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

The increasing demand for medicinal plants in traditional medicine as well as the pharmaceutical industry has created the need for some plants to be grown commercially, but the lack of soil moisture poses a serious threat to their production. Planting method can affect the emergence and growth rate of crop and lead to decrease water consumption and increase irrigation water efficiency as yield increases. Roselle (Hibiscus sabdariffa L.) is one of the drought tolerant plants. Saving water consumption by cultivating drought tolerant plants has been proposed as a strategy to combat drought. It should be noted, however, that irrigation without proper planning can reduce the growth and production of crops. In this regard, determining time of deficit irrigation with minimum damage is an appropriate solution that achieves optimum yield while saving water consumption. The aim of this study was to investigate the effect of different irrigation regimes and planting method on some physiological traits, yield and water use efficiency of Roselle plant.

The experiment was conducted as split plot based on randomized complete blocks design with three replications at the Research Farm of Kashmar Agricultural and Natural Resources Research Station, during two growth seasons 2016 and 2017. Irrigation (in seven levels i.e. I100: 100% crop water requirement (CWR), I180: 80% CWR from 8-leaf stage to end of flowering, I280: 80% CWR from 8-leaf stage to beginning of flowering, I380: 80% CWR from beginning to end of flowering, I160: 60% CWR from 8-leaf stage to end of flowering, I260: 60% CWR from 8-leaf stage to  beginning of flowering, I360: 60% CWR from beginning to end of flowering) and planting method (in two levels i.e. direct and indirect) were in main plots and sub plots, respectively. In the transplanting method, the seeds were sown in the transplant tray on March 10, 2016 and 2017 and transplanted to the farm in four-leaf stage. Direct cultivation was also carried out in April, in 2.5 × 7 meter plots at a depth of 1.5 cm.In order to measure physiological traits, sampling from the youngest leaves of plants under stress and control conditions was carried out at the maximum flowering stage. Physiological traits including chlorophyll a, chlorophyll b, carotenoid, leaf relative water content and proline content were measured using these leaves. At the harvest time, two square meters of each plot were harvested. Then, seed and calyx yield were measured and using the measured amount of water consumed, water use efficiency based on seed and calyx were calculated.Data were analyzed with SAS software; obtained averages compared with using Tukey's Studentized Range (HSD) Test at the 5% probability level.

The results showed leaf relative water content was affected only by irrigation and planting method and seed and calyx yields were affected only by irrigation. The leaf relative water content in seedling planting method was higher than direct planting. The highest relative leaf water content (84.66%), seed (667.54 kg ha-1) and calyx yield (392.73 kg ha-1) were obtained in I100 treatment that for yield had no significant difference with I801 treatment. The lowest these traits were also obtained in I360 treatment.The interaction effect between irrigation and planting method was significant on chlorophyll a, chlorophyll b, carotenoids, leaf proline content, seed and calyx water use efficiency. In most irrigation levels, transplanting improved these traits compared to direct sowing. I100 and transplanting treatment had the highest chlorophyll a (0.31 μmol g-1 fw), chlorophyll b (0.16 μmol g-1 fw) and carotenoids (0.56 μmol g-1 fw) and I360 and transplanting treatment had the highest leaf proline content (7.95 μmol g-1 fw). The highest seed (0.15 kg m-3) and calyx (0.08 kg m-3) water use efficiency were obtained in I160 and transplanting treatment and I180 and transplanting treatment was located in the second level. I360 and direct planting method had the lowest seed (0.06 kg m-3) and calyx (0.03 kg m-3) water use efficiency.

The results of this study revealed that deficit irrigation at 80% of the crop water requirement from 8-leaf stage to the end of flowering along with transplanting method was more effective in saving irrigation water with a good yield of the Roselle plant compare to treatment of 100% of the crop water requirement.

