Pomology
Mohammad Javad Karami
Abstract
Introduction
The Rotabi grape cultivar holds significant importance in the Bavanat region of Fars province. There are two distinct methods of pruning employed for this cultivar: Cane pruning and Spur pruning. These methods vary primarily in the length of one-year-old wood that is preserved after ...
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Introduction
The Rotabi grape cultivar holds significant importance in the Bavanat region of Fars province. There are two distinct methods of pruning employed for this cultivar: Cane pruning and Spur pruning. These methods vary primarily in the length of one-year-old wood that is preserved after pruning. Cane pruning involves retaining long fruiting canes, typically those with more than 3 buds per cane. Conversely, Spur pruning utilizes shorter canes, usually those with 1-2 buds. The common method of training Rotabi vines in Shiraz vineyards is in the form of bush training. This method of vine training is compatible with spur pruning, in which the canes are usually pruned into 2 to 3 buds. For this reason, there is not enough information about the response of this cultivar to cane pruning. This study was conducted in order to determine the correct method of pruning Rotabi vines based on scientific principles appropriate to its genetic characteristics.
Materials and Methods
This study was performed on 17-year-old vines of Rotabi cultivar in one of the vineyards of Shiraz of Fars province (Iran). In this study, the response of this cultivar to two levels of pruning severity (light pruning with formula 40 + 20 and severe with formula 20 + 20) and three levels of the number of the buds per cane (3, 6, and 9 buds) during three years in Shiraz region of Fars province (Iran) was evaluated. A factorial experiment based on randomized complete block design was used with three blocks. Quantitative and qualitative characteristics such as yield, average weight of cluster, average number of clusters/vine, titratable acidity (TA), pH of fruit juice, TSS%, bud fruitfulness, the average weight and the number of berries/bunch was recorded.
Results and Discussion
Results showed that effects of pruning severity on yield, the number of bunch/vine, bunch weight, pH, bud fruitfulness and berry weight was significant (p≤0.01). Effect of cane length on yield, the number of bunch/vine, bunch weight, bud fruitfulness and the number of berry/bunch was significant (p≤0.01). but on berry weight, TA, pH and TSS% of fruit juice was not significant. Interactions between pruning severity with buds per bearing unit on yield, the number of bunch/vine, berry weight and the number of berry/bunch (p≤0.01) and on TA (p≤0.05) was significant. The highest fruit production per hectare (yield) and the number of bunches per vine were obtained in vines subjected to light pruning. However, in vines that underwent severe pruning, bud fruitfulness and berry weight were greater than in lightly pruned vines. The most substantial yield was achieved with 6-bud and 9-bud canes. Yet, the highest number of bunches was observed in vines with 3-bud and 6-bud canes. Bud fruitfulness reached its peak in the 6-bud cane category, while it was at its lowest in the 3-bud cane group. The number of berries was the same in the 3-bud and 9-bud cane treatments, and it exceeded the number of berries in the 6-bud cane group. Notably, due to the interaction between pruning severity levels and the number of buds per cane, the highest yield was recorded in light pruned vines that underwent cane pruning, specifically in the groups of light pruning with 6-bud canes and light pruning with 9-bud canes. The highest number of berries was observed in light pruning with 9 buds. As a result of this study, it was found that by increasing the number of buds/cane or in other words by increasing the cane length to 6 and 9 buds in this cultivar, the fruit yield/vine increased, and but fruitfullness decreased. Increased yield in light pruning can be due to the increase in the number of bunches/vine due to the increase in the number of buds in this type of pruning. Therefore, to increase the yield of this cultivar, cane pruning + 9 buds/cane should be applied. This type of pruning is not compatible with conventional pruning methods (spur pruning) in the cultivation area of this cultivar. Therefore, it is necessary to develop training systems compatible with cane pruning (such as four-arm kniffin system) in these areas.
Conclusion
While severe pruning led to higher bud fruitfulness, it resulted in lower fruit production per vine (yield) compared to lightly pruned vines. One possible explanation for this difference is that light pruning retained more buds compared to severe pruning. As a consequence, light pruning produced more bunches, ultimately yielding a greater quantity of fruit compared to the severe pruning method. The highest yield (31.3 t/ha) and the highest number of bunches/vine (103) was observed in light pruned vines. Also, the highest yield was obtained in 6-bud and 9-bud canes (31.4 and 31.3 t/ha) respectively. Yield increased with increasing cane length to 6 or 9 buds. Therefore, in order to achieve more yields in this cultivar, cane pruning of at least 6 buds should be applied. But in the end, for better management of vines and the possibility of using standard vine training systems compatible with cane pruning, preferably cane pruning with 9-bud/vine is recommended.
