مجله تولید و فرآوری محصولات زراعی و باغی
سال ششم شماره 4 (زمستان 1395)

Little is known about genetic variation of seed related traits and their association with forage characters in sainfoin. In order to investigate the variation and relationship among seed yield and its components, 93 genotypes from 21 wild and cultivated species of genus Onobrychis were evaluated using a randomized complete block design with four replications at Isfahan University of Technology Research Farm, Isfahan, Iran. Analysis of variance showed that there was significant difference among genotypes, indicating existence of considerable genetic variation in this germplasm. Panicle fertility and panicle length had the most variation in cultivated and the wild genotypes, respectively. Results of correlation analysis showed that seed yield was positively correlated with number of stems per plant and number of seeds per panicle and negatively correlated with panicle length and days to 50% flowering. Seed yield had positive correlation with forage yield in wild species while this correlation was not significant in cultivated one. Cluster analysis classified the genotypes into three groups which separate wild and cultivated species. Based on principal component analysis the first component was related to seed yield and the second one was related to components of forage yield which can be used for selection of high forage and seed yielding genotypes.

Recently, application of biofertilizers has been introduced as a new strategy in crop nutrition. In order to investigate the effect of application methods of biofertilizer in combination with nitrogen levels on yield and yield components of weed-infested triticale a field experiment was conducted at College of Agriculture and Natural Resources of Darab, Shiraz University in 2013-14 growing season. Experimental design was a split split plot with three replications. The main factor included weedy and weed free plots, subplots included three levels of nitrogen; control, 90 and 180 kg N ha-1 and the sub-sub plots were composed of Azotobacter biofertilizer application methods; seed inoculation, topdressing and without Azotobacter (control). The results showed that the effects of nitrogen and biofertilizers on plant height, number of grains per ear, 1000 grain weight, grain yield and yield components, N content in shoot and grain of triticale were significant. Seed inoculation of biofertilizer showed higher efficiency due to its close relationship with plant root systems. Nitrogen amendment had a positive effect on biofertilizer efficiency, so that application of biofertilizer without use of chemical N, had a lower impact on shoot N content. Application of biofertlizer combined with N fertilizer had a higher impact on shoot N content. Owing to a great competitive ability of this small-grain cereal crop against the weeds, triticale yield was not adversely affected by the weed interference.

Excessive application of P fertilizers, use of the bicarbonated water sources for irrigation concomitant to a low level of organic matter have resulted in widespread iron deficiencies in crop plants in Iran. One of the strategies to overcome this problem is to select tolerant genotypes to iron deficiency (i.e. iron-use-efficient genotypes) or bred genotypes with high-micronutrient-uptake ability. Therefore, this experiment was conducted to study the behavior of twelve Iranian rice landraces and improved genotypes to iron deficiency (Tarom Mahalli, Amol 2, Musa-Tarom, Gharib, Shiroudi, Bejar, Neda, Nogouran, Jozdan, Sazandegi, Zayande Roud, and Kouhrang) as exposed to two levels of chelated iron fertilizers, including 5mM (iron deficiency) and 50mM (no iron deficiency) in Yushida nutrient solution culture. A factorial experiment based on a completely randomized design with four replicates was carried out in Soilless Culture Center at Isfahan University of Technology, Isfahan, Iran in 2013. The results showed that the iron content, shoot and root dry weights, total dry weight, leaf area, root length and volume and the number of tillers were significantly affected by genotypes, iron fertilizer, and their interaction. The mean dry weights were 0.215, 0.138, and 0.255 g per plant in northern landraces, northern improved, and central Iranian genotypes under no iron deficiency condition, but they were decreased by 25.7, 35.2, and 23.0% under iron deficiency condition, respectively. Based on the magnitude of decrease of total biomass under iron deficiency condition, genotypes such as Musa-Tarom, Bejar, and Zayande Roud seemed to be more tolerant in comparison to Jozdan, Amol 2, and Shiroudi.

In order to study the effect of application of nitrogen, phosphorus and biologic fertilizers on yield and yield components of native bean, an experiment was conducted as factorial in randomized complete block design with three replications in Lahijan, northern Iran in 2013. Treatments consisted of chemical nitrogen fertilizer (0, 60 and 120 kg ha-1 urea), chemical phosphorus fertilizer (0, 40 and 80 kg ha-1 P2O5) and mixture of rhizobium, bacillus and pseudomonas biofertilizers (application and on application). The maximum and minimum seed yields (1556 kg ha-1and 451 kg ha-1) were obtained at the presence of 120 kg ha-1 urea with 80 kg ha-1 P2O5 and control (no fertilizers), respectively. The results showed that seed yield was significantly affected by interactions of nitrogen and phosphorus, and phosphorus with bio-fertilizers. The triple interaction effect of nitrogen, phosphorus and biofertilizers was significant on pod number per plant, seed number per pod, seed number per plant and 100 seed weight. The maximum pod number per plant, seed number per pod and 100 seed weight were found in interaction of 120 kg ha-1 urea and 40 kg ha-1 P2O5 with biological fertilizers. Overall, it seems that application of biological phosphorus with both N and P chemical fertilizers is more beneficial to bean; however, the present one-year study needs to be continued in years ahead to ascertain our results.

