Yoko Miyama
Abstract
Intumescence is a physiological disorder in which cell walls are disrupted. Intumescence causes leaf deformation, browning and defoliation, and commonly affects tomato plants. This is a limitation in seedling production. The causes of intumescence are not known; however, ultraviolet (UV) deficiency is ...
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Intumescence is a physiological disorder in which cell walls are disrupted. Intumescence causes leaf deformation, browning and defoliation, and commonly affects tomato plants. This is a limitation in seedling production. The causes of intumescence are not known; however, ultraviolet (UV) deficiency is considered as one of the causes of intumescence. Other possible causes include high humidity and rapid changes in the water environment. In this study, tomato seedlings were grown in a commercially-available closed seedling production system under either newly installed LEDs with a low UV light intensity or conventional fluorescent lamps sources. The relationship between the shoot/root (S/R) ratio and incidence of intumescence was evaluated. In addition, the effects of different light sources were evaluated on the xylem pressure potential in the seedlings under rapidly fluctuating water conditions. As a result, the S/R ratio of seedlings grown under LEDs, with low UV intensity, was greater than that of seedlings grown under fluorescent lamps. There was a positive correlation between the S/R ratio and the incidence of intumescence of four types of seedlings with different combinations of light sources and varieties. Xylem pressure potential decreased more in seedlings grown under LEDs, compared to seedlings grown under fluorescent lamps and dry conditions, but increased significantly when irrigated. These results suggest that reducing the occurrence of intumescence in seedling production systems can be possible by a light source that can help seedlings grow with small S/R ratios and reduce fluctuations in the water condition.
Mohamed Habib Sellami; Farhat Sahbani
Abstract
Farmers and experts are continuously searching for optimal conditions to improve the productivity of tomatoes in greenhouses. To provide an answer to their concerns, we have developed a modeling approach to automate the functioning of a greenhouse cultivated with tomato plants. For the aeration, heating, ...
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Farmers and experts are continuously searching for optimal conditions to improve the productivity of tomatoes in greenhouses. To provide an answer to their concerns, we have developed a modeling approach to automate the functioning of a greenhouse cultivated with tomato plants. For the aeration, heating, and irrigation systems, we compared the Proportional Integral Derivative (PID) controller response to the Fuzzy logic (FL) controller response. For the aeration system, the response of both controllers was stable, with a pick of about 1.09 for the PID controller and zero for the fuzzy controller. Likewise, there was no overtaking for the fuzzy controller but about 8.28% for the PID controller. The rise time for the fuzzy controller was less than that of the PID controller (627 s). We signaled a stable response for the PID controller and the fuzzy logic controller for the irrigation system. The pick and the overtake were equal to zero for the fuzzy logic controller but were 1.28 and 28.2 s for the PID controller, respectively. In the case of both controllers, the rise time was the same, equaling 18.3 s. The regulation time was less than 35 s for the fuzzy logic controller and 31.1 s for the PID controller.
Najmeh Hosseini; Farkhondeh Rezanejad; Elaheh ZamaniBahramabadi
Abstract
Fruit blankness is an important problem of pistachio cultivation, which results from many reasons. The aim of this study was to determine the effects of soil texture, irrigation interval, and cultivar on nut quality and blankness of pistachio. The treatments included soil texture (light and heavy), irrigation ...
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Fruit blankness is an important problem of pistachio cultivation, which results from many reasons. The aim of this study was to determine the effects of soil texture, irrigation interval, and cultivar on nut quality and blankness of pistachio. The treatments included soil texture (light and heavy), irrigation intervals (24 and 48 days), cultivar (Kaleghoochi and Ahmadaghaei), and their interactions were studied. Measured traits were flower and small fruit abscission rate, nut weight, blank and semi-blank fruit percentage, splitting percentage, and ounce. Symptoms of fruit blankness were determined by anatomical study of blank fruits. Results showed that a 48-day irrigation interval produced nuts with higher quality, lower blankness percentage, higher weight and size, and higher number of split ones than the other treatments. It is assumed that plants produce more fruits by sufficient water supply, thus the competition for photosynthetic products results in smaller, lower-weight seeds. Light soil was more suitable regarding nut qualities, but flower and small fruit abscission rates were higher in light soil probably because of temperature fluctuations in this soil. Anatomical studies showed that blankness could result from a lack of fertilization (parthenocarpy) or embryo abortion (stenospermocarpy). Parthenocarpy mostly occurred in the more sensitive cultivar, Kaleghoochi, while the more tolerant cultivar, Ahmadaghaei, mostly had stenospermocarpic blank fruits. It was also determined that embryo abortion could occur at different stages of development.
