نشریه فیزیولوژی گیاهان زراعی
پیاپی 27 (پاییز 1394)

Much of the lands under wheat in the world is in arid and semiarid regions. In these regions the water requirement of wheat in all development stages can not be fully met. This research was conducted in this regard and in order to investigate the effect of post anthesis water deficiency tension on quantity and quality of grain yield and some physiological characteristics of wheat different cultivars. This experiment was conducted in the potted form as three-factors factorial for physiological traits and two-factors for yield quantity and quality and based on randomized complete blocks design with three replications at Campus of Agriculture and Natural Resource of Kermanshah Razi University during 2011-12 cropping year. Three investigated factors included: 1) humidity treatment in two levels of non-tension (field capacity) and water deficiency tension from pollination stage till the end of growing season (30 percentage field capacity), 2) different wheat genotypes (Pishtaz, DN-11, Sivand and Marvdasht) and 3) sampling date in two levels including: 11 and 17 days after anthesis. The results showed that in tension and non-tension water deficit conditions Marvdasht cultivar had the lowest grain yield. Among the other investigated genotypes (in two humidity conditions), Pishtaz had the highest grain yield. The lowest grain yield drop in water deficit conditions compared to non-tension was relared to Pishtaz cultivar, as well. Applying water deficit tension caused significant reduction of chlorophyll a and b concentration, total chlorophyll and carotenoids, maximum quantum yield of photo system II, viability index and relative water content. Also, water deficit tension caused decreasing in starch content and total dry mater and increasing in fiber content and grain protein of investigated genotypes.

In order to investigate the response of leaf chlorophyll, sink capacity and yield components to the application of Rhizobium and mineral nitrogen in different crop densities, this experiment was carried out in a randomized complete blocks statistical design as a split-factorial in Broujrd in 2012-2013 cropping year. The main factor of experiment includes density with three levels, 20, 40 and 60 plants per square meter and seed inoculation factors with Rhizobium bacteria in two levels (bacteria and control) and mineral nitrogen application from urea source with three levels (zero, 90 and 180 kilogram per hectare) as factorial 2×3 were placed on sub plots. Results showed that the density factor had significant effect on the whole traits except the number of grain per pod and the highest amount for leaf chlorophyll content, sink capacity and grain yield was obtained in 60 plants density. Conversely, 20 plants density had the highest pod numbers in plant and one hundred-grain weight. The effect of nitrogen on leaf chlorophyll content, number of pod per plant, one hundred-grain weight, sink capacity and grain yield was significant statistically and the highest amount of these traits was obtained by 180 kilogram fertilizer treatment. Also, inoculation treatment had positive and significant effect on one- hundred grain weight, sink capacity and grain yield. Interaction of bacteria and nitrogen on leaf chlorophyll content and one hundred-grain weight, interaction of density and bacteria for sink capacity and grain yield and interaction of density and nitrogen on one hundred-grain weight was significant, as well.

In order to investigate the effect of salicylic acid (zero, 0.5, 1, 1.5 and two mM) on yield and canopy temperature of two rapeseed cultivars (Sarigol and RGS) under full irrigation and late season drought tension conditions, this research was conducted at Research Station of College of Agriculture and Natural Resources of Darab Shiraz University in 2013-14 cropping year. The experiment was as split split plots based on randomized complete blocks design with three replications. Results showed that all investigated factors including (terminal drought tension, salicylic acid and cultivar) had significant effect on pod length, grain number and grain yield. Both cultivars used in this research were highly sensitive to terminal drought tension at flowering date so that drought tension caused 40 percentage yield reduction in both cultivars. In RGS cultivar yield from 6780 kilogram per hectare in full irrigation conditions reduced to 3930 kilogram per hectare in terminal drought tension conditions. In both cultivars in full irrigation conditions one mM treatment and in tension conditions two mM salicylic acid produced the highest grain yield in rapeseed. Both cultivars had similar responses to drought tension and salicylic acid, but as a whole RGS cultivar produced higher yield (5354 kilogram per hectare) than Sarigol cultivar (4911 kilogram per hectare). Also, in both cultivars the application of salicylic acid reduced canopy temperature under drought tension conditions. In general, it can be concluded that although drought tension causes reduction in rapeseed growth and yield but the application of salicylic acid with the amount of two mM could alleviate 13 percent of yield reduction.

