جستجوی مقالات مرتبط با کلیدواژه "pigments" در نشریات گروه "زراعت"

The field experiment has been conducted as a split split plot based on a randomized complete block design with three replicaitons at Rice Research Institute of Mazandaran Province, Amol, in 2017. In this experiment, the seeds are sown in seedling box with different six bed treatments. These beds include S1: sulfur bed with 50% rice bran, S2: sulfur-free soil with 25% rice bran, S3: sulfur bed with 25% rice bran, S4: sulfur bed with Thiobacillus and 50% rice bran, S5: sulfur-free bed with wood compost and 25% rice bran, and S6: sulfur bed with Thiobacillus with 25% bran rice. After some measurements, the seedling is transplanted in the main field. In the field, different beds in box, seedling number per hill (3 and 5) and planting space (20×20 cm, 30×14cm) are assigned to the main plot, sub plot, and sub sub plot, respectively. The results of main cultivation show that the highest grain yield (5043 kg.ha-1) and biological yield (12319 kg.ha-1) are obtained from the treatment of bed soil with sulfur with 50% bran. Planting arrangement treatment in ratoon cultivation on number of hollow seeds (4.1), grain yield (1617 kg.ha-1), number of plants per hill treatment on number of tillers (10.3), leaf area (10.6 cm2), panicle length (20.4 cm) and grain yield (1613 kg.ha-1), and seedling type treatment on tiller number (10.4) show a statistically significant difference. Seedling grown in sulfur with 50% rice brain display the best performance in terms of yield and yield components in both main and ratoon cropping.

Effect of different levels of nitrogen fertilizer on chlorophyll a, chlorophyll b, carotenoid, flavonoid, yield and yield components of four wheat cultivars in two locations (Kudian and Nasrabad, Fars province, Iran) were investigated. The experiment was conducted as split plot in a randomized complete block design with two main irrigation levels (normal and interrupted irrigation at the stem stage). Four wheat cultivars (Shiroodi, Chamran 2, Chamran matri, and Siamran) and four levels of nitrogen fertilizer (0, 120, 240 and 360 kg ha-1) with three replications were used as sub-factors. Grain yield traits, number of grains per spike, number of spikes per square meter, 1000-grain weight, chlorophyll a, chlorophyll b, carotenoid and flavonoid pigments were evaluated. The results showed that drought stress reduced chlorophyll a, chlorophyll b, carotenoid, flavonoid, yield and yield components. Drought stress reduced grain yield by 29% but application of 120, 240 and 360 kg ha-1 nitrogen increased yield by 25, 32 and 15%, respectively. Therefore, the use of 240 kg nitrogen could be useful for these cultivars in both drought and non-stress conditions.

To evaluate the integrated management of weeds in red kidney bean, a split-plot experiment using randomized complete block design with three replications was conducted in 2013 in the Damavand County. In this experiment, the mechanical control treatments consisted of two levels (no cultivation and one cultivation) asseigned to main plots and controlling chemical treatments consisted of six levels (non-application of herbicides, pre-emergence herbicide application of Pursuit with full dose of 1 liter per hectare, pre-emergence herbicide application of Pursuit a dose decreased 0.5 liters per hectare, post-emergence herbicide application of Pursuit dose reduced to 0.3 liters per hectare 2 thousand citogate, post-emergence herbicide application of Pursuit with a reduced dose of 0.5 liters per hectare 2 thousand citogate, post-emergence herbicide application of Pursuit full dose of 1 liter per hectar 2 thousand citogate) to subplots. The results showed that the effects of interaction between herbicide application and cultivation for traits of carotenoids, chlorophyll a, chlorophyll b and total chlorophyll contents, density of weeds and their dry weights were significant at 1 %, and grain yield at the 5% probability levels. The highest bean seed yield with an average of 5461.6 kg.ha-1 and lowest weed dry weight with an average of 345.9 kg.ha-1 were related to pre-emergence herbicide and cultivation with a dose of 1 liter per hectare treatment. The difference between full and reduced doses of chemical weed control was non-significant. It could be concluded that integrated mechanical and chemical weed control not only may increase seed yield but also reduce, environmental hazards.

Salinity is one of the most important widespread abiotic stresses which causes toxic and nutritional effects as well as loss of water absorption ability by plants. Plants respond to salinity with morphological changes. Due to high susceptibility of chickpea to salt stress، some physiological and morphological responses occur following the stress in this plant. Thus، different concentrations of salt stress (0، 8، 12 dS. m-1) impacts on morphophysiological characteristics were studied in candidate chickpea genotypes; a factorial experiment in a completely randomized design was performed with three replications and four sampling times of one week interval. The results indicated that the most tolerant and susceptible genotype to salinity were MCC760 and MCC806، respectively. By increasing the concentration of sodium chloride at week 4، root dry weight to shoot dry weight ratio increased 0. 8 and 2 folds in these genotypes but root dry weight decreased 1. 7 and 4 folds. At high stress level (12 dS. m-1)، MCC760 genotype had not only the more photosynthetic pigments (including chlorophyll a، b and carotenoids) but also the rate was less in which its chlorophyll stability index (75%) was significantly higher than the others، indicating more than 30% significant differences compared with MCC806. The third week determined as more appropriate time to compare the physiological parameters in which MCC760 and MCC806 genotypes with 1. 8 and 3. 4 folds had significant difference and lowest relative water content. Overall، the data showed that MCC760 was the most tolerant genotype in response to salinity in this study and also the appropriate time for tolerant assessment were 4th and 3rd weeks after sowing based on Morphological and physiological parameters، respectively.