Effect of polymer and irrigation regimes on dry matter yield and several physiological traits of forage sorghum

Drought stress is one of the most serious problems in crops production in the arid and semi-arid regions. Application of some materials such as superab A200 polymers (SAP) in soil can improve soil water reservation. They can also decrease water losses, fertilizer leaching in soils, effects of water deficiency in plants and so can improve the yield in the arid and semi-arid regions. This experiment was conducted on forage sorghum (Sorghum bicolor (L.) variety ‘Speedfeed’) in Zahedan, Iran during 2010 season. The experimental design was a split-plot with two factors including four irrigation regimes (providing 40, 60, 80 and 100% of the water requirement of sorghum calculated from pan evaporation) as main plots and four amounts of SAP (0, 75, 150 and 225 kg ha-1) as subplots in a completely randomized block design with three replications. Irrigation level and SAP had significant effects on chlorophyll index, leaf area index, leaf area duration, crop growth rate, relative water content and dry matter. The results indicate that irrigation to meet 80% of the water requirement with 75 kg ha-1 SAP which may provide a desirable dry matter.Keywords: Dry matter yield, forage sorghum, growth analysis, irrigation regime, superab A200 polyme

Evaluation of drought tolerance indices among some winter rapeseed cultivars

The main purpose of this study was to evaluate the effect of drought stress on seed yield of some winter rapeseed cultivars and to study relevant drought tolerance indices, along with identifying resistant cultivars to drought stress. Plant materials were sown in split plot arrangement based on a randomized complete blocks design, at Islamic Azad University of Tabriz research field. Three drought stress levels which include 80, 130, and 180 mm water evaporation from class A pan were considered as the main factor levels, while seven winter rapeseed cultivars which include Licord, Okapi, Opera, S.L.M.046, Zarfam, Modena, and Talaye were arranged to sub plots. Studied quantitative drought tolerance indices were, tolerance index (TOL), mean productivity (MP), stress susceptibility index (SSI), stress tolerance index (STI), geometric mean productivity (GMP), yield index (YI), yield stability index (YSI), and percentage of yield reduction (%Reduction). The yield stability analysis of the studied cultivars was done by GGE biplot method. According to the results derived from principal component analysis and regarding evaluation of correlation coefficients among indices, STI and GMP were selected as the two superior indices for identifying drought resistant cultivars. Three dimensional scatter plots based on STI and GMP indices showed that Licord and Talaye were the most suitable cultivars, and were situated in group, A. In addition, Modena and Zarfam were identified as sensitive and resistant to drought stress, respectively.Key words: Brassica napus L, principal component analysis, drought stress, drought tolerance indices, stability analysis (GGE biplot), 3D scatter plot

THE EVALUATION OF GRAIN AND OIL PRODUCTION, SOME PHYSIOLOGICAL AND MORPHOLOGICAL TRAITS OF AMARANTH ‘CV. KONIZ’ AS INFLUENCED BY THE SALT STRESS IN HYDROPONIC CONDITIONS

The purpose of this study was investigation of salinity effect on some traits of Amaranth. A split plot designed with three replications with two factors: 5 salinity levels (control, 75, 150, 225, 300 mM NaCl) and applied time at 4 levels (plant establishment, branching, flowering, grain filling) in a greenhouse under hydroponic system. Application of 300 mM salinity after plant establishment led to death of amaranth. Salinity application after establishment decreased significantly plant height and number of branches as 44.9 and 31.8, respectively. Production of grain weight was not affected by 75 mM salinity, but at higher salinity showed significantly decrease. The highest decrease in grain weight obtained by applying 225 mM salt after the plant establishment and salinity at 300 mM after branching as 86.6 and 71.3 percent respectively, resulting in a decrease in both 1000 kernel weight and grain number, respectively. Salinity application increased H2O2, MDA and total phenolics contents, severely. Most of characteristics hadnot affect by 75 mM NaCl, but other concentrations had a negative effect on the growth and production of Amaranth and increasing salinity had more negative impact. In this study, the most sensitive to salinity was after plant establishment and grain filling stage was the most tolerant

Study on relations between relative water content, cell membrane stability and duration of growth period with grain yield of lentil genotypesunder drought stress and non-stress conditions

Drought is one of the most important abiotic stresses that limits crop production in arid and semi-arid regions of the world. Lentil (Lens culinaris L.), a valuable legume crop, is produced mainly rain-fed in Iran. An experiment was conducted to study the relationships between relative water content (RWC), cell membrane stability (CMS) and duration of growth period with grain yield of 11 advanced genotypes, varieties and a local genotype in the Ardabil Agriculture and Natural Resources research Station. Experimental design was a randomized complete block design (RCBD) with three replication under both rain-fed and irrigated conditions. Combined ANOVA showed significant differences among all the evaluated traits. Significant differences between characters reveals that there are high variation between the traits studied. Means for characters under study showed that grain yield, RWC, CMS and duration of growth period decreased in rain-fed condition but cell membrane leakage (electric conductivity) increased. Correlation coefficients showed strongly positive relation between grain yield with RWC (r0.98**), strongly negative and non significant CMS (r-0.32ns) and strongly negative relation between grain yield and the days to maturity (r-0.78**). The results of the experiment also revealed that there weren’t a strong relation between yield and calculated attributes for drought tolerance except RWC. Therefore, this character could be effective in evaluation of drought tolerance and identification of high yielding genotypes (ILL 6031, ILL 9893 and ILL 8095)

