جستجوی مقالات مرتبط با کلیدواژه « کرچک » در نشریات گروه « زراعت »

Improving the nutritional status of plants is an effective method for enhancing their ability to withstand drought stress. To evaluate the quantitative, qualitative, and antioxidant properties of castor plant under water deficit conditions stress and foliar application of chemical fertilizers, an experiment was conducted as a split-plot design in a completely randomized block design with three replications. The first factor was irrigation levels including control (normal irrigation), irrigation after 80 mm and 140 mm evaporation from the pan evaporation in the main plots, and eight spraying chemical fertilizers (sulfur, potassium, nitrogen, sulfur+potassium, sulfur+nitrogen, potassium+nitrogen, sulfur+potassium+ nitrogen and control (no spraying)) were included in subplots. The highest proline content, catalase, peroxidase, superoxide dismutase, and total phenol were obtained under irrigation after 140 mm of evaporation conditions and foliar application of nitrogen+potassium+sulfur. Also, the highest grain yield, oil yield, and the lowest oil percentage were observed in the nitrogen+potassium foliar treatment under irrigation conditions after 20 mm of evaporation. Although the content of malondialdehyde increased in water deficit stress treatments, nitrogen+potassium+sulfur and nitrogen+potassium foliar application significantly reduced the peroxidation of membrane lipids (malondialdehyde) under irrigation conditions after 80 and 140 mm of evaporation compared to the control treatment. In conclusion, foliar application of chemical fertilizers in castor can improve the resistance to water stress by strengthening the antioxidant system and then increase its grain and oil yield.

Drought is an important factor affecting germination, early plant growth and its rate and decreasing economic performance of seedlings. Thus, seed priming to induce homogenice germination, emergence and increase the rate of growth and reduce adverse environmental effects results higher in yields. It also facilitates seedling emergence early and establishment of the plant. To study the effect of drought stress and seed priming on some vegetative and reproductive traits of castorbean (Ricinus communis), a split plot experiment based on randomized complete block design with three replications was conducted at the Saetlo Station of Agricultural and Natural Resources Research and Education Center of West Azerbaijan, during growing season of 2013. Main factors were drought stress with four levels (60, 90, 110 and 130 mm pan evaporation) and subfacotre were four seed priming treatments: control, hydro-priming, salicylic acid and hydrogen peroxide. Results of variance analysis showed that the drought stress significantly affected plant height, 1000 seed weight, grain yield, oil yield and grain harvest index. Seed priming also, significantly affected plant height, 1000 seed weight, seed yield, oil yield and harvest index. Interaction between water stress and priming treatments significantly affected grain yield. Considering the comparison of mean values, it was observed that plant height, 1000-seed weight, seed yield, oil yield and harvest index, at 60-mm evaporation from the pan had the highest values. Seed priming affected all of the traits and salicylic acid treatment also was able to affected the highest amount of all traits. The highest grain yield and 1000 grain weight were due to the interaction of 60 mm evaporation from the evaporation pan and seed priming with salicylic acid.

To evaluate the effect of humic acid on activity of antioxidant enzymes in castor bean a split plot experiment based on completely randomize block design with four replications was carried out at Islamic Azad University, Karaj Branch in 2014. Treatments were irrigation with three levels [irrigation at 80% of field capacity (S1) (normal), irrigation at 65% of field capacity (S2) (mid stress) and irrigation at 50% of field capacity (S3) (high stress)] assigned to main plots and humic acid with four levels (without foliar application, one time, twice and three times foliar application) to sub plots. In this study traits like seed yield, 100 seed weight and antioxidant enzymes were estimated. The results showed that the effect of humic acid was significant at 1% level on 100 seed weight and activity of antioxidant enzymes. Mean comparisons indicate that foliar application of humic acid could compensate relative effect of water deficit. It was also revealed that the rate of superoxide dismutase, glutathione peroxidase and catalase were increased with three times of humic acid foliar applications by 38.8, 34.75 and 37.88 percent under mid stress drought and 26.63, 41.15 and 43.14 percents under high stress drought as compared to control, respectively. Overall, it can be said that use of humic acid have different physiological effects. Humic acid not only increases seed yield of castor bean it also have a positive role in reducing water deficit effects and increasing activity of antioxidant enzymes.