Water deficit is one of the most importance of environmental tensions that has affected crops production and causes reduction in quality and quantity of agricultural production. In order to investigate the effect of water tension and application of different amounts of zeolite, two experiments were carried out as split plots in randomized complete blocks design with three replications in Payam Noor University of Markazi province in 2009-10 cropping years. Water tension as the main factor in four levels include: irrigation on the basis of plant water requirement (control), irrigation to the amount of 85, 70 and 55 percentage of plant water requirement were assigned in the main plots and different amounts of zeolite application as the sub factor in four levels include: without zeolite consumption (control), consumption three, six and nine tons per hectare zeolite in sub plots. The results showed that the effect of water tension treatment was significant on traits biological yield, number of unfertile boll, water saturation deficit, plant height, stem diameter and leaf eternity water. The effect of zeolite application was significant on traits number of unfertile boll, water saturation deficit, plant height, stem diameter and leaf eternity water, too. Plant biological yield was significant at one percentage level. As the highest amount of biological yield 8186 kilogram per hectare was related to control irrigation treatment and the lowest amount 6756 kilogram per hectare was due to sever water tension treatment (irrigation one the basis of 55 percentage of plant water requirement). Generally, increasing water tension severity, caused reduction in the amount of biological yield, plant height, stem diameter and leaves eternity water of safflower. But with increasing levels of zeolite consumption, the adverse effect due to water tension treatment on mentioned traits decreased.

This study was designed and conducted in order to investigate the effect of different levels of urea fertilizer and brown seaweed extract (Nizamuddinia zanardinii) on the physiological traits and grain yield of wheat. Experiment was carried out in the form of factorial in completely randomized design with three replications at five levels of brown seaweed extract (zero, 5, 10, 15 and 20 percent) and three levels zero, 25 and 50 percent of recommended using rate of 46 percent urea fertilizer (the recommended using rate of urea fertilizer was 300 kilogram per hectare). After the growth and complete ripeness of wheat, the amount of grain soluble carbohydrate, the average weight of spike, the average number grains of spike, grains weight of spike, harvest index of spike, grain yield and biomass were measured. The obtained results showed, using seaweed extract led to a significant increase in the amount of investigated growth indices in comparison to control. In treatments in which the combination of seaweed fertilizer with 25 percent recommended using rate of urea fertilizer was used, the mentioned growth indices significantly increased, which indicated the synergistic and interaction of seaweeds and urea fertilizer. In treatments in which the mixture of seaweed extract has been used along with 50 percent of recommended using rate of urea fertilizer, the investigated growth indices showed significant decrease in comparison to the mixture of seaweed extract treatments along with 25 percent recommended rate of urea fertilizer.

In order to investigate the effect of applying super absorbent polymer on yield, yield components and qualitative and quantitative characteristics of corn hybrid NS640 under irrigation cut tension conditions, this experiment was conducted in the form of split plots in randomized complete blocks design in three replications in 2013-14 cropping year. The main plots contained irrigation in four levels normal, irrigation cut at stem formation stage, irrigation cut at the tassel appearance stage, irrigation cut at ear flowering appearance stage and super absorbent polymer at three levels including non-applying super absorbent, applying 15 kilogram per hectare super absorbent and applying 30 kilogram per hectare super absorbent in sub plots were compared. The obtained results indicated that the simple effect of water deficit tension was significant on all experimented traits: the number of grain in corn, one thousand-grain weight, grain yield, biologic yield, harvest index, relative water content and protein percentage. Also, the simple effect of super absorbent on all traits was significant excluding the traits one thousand-grain weight, harvest index and relative water content. On the other hand, the interaction of water deficit tension and super absorbent became significant on the number of grain in corn and grain yield. The maximum grain yield equals to 1063 gram per square meter was related to normal irrigation and applying 30 kilogram per hectare super absorbent and among yield components the maximum number of grain in corn with 340/7 was related to this treatment, as well. The maximum amount of protein 9/79 percent was obtained at irrigation cut treatment in ear appearance stage. With regard to the obtained results, in irrigation cut tension conditions it was found that applying super absorbent causes improving the quantity characteristics of corn. As a result in these conditions consuming 30 kilogram per hectare of super absorbent for corn was recommended.

