Effect of potash application on growth, yield and yield components of spring maize hybrids
Productivity of spring maize hybrids was compared under different levels of potash at Agronomy Research Farm, The University of Agriculture KPK Peshawar during spring, 2014. The experiment was carried out in randomized complete block design (RCBD) with four replications. Four levels of K2O @ 0, 60, 90 and 120 kg ha , and four spring maize hybrids viz., 30K08, 2031, CS200 and 3025 were studied. The texture of the experimental area soil was silty clay loam with alkaline nature (pH 7.5-7.8). The soil was deficient in total N (≤ 0.53g kg soil) and K (≤ 92 mg kg) soil. A uniform dose of 150 kg N ha and 90 kg P ha in the form of urea and DAP was applied. Nitrogen was applied in two equal splits i.e. 50% at sowing and 50% at 2 irrigation. Sulphate of potash was used as a source of potash. All K and P dose was applied at sowing time. Results exhibited that there was a considerable effect of K2O levels on plant height, leaf area and yield and yield components except number of ears plant and plants at harvest. Applying K2O at the level of 90 kg ha boosted yield and yield components yet increasing level of K2O above 90 90 kg ha had no profound effect. Among the hybrids, CS200 performed better by producing more grain and biological yield. Hence for obtaining higher grain yield, Hybrid-CS200 with application of K2O at the rate of @ 90 kg ha -1 is recommended. Keyword: Potash levels; spring maize hybrids; yield and yield components
Effect of Potassium Fertilizer on Corn Yield (Jeta cv.) Under Drought Stress Condition
In order to consider yield changes and some characteristics of corn cv. Jeta reaction to water deficit stress and potassium fertilizer, a randomized complete block design base split plot experiment with three replications was conducted during 2009 at Agricultural Research Station, Islamic Azad University, Tabriz branch, Iran. Water deficit stress in four levels after 50, 90, 130 and 170 mm evaporation from class A in main plot and potassium sulfate in five levels 0, 50, 100, 150 and 200 kg/ha in sub plots. The obtained results indicated that increasing water deficit lead to reduce leaves number, stem diameter, biomass, grain numbers per row, grains weight per ear, 1000 grains weight, leaf area duration, grains effective filling period and grains yield. Increasing application of potassium fertilizer from 0 to 200 kg/ha increased number of leaves, stem diameter and biomass. The highest plant biomass was obtained by irrigation after 50 mm evaporation from head and application potassium fertilizer at the rate 200 kg/ha and the lowest by irrigation after 170 mm evaporation and lack potassium fertilizer. Also, application of 200 kg K/ha increased grains number per row, grains weight per row and 1000 grains weight that increased grains yield. The highest grains yield was 15.9 t/ha resulted in by application potassium fertilizer at the rate of 200 kg/ha and the lowest at lack application fertilizer equal 10 t/ha. Application of 200 kg K/ha increased leaves number, stem diameter, biomass, grains number per row, grains weight per row, 1000 grains weight relation lack application the rate 6.5, 92.49, 66.82, 24.96, 48.4, 13.92%, respectively. Increase in the application of potassium fertilizer caused to augmentation leaf area duration and in this way effective seed filling period find to increase. Base on the results of this experiment, application potassium fertilizer under water deficit condition decreased grains yield from 19.96 to 48.37%.
Inhibition of Root Growth and Polyamine Metabolism in Sunflower (Helianthus annuus) Seedlings Under Cadmium and Copper Stress
Although sunflower is usually regarded as a highly tolerant crop, impairment of root growth at initial stages of plant development may result in poor crop establishment and higher susceptibility to pathogen attack. In order to evaluate if Cd2+ and Cu2+ may impact on sunflower germination and initial root development, a pot experiment under controlled conditions was carried out. Possible involvement of polyamine metabolism in sunflower response to these stressors was also investigated. Although Cd2+ and Cu2+ treatments affect neither seed germination nor radicle emergence, sunflower seedlings grown in the presence of these heavy metals showed significant inhibition of root growth, being this inhibition greater for Cd2+. Both metals caused significant increases in proline contents at the highest concentrations tested (0.5 and 1 mM), and these increments were more pronounced for Cd2+ treatments, especially between days 3 and 10. Metals also increased putrescine (Put) contents at all concentrations assayed from the seventh day onward, causing no variations on this polyamine time-course pattern. Spermine and spermidine contents, however, were increased only by 1 mM Cd2+. Arginine decarboxylase seems to have been the enzyme responsible for Put increases under both metal treatments. This work demonstrates that initial root growth of sunflower seedlings may be significantly impaired in Cd2+ or Cu2+ contaminated soils. It also shows that polyamines are key biological compounds, which are probably involved in signaling pathways triggered under stress environmental conditions.