No abstract

This study evaluated the cycle duration, physicochemical characteristics of fruits and climatic adaptation of the 'SR 501-17' hybrid grape grafted on four rootstocks for the production of white wine. We tested four rootstocks, 'IAC 766 Campinas', 'IAC 572 Jales', 'IAC 571-6 Jundiaí' and 'IAC 313 Tropical', planted in two climatic regions, Cfa and Aw, in the state of São Paulo, Brazil in the cultivation years 2014 and 2015. Cycle duration, production, cluster weight, number of berries per bunch, content of soluble solids, titratable acidity, a maturation index and the weight, length and width of berries were evaluated. A principal component analysis characterized the cultivar AGROMETEOROLOGY -Article for both climatic regions and years. The rootstock did not influence the cycle, production or physicochemical characteristics of the 'SR 501-17' hybrid. The soluble-solid content in the must was higher and the production cycle in 2014 was longer for the Cfa climate. The production cycle was shorter and the weight and width of the berries were lower, mainly in 2015, for the Aw climate. The cycle was thus longer, production was higher and the chemical characteristics were better for the 'SR 501-17' hybrid under Cfa conditions, regardless of the rootstock.

Classifying vines regarding the number of days required to complete de productive cycle and the duration of intermediate phenologic phases are essential for genetic improvement programs, implementation of cultivation techniques and handling of the grape harvest. The objective of this study was to evaluate the access phenotypic divergence of grapes from the germplasm collection by the Agronomic Institute -IAC. Evaluations were performed for 4 years of production, from 2012 to 2015, when the plants were 4 years old. The training system applied the espalier, at a 2.0 x 1.0 m spacing between lines and plants, respectively. The IAC's grape germplasm collection comprised 110 varieties of the Vitis vinífera, Vitis labrusca species and inter-specific hybrids grafted into the IAC 766 rootstocks, being 3 plants per each variety. After the pruning of the main vine phonologic phases, the number of days was evaluated using the scale proposed by Eichhorn and Lorenz. Two evaluations a week were carried out until the flowering, and afterwards one evaluation was performed a week, the period between pruning and the beginning of sprouting, full flowering with 50% flowers opened, beginning of maturation (veraison) and maturation (harvest), visually mature fruits and content of soluble solids above 14ºBrix. Multivariate analysis, such as the correlation between varieties, analysis of the main components (PCA) and methods of non-weighted arithmetic means (UPGMA) was applied to classify the phenotypes according to the productive cycle. A relation was found between the sprouting and the flowering phases, as well as the starting maturation and maturation. The first two components explained 81% of the total variability, being that the starting maturation and maturation were the best variables to study the divergence of vine phenotypes. Also, combining the UPGMA method and the PCA analysis that distinguished three groups, allowed us to divide the phenotypes into 25 processes, 75 median and 10 late varieties, according to their productive cycle. It was possible to conclude that the techniques used to study the genetic diversity applied to phenologic characters were effective to evaluate the vines phenotypic divergence, and therefore, the multivariate analysis may be used to guide future vine improvement programs.

Abstract. The objective of this work was to evaluate five varieties of white grapes destined to winemaking, grafted on the two main rootstocks used in viticulture in São Paulo, Brazil, 'IAC 766 Campinas' and 'IAC 572 Jales'. The experiment was performed on the experimental area of Centro APTA de Frutas in the Jundiaí city, São Paulo state, Brazil. The experimental design was a randomized block with split plot with five replications, the plots represented by varieties and subplots by rootstocks. We evaluated the number of days to budding (NDB), number of days to flowering (NDF) and number of days to maturation (NDM), productivity (Prod) (ton.ha −1 ), content of soluble solids (SS), titratable acidity (TA) and maturation index (MI). There was no difference between rootstocks, and there was interaction among rootstocks and varieties for SS and TA. The varieties did not show significant differences for yield, but there was a significant difference for the other variables. We can concluded that among the assessed varieties on both rootstocks, in Jundiaí / SP, the variety SR 501-17 distinguished itself due to its precocity, productivity and chemical quality of the must.

RESUMOO milho (Zea mays L.) é uma das principais espécies agrícolas cultivadas no mundo, sendo que a sua produção pode ser encontrada em regiões com condições de solo e clima muito contrastantes. Este fato é determinante para que exista um estímulo para estabelecimento de um programa de melhoramento genético. A presente pesquisa teve como objetivos a produção de uma variedade sintética de milho a partir do intercruzamento de cultivares comerciais disponíveis no mercado, bem como a avaliação do seu desempenho agronômico, observado durante o processo de seleção recorrente fenotípica. Foi observado que a população selecionada apresenta uma grande homogeneidade, visando a criação de uma população uniforme exigida para o registro da cultivar. A avaliação do desempenho agronômico dos genótipos contribuiu para a geração de conhecimento básico necessário ao processo desenvolvimento desta nova variedade. Palavras-chave: milho, variedade sintética, melhoramento genético, seleção recorrente fenotípica, Zea mays L.

No abstract

Grapevine anthracnose, caused by Elsinöe ampelina, is a fungal disease with no mapped resistance loci. Thus, this study aimed to evaluate different traits used to phenotype grapevine anthracnose looking for correlated traits and reproducibility during evaluations. Phenotyping was conducted with F 1 siblings segregating for resistance to grapevine anthracnose. The progenies were inoculated with Elsinoë ampelina. Leaves, canes and shoots were phenotyped three times. Real severity and number of anthracnose spots were determined from digital photographs. Complementary, the number of spots was estimated using a scale from 0 to 9 and the severity using standard area diagram (SAD) developed for leaves and shoots. The results revealed positive correlation between real and estimated number of anthracnose spots, and the real and estimated severity. However, the number of anthracnose spots did not correlate with severity. The real data from severity and number of spots presented higher variation than the estimated data based on the SAD and scale, respectively. The evaluation strategy based on number of anthracnose spots showed reproducibility in the three independent bioassays, being the most accurate phenotyping strategy for grapevine anthracnose symptoms.

The interaction between variety, rootstock, and trellis height is important for grapevine management, mainly for producing new varieties of grapes for juice and wine in new wine-growing regions with high production potential. Then, this study aimed to evaluate the rootstocks and trellis height influence on photosynthesis, biochemical, and yield performance for grapevine hybrids. The experiment was carried out in a randomized block design using two factors, rootstocks (‘IAC 766’ and ‘106-8 Mgt’) and trellis height (until 1.6 and 2.0 m), evaluated for two grapevine hybrids (IAC 138-22 ‘Maximo’ and ‘BRS Violeta’). During grapevine flowering, it was evaluated photosynthesis and biochemical performance, for this, the gaseous exchanges were measured using the open system photosynthesis equipment with a CO2 analyzer and water vapor by infrared radiation, being net assimilation rate of CO2, stomatal conductance, transpiration rate, internal CO2 concentration, water use efficiency, carboxylation efficiency (Rubisco), and the flux density of photosynthetically active photons. At the stages of grapevine flowering and ripening berries were evaluated the antioxidant enzymes (peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT)), total soluble proteins, chlorophylls, and SPAD. The interaction between rootstock and trellis heigh influenced varieties’ photosynthesis, biochemical, and yield performance. In conclusion under subtropical conditions, better photosynthesis, biochemical, and yield performance were observed when both cultivars were grafted on the ‘IAC 766’ rootstock. The ‘IAC 138-22 Maximo’ was trained until 2.0 and grafted on the ‘IAC 766’ rootstock, increasing grape production and photosynthesis efficiency. In addition, this variety was more productive than ‘BRS Violeta’.