The effect of ring stripping and ethfen treatments on quantitative and qualitative traits of 'Rish Baba Red's' grape variety.

Dissertation for Master's Degree in Horticulture-Fruit Science

Abstract

Rish Baba grapes are one of the most popular fresh edible cultivars cultivated in Iran, but usually the grapes have poor color. In this study, the effect of ring removal and ethfen treatments on the quantitative and qualitative traits of 'Rish Baba Garmez' grape variety was investigated. The experiment was conducted as a factorial in the form of a basic design of randomized complete blocks with 3 replications. For this purpose, ringing was applied on the branches of the current year bearing clusters at two levels (ringing and without ringing) and foliar spraying with ethene at three levels (zero, 150 and 300 mg/liter) was applied on the clusters at the stage of color change of the cluster. The evaluated parameters included the amount of soluble solids, titratable acidity, ripening factor, pH of fruit extract, cluster length and width, weight of 20 kernels and cluster, kernel drop, texture firmness, total antioxidant, total phenolic compounds and kernel color. The obtained results showed that the lowest amount of soluble solids and curing coefficient were obtained in the control treatment. The treatments of ring removal and ethene significantly reduced the titratable acidity. Ring removal and ethene treatments had no significant effect on the pH of the fruit extract, the length and width of the cluster. The highest amount of kernel and cluster weight was obtained in the ring removal treatment, while ethene treatment was not effective on kernel and cluster weight. Ring removal treatment significantly reduced the drop of pods, while the treatment of 150 mg/L of ethene increased the drop of pods compared to the control. Ethene treatment reduced the firmness of the bean tissue, while ring removal treatment did not have a significant effect on this feature. Ethene foliar spraying and ring removal had a significant effect on the amount of total antioxidants, total phenolic compounds and the amount of color of the beans. Ring removal treatment produced the highest level of total antioxidant. Ring removal treatment with 300 mg/L produced the highest amount of total phenols. Ethefen treatment of 150 mg/l produced the lowest amount of brightness and the highest ratio of red to green. The use of ring removal and ethene increases the accumulation of pigment in the skin of the grape pods and accelerates the ripening of the fruit, and this is also important to prevent cracking by rain. The results of this research showed that the use of ring removal and ethene can be introduced as an effective strategy in the technology before grape fruit harvesting. According to the results, if ring removal and ethylene-generating substances (ethene) are applied at the optimal concentration and at the right time on the grapes of the red beard cultivar, the desired color and quality will be obtained in the fruit.

Keywords: grapes, ring removal, ethene, quantitative and qualitative properties, total phenolic compounds, total antioxidants, fruit color

Chapter One

Introduction and Generalities

1-1- Importance of agricultural products in providing human health

Fruits and vegetables are one of the most important sources of human food and in fact provide vitamins needed by the body and are necessary to maintain human health. They are also valuable crops that have good economic benefits even in small plots (Shahi et al., 2003). In human nutrition, there are three basic things to consider: First, food should be able to meet the needs of the body in terms of calories (in relation to physical activity) and satisfy hunger. Second, food should be qualitatively balanced; This means to provide sufficient amounts of proteins, vitamins, minerals, etc., which the body may suffer from malnutrition due to the lack of any of them. Third, it does not have adverse effects. As an important group of foods, fruits and vegetables can help to achieve all three of the above goals, but it is clear that the importance of a particular vegetable or fruit depends on the special compounds in it. Fruits and vegetables are of particular importance as an important part of human food resources, and since the beginning of its existence, humans have used these products to provide part of their food. Today, the use of horticultural products in the diet has been widely considered. The researches of modern nutrition science have proven that the consumption of fruits and vegetables prevents many common diseases.Therefore, in developed countries, people use fruits and vegetables more than animal products in their diet (Ethani Eshri and Zakai Khosrowshahi, 1387).

1-2- The origin and history of grapes

Grapes are one of the most important fruits that have been used by humans since ancient times. Commercial grape cultivars are mainly of the Vitis vinifera species [1], which is reported to originate from an area in southern Europe between the Black Sea and the Caspian Sea (Zhouri et al., 2015). The history of grape cultivation in Iran has been common since around 2000 BC, and its by-products were used especially during the Achaemenid period. According to the fact that the main habitat of the grape has been identified as the region between the Black Sea and the Caspian Sea, therefore, the northern part of Iran is considered the origin of the grape and its wild species are available in the mentioned areas. Vitis [3] are located. The genus Vitis is the only desirable genus from the economic and edible point of view, which has two subgenera Muscadine with n2=40 and Eovitis n2=38 (Jalili Marandi, 1388) and several important species including Vitis vinifera [4] or European grapes, Vitis amorensis [5] or Asian grapes and American grapes such as Vitis riparia [6] and Vitis labrusca [7]. The cultivated grapes in Iran are vinifera (European) grapes (Jalili Marandi 1384; Hulme, 1970). The grape is a treasured shrub, rarely evergreen and climbing, with tendrils and a brown stem core, which is cut by a diaphragm at the point of the nodes, and has simple, toothed leaves, usually congress, rarely compound claws, full flowers and fruit of the sete type (Rasoulzadegan, 1375). rtl;">It is a strong variety with medium growth, regular and high productivity, with thick and relatively long wooden branches with a circular cross-section, crisp and juicy with high hardness, average sugar percentage (17.8 percent) and acid content (4.65 grams per liter). Due to the thickness of the pod skin, it is used to prepare pendulum (locust) (Alizadeh, 1383).

1- 5- Nutritional value and economic importance of grapes

The value of grapes is very high in terms of its ability to be consumed in various ways, including fresh eating and preparation of raisins, concentrates, fruit juice, fermented products, jam, juice and grape seed oil, and in this sense it plays an important role in the economy of producing countries. In addition, other products such as ethanol and anthocyanin are also prepared from grapes (Carreno et al., 1997). Approximately 71% of grape production is used for wine, 27% for fresh consumption and 2% for dried fruit (Kunkee and Goswell, 1996). Grapes can be used from the grape stage, which means when the fruit is at the peak of growth and development, to the fully ripe stage and after that (Mokhtarian et al., 1379).

grape (Vitis vinifera) cv. 'Rish Baba Qermez'

Abstract

Vitis vinifera 'Rish Baba Qermez' is one of the most popular table-grape cultivars grown in Iran, but it usually has a poor berry color. In this study, the effect of girdling and ethephon treatments on quantity and quality attributes of 'Rish Baba Qermez' grapes were evaluated. The experiment design was a randomized complete block design (RCBD), with 3 replications. Girdling treatment in two levels (girdling and none girdling) and ethephon treatment on grape vine in three levels (0, 150 and 300 mg/L) at verasion were applied. Evaluated parameters include: total soluble solids (TSS), titratable acidity (TA), fruit maturity index, pH, cluster length and width, weight of the cluster and 20 berries, berry abscission, firmness, total antioxidant, total phenolic compounds and berries color. The results shown of the lowest level of TSS and fruit maturity index were in control treatment. Girdling and ethephon treatments significantly decreased titratable acidity