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Waterlogging is one of the limiting factors influencing durum wheat (Triticum durum L.) production. In this paper we investigated the impact of seven waterlogging durations of 4, 8, 12, 16, 20, 40, and 60 days, imposed at 3-leaf and 4-leaf growth stages, on grain yield, grain yield components, straw and root dry weight and nitrogen concentration of grain, straw, and roots of two varieties of durum wheat. Grain yield of both varieties showed a significant reduction only when waterlogging was prolonged to more than 20 days, and 40-d and 60-d waterlogging reduced grain yield by 19% and 30%. Waterlogging depressed grain yield preventing many culms from producing spikes. It slowed down spikelet formation, consequently reducing the number of spikelets per spike, and reduced floret formation per spikelet, thus reducing the number of kernels per spike.

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The interaction effects of phosphorus fertilization, applied at various rates and time intervals, with or without foliar spraying with citrine on the growth and macro- and micronutrient uptake of two new wheat cultivars (Triticum aestivum cv. Sakha 94 and Gmiza 10) in a sandy soil were investigated under greenhouse conditions at the Faculty of Agriculture, Zagazig University. Superphosphate was used at different rates (0, 7.5 and 15 mg P kg−1 soil) and timing: before planting (BP); 1 month after planting (AP) and 50% BP + 50% AP. The results confirmed that phosphorus fertilization and foliar spraying with citrine significantly increased both the straw and grain yield and the nutrient uptake compared with the control. The interaction effect of phosphorus fertilization and foliar spraying with citrine significantly increased Zn and Mn uptake by the straw and grain yield, as well as P and Fe uptake by the straw yield. The addition of 7.5 mg P kg−1 soil (50% BP + 50% AP) gave the highest value of apparent P recovery (APR) when spraying with citrine. APR and P use efficiency (PUE) were markedly decreased at the higher P addition rate, with or without citrine. Treating wheat plants with 7.5 mg P kg−1 soil combined with citrine saved 59% of the P fertilizer, and thus reduced environmental pollution.

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A field experiment was conducted at CCS Haryana Agricultural University, Hisar, India during the winter season for three consecutive years from 1995–96 to 1997–98 to study the effect of different nitrogen levels and Azotobacter inoculation on the growth, grain yield and nitrogen utilization efficiency of two varieties of oat. The experiment was laid out in a split-plot design with three replications. The results revealed that oat variety JHO-822 was superior to OS-7 for grain yield. However, the variety OS-7 produced a higher straw yield than JHO-822. Increasing levels of nitrogen up to 60 kg/ha significantly increased the grain and straw yields over the lower doses on a pooled data basis. Nitrogen application also had a beneficial effect on the yield attributing traits of oat. Nitrogen utilization efficiency was highest at 60 kg N/ha and declined thereafter. Azotobacter inoculation was found beneficial in terms of increased grain and straw yield and higher nitrogen utilization efficiency over the uninoculated treatments.

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The aim of the study reported in this paper was to derive factors describing the translocation of radiocesium from the green plant parts to the crop. Wheat, rye and potatoes were contaminated and harvested at different growth stages to allow the assessment of the contamination of the crop with known date of the radioactive deposition. At harvest, the cesium concentrations in the crop, the green plant parts (i.e., straw without ears) and the roots were measured. The results show that the contamination of the crop depends strongly on the date of134Cs application and on the type of plants. The highest translocation was observed when cesium was applied during flowering.

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Two types of agricultural residues (wheat straw and olive residue) in untreated and pretreated (fractionation, leaching) form were tested as concerns their ash melting behaviour during fluidized bed combustion and gasification by means of thermal analysis techniques. The techniques applied included DSC, simultaneous DSC/TG and TG-MS for the determination of low-temperature ash melts and losses caused by the volatilization of alkali material. In combination with ash elemental analyses on the materials, the applied techniques proved to offer valuable information for prediction of the ash behaviour in fluidized bed reactors.

