JWSS - Journal of Water and Soil Science

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Green skin (hull) of pistachio fruits is a barrier against the penetration of fungi and insects into the kernel of pistachio. Splitting of husk facilitates the entry of fungi and infection of pistachio kernels during the harvest. So far no effective way has been reported for controlling this problem. To evaluate the effects of gibberellic acid on hull spliting the present research was conducted in a commercial orchard of pistachio during 2001-2002 in Rafsanjan, Iran. Gibberellic acid (GA₃) at 0,25,50 and 100 mg ^–1 was applied on 25-year-old of “Owhadi” pistachio cultivar. Two branches of each tree was sprayed during two years of study. GA₃ at 25,50 and 100 mg ^–1 significantly reduced hull splitting and penetration by Aspergillus spp. into pistachio fruits. There was a positive correlation between the hull splitting and fungi penetration (r=0.92^*). The exocarp, mesocarp and endocarp of pistachio fruits cultured on selective medium of Aspergillus spp. showed no infection of pistachio kernel by Aspergillus spp. The highest concentration of aflatoxin was detected in the kernel of non-treated fruits (6.25 ppb) and the lowest (0.5 ppb) fruits treated by GA₃ . GA₃ reduced husk slippery of pistachio fruits at harvest. The rate of husk slippery was reduced by increasing the concentration of GA₃. Gibberellic acid treatments had no significant effect on dehiscence, weight of 100 fruits, total soluble solids, but significantly increased fat and chlrophyll content of kernel of pistachio fruits. The results of the study is recommended for commerical pistachio production in Iran.

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To obtain a suitable explant and efficient culture medium for plant regeneration in spinach, two cultivars of Melody and Karaj local seedlings were chosen. A hypocotyl and cotyledon segments as well as shoot tip explants were dissected from seedlings. The explants were then cultured on MS medium supplemented with IAA, GA₃, NAA, and BAP and their response to this media was studied. A completely randomized design with different replicates was used to conduct the experiments. Callus was formed at the base of the hypocotyl explants on the medium containing 15 mg.l^-1 IAA, and 3.4 mg.l^-1 GA₃. Calli capable of regeneration was obtained after subculturing on the medium containing 2 mg.l^-1 IAA, and 3.4 mg.l^-1 GA₃ at the rate of 38 percent. The vitrified plantlets were abnormally glassy, and translucent which might have high water content. It was a physiological disorder which was overcome when an improved agar medium raising to 9 gl^-1 was used. Callus has been obtained only from the hypocotyl explants, while regeneration has been obtained from shoot tip cultured on the medium containing 0.02 mgl^-1 BAP at the rate of 80 percent.

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  Navel oranges and Clementine mandarin are classified as early cultivars and when fruits are left on the trees, fruit firmness and juice content will decrease. Plant growth regulators have been used to improve fruit quality. Gibberellic acid (GA₃) and 2,4-D isopropyl ester sprays were used to increase juice content ,peel firmness and delay senescence in Navel oranges and Clementine mandarin. Factorial experiments were arranged in a complete randomized block design with three replications and each block consisted of three trees. Chemicals were sprayed on the branches (north and south of each tree) with 10 liter sprayer to the point of run-off during fall of 2004 and 2005 ,in a commercial orchard in Jahrom in the south east of Fars province, Iran . In both years of study, GA₃ at 100,150 and 200 mgl^-l and isopropyl ester 2,4-D at 8,12 and 24 mgl^-1 were sprayed on September 30 (diameter of Navel 64 mm and diameter of Clementine 46 mm), October 14 (diameter of Navel 69 mm and diameter of Clementine 48 mm ) and November 7 (diameter of Navel 70 mm and diameter of Clementine 50 mm) and fruits of Navel oranges and Clementine mandarin were harvested 45 and 35 days after last the spray treatment, respectively . The results of experiment revealed that Navel oranges responded better with second application (Oct.14, diameter 69 mm ) and Clementine mandarin with the first application (Sept.30, diameter 46 mm ). Juice content and fruit firmness at harvest increased. GA₃ increased juice content even better than 2,4-D isopropyl ester but delayed senescence, 2,4-D was more effective in increasing fruit sizing in both cultivars. GA₃ at 150 and 200 mgl^-1 and 2,4-D at 24 mgl^-1 when compared with the untreated resulted in highest juice content of fruits.

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  Experiments were conducted to study the effects of temperature and chemical treatments on the vase life of cut Asiatic hybrid lily cultivar Pisa, with sixteen chemical treatments using factorial design with 3 replication arrangements. Lilium cut flowers were harvested when the first flower colored fully. Following chemical treatments, they were grouped in different combinations before storage. The treatments included sucrose, 8- hydroxy quinoline sulfate (HQS), citric acid (CA), gibberellic acid (GA₃), kinetine (KI) and distilled water as control. Lilium cut flowers were pulsed for 24 hours in different solutions, then brought out and kept in the distilled water at temperatures of 4^°C and 22 ^° C .Effects of applied treatments were evaluated on different characteristics like vase life, the amount of water absorbed, flower diameter, total soluble solids and fresh weight. Results showed that the temperature of 4^°C had the most effect on vase life, keeping the quality of lilium cut flowers. The results also displayed that the chemical treatments kinetine + sucrose had the most effect on vase life and percentage of sucrose, gibberellic acid + kinetine delayed yellowing of the foliage, 8- hydroxy quinoline absorbed the most amount of water, and treatments sucrose + kinetine , gibberellic acid + 8- hydroxy quinoline sulfate and gibberellic acid + citric acid were most effective in increasing the flowers diameter.