In order to study the effect of planting pattern on vegetative and reproductive traits of caster bean, an experiment was done during (2010) in Agriculture and Natural Resources Research Institute, West Azerbijan, Iran. This study performed as a split plot in a randomized complete block design with 3 replications. The treatments include 3 row spacing (60, 80 and 100 cm) as the main plot, the plant spacing in the row (30, 40 and 50) as the sub plat. The results showed that the effect of row spacing on the length of main ear, the number of branch, leaf weight, the ratio of female/ male flowers, 100 seed weight on the main ear, biological yield, oil yield, oil percentage, grain yield and its components, such as, the number of capsules and grain/main ear, were significant. Also, the effect of inter row spacing on the length of main ear, number of branch, ratio of female/ male flowers, leaf weight, stalk diagonal, biological yield, oil percentage, seed weight/ main ear, seed yield and its components, such as capsule/ main ear and weight of 100 grain were significant. The interaction between row spacing and iner row spacing, the most biological yield produced in 60 intera row*30 inter row and most seed and oil yield were assigned to 80cm intera row*50cm inter row spacing. In this experiment, a positive correlation between grain yield and number capsule/ ear was found. According of this study planting in 80*50cm (intera row * inter row) suitable for castor bean plant in West Azerbijan.

To study the effect of mychorizha, glysin betaein and sugar beet extract on some physiological and biochemical parameters of castor bean as a second crop under drought stress conditions, a split plot arrangement in randomized complete block design with three replications was carried out in the Agricultural Research Station of Oshnaviya, West Azarbijan, Iran, in 2012 and 2013. Drought stress applied at four levels (irrigation after soil moisture reached to 80%, 70%, 60% and 50% of field capacity) were as assigned to the main plots and foliar application with glycine betaine (50 mM), sugar beet extract (100%) and water (control) and the use of super absorbent gel A200 (225 kg.ha-1) and inoculation with mycorrhiza (Glomus mossea) were randomized in sub-plots. Foliar application of glycine betaine, sugar beet extract and water were carried out at leaf 10 stage of the plant, and mycorrhiza and super absorbent gel were applied at planting. Mean comparison showed that increasing stress intensity from 80% to 50% of field capacity decreased seed yield by 49%. The highest malondialdehyde content (177.2 nmol.gFW) was achieved in severe water deficit stress with spraying water (control). The highest seed yield (2730 kg.ha-1) and the highest activity of APX (117.9 A290.mg protein), CAT (87.1 A240.mg protein) and SOD (46.9 unit.mg protein) enzymes were achieved from foliar application of sugar beet extract. Therefore, at all levels of irrigation, glycine betain and sugar beet extract treatments through induction of tolerance mechanisims increased the activities of antioxidant enzymes and thus increased seed yield compared to control due to decreasing adverse effect of water deficit stress. Therefore, foliar spraying with sugar beet extract can be suggested to alleviate water deficit stress effect in castor bean.

To determine the effects of foliar applications of some macroelements on castor seed yield and its components under drought stress conditions, an experiment was conducted at the Agricultural Research Center of East Azerbaijan province. A factorial experiment, based on randomized complete block design with three replications, was carried out during 2013 growing season. Treatment factors consisted of irrigations with two levels (no water deficit and water deficit during grain filling stage) and of foliar applications of macroelements with four levels [control, wettable sulfur (0.2 percent), nitrogen (urea: 0.6 percent) and phosphor (super phosphate triple: 0.4 percent). Traits studied were: plant height, number of inflorescence, number of lateral branches, number of leaves, leaf temperature, relative water content, number of seeds per plant, 1000-kernal weight and seed yield. All traits, except number of inflorescence, were affected significantly by drought stress. Water deficit reduced plant height, number of leaves, number of seeds per plant, 1000-kernal weight, seed yield, relative water content, while it increased leaf temperature. Number of lateral branches was affected significantly by interaction between factors. Maximum latral branches (1.86) were obtained under non-stress treatment with nitrogen foliar application. Moderate drought stress had significant effect on leaf temperature and relative water content. It seems that, these traits can be used in determination of water deficit effects on castor bean.

The experiment was conducted in 2012 to evaluate the effect of salinity stress on oil percent, oil yield, seed yield and some physiological charactristics on three local populations of castor bean (Ricinus communis L.), at the University of Shahrekord, Iran. Experiment was carried out with three replications in a completely randomized design including five levels of salinity (1.2, 2, 2.6, 3.8 and 4.8 dS/m in soil saturation paste) as the first factor and castor populations (Shiraz, Kerman and Urumieh) as the second factor. The effect of salinity was statistically significant (α>0.01) on seed yield, oil percent and oil yield, chlorophyl a, chlorophyll b and proline, while a significant effect (α>0.05) was observed for total chlorophyl. The results also showed that different populations had a significant difference (α>0.01) with regard to all studied factors. The highest and the lowest proline content were observed for Kerman and Shiraz populations, respectively. Increasing salinity increased the leaf proline content while it decreased the chlorophyll content was decreased. At low salinity levels, Shiraz population resulted to the highest seed and oil yield. However, with increasing salinity, seed yield and oil content of Shiraz population was less than other populations. Although more research is needed in this respect, but it seems that in castor been Shiraz population for soils with a low salinity and Kerman population for more saline conditions can be recommended.