Postharvest physiology
Mohammad Javad Karami; Majid Rahemi; Mohsen Yassaie; Ashkan Karami
Abstract
Introduction
Raisins are dried grapes and are prepared from some varieties of grapes (Vitis vinifera) in different ways, such as exposing grapes to direct sunlight and mechanical methods. There is a possibility of contamination of various types of raisins with different microorganisms during the ...
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Introduction
Raisins are dried grapes and are prepared from some varieties of grapes (Vitis vinifera) in different ways, such as exposing grapes to direct sunlight and mechanical methods. There is a possibility of contamination of various types of raisins with different microorganisms during the stages of harvesting and drying grapes, transportation and marketing of raisins, especially when they are presented in open boxes. The traditional process of preparing and packing raisins in Bovanat region (the main raisin production area of Fars province) makes this product prone to microbial contamination dangerous for human health. The history of consumption of raisin is very old. The Bible provides the first written mention of raisin around 1000 B.C., drying is one of the oldest methods of food preservations; the main purpose of this experiment is reducing the moisture content to level which allows safe storage without spoilage. It has been reported that the use of hydrogen peroxide (H2O2) treatments reduces the microbial contamination loads in dried raisins. Moreover, washing with hydrogen peroxide solution can markedly reduce the loads of human pathogens including Escherichia coli. Primitive methods of making and packaging of raisins in Bavanat region contribute to make them vulnerable to microbial contamination and may be harmful for health. This research was conducted in order to determine the initial microbial contamination on the surface of three types of raisins prepared from the Keshmeshi grape cultivar and using hydrogen peroxide to reduce these microbial contaminations.
Materials and Methods
The use of hydrogen peroxide as a potential antimicrobial treatment was investigated for three types of raisins in Bovanat region. For this purpose, three samples of raisins (Sun-dried, Shade-dried and Sultana raisins) have investigated. Raisins samples randomly were purchased from a local retailer in Shiraz (Iran). For this experiment, raisin samples with uniform size were selected and damaged or diseased berries were discarded. Two concentrations of hydrogen peroxide applied to microbial disinfection were 0% and 0.9%. The raisins that were prepared underwent a treatment process where they were dipped for 5 minutes in solutions containing either 0% or 0.9% hydrogen peroxide. Afterward, the raisins were washed with distilled water for 1 minute to remove any residue. A control group was also included, consisting of raisin samples treated with water (0% hydrogen peroxide). For each sample, measurements were taken for microbial count, population of yeasts and other molds, Aspergillus, Coliform bacteria, and Escherichia coli. The experiment was designed as a factorial (2x3) based on a completely randomized block design with 3 replications. The data were analyzed using SPSS 22.0, and mean data were compared using Duncan's multiple range tests at a 1% probability level.
Results and Discussion
The results showed that there was a significant difference (P≤1%) between hydrogen peroxide concentration treatments regarding to microbial contamination. There was also a significant difference (P≤1%) between the raisin samples in terms of microbial contamination. The results also revealed the presence of high amount of microbial infection on surface of all raisin samples. The microbial contamination load of Sultana raisins was higher than other raisins. The results also indicate that Escherichia coli was not detected in both sun-dried and shade-dried samples, but it was observed in Sultana raisins. Surface disinfection of Sultana raisin samples with 9% of hydrogen peroxide removed Escherichia coli infection. Hydrogen peroxide was effective in reducing the microbial contamination of all three raisin samples. It seems hydrogen peroxide to be more effective in reducing microbial contamination in sun-dried and shade-dried samples. Sultana raisin had highest contamination of mold and yeast while sun-dried and shade-dried raisins were lowest. The effect of hydrogen peroxide on reducing mold and yeast contamination was not the same in all raisin samples, so that the highest effect on reducing mold and yeast contamination was found in sun-dried and shade-dried raisins. The least effect on this contamination was observed in sultana raisins. Aspergillus was not detected in sun-dried and shade-dried samples but it was observed in sultana raisins. Hydrogen peroxide was not effective against Aspergillus. The microbial contamination of all raisin samples which affected by 0.9% hydrogen peroxide was decreased significantly (P≤1%). Effect of hydrogen peroxide at 0.9% on removing of microbial infection in sun-dried and shade- dried raisins was similar and it was more than Sultana raisins.
Conclusion
All three raisin samples were infected with Coliform bacteria, mold and yeast. In the case of Escherichia coli infection, it was detected only in sultana samples. Hydrogen peroxide was effective in reducing the microbial infection of all raisin samples. It was more effective in reducing the total number of microbes in sun-dried and shade-dried raisins. Hydrogen peroxide with a concentration of 0.9% is effective for eliminating the microbial infection of raisins, and the use of hydrogen peroxide with a concentration of 0.9% can be used to disinfect raisins.
