Ali Ansori Savari; Majid Nabipour; Masoume Farzaneh
Abstract
Introduction
The high-water requirement of sugarcane in arid and semi-arid regions, coupled with a decrease in rainfall, has led to an increase in the use of drainage water for sustainable production management. It has been estimated that 20% of all cultivated land and 33% of irrigated agricultural land ...
Read More
Introduction
The high-water requirement of sugarcane in arid and semi-arid regions, coupled with a decrease in rainfall, has led to an increase in the use of drainage water for sustainable production management. It has been estimated that 20% of all cultivated land and 33% of irrigated agricultural land are affected by high salinity. Salinity stress poses two main threats to plants: ionic toxicity and osmotic stress. Ionic toxicity occurs when there is a significant buildup of Na+ in the leaves in a saline environment. This disrupts the balance of water and ions in plants, damages organelle structure, and inhibits plant growth, potentially leading to death. Some studies have shown that ion toxicity caused by Na+ can inflict more irreversible damage on plants than osmotic stress. Silicon application (Si) showed improved photosynthetic efficiency, growth, and yield compared to plants under salt stress. Previous studies have also shown that silicon treatments can increase salinity tolerance in various plants, including wheat, corn, rice, and canola. However, the extent of silicon-mediated benefits under salinity can vary greatly between species and is largely dependent on the plant's capacity for element uptake dictated by its genetic makeup. There is limited information regarding the use of drainage water in sugarcane irrigation management in arid and semi-arid regions, as well as the potential for improving salinity stress through silicon application. Therefore, this study was conducted to evaluate the effects of Si on two sugarcane varieties irrigated with salt water.
Materials and Methods
The pot experiment was conducted in a greenhouse with natural light at the agricultural site of Sugarcane Dehkhoda Company in Khuzestan Province, Iran, in 2021-2022. The temperature and humidity percentages are indicated in Figure 1. This study caried out as split-split plot design based on randomized Block design (RBD). The main plot factors included three levels of salinity: control of 1.4±0.2 dS.m-1 (S0) from the river water source, salinity stress of 4.1±0.2 dS.m-1 (S1), and salinity stress of 8.2±0.2 dS.m-1 (S2) from the drain water source, with a sub-factor of variety treatment (CP73-21 and CP69-1062). The silicon application timing was also considered as a sub-factor, with four levels: Si0, non-silicon application (Control); Si1, one month before salinity stress; Si2, during salinity stress; and Si3, (After 30 days of salt stress, silicon was applied). The sugarcane sprouts are grown in polyethylene pots 100 cm in height and 45 cm in width. Each pot contained 100 kg of soil. A total of 216 experimental units were used during the experiment. The experimental pots were filled with a mixture of field soil and sugarcane filter cake in a 3:1 ratio. The results of the chemical analysis of field soil and filter cake are presented in Table 2. The salt stress was applied 113 days after growing cuttings and continued until harvest.
Results and Discussion
The results of the first year showed that salt stress significantly reduced the height of the sugarcane stalk. Also, at the salinity stress levels of 4.1 and 8.2 dS/m, the SPAD index decreased by 22.3% and 27%, respectively. Additionally, leaf sheath moisture dropped by 6.4% and 11.8%, electrolyte leakage increased by 11% and 22.7%, and the photosynthesis rate decreased by 28% and 42% compared to the control treatment. The optimal time to apply silicone fertilizer was one month prior to the onset of stress, which resulted in a significant improvement in all studied traits at salinity stress levels of 1.4 dS/m (control) and 4.1 dS/m. Furthermore, the qualitative analysis of sugarcane syrup in the second year revealed a decrease in sucrose percentage (14.1% and 33.5%, respectively) and white sugar content (12.6% and 40.9%, respectively) at salinity stress levels of 4.1 and 8.2 dS/m. The photosynthesis rate of sugarcane leaves decreased by 28.3 to 41.8 percent under salt stress levels of 4.1 and 8.2 dS, respectively. The CP69-1062 variety exhibited a better response compared to the CP73-21 variety, showing relative superiority in all growth and physiological traits studied.
