مجله علوم و فنون باغبانی ایران
سال سیزدهم شماره 2 (تابستان 1391)

Tomato fruit (Lycopersicun esculentun L.) due to having climacteric behavior has different postharvest problems including irregular and uncontrolled fruit ripening. In this research, the effects of some chemicals i.e. 1-MCP and ethephon on qualitative changes of tomato fruit cv. ‘Verona’ during storage period were studied. For this purpose, in a factorial experiment, mature green harvested fruitswere treated with 1-MCP (at 0, 0.5 and 1 μl l-1 concentrations) and ethephon (at 0 and 1000 μl l-1 concentrations) and stored at 20°C for 25 days. During storage duration, different quality properties including firmness, pH, total soluble solids, titratable acidity, weight loss, chlorophyll content, lycopene content and vitamin C were evaluated at 5 days intervals. The results showed that 1-MCP could maintain flesh firmness, chlorophyll content and titratable acidity even in the presence of ethephon and lowered the pH changes and lycopene formation during storage. Ethephon treatment increased the fruit softening and chlorophyll degradation especially at the start of storage duration but it did not have significant effect on lycopene formation. TSS were not affected by 1-MCP or ethephon but increased gradually in terms of storage duration. From the obtained results, it can be concluded that applying 1-MCP and ethephon treatments affect fruit ripening process and postharvest quality changes and postharvest problems of tomato fruits can be reduced.

Postharvest losses, particularly fungal infection, are major factor in limiting the shelf life of many fruits and vegetables. In order to control the green mold caused by (Penicillium digitatum), preservation quality and increase the shelf life of mandarins cv. ‘Pertangelo’, the treatments of eucalyptus essential oil and UV-C irradiation were applied. The effectiveness of essential oil in vitro and in vivo were tested at concentrations of 0 (control), 150, 300 and 400 mg l-1 by using a disc diffusion method and 0 (control), 400 mg l-1, respectively. The dose of UV-C irradiation used was 0.72 k j/m2. The results of in vitro and in vivo tests indicated that, essential oil and UV-C irradiation treatments significantly (P=0.01) inhibited the growth of pathogen. These treatments decreased and increased the titratable acidity contents and pH values, respectively. There were no differences in total soluble solids contents. In both tests the UV-C treated fruit showed noticeable decrease in the lightness (L*) and superficial color (Hue˚).

This study was conducted to investigate the effect of growing media, planting date and GA3 on quality and quantity of Polianthes tuberosa L. cv. ‘Double’ in Isfahan. The first experiment was carried out to determine the effects of 8 growing media composed of different proportions of garden soil, sand, and manure. Second experiment was evaluated the effect of 3 planting dates on the preferred medium based on the first experiment’s results (equal garden soil and manure). The third experiment was based on the second experiment’s findings. Thus, GA3 was applied at 0, 100, 200, 250, and 300 ppm with two methods (dip and dip + spray). These experiments were arranged in randomized complete block design with three replications. The results of the first experiment showed that the greatest number of sprouting bud and the highest number bulblet production were obtained in media containing equal garden soil + sand. Maximum number and length of inflorescence were observed in combination of garden soil 1 + manure 1. The results of the second experiment indicated that the greatest numbers of sprouting bud, inflorescence, floret and the maximium of inflorescence length were obtained when the bulbs planted on 10 May. The results of the third experiment showed that maximum number of sprouting bud observed at concentrations of 100 and 200 ppm of GA3. The different concentrations of GA3 did not affect flowering characteristics but had significant effects on length and number of leaves. The highest number of bulblet production was obtained at 250 and 300 ppm GA3.

In order to investigate the effects of four N-NH4/NT ratio, spraying intervals of nutrient solutions and light of root medum on the uptake of some of microelements and some of vegetative traits of Gerbera an experiment was carried out. Four N-NH4/NT ratio control (without N NH4), 0.03, 0.08, 0.16, two levels of spraying intervals including either three minutes spraying-fifteen minutes off or three minutes spraying-thirty minutes off and two levels of complete darkness and full light in root medium were applied. After 45 days the nutrient solutions were analyzed and amounts of copper, iron, manganese and zinc in nutrient solution and also increasing root length in three periods (every 15 days), increasing total length of root and leaf number were measured. The results showed that the effect of nutrient solution was significant on root length in second and third period, total length of root, leaf number and the uptake of manganese and zinc. The maximum of root length in second and third periods and total length of root observed in nutrient solution with N-NH4/NT ratio 0.03 and the maximum leaf number observed in nutrient solutions with N-NH4/NT ratio 0.03, 0.08 and 0.16. Maximum amount of manganese and zinc were observed in control nutrient solution. The treatment of spraying intervals had a significant effects on root length in all three periods, total length of root, leaf number and iron uptake. The maximum root length in all three periods, total length of root and iron uptake observed in three minutes spraying-fifteen minutes off and the maximum of leaf number observed in three minutes spraying-thirty minutes off treatment. The treatment of light in root media had a significant effect on root length in first and third periods and the uptake of manganese, zinc, and iron. Root had more growth, in first period when light was present in root media and in third period when darkness was present in root media. Manganese, zinc and iron were absorbed more, when light was present in root media. The maximum uptake of manganese and zinc was observed in control nutrient solution.