In order to evaluate the effects of different sowing dates and plant densities on yield and yield components of castor bean crop, an experiment using a factorial based on randomized complete blocks with three replication was conducted at the research farm of west Azarbaijan Agricultural Research Center during 2007- 08. The first factor included three sowing dates in spring and the second factor included three planting density. Analysis of variance indicated that the effects of different sowing dates and plant densities on diffrent characteristics of castor bean crop were significant. Interaction sowing dates and plant densities was significant on biological yield. Results indicated that the highest grain and oil yield were producedof the last sowing date (5 June) and plant density 25000 plant per hectar. According to these results, last sowing date (5 June) and plant density 25000 plant per hectar are recommended.

This experiment was conducted to investigation of some agronomical traits in different castor bean genotypes at west Azarbaijan, in Agricultural Research Station of Urmia, as completely randomized block design with three replications, during 2007-2008. Result showed that the effect of different genotype were significant on all characteristics. The highest and lowest number of grain per plant observed in 80-11-1 (Shahreza) and 80-16-1 (Fasa) genotypes, respectively. The maximum 1000 grains weight (388.3 gr) observed in 80-29 genotype. Also, the highest seminals ear height from surface of ground (105.6 cm) observed at genotype of 80-4 and the lowest seminals ear height from surface of ground (27.3 cm) observed at genotype of 80-31. The greatest percent of pistil flower (91%) observed at genotype of 80-16-1. The highest grain yield and oil yield obtained at genotype of 80 -7. Therefore, if the purpose of planting this plant is achieving high economic performance, 80-7 genotype can be recommended for this area.

This study was conducted to evaluate the effect of sowing date on morphology,yield parameters, as well as oil percentage and fatty acids composition of castor bean. The experiment was carried out at research farm of Tarbiat Modares University, in randomized complete blocks design with three replications during 2010. Plants were grown at six sowing dates of 5th April, 20th April, 5th May, 20th May, 5th June and 20th June. The results showed that morphological traits and yield traits were influenced by sowing dates. The highest seed yield (1590.67 kg/h), oil yields (774.43 kg/g) were obtained at 5th April, and delay in sowing date, led to significant reduction in these traits. Fifteen fatty acids were detected in oil. Nevertheless, the highest amount of fatty acid belonged to Ricinoleic acid. Results showed that fatty acid composition of castor oil influenced by sowing date. Therefore, it can be concluded, that 15th April could be recommended as an appropriate sowing date in the studied location and similar climates for achieved high oil yield of castor bean.

In order to study the effects of sowing dates and different fertilizers on yield, yield components, and oil percentage of castor bean, an experiment was conducted at Experimental station, College of Agriculture, Ferdowsi University of Mashhad, Iran in years 2004-2005. The experimental treatments comprised all combinations of four sowing dates (11 April, 25 April, 8 May and 22 May) and three different fertilizers (cow manure (30 tons/ha), compost (30 tons/ha), chemical fertilizers (100 kg/ha N and 250 kg/ha of super phosphate) and no fertilizer as control. Different characteristics such as plant height, main inflorescence height, number of inflorescence per plant, number of secondary stems per plant, number of capsules per plant, number of grain per plant, grain weight per plant, 100 seed weight, grain yield, oil percentage and oil yield were recorded. A factorial arrangement based on a randomized complete block design with three replications was used. The results showed by delaying sowing date grain yield, seed oil percentage and oil yield were decreased, but there was no significant differences between 25 April, 8 May and 22 May sowing dates. Harvest index and 100 seed weight did not affect by neither sowing dates nor fertilizer treatments. The highest number of branches per plant, number of fertile inflorescences per plant, number of fertile capsules per plant, number of grain per plant, grain weight per plant and biological yield were obtained at 8 May sowing date on chemical fertilizer. Percentage of seed oil, grain yield and oil yield was higher at the first sowing date (11 April) in compost and chemical fertilizer treatments.

Because of importance of castor bean oil in different industries and limited water resources in many parts of Iran, an experiment was conducted to determine the effect of irrigation intervals and plant densities on grain, oil yield and yield components of castor bean, at Experimental Station, College of Agriculture, Ferdowsi University of Mashhad. Four irrigation intervals (one, two, three and four weeks) and four plant densities (1, 2, 3 and 4 plants per square meter) were compared in a split arrangement based on completely randomized block design with four replications. The plant characteristics were studied in terms of plant height, inflorescence height, the first inflorescence height from soil surface, inflorescence number, branch number, number of capsule per plant, number of grain per plant, biomass per plant, 1000 grains weight, grain yield, harvest index and oil yield. Result showed that the effect of different irrigation intervals was significant on all of characteristics under study except harvest index and oil percentage