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To investigate some common herbicides of transplanted rice for direct wet-seeding of Hashemi cultivar, this study was conducted in a randomized complete block design with three replications. Treatments were as follow: (i) recommended dose of pretilachlor, (ii) oxadiargyl + bensulfuron-methyl, (iii-vi) adding propanil or thiobencarb to treatment (i) and (ii), (vii-x) adding cinosulfuron to treatment (iii) to (vi), (xi) weed free condition, and (xii) weed infested condition. The highest total weed infestations were observed when pretilachlor, oxadiargyl + bensulfuron-methyl and pretilachlor plus propanil or thiobencarb had been applied. The highest rice height was recorded in weed infested, but for other traits, comparison of herbicide treatments showed the least rice growth and yield for pretilachlor (due to the highest weed competition) and oxadiargyl + bensulfuron-methyl + thiobencarb. In the recent treatment panicle and grain number, and 1000-grain weight were lower than those for individual application of pretilachlor. Since applying oxadiargyl + bensulfuron-methyl suppressed weeds better than treatments containing pretilachlor, and also considering the effective control of nutsedge by bensulfuron-methyl, and barnyardgrass by thiobencarb, it seems that the phytotoxicity effects of oxadiargyl + bensulfuron-methyl + thiobencarb on rice are serious. In the herbicide applied treatments, the maximum number of tiller and panicle, and biological and grain yield were observed in oxadiargyl + Bensulfuron-methyl+ Propanile treatments. Despite the acceptable weed control, it seems that Hashemi cultivar was susceptible to herbicides in saturated soil condition and symptoms of phytotoxicity were appeared in crop plants.

In order to investigate the effect of planting date and sowing method on ear yield, water use efficiency and some physiological characteristics of sweet corn, an experiment was carried out as a split plot based on a randomized complete block design with three replications in Yasouj, south-west of Iran. Planting date consisted of five levels (4 May, 19 May, 4 June, 19 June, 5 July) and considered as the main plots and three levels of planting methods (seed cultivation, transplanting cultivation [15-days after planting (3-leaf stage)] and [20-days after planting (4-leaf stage)] were assigned to the sub-plots. Planting date and sowing method interaction effects were significant on ear yield and water use efficiency. Transplanting at 3-leaf stage on the 4th of May had the maximum ear yield (16000 kg ha-1) and at 4-leaf stage on the 5th of July had the minimum ear yield (8000 kg ha-1). The highest water use efficiency (2.93 kg m-3) was obtained by transplanting on the 4th of May and 3-leaf stage, which was 66% higher than the water use efficiency of those transplanted on the 5th of July and at 4-leaf stage. The effects of planting date and sowing method were significant on grain protein content. With a delayed planting, the grain protein content was increased so that the maximum of grain protein content (8.7%) was obtained in the 5th of July and the lowest (8%) in the 4th of May transplanting. The grain protein concentration of the transplanting treatments was less than the grain protein of the seed cultivation treatment. The high temperature stress experienced by sowing at the 19th of May until the 19th of June decreased the grain sugar content. Transplanting cultivation led to increase in the amount of total sugar compared to seed cultivation. The best treatment in this study was found to be transplanting at 3-leaf stage on the 4th of May.

To assess the effects of IAA and Kinetin plant growth regulators in order to improve the drought tolerance in rice seedlings (Oryza sativa L.), a factorial experiment was carried out based on complete randomized design with three replications. The experimental factors included different rice genotypes [‘Gharib’, ‘Khazar’, ‘Sepidrood’ and ‘IR83750 -131-1’ (‘IR83750’ )], drought stress from 1 to 4 code of the Vergara coding system and control (normal irrigation) and growth regulators in three levels (IAA and Kinetin through foliar spraying and non-application as control). The results indicated, under normal irrigation condition together with IAA application, ‘IR83750’ rice had the highest number of tillers and leaf greenness, with mean of 18.27 and 49.46, respectively. The highest amount of leaf relative water content) 95.11 percent) was related to ‘Sepidrood’. Under drought stress condition, the highest electrolyte leakage (36.59 percent) was observed in ‘Gharib’. In drought condition, the highest leaf drying score was related to ‘Gharib’ in both years, but the highest score of leaf rolling index (9) was observed in ‘Gharib’ and ‘Khazar’. The present findings showed that drought stress had harmful effects in all examined genotypes and the impact in susceptible genotypes (‘Gharib’ and ‘Khazar’) was more than ‘IR83750’ and ‘Sepidrood’. Application of growth regulators (IAA and Kin) improved conditions for the growth of all genotypes. Therefore, using the tolerant genotypes along with growth regulators can improve the rice growth traits.