In order to study the seasonal fluctuation of some mineral nutrients in pomegranate leaves, an experiment was conducted as a split plot design with three replications. Treatments included four pomegranate cultivars (‘Zagh-e-Yazdi’, ‘Zagh-e-Gorch-e-Torsh’, ‘Gorch-e-Shavar’ and ‘PostGhermez-e-Aliaghaei’) and five sampling dates (May, June, July, August and September). Results showed that the concentrations of P, K, Mg and Mn were constant during first sampling stages and then increased with aging of leaves. The highest iron concentration observed during first sampling date. Iron concentration decreased with the increasing the age of leaves, so that the lowest concentration of iron was observed in September. Potassium concentration was fairly constant during sampling stages. These results showed that the mineral concentrations in leaves were the lowest in July, because of competition between developing fruits and it is necessary to perform a good balance of mineral nutrients at this stage. Also it was suggest that 90 days after start of leaf growth is the best time for analysis nutrient situation in pomegranate plants.

In order to study the effects of foliar applications of iron and zinc on pomegranate yield, fruit qualitative and quantitative characteristics and leaf mineral composition, an experiment was carried out in an orchard in Marvdasht city in 2010. A total number of 36 pomegranate trees were selected and the experiment was conducted as a completely randomized block design with 4 replications. The first stage of foliar applications was at full bloom and the second stage carried out approximately one month later. Leaves samples collected in late summer. Fruit yield (fruit weight per unit of cross section area of stem) measured in the beginning of fall and length, diameter and weight of fruit, seed weight, juice weight, vitamin C, total soluble solids (TSS) and pH were measured. Results showed that 3 g l-1 Fe-EDTA caused significant increase of Fe-EDTA concentration in pomegranate leaf, fruit length, weight and diameter, weight of seed and juice, total soluble solids and yield in comparison to control. Application of 1.5 g l-1 iron significantly increased vitamin C compared to control. Application 3 g l-1 Zn-EDTA significantly increased Zn concentration in leaf, seed weight, and juice weight in comparison to control, while 1.5 g l-1 Zn-EDTA caused significant increase of fruit length, diameter and weight. Application of 3 g l-1 Zn-EDTA and Fe-EDTA produced maximum yield, fruit length, diameter and weight, seed and juice weight. It seems that combined application of 3 g l 1 Fe- EDTA and Zn- EDTA was the best treatment for foliar nutrition of pomegranate.

The effects of IBA regulator and environmental stress (Fosamco fertilizer and irrigation periods) on leafy cuttings of olive cultivars were evaluated. The treatments were allocated to split plots in time and space arranged in a Randomized Complete Block Design with four replications. The main factor consisted of three fertilizing applications in irrigation periods of every week, every two weeks and every three weeks by Fosamco fertilizer (2.5 mg l-1 of effective gradient). The subfactors were five levels of indolbutric acid and three cultivars of olive (‘Mission’, ‘Zard’, ‘Roghani’) in a factorial arrangement. The time factor (sampling time) consisted of five removal periods of one week intervals from growing medium. Cuttings were planted in perlite after being treated by growth regulator and fungicide. The results of this study showed a significant effect of stress and growth regulator applications on all the measured traits in most cases. The highest number of roots and root length were obtained with 3 g l-1 of regulator application. However, the number of buds did not show any response to the increased concentration of growth regulators. In general ‘Zard’ cultivar had better performance in studied trait. The average of root numbers in ‘Zard’ cultivar was significantly more than that in oily cultivar. Also, ‘Zard’ cultivar had the highest and second highest average amount for root length and bud numbers, respectively. It could be concluded that remaining the cuttings for prolonged time in propagation bed had a positive effect on the evaluated traits.

The rapid senescence is the main limiting factor of postharvest life in broccoli florets. In this study, effects of different concentrations of putrescine (Put) on delaying florets senescence of two broccoli cultivars, ‘General’ and ‘Liberty’ during cold storage were investigated. Broccoli florets were treated with 0.5, 1 and 1.5 mM Put and distilled water was used as control. The treated florets was placed in polyethylene bag and transferred to storage with 0±1°C and 90±5% RH. Characteristics such as general visual quality, total chlorophyll, lipid peroxidation, activity of lipoxygenase (LOX), superoxide dismutase (SOD) and peroxidase (POD) was determined at harvest time, after 40 days cold storage and 2 additional days in room temperature. The results showed that 1.5 mM Put delayed chlorophyll degradation and senescence and improved florets quality in both ‘General’ and ‘Liberty’ cultivars. Application of Put delayed more lipid peroxidation during long term storage. Also, it suppressed increasing POD and LOX activity and maintained higher SOD activity, and delayed florets senescence in broccoli during long term storage.

The main problem of area near the oil regions is pollution of waste oil. Due to this event, cultivation will be difficult and then agricultural areas gradually will change to unusable lands. In order to evaluate phytoremediation rate, increasing resistance, waste oil concentrations and calcium oxide levels of Conocarpus erectus L. were studied. In this research, effects of waste oil 0, 5, 10, 15 and 20 ml kg-1 soil), calcium oxide (0, 2.5, 5, 7.5 and 10%) were evaluated on four leaves seedlings. The results showed that despite of the relative tolerance of seedlings to the waste oil, increasing effluent oil concentration to 20 ml, significantly decreased vegetative traits such as stem length, root length, shoot dry weight and root dry weight. In addition, 20 ml kg-1 waste oil reduced 3.3% leaf relative water content. In comparison of control, chlorophylla reduced 19% at 5 ml kg-1. Whereas, increasing waste oil to 20 ml kg-1 enhanced chlorophylla to 13.6% compared with the control. According to the results, chlorophyllb increased in all levels of waste oils. The highest concentration of waste oil elevated chlorophyllb to 47.9% more than that of control and the total chlorophyll only significantly reduced in waste oil level of 5 ml kg-1 compared with the control. On the other hand, calcium oxide enhanced stem length, root length, root to shoot length ratio, shoot dry weight, root dry weight and shoot dry weight to root dry weight ratio. Calcium oxide treatments also improved leaf relative water content and chlorophylla&b and total chlorophyll.