Agriculture and horticulture
Gh.R. Pourshaban Kateshali; Gh.A. Akbari; I. Alahdadi; E. Soltani
Abstract
To evaluate the plant adaptation and effects of irrigation cycles and NPK elements on growth and yield parameters of Zingiber officinale R., a split-plot experiment was conducted as a randomized complete block design with nine treatments and three replications in two regions including Pakdasht (Tehran ...
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To evaluate the plant adaptation and effects of irrigation cycles and NPK elements on growth and yield parameters of Zingiber officinale R., a split-plot experiment was conducted as a randomized complete block design with nine treatments and three replications in two regions including Pakdasht (Tehran province) and Lahijan (Gilan province) in 2021. The experimental factors included irrigation cycle at three levels (4 (V1), 6 (V2), and 8 (V3) days) as the main factor and NPK elements at three levels (N300P100K200 (F1), N350P150K250 (F2), and N250P50K150 (F3) (kg.ha-1)) as the sub-factor. The results showed that the irrigation×NPK effects was significant on plant height, number of leaves per plant, leaf area, number of branches per plant, leaf area index, fresh and rhizome dry weight, and rhizome yield at the 1% probability level and on stem diameter at the 5% probability level in Pakdasht region. The V1F2 treatment was the best one in this region. In Lahijan region, the irrigation×NPK effects was significant on number of leaves per plant and rhizome yield at the 1% probability level and on plant height and stem diameter at the 5% probability level. The best result in Lahijan was obtained in the V1F2 treatment. Also, in terms of leaf area, number of branches per plant, and leaf area index, V1 and F2 was the best treatments in Lahijan. Fresh and rhizome dry weight had the best results in the V2 and F2 treatments. Overall, the studied traits in Lahijan climate were superior to Pakdasht climate and every 4 days irrigation for Pakdasht and every 6 days for Lahijan had the best results.
K. Parvanak
Abstract
The reduction of photosynthesis is the most important reason for the decrease in productivity under drought stress conditions. For this purpose, this research was carried out to investigate the effect of moisture stress on shoot dry matter yield, water relations, chlorophyll fluorescence, photosynthesis, ...
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The reduction of photosynthesis is the most important reason for the decrease in productivity under drought stress conditions. For this purpose, this research was carried out to investigate the effect of moisture stress on shoot dry matter yield, water relations, chlorophyll fluorescence, photosynthesis, and gas exchanges in Salvia sahendica L. at Mobarakeh city, Isfahan, in 2016. The treatments included irrigation intervals of 4 (control), 8, 12 and 16 days conducted in a randomized complete block design under field conditions. The results of the analysis of variance showed that the effect of irrigation intervals treatments was significant on shoot dry matter yield, water relations, chlorophyll fluorescence, photosynthesis rate, and leaf gas exchanges. Based on the results of mean comparison, with increasing irrigation interval from 4 to 16 days, photosynthesis rate, transpiration rate, stomatal conductance, photosystem II efficiency, shoot dry matter yield, and harvest index decreased significantly by 55, 62, 73, 57, 58 and 45 percentage, and water use efficiency and gas exchanges increased significantly by 35 and 92 percentage, respectively. For the attributes mentioned above, the irrigation intervals of 8 and 12 days had no significant difference with control treatment. By increasing stress, the amount of intercellular carbon dioxide below the stomatal cells did not change significantly, but the leaf temperature increased significantly. Correlation coefficients showed that the shoot dry matter yield had a positive and significant correlation with photosynthesis and transpiration rate, stomatal conductance, and photosystem II efficiency, and a negative and significant correlation with leaf temperature, gas exchanges, and water use efficiency. Regarding the absence of significant difference between the indices studied at 8 and 12-day irrigation intervals in comparison with normal irrigation regime (control treatment), it can be concluded that the irrigation interval of 12 days is an optimum irrigation regime for using this plant in arid and semi-arid regions.
M. Nekookhoo; S. Fallah
Abstract
Hull-less seed pumpkin (Cucurbita pepo L.) is an important medicinal plant and its seed and byproducts are used in the treatment of many diseases. Production of this plant uses a lot of water and nitrogen. Plastic mulch application may reduce the water and nitrogen requirements. Therefore, an experiment ...
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Hull-less seed pumpkin (Cucurbita pepo L.) is an important medicinal plant and its seed and byproducts are used in the treatment of many diseases. Production of this plant uses a lot of water and nitrogen. Plastic mulch application may reduce the water and nitrogen requirements. Therefore, an experiment was conducted with the aim of evaluation of deficit irrigation and nitrogen effects on fruit, seed, and oil yield of hull-less seed pumpkin (Cucurbita pepo L.) under plastic mulch in 2016. A split plot layout in a randomized complete block design with three replications was used. Main plots included complete irrigation under plastic mulch, moderate stress (75% of complete irrigation under plastic mulch), severe stress (50% of complete irrigation under plastic mulch), normal irrigation without plastic mulch and sub-plots consisted of complete nitrogen requirement, 80% of the full nitrogen requirement and 60% of the full nitrogen requirement. The results showed that there were no significant differences between moderate stress (75% complete irrigation under plastic mulch) and normal irrigation without mulch for fruit, grain and oil yield. However, under moderate stress, the plastic mulch reduced water and nitrogen requirements by 25 and 20%, respectively and produced a grain yield and oil yield similar to complete irrigation. Therefore, this technique can be used for water conservation and sustainability of agricultural production systems in arid and semi-arid areas.