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The long-term effect of organic and inorganic fertilizers on nutrient build-up and their relationship with microbial properties in a rice-wheat cropping sequence were studied in surface (0–15 cm) and subsurface (15–30 cm) soil samples. This experiment has been in progress since 1990 in the Department of Agronomy, CSK, Palampur with twelve treatments involving combinations of organic and inorganic fertilizers. In these treatment combinations, 25 and 50% of the recommended nitrogen levels were supplemented with organic sources, i.e. FYM (farm yard manure), green manure and wheat straw. The buildup of organic matter, and the total and available pools of nitrogen, phosphorus and sulphur were determined in surface (0–15 cm) and subsurface (15–30 cm) soil samples. The substitution of 25 and 50% nitrogen through organic fertilizers proved to be better than inorganic fertilizers alone. Amongst the organic sources, the substitution of FYM resulted in higher organic carbon, total and available nitrogen, phosphorus and sulphur than green manure or wheat straw. The substitution of 50% nitrogen through organic fertilizer was more effective than the substitution of 25% nitrogen. The relationships between the total and available pools of nutrients and the total microbial count, biomass carbon, microbial respiration, and the dehydrogenase and phosphatase enzymes were studied. The total pool of nutrients showed a high, positive, significant relationship with all these parameters.

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Among the abiotic stress factors influencing the growth and productivity of wheat varieties, extremely high temperatures have the most limiting effect. In an experiment set up in the gradient chamber of the Martonvásár phytotron to test the effect of various temperatures on four winter wheat varieties and one variety of spelt, substantial differences were observed in the heat stress tolerance of the varieties. There was a considerable reduction in the number of shoots and spikes as the result of heat stress, leading to a drastic loss of grain yield. It was clear from changes in the biomass and in the grain:straw ratio that extremely high temperatures led to a substantial reduction in the ratio of grain to straw in the varieties tested. In response to high temperature the wheat plants turned yellow earlier due to the rapid decomposition of the chlorophyll content. This resulted in a considerable shortening of the vegetation period and early ripening. Reductions in the parameters tested were observed at different temperature levels for each variety, indicating considerable differences in the ability of the varieties to adapt to abiotic stress factors.

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In the sub-tropical regions of India, the 1st to 3rd week of November is the optimum time for sowing wheat. A delay in sowing due to various factors causes a substantial yield reduction. Seeds of four wheat varieties (Sonak, UP 2338, Raj 3765 and PBW 343) were subjected to seed priming treatments involving water, salts, growth regulator and the sowing of sprouted seed under late-sown conditions during the winter seasons of 1998-99 and 1999-2000. The sowing of sprouted seeds resulted in significantly more rapid emergence of seedlings, accompanied by higher grain and straw yields. Seeds primed with IAA, KCl, water, ZnSO4 and Na2SO4 followed in this order. The lowest seedling emergence and grain yield were obtained for unprimed seeds. Seedling emergence was higher in the variety Sonak, while Raj 3765 and UP 2338 had higher leaf water, osmotic and turgor potentials during the 1998-99 season. The variety PBW 343 produced significantly higher grain and straw yields in the 1999-2000 season.

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A field experiment was conducted for 2 years at the Indian Agricultural Research Institute, New Delhi to study the effects of duration of variety and nitrogen fertilization on the Ca, Mg and S concentration and uptake in rice. In general, the concentrations of Ca, Mg and S were not significantly influenced by the duration of the rice variety. N fertilization had a tendency to increase the concentration of Ca, Mg and S at 45 days after transplanting as well as at harvest; however, the difference was significant only in the case of the Ca concentration in the grain and only when the N level was raised from 60 to 120 kg N/ha. The duration of the rice variety had a significant effect on the Ca, Mg and S uptake by the straw and grain at harvest, which was higher in the medium duration variety Pusa Basmati-1 than in Pusa Jaldi Dhan-1, mainly due to the higher yields obtained with the former cultivar. Nitrogen application significantly increased the Ca, Mg and S uptake at harvest mainly due to its increasing effects on the grain and straw yields of rice. The average uptake of Ca, Mg and S was 12.6, 13.6 and 3.5 kg per metric ton of grain, respectively.

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Abstract  

Rice plants were grown in an experimental field and separated at harvest into different components, including polished rice, rice bran, hull, straw and root. The distribution of chlorine in these components was determined by instrumental neutron activation analysis. The concentration of chlorine in the roots was the highest (4800 mg·kg−1 dry wt.) and that in the polished rice was the lowest (140 mg·kg−1 dry wt.) among the plant components. The content of chlorine in the polished rice was about 2% of the entire plant, and the rest was present in the inedible portions; about 75% of the total chlorine content was in the straw. The percentage of chlorine removed from the surface soil layer to the above ground biomass of the rice plants was calculated as 5% every year. The chlorine concentrations in leaf blades of different positions collected from four growing stages varied by more than one order of magnitude, and were well correlated with the sum concentrations of major cations (potassium + calcium + magnesium). This may be attributed to the fact that the translocation rate of chlorine among the leaf blades with age depends on the concentrations of the major cations.

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