraw (Galium tricurnatum), Fumitory(Fumaria vaillanti)and wildradish (Raphanus raphanistrum) were dominant broad leaf weed species and wild oats (Avena fatua), rye (Secale cereal) and mouse foxtail(Alopecurus myosuroides) dominant grassy weeds species in irrigated wheat fields of Ardabil province. Bindweed (Convolvulus arvensis), Canada thistle(Cirsium arvense)and Acroptilon repens were the most important disturbing plants prior to harvesting in irrigated wheat fields of Ardabil province.

To study the effect of water deficit on growth indices of different maize hybrid, a split plot experiment based on randomized complete block design with three replications was carried out at Agriculture Research Station of Kermanshah during 2006. Different levels of water irrigation (full irrigation, stress before tasseling and stress after pollination and embryo formation) were measured assigned to main plots and maize hybrids (SC500, SC582, SC647, SC666, SC700 and SC704) to subplots. To determine growth indices including leaf area index, crop growth rate, dry matter accumulation, relative growth rate and net accumulation rate means of 14 times sampling were calculated. Results indicated that growth trend for leaf area index, crop growth rate, dry matter accumulation, relative growth rate and net accumulation rate in corn hybrids were similar, but they were different for levels of irrigation significantly. In such a way that drought stress decreased growth indices. The highest growth indices were obtained from full irrigation and lowest values from drought before tasseling.

To investigate the responses growth indices of corn (Zea mays L. cv. SC 604) to using plant growth promoting rhizobacteria (PGPR) and phosphate solubilizing microorganisms (PSM) and rhizobacteria, a field experiment was conducted during 2008. The study was arranged in split plot experiment based on randomized complete block design with three replications. Three levels of manures, consisted of 20 Mg.ha-1 farmyard manure, 15 Mg.ha-1 green manure and check or without any manures assigned to main plots and eight levels of fertilizer combinations (consisted of 1-NPK or recommended fertilizer application; 2-NPK㴣㸼揑; 3-NP50%K㴣 㱣; 4-N50%PK㴣 PGPR; 5-N50%P50%K㴣 PGPR; 6-PK㱣; 7-NK㴣 and 8-PSM PGPR) to sub plots. Results showed that the maximum dry matter (13/2 g.m-2), leaf area index (3/8) and crop growth rate (34/5 g.m-2.day-1) were, produced by using both farmyard manure and application of NPK plus biofertilizers. Application of green manure and biofertilizer significantly increased dry matter by 11% compared to control. Meanwhile, farmyard manure and green manure application markedly increased the leaf area index by 17 and 10%, respectively. NPK treatment in farmyard manure plots and inoculation of PGPR and PSM significantly increased crop growth rate in corn plants compared to green manure and control plots. However, inoculation of biofertilizer and reducing P application by 50% did not significant influence growth indices such as total dry matter accumulation, leaf area index, and crop growth rate significantly. In conclusion, it seems that biofertilizers could be recommended as an effective option to reduce phosphate chemical fertilizers, improve the growth indices of corn plants, which ultimately result in grain yield increase.

This study performed to investigate the effects different concentrations of salicylic acid (0, 5, 10, 15 and 20 µM) on membrane lipid peroxidation of fenugreek under levels of salinity stress (0, 50, 100, 150 and 200 mM) in hydroponic condition. The experiment conducted as factorial, in completely randomized design with three replications. Results showed that in plants treated with salinity, chlorophyll a, chlorophyll b and carotenoid contents were reduced in comparison with control plants. However, the salinity increased MDA, other aldehydes, catalase and peroxidase activity in shoots. Results also indicted that applying salicylic acid, especially with concentration of 10 and 15µM, increased the membrane lipid peroxidation and decreased the membrane stability index as compared to the control plants. Results also showed that using 5µM salicylic acid did not significantly improve the salt stress effects compared to the control plants. However, concentration of 20µM salicylic acid increased stress, and decreased the above mentioned parameters.

Mixed-cropping of barley (Hordeum vulgar L.) and clover (Trifolium alexanderium L.) was studied in a randomized complete block design with 4 replications to detect their best planting patterns at Agriculture Research Center of Miandoab. The experiment comprised of 10 treatments: 9B:1C (nine rows of barley: one row of annual clover), 8B:2C, 7B:3C, 6B:4C, 5B:5C, 4B:6C, 3B:7C, 2B:8C, 1B:9C and sole croppings of each plants. The results indicated that intercropping as a whole had a significant effect on number of stem, plant height and yield of clover. On other hands, the highest clover yields (8.3 t/ha) was achieved in sole cropping and lowest (1.2 t/ha) in 10:90 (Barley: Clover) treatment. Results also showed that spike length, number of seed per spike, 1000-grain weight, protein percent, economical yield and biological yield were affected by mixed-cropping. Reducing planting rows of barley relative to clover caused 87% reduction in both economical and biological yields. 1000-grain weight also decreased from 45.82 to 39g. Total LER was 1 in all of patterns and in 40:60 (barley: clover) pattern was the highest. LER calculated based on forage in two crops was similar to LER which achieved on seed yield of barley and forage yield of clover. Decreasing in rows of barley diminished LER to