Journal of Research on Crop Ecophysiology
Volume:10 Issue: 2, Spring 2016

Variable rates (0, 20, 40, 60 and 80 kg ha-1) of potassium (K) fertilization effects on growth, yield as well as the  relationship between yield and growth parameters of T. Aman (monsoon season) rice were examined in 2010 at Bangladesh Rice Research Institute (BRRI) research farm, Gazipur, Bangladesh following randomized complete block design with three replications. Test rice variety was BRRI dhan49 and the soil was Aeric Haplaquept. Plant height, panicle length, dry matter production at maturity, straw and grain yields significantly (p < 0.01) increased in a quadratic fashion; but tillersm-2, panicles m-2, spikelet panicle-1, filled grains in a panicle, dry matter yield at panicle initiation (PI) stage increased significantly (p < 0.01) in a linear fashion when K rates were increased from 0 to 80 kg ha-1. Maximum grain yield (4958 kg ha-1) was obtained at 80 kg K ha-1. Panicles m-2, spikelets in a panicle, filled grains, dry matter yield, harvest index, 1000 grain weight had significant positive association with grain yield. Optimum K rate and K requirement of BRRI dhan49 was found to be 64.14 kg ha-1 13 kg t-1 rice. Calculated K dose for T. Aman rice was much higher than the recommended dose. Therefore, potassium dose for wet season rice should be increased for desired yield otherwise potassium mining from soil and yield reduction might be occurred.

In order to determine forage yield, land equivalent ratio (LER), relative yield of crop (R), relative yield total (RYT) and corn organic matter, a study was done at Research Farm, Islamic Azad University, Isfahan Branch. A factorial experiment in randomized complete block design with 3 replications was used. Berseem clover cultivars intercropped with corn SC704 were Karaj, Sacromont and Multicut, and nitrogen levels included were 0, 40 and 60 kg/ha. The nitrogen fertilizer was provided from urea source (46% pure N). The effect of cultivar was significant on total corn fresh and dry yield, R of clover, RYT and LER. Total clover fresh yield, total corn fresh yield, R of clover, RYT and LER were significantly influenced by nitrogen fertilizer. Cultivar and nitrogen interaction had significant effect on total corn fresh and dry yield, R of clover, RYT and LER. The highest total fresh and dry yields of corn were obtained in forage corn intercropped with Sacromont and Multicut, respectively. These two parameter significantly increased from application of 0 kg N/ha to 60 kg N/ha. In all intercropping treatments, land equivalent ratios (LER) were well above one indicating yield advantages for intercropping. The highest LER and RYT observed in intercropping of forage corn with Sacromont. There were no significant differences in corn organic matter between intercropped cultivars and nitrogen treatments. On the basis of the results total and dry yields were significantly increased from application of 0 to 60 kg N/ha. Forage corn intercropped with Multicut also had the highest total dry yield, but the maximum total fresh yield was achieve in forage corn and Sacromont intercropping system. In central of Iran and on the basis of low input farming system, cultivation of berseem clover cultivar intercropped with forage corn can be introduced for development of sustainable food production systems.

Wheat is one of the main resources of human food. Lodging is one of the most important factors that occurs in various regions and reduces wheat growth and yield. Therefore to study the effect of potassium and zinc application on resistant to lodging of two wheat cultivars, an experiment in a split-plot arrangement based on randomized complete block design (RCBD) in three replications was conducted in Dezful Agricultural Research Station at 2013-2014. The main plot was the use of the micronutrient zinc at three levels (0, 30, and 60 kg.ha-1 of zinc sulfate), and the sub plot was potassium application at four levels (0, 100, 200, and 400 kg.ha-1 of potassium sulfate). The results showed that zinc and potassium application increased their absorption by 90.34% and 34.96%, respectively, compared to the control. Moreover, the fiber content was 5.89% more compared to the control. Application of these elements had no significant effects on cellulose content, although its content was 3.47% higher than the control. The lignin content also rose by 60.51% compared to the control, and zinc at 30 kg.ha-1 and potassium at 400 kg.ha-1 reduced lodging percentage.

Fertilizer management is an important factor in successful cultivation of pharmaceutical plants. In order to investigate the effects of vermicompost and manures on growth characteristics and yield components of purslane (Portuleca oleracea L. var Behbahani), this study was carried out in a randomized complete blocks design with three replications in research greenhouses of Islamic Azad University- Isfahan Branch in 2014. Treatments were cow manure, sheep manure, buffalo manure and vermicompost of cow in 10, 20, 30, and 40% levels plus control (17 treatments). According to results, using manure had significant superiority (p<0.05) in all studied traits, so that, the highest fresh and dry weights of leaves, stem, and root, stem length, number of leaves, fresh and dry weights of aerial parts were obtained in 30% cow manure. Also, this treatment had the highest number of capsules per plant, seeds per plant, and 1000- seeds weight as yield components. On the whole, results showed that using manure can play important role in production and yield increment of Behbahani pursalne to reduce chemical fertilizers pollution and reach to sustainable agriculture.

To evaluate the effect of different nitrogen fertilizer on morphological properties of biomass of different corn cultivars, a field experiment was performed in a farm located in Kabutarabad area of Esfahan in 2014. Experiment was conducted in split plot design in complete randomized blocks layout with three replications. Different levels of nitrogen fertilizer in four levels of 100, 150, 200 and 250 Kg ha-1 of pure nitrogen from urea source and different varieties SC500, SC604, SC 700 and SC704 were considered as main and sub plots. The highest dry weights of leaf, stem and plant were obtained in 250 Kg N ha-1 treatment. SC704 due to longer growing period had the highest leaf, shoot, and plant dry weights relative to the other single crosses. With regard to sustainable agriculture and optimizing the use of fertilizer it seems under the same conditions of this study SC704 and 250 Kg ha-1 of nitrogen would give the best performance.

Nowadays, soilless cultivation as a modern technology for plant production with the objective of increasing quality and quantity of horticultural crops has been increasing developed. This research project was conducted to investigate the effect of perlite, cocopeat, and sand on the vegetative growth indices of tomato varieties Goldi, Santella and Vay using F1 and F2 generations. Results indicated that the highest plant total volume and weight, root wet weight and aerial parts in the second stage were obtained in 70% cocopeat + 30% perlite media for Santell F1 avariety. While the highest leaf area was obtained in 70% cocopeat + 30% perlite media for F2 Vay variety. The highest stem dimeter in the second measurement was obtained in 40% cocopeat + 40% perlite + 20% sand media for F1 Vay. Regarding some of the characteristics, only the simple effect of the tomato varieties and growing media were significant. Growing media containing more cocopeat, through providing more appropriate conditions led to better growth and development.