No abstract

Experiment was carried out throughout two successive seasons of 2016 and 2017 on Flame Seedless, Ruby Seedless and Thompson Seedless grapevines grown at the Experimental Orchard of Assiut University, Faculty of Agriculture. The aim of this study was to assess the impacts of abscisic acid (ABA), cluster thinning and their combinations with GA 3 on yield weight of three important grape cultivars grown under hot region. Data revealed that, the application of abscisic acid (ABA) increased yield weight (kg/vine), while cluster thinning decreased it. During the 1 st season of study (2016), all individual ABA treatments and ABA at 400 ppm combined with GA 3 at 10 ppm significantly increased yield weight (kg/vine) comparing with the control treatment. As a result of ABA treatments at 200, 400 and 600 ppm and ABA at 400 ppm plus GA 3 at 10 ppm, the yield was increased by 15.5%, 10.5%, 9.8% and 9.2%, respectively. During the 2nd season of study (2017), only ABA at 600 ppm treatment significantly surpassed the control treatment with an increment percentage of 20.5%. The rest of treatments either had no effect or reduced the yield weight comparing with the control. On the other side, cluster thinning by removing 30% of the total clusters that the vine bearing significantly reduced the yield weight (kg/vine) during the two studied seasons. As a result of such treatment, the yield was reduced by 37.2% and 39.2% in 2016 and 2017 seasons, respectively.

The effect of berry thinning, shoot topping and basal leaves removal on productivity of Ruby and Thompson seedless grapevines during 2008 and 2009 seasons were studied. All grapevines were 12 year old, grown at the Experimental Orchard, Faculty of Agriculture, Assiut University. Berry thinning was performed after berry set, whereas pinching and leaves removal were carried out at two weeks of berry set and at verasion phase respectively. The experiment was set up as complete randomized block (CRB) with four replicates, one vine per each.The obtained results could be summarized as follow Berry thinning as removing either 25% of apical cluster or 25% of shoulders significant decreases the berries number per cluster and consequently unsignificantly decreased the cluster weight and yield/vine compared to untreated one. Such berry thinning methods significantly increased berry weight and the chemical constituents of juice compared to untreated ones. In addition, removing 25% of apical cluster significantly decreased the compactness coefficient of clusters.Shoot pinching alone or along with defoliation significantly increased the berry weight and consequently significantly increased the cluster weight and yield/vine as well as improved the berry chemical quality compared to untreated one (control). Whereas, the defoliation at verasion phase significantly improved juice chemical constituents, but the effect was unsignificant on the berry weight, cluster weight and yield/vine compared with undefoliation ones.From this study, it is clear that to improve cluster and berries quality we can make berry thinning as alternatively about 25% of shoulders or combined pinching plus defoliation.

Pollination is a critical process in date palms production series that affect yield and fruit quality. This study aimed to evaluate the effect of different pollination methods (spray pollen grain with zinc, boric or ascorbic acid solution) on yield and fruit quality of Barhy date palm. This study was conducted at Kom Ombo, Aswan Governorate, Egypt during 2019 and 2020 seasons.Results showed that most beneficial treatment in this concern is spraying female spathes with 0.5 to 1 g pollen grains plus 1 g zinc or ascorbic acid/L water which gave economical yield with good fruit quality. Moreover, it distinguished to save time, effort, labor, cost and more practical to it is a promising technique in the future.

Little is known about the effect of foliar nano-nutrients application on pomegranate trees. The experiment was split-plot arranged in a randomized complete block design on some pomegranate cultivars grown at the Experimental Orchard, Faculty of Agriculture, Assiut University, Egypt during three successive season of 2018, 2019 and 2020. The research was to study response of some pomegranate cultivars to foliar spraying with nano-boron and nano-calcium. All the tested applications significantly increased the growth of trees as well as significantly improved the yield and fruit quality and reduced the fruit cracking percentage. Spraying nano-boron plus nano-calcium gave the highest values of growth traits, yield and fruit quality. No significantly differences on all studied traits due to spray nano-boron or nano-calcium singly or in combination. The highest growth traits and yield were recorded on Wonderful followed by Higazy cvs. On other hand, the best fruit quality was detected on Manfalouty pomegranate compared to other studied cultivars.It is recommended to spray Manfalouty, Higazy and Wonderful pomegranate trees with nano-boron or nano-calcium individually or in combination three times to get high yield with good fruit quality.