Canopy management effects on Syrah grapevines under tropical semi-arid conditions.

The aim of this study was to evaluate the effects of shoot topping and leaf removal practices on vegetative vigor, yield and physicochemical characteristics of the 'Syrah' grape in the semi-arid tropical climate conditions of the São Francisco River Valley in the northeast of Brazil. The experiment was conducted over five growing cycles from 2010 to 2012 in a 'Syrah' commercial vineyard in the municipality of Casa Nova, Bahia, Brazil. Treatments consisted of leaf removal once or twice during fruit set or at the beginning of bunch closure, and one or two shoot toppings of the berry when pea-sized or 10 days after berry growth had commenced. Leaf removal and shoot topping did not affect yield, plant vigor components nor the main attributes of fruit quality. In contrast, there was a seasonal effect with higher yield and better balance between production and vigor in grapes produced in the first half of 2012. The Syrah grape quality was favored in cycles in the first half of the year when its ripening phase coincided with the period of mild temperatures.

Effect of insecticides sprayed on leaves and applied via soil to Aphis illinoisensis Shimer, 1866 (Hemiptera: Aphididae) on grapevines.

2016

Detection and molecular characterization of Grapevine yellow speckle viroid 1 isolates infecting grapevines in Brazil.

Abstract Presently, Hop stunt viroid(HSVd) and Citrus exocortis viroid (CEVd) are the only viroids reported to infect grapevines (Vitis spp.) in Brazil, among the seven viroid species already reported infecting this host in other countries. All grapevine viroid diseases are graft-transmissible and can induce losses especiallywhenassociatedwithviruses.Theaimofthisworkwas to confirm infection by Grapevine yellow speckle viroid 1(GYSVd-1) in grapevine samples exhibiting yellow speckle symptoms in the leaves and in asymptomatic samples sequenced by next generation sequencing (NGS). The occurrence of this viroid in Brazil was further investigated in a second study. Total RNAs and dsRNAs were extracted from five symptomatic plants and 16 asymptomatic samples, respectively. Specific primers were used for RT-PCR and amplified DNA fragments were cloned and sequenced by the Sanger method. Eleven complete nucleotide sequences of GYSVd-1 isolates (366 ?367 nt) were obtained from NGS and from RT-PCR amplicons. Comparisons showed high identities (95.9 ?100 %) among ten isolates and an identity of 87.2 ?90.4 % with a divergent isolate (RM-BR). Phylogenetic analyses placed GYSVd-1 isolates in four clusters (types 1, 2, 3 and 4). All GYSVd-1 infections were confirmed by conventional RT-PCR and RT-qPCR using specific oligonucleo-tides and a labeled probe. This is the first report and molecular characterization of GYSVd-1 infecting grapevines in Brazil, and our survey indicates that this viroid could be widespread in the major grape producing regions of Brazil. Keywords GYSVd-1 . Incidence . Next generation sequencing. Secondary structure. Vine.

Production of Syrah wines in tropical conditions of Northeast Brazil.

Twenty years ago, in the Northeast Brazil, a tropical semi-arid area, the production of tropical wines from some Vitis vinifera L. cultivars started. In this region, it is possible to harvest two times a year, between April and December, and nowadays Syrah is the most cultivated wine grape. Research works about irrigation rnanagement in Syrah started in 2000 at Brazilian Agricultural Research Corporation (Embrapa). The aim of this paper is to introduce some characteristics about the region where Syrah grapevines is being cultivated under irrigation in Northeast Brazil, and to present some results obtained from field experiments as well as some grape and wine charcteristics already determined.

Organic and nitrogen fertilization of soil under Syrah grapevine: effects on soil chemical properties and nitrate concentration.

Viticulture is an activity of great social and economic importance in the lower-middle region of the São Francisco River valley in northeastern Brazil. In this region, the fertility of soils under vineyards is generally poor. To assess the effects of organic and nitrogen fertilization on chemical properties and nitrate concentrations in an Argissolo Vermelho-Amarelo (Typic Plinthustalf), a field experiment was carried out in Petrolina, Pernambuco, on Syrah grapevines. Treatments consisted of two rates of organic fertilizer (0 and 30 m3 ha-1) and five N rates (0, 10, 20, 40, and 80 kg ha-1), in a randomized block design arranged in split plots, with five replications. The organic fertilizer levels represented the main plots and the N levels, the subplots. The source of N was urea and the source of organic fertilizer was goat manure. Irrigation was applied through a drip system and N by fertigation. At the end of the third growing season, soil chemical properties were determined and nitrate concentration in the soil solution (extracted by porous cups) was determined. Organic fertilization increased organic matter, pH, EC, P, K, Ca, Mg, Mn, sum of bases, base saturation, and CEC, but decreased exchangeable Cu concentration in the soil by complexation of Cu in the organic matter. Organic fertilization raised the nitrate concentration in the 0.20-0.40 m soil layer, making it leachable. Nitrate concentration in the soil increased as N rates increased, up to more than 300 mg kg-1 in soil and nearly 800 mg L-1 in the soil solution, becoming prone to leaching losses.

Characteristics of the vitiviniculture area in NE Brazil.

The aim of this paper is to introduce some characteristics about the region where syrah grapevines is being cultivated under irrigation in Northeast Brazil, and to present some results obtained from field experiments as well as some grape and wine characteristics already determined.