Yield and Quality of `Banaty' Grapes in Response to Spraying Iron and Zinc

Abstract

<jats:p>During 1995 and 1996, yield and quality of `Banaty' grapes in response to spraying chelated iron and zinc singly or in combination each at 0.025%, 0.05%, 0.1%, 0.2%, or 0.3% was investigated. Each concentration was applied once, twice, three, four, or five times. Results showed that there was a gradual increase in berry set, cluster number, yield, cluster weight, berry weight, total soluble solid sugars, and total anthocyanins with rising concentrations and number of sprays of each fertilizer. Total acidity tended to reduce with such treatment. Combined spray of both fertilizers, particularly at 0.1% four times, gave satisfactory improvement in both quantity and quality of grapes. Spraying at concentrations higher than 0.1% or spraying more than four times failed to show any measurable effect on all of the studied traits. The best results with regard to yield and quality of `Banaty' grapes were obtained on vines that received four sprays of iron and zinc each at 0.1% in chelated form.</jats:p>

Iron Supply Affects Anthocyanin Content and Related Gene Expression in Berries of Vitis vinifera cv. Cabernet Sauvignon

“…Numerous studies have described the enhancing effects of Fe treatments on the content of TSS or sugar in mature fruits [ 11 , 14 ]. In Fe-deficient plants, the activity of ribulose-1,5-bisphosphate carboxylase (RuBPC) and the content of Chl and carotenoids decrease, hence leaf CO 2 exchange rate and Chl photosynthetic efficiency were decreased [ 2 , 4 , 8 ].…”

“…The proportion and amount of each anthocyanidin is influenced greatly by cultivar type and viticultural conditions. Among the many viticultural factors, fertilizer such as nitrogen [ 17 , 20 ], phosphate [ 22 ], potassium [ 21 ], zinc [ 23 ], iron [ 14 ], and so on are very important factors which can influence anthocyanin biosynthesis. Low nitrogen supply caused a significant increase in anthocyanin levels [ 17 ], higher nitrogen levels significantly decreased the anthocyanin concentration in the skin of berries at harvest [ 21 ].…”

“…Numerous studies have investigated the effect of Fe on fruit quality. Most of the studies have focused mainly on the effect of Fe on fruit size, firmness, the concentrations of sugar, acidity, vitamin C, dry matter, and phenolic compounds [ 2 , 10 , 11 , 12 , 13 , 14 ]. Among the studied chemical compositions, anthocyanins are very important for fruit color and are involved in many biological functions in plants such as antioxidant capacity, protective effects against UV irradiation, and pathogen attack [ 15 , 16 , 17 ].…”

“…The biosynthesis of anthocyanins are through the flavonoid pathway, starting with phenylalanine as a precursor. The accumulation and the proportion of individual anthocyanins in the berry skin or cultured grape cells can be influenced by several mineral nutrients [ 17 , 20 , 21 , 22 , 23 ] including iron [ 14 ]. The molecular regulations of anthocyanin biosynthesis in response to mineral nutrients—such as nitrogen [ 17 ], phosphorus [ 22 ], and zinc [ 23 ]—have been studied.…”

“…However, the effects of Fe on the anthocyanins have been little studied. Ahmed et al reported that Fe supply increased the total anthocyanins of ‘Banaty’ grapes [ 14 ], furthermore, it has not yet been elucidated how individual anthocyanins and their biosynthesis pathway genes respond to different concentrations of Fe.…”