In a 2yrs field study the effect of concentration and time of salicylic acid (SA) foliar application on growth of barley under non-saline and saline (2 and 12 dS m-1 of NaCl, respectively) conditions was evaluated in National Salinity Research Center of Iran, Yazd, central Iran during 2012-2014 growing seasons. The treatments of SA (11 treatments) included without SA and SA foliar application at 0.0, 0.35, 0.70, 1.05, 1.40 and 1.75 mM applied at tillering stem elongation ear emergence or stem elongation ear emergence. Salt stress led to significant decreases in seed yield and yield components; however, grain yield of barley plants were considerably increased when subjected to SA. This positive impact of SA was due probably to its effect on grain number. Average of grain yield in 0.0, 0.35, 0.70, 1.05, 1.40 and 1.75 mM SA concentrations were 496.1, 539.7, 538.5, 553.8, 517.4 and 501.3 g m-2 under non-saline and 189.2, 212.5, 219.1, 206.9, 200.3 and 182.3 g m-2 under saline conditions, respectively. Considering the negative correlation between sodium concentration in shoot and grain yield, modulating role of exogenous SA on adverse effect of salinity might be related to a SA-induced lowered Na concentration in such organs. The appropriate treatment seems to be SA foliar application at 1.05 mM for non-saline and 0.70 mM for saline conditions applied at stem elongation ear emergence, as they increased grain yield by 16.6% and 18.6%, respectively. The result of this study revealed that higher concentration or frequency of SA application could be associated with negative impacts on barley.

In order to evaluate water stress tolerance-related traits and their relationships in barley genotypes, as well as identification of drought tolerant genotypes, a field experiment was carried out during 2012-13 and 2013-14 growing seasons in College of Agriculture, Shiraz University, Iran. Seventy four foreign barley genotypes and two Iranian varieties (Reyhan and Nosrat) were evaluated under normal irrigation and water stress (water withheld at flowering stage) conditions according to a split plot experiment based on a randomized complete block design. Correlation analysis indicated that stress tolerance index (STI) was the best criterion for selecting barley drought-tolerant genotypes and significant correlations between number of fertile spikes, spike length, biomass, and seed yield and stress tolerance index were observed. Based on STI, the genotypes number 17, 23, 24, 41, 47, 58, 65, 71 and 72 were proved to be the most tolerant and high-yielding genotypes under both normal and water stress conditions.

Cultivation of winter cover crops such as wheat and barley is one of the practical approaches for weeds control in cereal-based rotations. In order to investigate the effect of cover crop species and nitrogen rates on weed control of rapeseed (Brassica napus L.), a field experiment was arranged in split-plot based on a RCBD with three replications during 2013-2014 growing season at Research Field of School of Agriculture, Shiraz University, Shiraz, Iran. Treatments included nitrogen levels (75 and 150 kg N ha-1) as the main factor and cover crops (no cover crop as control, 25% wheat, 50% wheat, 75% wheat, 25% barley, 50% barley and 75% barley) as sub factor. The results showed that there was significant difference between the presence and absence of cover crop and its interaction with nitrogen level in terms of an array of measured traits. The lowest density, dry weight and height of weeds were obtained from the using barley as a cover crop at the presence of both nitrogen rates, suggesting that barley cover crop is more potent to suppress the weeds compared to wheat cover crop. The highest grain yield (5290 kg ha-1) and oil yield (1760 kg ha-1) of rapeseed were obtained from 50% barley cover crop and the highest rapeseed protein percentage (43%) was obtained from using 25% wheat cover crop at 150 kg N ha-1. Overall, the highest grain and oil yields were achieved from application of 150 kg N ha-1 along with using 50% barley cover crop treatment, though the latter combination did not significantly differ from 75 kg N ha-1 at 50% wheat cover crop

Application of humic acid as an organic acid derived from humus and other natural resources along with iron could be beneficial to overcoming, at least in part, the nutrients deficiencies in the grapes. In order to evaluate the effects of humic acid and iron on fruit yield and concentration of nutrient elements in the leaf of grape, a factorial experiment based on a randomized complete block design in three replications was done during growing season of 2013- 2014. The treatments included combinations of humic acid (control, 1 and 2 per thousand) and ferrous sulfate (control, 1 and 2 per thousand), sprayed in two steps (i.e. before flowering and two weeks after fruit set). The results indicated that treatments significantly increased the grapes fruit yield, e.g. the maximum yield (8.27 kg per plant) was obtained when 2 per thousand of iron sulfate was applied. The above treatments significantly affected nitrogen, iron, zinc and copper content of leaves. Foliar application of ferrous sulfate increased leaf iron concentration, i.e. the highest (189.6 mg per kg tissue) iron content was observed at the presence of 2 per thousand ferrous sulfate treatment. Positive correlations were observed between the leaf iron concentration with fruit yield, cluster weight, berry diameter, leaf chlorophyll concentration and TSS of fruit. Hence, foliar application of humic acid and iron sulfate (e.g. each at a two per thousand concentrations) in vineyards might be effective in increasing quality and quantity of grapes.

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.

Mushrooms are characterized by a very short shelf life and browning, weight-loss and microbial infections are known as the most deteriorating postharvest modifications in the mushrooms, leading to notable economic losses. In this study, the effects of some postharvest treatments including calcium chloride (0.30 and 0.45%), ascorbic acid (1, 2 and 3 mM) and hydrogen peroxide (1%) on increasing mushroom shelf life were evaluated. Mushrooms were dipped in the solution treatments for 2 min, then dried at room temperature and packed in polyethylene container by cellophane cover and were stored at 4°C. Some qualitative and quantitative parameters were measured on 8th and 16th days of storage. Results showed that, 0.45% CaCl2, as well as 2 and 3 mM ascorbic acid and 1% peroxide hydrogen effectively maintained mushrooms marketability and kept the cap closed. CaCl2 treatment was effective in extending the postharvest life of mushrooms due to reducing weight loss, maintaining firmness, reducing electrolyte leakage and lowering bacterial populations. Ascorbic acid was an effective treatment in reducing the weight loss, electrolyte leakage, bacterial populations and, thereby, maintaining the firmness. Hydrogen peroxide treatment improved the postharvest quality of mushrooms only through reducing bacterial populations.