Effect of Foliar Spraying Some Nano-Fertilizers or Potassium Silicate in Reducing the Use of Traditional Fertilizers on Growth, Yield and Bunch Characteristics of Flame Seedless Grapes

Abstract

This study carried out throughout two successive seasons 2017 and 2018, on 4 yearsold Flame seedless grapevines grown in sandy soil at 2x3 m apart under drip irrigation system and vines were trellised with Y-shape system in a private vineyard at Belbies District, Sharkia Governorate, Egypt. The experiment included 8 treatments as follow: T1-Control (spraying water) vines will be fertilized according to the used fertilization program followed in the vineyard (60 N, 40 P2O5 and 80 K 2 O g/vine/year). T2-Spraying vines with mixture of a nano fertilizer containing potassium (36%), amino acid (5%), total nitrogen (5%), total phosphorus (2%) and micronutrient (2%) [Potacrystal at 3 cm/L] (except potassium and 1/5 nitrogen). T3-Spraying vines with mixture of a nano fertilizer containing calcium (15%), magnesium (2%), boron (1.5%) with amino acid (2%) and nitrogen (10%) [Kalmagbor at 3 cm/L] (except 1/10 nitrogen). T4-Spraying vines with mixture of a nano fertilizer containing phosphorus (40%), potassium (28%), amino acid (5%) and nitrogen (5%) [Phospho one at 3 cm/L] (except potassium and phosphor and 1/5 nitrogen). T5-Spraying vines with mixture of nano micro nutrient + citric acid (Magro nano mix at 1 g/L) + (60 N, 40 P 2 O 5 and 80 K 2 O g/vine/year). T6-Spraying vines with normal chelated iron at 2 g/L+ (60 N, 40 P 2 O 5 and 80 K 2 O g/vine/year). T7-Spraying vines with nano chelated iron at 3 cm/L + (60 N, 40 P 2 O 5 and 80 K 2 O g/vine/year). T8-Spraying vines with normal potassium silicate at 5g/L+(60 N, 40 P 2 O 5 and 80 K 2 O g/vine/year). All spraying treatments carried out three times a year at monthly intervals i.e., the first week of each of March, April and May. The results showed that total yield/feddan (ton) significantly increased by application of all treatments compared with control in both seasons. The uppermost values of total yield per feddan (ton) recorded for treatments T4 (15.59 and 19.94 ton) and T7 (17.20 and 22.11ton) in the first and second season, respectively. The shortest bunches were from treatments control and Normal potassium silicate in the first and second season, respectively, while, other treatments recorded higher values of bunch length in the two seasons without significant differences between them. Leaf surface area (cm 2 ) and leaf fresh and dry weight were significantly increased by the tested treatments compared with control (T1) in the two seasons. However, leaves of T7 treatment (Nano chelated iron) contained the highest chlorophyll a (1.133 and 1.233 mg/100 mg FW), b (0.933 and 0.920 mg/100 mg FW), total chlorophyll (2.033 and 2.153 mg/100 mg FW) and carotenoids (0.950 and1.077 mg/100 mg FW).