Roselle (Hibiscus sabdariffa) is an annual plant with a height of about 64 to 429 cm belongs to Malvaceae family. Roselle is self-pollinated and sensitive to cold. Sepals of Roselle are used in food and pharmaceutical industries. It has been reported that Roselle is not native to Iran but it is cultivated extensively in Sistan and Baluchistan province, Iran. In order to achieve high quality and quantity yield of Roselle sepal it is necessary to improve nutritional systems of plant. Proper management of soil fertility and plant nutrition can preserve environment, improve biodiversity and also increase inputs efficiency. Results showed that use of nutritional resources will improve plant growth. Organic fertilizers such as compost can improve soil fertility as an important source of food that increase yield of plants. Nabila and Aly (2002) observed that use of hen and cow manure increased plant height, number of lateral branches, numbers of fruit and sepal yield of Roselle. Each plant species has the maximum potential in favorable conditions. Therefore, evaluation the effect of climatic and agronomic factors and nutritional management for plants is essential. This experiment was conducted to evaluate the yield and yield components of Roselle in response to use of single and combined nutritional resources.
Materials and Methods : In order to study the effects of single and combined organic, biological and chemical fertilizers on yield and yield components of Roselle (Hibiscus sabdariffa), a field experiment was conducted with 12 treatments based on a Randomized Complete Block Design with three replications at Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, in 2013-2014. Treatments included: 1- mycorrhiza (Glomus intraradices), 2- cow manure, 3- chemical fertilizer, 4- vermicompost, 5- chemical fertilizer cow manure, 6- chemical fertilizer vermicompost, 7- chemical fertilizer mycorrhiza, 8- cow manure mycorrhiza, 9- vermicompost mycorrhiza, 10- cow manure vermicompost mycorrhiza, 11- control. Roselle seeds were planted in seedling trays at greenhouse in mid-March 2014. Then seedlings transferred to field in last April 2014. The distance between rows and plants were 75 and 25 cm, respectively. Chemical fertilizer (200 kg ha-1), vermicompost (8 ton ha-1) and cow manure (32 ton ha-1) were put at the depth of 30 cm soil. Along with the cultivation Glomusintraradice was used 30 g per seedling. Roselle was harvested in mid-October before the arrival of the first winter cold in Mashhad. Statistical analysis of the data was performed by using of Minitab Ver.16. Also, means comparison were compared by Duncan multiple range test at 5% probability level.
The results indicated significant effect of treatments on most of the traits of Roselle. The maximum plant height (138 cm) was obtained in chemical fertilizer cow manure. The combined use of fertilizers increased plant height by 9% compared with using of single it. Results showed that the maximum height was observed by combined using of organic and chemical fertilizers. The highest sepal yield was observed in mycorrhiza (854.1 kg ha-1) and then chemical fertilizer cow manure (791.6 kg ha-1) and the lowest sepal fresh weight and yield (3202.1 and 420.8 kg ha-1, respectively) were obtained in cow manure treatment. Combined use of fertilizer improved sepal yield 11% compared with using of single it. Researchers concluded that combined use of fertilizers by creating a stimulatory effect on the balance of elements in the soil can be improved growth of plants. Also, the maximum amount of biological yield was obtained in vermicompost mycorrhiza (10482.9 kg ha-1) and then chemical fertilizer cow manure (9887.2 kg ha-1). Several studies showed that the combined application of manure and chemical fertilizers by improving soil physical properties and increasing the availability of nutrients, improve the efficiency of nutrient uptake and yield of plants.
Generally, combined application of organic and chemical fertilizers through improvement of growth indices, increased quantity yield of Roselle compared with single application. As well as, transplanting of this plant had a positive effect on sepal and biological yield. Therefore, with the advent of early winter cold in Mashhad, recommended that Roselle cultivated three month earlier as transplanting in the greenhouse.

Pondweed is a waterlogging habitat weed of paddy fields margin which has recently invaded rice fields. Because barnyardgrass is the most abundant and important weed of paddy fields in Iran, hence adopting any program for pondweed chemical control should involve barnyardgrass control as well. Therefore, two separate trials were carried out to evaluate the efficiency of selective rice herbicides for managing both pondweed and barnyardgrass. In this experiment the treatments included applying thiobencarb (2500 g.ai.ha-1), butachlor (1800 g.ai.ha-1), oxadiargyl (105 g.ai.ha-1), pretilachlor (1000 g.ai.ha-1), bensulfuron-methyl (45 g.ai.ha-1), cinosulforun (45 g.ai.ha-1) and metsulfuronmethyl (10 g.ai.ha-1). In the first trial, each herbicide was applied separately. In the second trial herbicides were mized. Results showed that thiobencarb, butachlor and pretilachlor were effective on barnyardgrass control (≤95%) but had no effect on pondweed. Oxadiargyl was more effective on barnyardgrass (75-90%) than pondweed (35-45%). Sulfonylurea herbicides showed very good efficacy on pondweed control (≤95%) while low effect on barnyardgrass (≥35%). The second experiment was carried out in order to investigate the mixture compatibility of the two groups of herbicides with different weed control spectrum. Data of the second trial confirmed the results of the first trial and revealed that mixing the recommended dose of herbicides controlled both weeds by 95%.

While producing medicinal plants is more economic in their natural habitat than in farms, their establishment problems and slow growth rate are the main constraints under the natural conditions. This study was conducted to investigate the possibility for seedling transplantation of thyme into the natural conditions, in order to investigate the effect of mycorrhiza inoculation on establishment of this species in Bahar Kish rangeland, Quchan. Seeds were planted in glasshouse in small trays for 45 days, after that, seedlings were inoculated with two mycorrhiza species, Glomus mosseae and Glomus intraradices. After one month growth, the inoculated seedlings were transplanted into the natural. A complete randomized Block design with 30 replication was used. The results showed that mycorrhiza colonization with G. mosseae was 92% and with G. intraradices was 68%. There was no significant effect of inoculation on seedling establishment at early season, but at the end of growth there was a negative effect by G. intraradices but a positive effect by G. mosseae. Symbiosis with G. mosseae increased dry matter of leaf, stem, total dry matter and height of the plants while with G. intraradices had reduced these traits or the effects were non-significant. In conclusion pot planting can be an efficient method for establishing T. vulgaris under natural habitats, G. mosseae can be a beneficial symbiant for establishment of T. vulgaris in Baharkish rangelands.