Molybdenum (Mo) are among the essential micronutrients and Silicon (Si) the useful element for wheat growth. In order to investigate the effect of Molybdenum and Silicon on the wheat yield (Triticumaestivum) this field experiment was conducted on Shiraz wheat cultivar at the farms of Karaj Soil and Water Research Station in 2012-12 cropping year. This experiment was carried out in as factorial in a randomized complete blocks design including two factors of Molybdenum as aluminum molybdate at three levels of zero, 10 and 20 kilogram per hectare and Silicon as sodium silicate at three levels of zero, 300 and 600 kilogram per hectare and with three replications at a sandy soil. Fertilizer recommendation was conducted according to the soil test and Water and Soil Research Institution recommendation. In order to investigate the spike length and grain number per spike, 10 samples were taken from each plot randomly before harvesting and after that wheat plants were picked from the surface of six square meters. The traits of grain yield, straw, one thousand- grain weight and the grain protein percentage were measured. The results of analysis of variance of data indicated that the treatments in which ammonium molybdate at the rate of 10 kilogram per hectare added into soil, significant and positive effect at the level of one percentage was been showed on the grain number per spike, grain yield and protein percentage. As wheat grain yield increased on average from 3566 kilogram per hectare to 4085 kilogram per hectare (14/53 percent) and the amount of protein increased from 12/89 percentage to 14/42 percent (12 percent). Molybdenum concentration of grain increased from 3/54 to 5/4 milligram per kilogram. The effect of Molybdbenum on spike length, one thousand-grain weight and straw yield was not significant. The treatment of 300 kilogram per hectare sodium silicate had significant effect on the straw yield at the level of one percentage and increased its amount from 8074 kilogram per hectare to 9188 kilogram per hectare(14 percent).

Prediction of germination time is one of the main goals of seed researchers. Therefore in order to evaluation the cardinal temperatures and the investigation response of promising forage sorghum lines to temperature, this experiment was conducted as factorial in a completely randomized design with three replications, 15 forage sorghum lines and nine fixed temperatures 10, 15, 20, 25, 30, 35, 40, 45 and 50˚C at Seed Technology Laboratory of Islamic Azad University Shoushtar Branch in 2013. Results of analysis of variance showed that investigated germination components for factor line, temperature and interaction line × temperature were significant. The maximum germination percent-age in temperatures 20, 25 and 30˚C and the most speed rate, uniformity of germination and the minimum duration time till 95 percent the maximum germination (D95) in temperature 40˚C was obtained. With temperature drop from 40˚C, germination speed rate and D95 gradually decreased and increased, respectively. The base temperature (Tb) of forage sorghum lines from 9.36˚C (KFS11) to 14.28˚C (KFS2), optimum temperature (To) from 23˚C (KFS2) to 37.2˚C (KFS11) and maximum temperature (Tc) from 40.7˚C (KFS2) to 49.76˚C (KFS15) varied. Cluster analysis with ward’s method in the basis 7 studied traits led to three clusters formation. Third cluster included the lines KSF6, KSF7, KSF9 and KSF10 with the maximum percentage, rate and uniformity of germination and the minimum D95 jointly in temperatures 25˚C, 30˚C, 35˚C and partially 40˚C therefore these lines are recommended for supplementary researches.