Conclusion
The results also indicated that the optimal time to apply silicon fertilizer to sugarcane plants was one month before the onset of stress, resulting in a significant improvement in all studied traits. The application of silicon fertilizer led to a 1 percent increase in sucrose, 3.7 percent increase in syrup purity, and 3 percent increase in white sugar yield compared to no application.
rahim motalebifard
Abstract
Introduction: With 12 million tons production per year, garlic is the fourth important crop in world. In addition to its medical value, it has been used in food industry. The Hamedan province with 1900 ha cultivation area and 38 percent of production is one of the most important garlic area productions ...
Read More
Introduction: With 12 million tons production per year, garlic is the fourth important crop in world. In addition to its medical value, it has been used in food industry. The Hamedan province with 1900 ha cultivation area and 38 percent of production is one of the most important garlic area productions in Iran. Few studies on water use and management of garlic exist in the world. Garlic is very sensitive to water deficit especially in tubers initiation and ripening periods. The current research was done because of scarce research on garlic production under water deficit condition in Iran and importance of plant nutrition and nutrients especially nitrogen on garlic production under stressful conditions. Nitrogen is necessary and important element for increasing the yield and quality of garlic. Application of nitrogen increases the growth trend of garlic such as number of leaves, leaf length and plant body. Reports have shown that garlic has high nitrogen requirement, particularly in the early stages of growth.
Materials and Methods: This study was conducted for evaluating the combined effects of nitrogen and irrigation on the yield and quality of garlic (Allium sativumL.). The study was performed as a split-block based on randomized complete blocks design with factors of irrigation at four levels (0-3(normal irrigation), 3-6 (slight water deficit), 6-9 (moderate water deficit) and 9-12 (sever water deficit) meters distance from main line source sprinkler system), nitrogen at four levels (0, 50,100 and 150 kg nitrogen per ha) using three replications and line source sprinkler irrigation system. The total water of irrigation levels was measured by boxes that were fixed in meddle of each plot. The statistical analysis of results were performed using themethod described by Hanks (1980). The chlorophyll index was measured using the chlorophyll meter 502 (Minolta, Spain). The chlorophyll a and bwas measured by the method described by Arnon (1946) and Gross (1991) in fresh leaf samples using spectrophotometer at 645 and 663 nm. Data were subjected to analysis of variance using MSTATC and SPSS softwares. Duncan’s multiple range test at p≤0.05 probability level was applied to compare the mean values of measured attributes. The Excel software (Excel software 2007, Microsoft Inc., WA, USA) was used to draw Figures.
Results and Discussion: The results showed that, the application of nitrogen significantly affected most of measured attributes. The application of 150 kg N per ha showed highest stem height (40.5 cm), dry weight of stem (5.34 g),wet weight of stem (69.5 g), chlorophyll index (49.7),chlorophyll a (9.8 mg.g-1dw) and chlorophyll b (4.04 mg.g-1dw) and increased stem height, dry and wet weight of stem, chlorophyll index and chlorophyll a and b around 7, 6, 7, 12, 22 and 36 percent, respectively. The irrigation levels significantly affected most of measured attributes similar to the nitrogen levels. The application of 409 mm irrigation water per growing season resulted to maximum stem height (41.9 cm), leaf number (7.5), dry weight of stem (5.39 g) and wet weight of stem (70.1 g), chlorophyll index (50.5) and chlorophyll a (10.2 mg.g-1dw) and chlorophyll b (4.04 mg.g-1dw). The severe water deficit (application of 138 mm irrigation water per growing season) decreased stem height, leaf numbers, dry and wet weight of stem, chlorophyll index and chlorophyll a and b about 13, 36, 12, 12, 19, 42 and 44 percent, respectively. The two way interaction of nitrogen and irrigation was significant and mostly synergistic on wet and dry weight of stem. The highest amounts of stem wet weight (73.2 g) and stem dry weight (5.63 g) were resulted from application of 150 kg nitrogen per ha under full irrigated condition that increased dry and wet weight of stem 17 and 25 percent respectively comparing with without nitrogen application under sever water deficit condition. Application of 409 mm irrigation and 100 kg N per ha is suitable for condition that enough irrigation waterexists. However in water deficit condition, the application of 150 kg nitrogen per ha could be recommended.
Conclusion: In general, to achieve the optimum growth of garlic in similar soils and climatic conditions, application of 100 kg nitrogen per ha would be recommended under normal irrigation conditions while at water deficit conditions the application150 kg nitrogen per ha could be recommended that had only two percent difference with the mentioned treatment and this difference was not significant.
