نوع مقاله : مقاله پژوهشی
نویسندگان
1 استادیار، پژوهشکده خرما و میوههای گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات و آموزش و ترویج کشاورزی، اهواز، ایران.
2 کارشناس، پژوهشکده خرما و میوههای گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات و آموزش و ترویج کشاورزی، اهواز، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
This research was carried out to investigate the effect of preharvest bagging, with different bag types, on the quantitative and quality characteristics of palm date fruit cv. Medjool (25-26 years old trees) in the date palm and tropical fruits research center under Ahvaz weather conditions in 2020 and 2021. The experimental design was randomized complete block design with seven treatments and eight replications. The studied bag types included kraft paper, black, white, and blue cloth, green greenhouse net, straw bag and control (without bagging). Bagging was applied in the khalal stage, and the ends of the bags were open and they remained on the tree until harvest time. The results showed that the weight of bunch, rutab weight bunch-1, tamar weight bunch-1 and the final fruit yield tree-1 were affected by the bag type. Bunch weight, rutab weight and tamar weight in each bunch and final fruit yield tree-1 in all treatments were more than the control. The highest bunch weight (5.69 kg), tamar weight bunch-1 (2.12 kg) and final fruit yield tree-1 (29.3 kg) related to green greenhouse net bag and the highest rutab weight bunch-1 (0.86 kg) related to blue cloth bag. Acidity (pH), titratable acidity (TA) and soluble solids content (SSC) of fruits were not affected by bag type. In general, the green greenhouse net and straw bags were more effective in increasing the final fruit yield tree-1 and reducing the population of eggs, nymphs and adults of Date palm mite.
Keywords: Palm date, soluble solids content, tamar weight bunch-1, bunch weight, Final fruit yield.
Introduction
Date palm (Phoenix dactylifera L.) is a monocotyledonous and dioecious plant from the Arecaceae family. Iran as one of the major dates producers ranks third in the world following Egypt and Saudi Arabia (FAO, 2021). Palm dates with about 234,012 hectares cultivated area are one of the most important horticultural products in the southern regions of Iran. Medjool cultivar is one of the valuable palm date in the International markets, which has attracted the attention of palm farmers due to its adaptation high performance and price compared to other cultivars in the southern regions in Iran (Zargari, 2023). The preharvest bagging technique is particularly used to improve the appearance and quality of fruit, especially in Asia (Moaaz Ali et al., 2021).
Bagging may cause various changes in the physiology of the fruit and its quality characteristics (Moaaz Ali et al., 2021). Kassem et al. (2011) stated that bagging with blue polyethylene bags decreased the soluble solids content, dry matter, total sugar and reducing sugar and increased the moisture content of date fruits. Omar et al., (2014) studied the effect of bagging with kraft paper and mesh cloth on the quality characteristics of Rothana dates and reported that bagging increased the soluble solids content (SSC) and reducing sugar, however the amount of total sugar was not affected by bagging types. The present study was carried out to investigate the effect of preharvest bagging, with different bag types, on the quantitative and quality characteristics of palm date fruit cv. Medjool in Ahvaz region in Iran.
Materials and Methods
This research was carried out to investigate the effect of preharvest bagging, with different bag types, on the quantitative and quality characteristics of palm date fruit cv. Medjool (25-26 years old trees) in the date palm and tropical fruits research center under Ahvaz weather conditions in 2020 and 2021. The experimental design was randomized complete block design with seven treatments and eight replications. The studied bag types included kraft paper, black, white, and blue cloth, green greenhouse net, straw bag and control (without bagging). Bagging was applied in the khalal stage, and the ends of the bags were open and they remained on the tree until harvest time.
After harvesting the fruits and transferring them to the laboratory, the quantitative and quality characteristics of fruits were evaluated and measured. Bunch weight, tamar weight bunch-1, rutab weight bunch-1 and final fruit yield tree-1 (sum of rutab and tamar weights) were measured and recorded. Moisture content was determined according to AOAC (2012) method. To measure pH, total soluble solids (SSC), titratable acid (TA), total sugar, and date- reducing sugars, extracting date fruit with one-fifth concentration was done in the same way (AOAC, 2012).
Combined analysis of variance for data performed using SAS 9.4 software. Tukey's Test was used for mean comparisons at the 5% and 1% probability levels. Six branches were randomly sampled from each treatment one day before covering with different bagging and also when bags were opened. The number of eggs, nymphs, adualts of mites were counted on fruits on the branches. Corrected mortality rate and mean comparison were determined using the Henderson-Tilton formula and Tukey’s test at the 5% probability level, respectively.
Results and Discussion
Combined analysis of variance showed that the effect of year and bag type on bunch weight, rutab weight bunch-1, tamar weight bunch-1 and final fruit yield tree-1 were significant. The highest bunch weight, tamar weight bunch-1 and final fruit yield tree-1 were related to the green greenhouse net bag and the lowest to the control. The highest rutab weight bunch-1 was obtained under the blue cloth bags. All the bagging treatments caused an increase in bunch weight, rutab weight bunch-1, tamar weight bunch-1 and final fruit yield tree-1.
The results of the present research are consistent with the results reported by Mostafa et al. (2014) regarding the increase in bunch weight with the application of bags. Considering that bunches with bag had more weight than the control, and on the other hand, the weight of a single fruit was not affected by the bag type, it can be concluded that bunches under bagging treatments had less fruit drops than the control. The pH of the fruits was higher in the second year, and the titratable acidity and moisture content of the fruits were higher in the first year.
Among the examined bag types, straw bags (65.52%) and white cloth (54.39%) caused a significant increase and decrease in SSC compared to the control, respectively. The highest efficiency of bagging (highest mite mortality rate) was observed in the straw bag and green greenhouse net, and the lowest efficiency was observed in white cloth and kraft paper. Therefore, preharvest bagging of bunches could protect the palm date fruit cv. Medjool from pests and environmental factors and improved the quantitative and quality characteristics as well as marketability of the fruits.
References
Kassem, H.A., Omar, A.K.H. and Ahmed, M.A. 2011. Response of ‘Zaghloul’ date palm productivity, ripening and quality to different polyethylene bagging treatments. American–Eurasian Journal of Agricultural and Environmental Science, 11, pp.616–621. DOI: 10.17660/ActaHortic.2010.882.126
Moaaz Ali, M., Anwar R., Yousef, A.F., Li, B., Luvisi, A., Bellis, L.D., Aprile, A. and Chen, F. 2021. Influence of bagging on the development and quality of fruits (Review). Plants, 10(2), 358. DOI: 10.3390/plants10020358
Omar, A.D.E.K., Al-Saif, A.M. and Ahmed, M.A.E.A. 2014. Bagging of bunches with different materials influences yield and quality of Rothana date palm fruit. Journal of Food, Agriculture & Environment, 12(2), pp.520-522.
Zargari, H. 2023. Evaluation of compatible pollen application on yield and some quantitative characteristics of tissue culture derived date palm of Medjool cultivar. Iranian Journal of Horticultural Science, 54(2), pp.195-212. DOI: 10.22059/IJHS.2022.339366.2004
)