In order to determine the optimal rates of Pertilachlor and Sunrice­-plus herbicides for weed control of rice (Oryza sativa Var.Tarom Hashemi), a factorial experiment was conducted with a randomized complete block design with four replications in Rice Research Farm of Faculty of Agriculture, University of Guilan, Rasht, northern Iran. The first factor was weed control treatment which consisted of lower than, equal, and more than recommended levels of Pertilachlor (i.e. 0.5, 0.75, 1 kg a.i ha-1) and Sun­rice plus (0.45, 0.9, 1.35 kg a.i ha-1) herbicides, along with unweeded and twice hand-weeded controls. The second factor consisted of two levels of nitrogen fertilizer (N) application (i.e. 0 and 90 kg ha-1 of N). Barnyardgrass (Echinochloa crus-galli L.) and Purple nutsedge (Cyperus rotandus L.) were the most dominant weeds of the experimental plots. The highest number of filled panicles per plant, number of grains per panicle, and grain yield were found in recommended rate of Pertilachlor, Sun­rice plus and more than recommended rate of Sun­rice plus due to adequate weed control (>70%) at the presence of 90 kg ha-1 of N. The lowest number of grains per panicle, number of panicles per plant and grain yield were observed in unweeded treatment, at both levels of nitrogen fertilizer application. It was concluded that application of N is effective in increasing grain yield of the examined rice genotype only if weeds are effectively controlled by herbicides. Hence, application of N in the unweeded conditions does not lead to an increase in grain yield of rice, because the consumption of N by weeds decreased the effect of nitrogen on rice grain production.

In order to evaluate the benefits of maize, pinto bean and naked pumpkin triple cropping, an experiment was carried out as a randomized complete block design with three replications at Faculty of Agricultural Science, University of Guilan, Rasht, Iran in 2012. The treatments consisted of maize, pinto bean and naked pumpkin sole cropping (100, 75 and 50% of conventional densities), maize – pinto bean and maize – pumpkin double cropping (100-100%, 75-75% and 50-50%), and maize-pinto bean-pumpkin triple cropping (100-100-100%, 75-75-75% and 50-50-50%). The highest and lowest forage fresh weights were obtained in triple cropping system with high density and sole cropping systems with low density, respectively. In double cropping systems, the maize-pumpkin out-yielded the maize-pinto bean in terms of fresh weight. The relative crowding coefficient, competitive ratio and aggressivity of maize in double cropping of maize-pinto bean and naked pumpkin in double cropping of maize-naked pumpkin were dominant. In triple cropping systems, while maize and naked pumpkin were comparable, but both of the latter crops were dominant over pinto bean. Land Equivalent Ratio (LER) for double and triple cropping was greater than one, revealing the profitability of double and triple cropping systems on sole cropping. According to the LER, the cropping systems can be ranked as follows: triple cropping > double cropping maize/pinto bean > double cropping maize/pumpkin

Intercropping of grass-legumes could be increase quantitative and qualitative yield per unit of dry land area. A series experiments were carried out to evaluate five treatments % (w/w) including: T1:Hurdeume0Vetch100, T2: Hurdeume 25 Vetch 75, T3: Hurdeume 50 Vetch 50, T4: Hurdeume 75 Vetch 25, T5: Hurdeume 100 Vetch 0 as randomized complete blocks design during three years (from 2004 to 2007) with 3 replications at Maraghe station. Seeds were planted in 20cm row spacing in autumn. ANOVA results showed that the effects of treatments were significant (p≤%1). The results at three growth stages showed that the highest wet and dry forage yield before and after flowering and also stubble and grain yield belong to T3, T4 and T5 treatments. The lowest yield was obtained from T1 treatment. But for highly ratio present of legume in T3 this treatment recommended for dry lands. In flowering stage of vetch, gravimetric soil water content in 3 different depth (0-10, 10-20. 20-30 cm) of soil were significantly different between treatments and in each depth highest value belong to T3 respectively 23.39, 25.43 and 25.90 % .

Peanut are one of the paired plants of oilseed and protein seed oil is a rich source. In order to evaluate effects sulphur and zinc on growth characteristics and yield of peanuts, a experiment was conducted in Bandar Kiashahr, Guilan province, Iran in 2008. The experiment laid out in a factorial arrangement with two factors sulphur (0, 40, 80, 120 kg ha) and zinc chelate on (0, 0.5, 1 and 1.5 g per lit) in a completely randomized complete block design with three replications. Results showed that amounts of sulphur and zinc significant effects were on Peanut plant traits, as pod yield, seed yield and oil content. The mean comparison of the properties studied showed that rate of 120 kg.h-1 sulphur was better than other treatments. Also had better efficacy between treatments of zinc chelate on treatment to 1.5gr per lit. Also, the interaction of the sulphur and zinc had the most increase on these parameters.

Increases forage production and economic production in rainfed condition requires attention to agricultural issues such as determination of appropriate sowing depth. So in order to determine the effect of different sowing depths of vetch this experiment was conducted in Agricultural Research Station of Maragheh as strip plot based on randomized complete block design with three species of vetch V. sativa , V. dasycarpa-kouhak and V. narbonensis velox67 as main plots and three sowing depth as sub factor. Results showed that the effect of sowing depth on Vicia yield was significant at the 1% level and the maximum yield of wet hay, dry hay, straw and seed depth of belong to 8-10 cm depth and respectively are 5.364, 3.416, 4.389 and 1.081 ton per ha whereas the minimum yield of wet hay, dry hay, straw and seed depth of belong to 2-4 cm depth and respectively are 4.888, 2.318, 3.729 and 0.825. Among the three Vicia species the highest yield of wet hay, dry hay , straw and seed belongs to V. dasykarpa and respectively are 5.632, 3.532, 4.614 and 1.065 ton/ha. Soil moisture study in the field of these vetches at the time of 10 % vetch flowering showed water differences. V.dasycarpa had lower water depletion from soil. The amount of average soil water for species included: V. dasycarpa 26.31, V. sativa 23.76 and V. narbonesis 22.5.