نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه علوم باغبانی، دانشکده کشاورزی، دانشگاه ایلام، ایلام، ایران
2 گروه تولید و ژنتیک گیاهی، دانشگاه جهرم، جهرم، ایران
3 گروه آب و خاک، دانشکده کشاورزی، دانشگاه ایلام، ایلام، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Fruit cracking and sunburn are two major disorders that can negatively impact pomegranate (Punica granatum L.) production. To address these problems, an experiment was conducted to evaluate the combined effects of silica (0, 100, 300, and 500 ppm) and calcium nitrate (0, 0.75%, and 1.5%) spraying on the fruit of ‘Malase-Saveh’ pomegranate. The treatments were applied three times during the growing season and a factorial experiment was conducted based on the completely randomized block design. The results indicate that most of the qualitative and quantitative traits were influenced by foliar spraying of these substances. Furthermore, the results demonstrated that foliar application of silica, calcium nitrate, and their interaction significantly affected fruit cracking. The lowest fruit cracking (1.06%) was obtained by spraying 500 ppm silica and 1.5% calcium nitrate, while the highest fruit cracking (21.6%) was recorded from untreated plants. The highest fruit weight (215.4 g) was observed in the treatment 1.5% calcium nitrate. Most of the treatments had a positive effect on fruit weight and increased it compared to the control. Moreover, the treatments improved some qualitative characteristics, such as an increase in fruit acidity and decrease in sunburn disorder. Ultimately, this study concluded that combined spraying of silica with calcium is more effective than individual use and results in the highest fruit yield and quality, as well as the lowest cracking and sunburn disorders. These findings suggest there are synergistic effects between these compounds.
کلیدواژه‌ها [English]
Extended Abstract
Introduction
Pomegranate (Punica granatum L.), a member of Lytraceae family, is one of the oldest fruit species that has been cultivated by humans. The growing body of evidence indicates that this fruit tree originated in Iran and some surrounding regions. Iran contains a range of different pomegranate accessions, including wild, semi-wild and cultivated ones, and is considered the main center of origin and center of diversity for this fruit crop. Although the pomegranate is considered a fruit species that is relatively tolerant to various unfavorable conditions such as hot and dry climates, salty soil as well as water deficit, however, various physiological disorders as well as biotic/abiotic stresses are able to impede fruit production and significantly reduce the fruit yield, quality and commercial acceptance. Fruit skin sunburn and fruit cracking are among the main physiological disorders that cause serious economic losses to pomegranate growers all around the world. Adequate nutrition through foliar spraying is considered as one of the effective orchard management strategies that can be used efficiently to reduce the physiological disorders in fruit crop. Calcium (Ca) is an essential macronutrient and plays crucial roles during different stages of plant growth and development; including fruit firmness and quality as well as acting as a secondary messenger. Although silicon (Si) seems to be a nonessential nutrient for the majority of plant species, its beneficial effects on plants as a nutrient cannot be overlooked. This element improves plant resistance to unfavorable conditions and its positive effects on the qualitative and quantitative characteristics of agricultural crops have been well documented.
Materials and methods
This research was carried out in a commercial orchard of the pomegranate cultivar ‘Malase-Saveh’. The orchard was located in the central part of the Ilam province in the west of Iran (Chardavol city; latitude: 33°56'51"N, longitude: 46°81'32" E, altitude: 787m). In the present study, an experiment was conducted to assess the combined effects of silica (0, 100, 300 and 500 ppm) with calcium nitrate (0, 0.75% and 1.5%) spraying on the fruit of ‘Malase-Saveh’ pomegranate. The treatments were repeated three times during the growing season. A factorial experiment was conducted based on the completely randomized block design. The first spraying was performed at full bloom (FB) (late in June), while the second and third sprayings were at 30 and 60 days after FB, respectively. At the time of fruit ripening, the number of healthy, sunburned and cracked fruits from each tree was counted, and 15 healthy, sunburned or cracked fruits from each tree were randomly selected and some fruit traits were evaluated. Data analysis was performed using SAS statistical software and the means were compared using the Duncan Multiple Range Test (DMRT) at the 5% level of significance.
Results and Discussion
Results indicated that most of the qualitative and quantitative traits were affected by foliar spraying of these substances. In addition, the results showed that foliar application of silica and calcium nitrate and their interaction were significant in fruit cracking. The results showed that the lowest fruit cracking (1.06%) was obtained by combined spraying of 500 ppm silica and 1.5% calcium nitrate, while the highest fruit cracking (21.6%) was recorded from untreated plants. The highest fruit weight (215.4 g) was recorded from trees treated with 1.5% calcium nitrate. Calcium nitrate spraying also significantly increased 100 arils fresh weight, peel thickness, and fruit dimensions, as the highest values for these factors were recorded at 1.5% calcium nitrate treatment. The results also revealed that 300 and 500 ppm silica treatments significantly increased fruit weight, while all concentrations of this element reduced TSS and TSS/TA indices. Altogether, the results indicated that combinatorial spraying of silica with Ca was more efficient than their individual treatment and resulted in the highest fruit yield and quality as well as the lowest cracking and sunburn disorders, which suggests there are synergistic effects between these compounds.
Conclusion
Fruit cracking is one of the main disorders in pomegranate fruit, which negatively affects the quality and quantity of pomegranate fruit. In general, our results showed that the lowest fruit cracking and sunburn were recorded in the treatment of 500 ppm silica and 1.5% calcium. Foliar spraying with silicon and calcium nitrate increased aril and fruit weight and improved some biochemical characteristics of pomegranate fruit. The data obtained from this study could provide valuable insights into the positive effects of appropriate fertilization on reducing one of the main pomegranate disorders.
)