Effect of nitrogen foliar application in different growth stage on canopy light receiving on 3 polygerm sugar beet yield

An experiment was conducted on three sugar beet cultivars(IC, PP22 and 7233) and different application method of Nitrogen in a RCBD base factorial in three replication in 2005. Results showed that there was significant difference between light receiving in bottom and head of canopy among cultivars. N affected this attribute also. In IC the highest light receiving to bottom and head of canopy and yield in foliar N application at 6-8 leaf stage were 627 PPF, 1198PPF respectively. In soil application and 14-16 leaf stage foliar application of N led to 248 PPF in bottom and 988 PPF in head of canopy, recpectively.In IC the least root yield obtained in foliar application at 14-16 stage as 75/2 ton/ha. In PP22 light receiving to bottom and head of canopy was 472 PPF, 1134 PPF for soil and foliar application at 14-16 leaf stage and yield at that stage was 100 ton/ha. There was a %58 and %21 decreasing in light receiving to bottom and head in 6-8 leaf stage in compare with 14-16 leaf stage, foliar application at 14-16 leaf stage led to root yield increasing as %38 and %42 than soil and 6-8 leaf stage application, respectively. In 7233 cultivar highest light received to bottom was 491 PPF in 14-16 leaf stage which was %17 higher than soil application. The highest light received to head of canopy was 1190 PPF in 6-8 leaf stage foliar application. There wasn’t difference between root yield in different method N application in this cultivar. In spite of N fertilizer application led to increase leaf area and light absorption by plant canopy, there is limited information on the higher rates of N application between cultivars

Allelopathic Effects of Bermuda grass (Cynodon dactylon) on Seed Germination, Growth and Yield of Bread Wheat (Triticum aestivum)

Because of abundance and importance of Cynodon dactylon in wheat fields a factorial experiment was conducted with three replicates to study allelopathic effects on Cynodon dactylon on wheat in 2oo7. Extract of different parts of this weed in five levels (control, leaf, shoot, root, and flower extract) and its different concentrations in 4 levels (1:5, 1:10, 1:15, and 1:20) were used to evaluate its concentration effects on seed germination, vegetative growth and seed yield of wheat. Anova showed that effect of main factor and interactions on some attributes studied were significant. All concentrations of extracts decreased germination as compared to control. But, weed root and total plant parts extracts showed highest reduction on germination. 1:5 extract concentration decreased radical and plumole length, seedling dry weight, seed and percentage of germination by 81.38, 79.37, 73.75, 97.33 and 70.31%, respectively. ANOVA in green house showed significant effect of some main factors and interactions. Increasing extract concentrations from 1:20 to 1:5 decreased significantly all attributes. Rate of reduction in plant height, spike length, leaf number, peduncle length, biomass, seed number, TKW, and yield in 1:5 concentration as compared to control were 53.88, 40.42, 52.80, 63.85, 82.84, 88.63, 76.10 and 95.84%, respectively. Base on this experiment, it can be said that Cynodon dactylon produces allelopatic chemical materials and thus decreases germination, growth and seed yield of wheat considerably

The Effect of Zinc Sulfate Different Amount Soil and Foliar Application on Correlated Grain Characters in Sweet Corn

This research was conducted to evaluate the effects different concentrations of zinc sulfate applications at different growth stages on sweet corn at the Research Station of Faculty of Agriculture in Islamic Azad University, Tabriz branch in 2012. The study was conducted in split plot experiment based on Randomized Complete Block Design with three replications. Treatments were seven levels of zinc sulfate application methods: (control, soil application, foliar application at 6-8 leaf growth stage, tasseling, grain filling stage, foliar application at three stages, soil application with foliar application at three stages) as main plot, three levels of foliar and soil application of zinc sulfate: (0.003, 0.005 and 0.007 for foliar application and 15, 25 and 35 kg/ha for soil application) as sub plot. Results showed that the highest grain yield correlated characters were obtained in foliar application at three stages and soil application with foliar application at three stages. In these conditions increasing of dry grain yield and ear were more than 50%. The higher values for grain production were obtained in Zn foliar application with 0.005 concentration (25 kg/ha soil application). Zinc sulfate increased Zn content of grains produced more than 100%. Thus, using Zn not only increases sweet corn grain and ear yield but also increased quality of products

Evaluation of Grain Yield and Some Agronomic Traits of Tow Corn (Zea mays) Varieties as a Second Crop under Drought Stress and Application of Cycocel

To evaluate grain yield and some agronomic traits of tow corn varieties as a second crop under drought stress and application of cycocel an experiment was conducted at Agricultural Research Station of Jahad-Keshavarsi of Khoy during summer growing season of 2005.  Experimental design was a split-split plot based on RCBD with four replications. The factors consisted of irrigation as the main factor with three levels (irrigation after 70±5, 100±5 and 130±5 mm evaporation from class A pan), varieties 260 and 301 of corn as subfactor and application of different rates of cycocel (with and without application) as sub-subfactor. Results showed that drought stress reduced plant height, stem diameter, number of leaves and the leaf area index, biological yield and grain yield. Application of cycocel increased the stem diameter, biological yield and grain yield as compared with not application of cycocel. Generally, It can be concluded that irrigation after 70 mm evaporation and the application of cycocel can play major roles in increasing corn grain yield