Md. Farid Hossain
Abstract
To investigate the effects of organic fertilizers and irrigation frequencies on yield and quality of cherry tomato an experiment was conducted using six fertilizer doses including control (no fertilizer), NPK fertilizer (urea at 300 kg, TSP 200 kg and MoP 250 kg), cow-dung at 5 t ha-1, cow-dung at 10 ...
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To investigate the effects of organic fertilizers and irrigation frequencies on yield and quality of cherry tomato an experiment was conducted using six fertilizer doses including control (no fertilizer), NPK fertilizer (urea at 300 kg, TSP 200 kg and MoP 250 kg), cow-dung at 5 t ha-1, cow-dung at 10 t ha-1, poultry manure at 5 t ha-1 and poultry manure at 10 t ha-1 with two levels of irrigation frequencies including alternate day irrigation and two day interval irrigation in a split plot design with three replications. Data on yield and quality attributes of cherry tomato like plant height, number of fruits per plant, fruit yield per plant (g), yield (t ha-1), TSS (%) and vitamin C contents (mg 100 g-1) were recorded. Results revealed that poultry manure had significant effects on the yield and quality of cherry tomato. Among the fertilizer treatments, poultry manure at 5 t ha-1 showed the best results on yield and quality of cherry tomato. On the other hand, cherry tomato showed best performance in relation to yield and quality when field was irrigated in one-day interval. It can be concluded that application of poultry litter at 5 t ha-1 in combination with one day interval result in highest yield and quality on cherry tomato.
Shima Alaei
Abstract
Dracocephalum moldavica L. is an annual species of Lamiacea family whose essential oil is widely used in medicinal, food, cosmetic and health industries. Drought stress is a major factor limiting plants growth and yield. The main objective of this study was to evaluate the influence of irrigation regime ...
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Dracocephalum moldavica L. is an annual species of Lamiacea family whose essential oil is widely used in medicinal, food, cosmetic and health industries. Drought stress is a major factor limiting plants growth and yield. The main objective of this study was to evaluate the influence of irrigation regime on essential oil content and composition of D. moldavica L. The Irrigation regimes were 100%, 85%, 75% and 55% of field capacity (FC). The results showed that 53 essential oil components were identified in different irrigation regimes. Thirty-six, twenty-two, twenty and thirty components were identified at 100%, 85%, 75% and 55% of FC, respectively. The amounts of identified components were 99.4%, 96.6%, 97.8% and 99.9% at 100%, 85%, 75% and 55% of FC, respectively. The highest of main components were geranyl acetate, geraniol and geranial in all the irrigation regimes. The amount of oxygen-containing monoterpenes of essential oil were 81.6%, 94.5%, 91.8% and 92.0% at 100%, 85%, 75% and 55% of FC, respectively. Our results showed that essential oil content increased significantly by 3.4%, 13.8% and 27.6% at 85%, 75% and 55% of FC, respectively. Furthermore, the amount of oxygen-containing monoterpenes of D. moldavicum increased by 15.8%, 12.5% and 12.7% at 85%, 75% and 55% of FC, respectively, but oxygen-containing sesquiterpenes decreased by increasing the level of drought. In conclusion, our results indicated the advantage of drought for increasing essential oil content and oxygen-containing monoterpenes (OM), especially geranyl acetate, geraniol and geranial in D. moldavica.
