ABSTRACT The objective of this study was to investigate the effect of different rates of ethephon on return bloom and yield, and fruit quality of ‘Fuji’ apple trees. The experiment was performed during the 2014/2015 and 2015/2016 growing seasons. Eighteen-year-old Fuji Standard apple trees grafted on M.9 were sprayed with different rates of ethephon (300 mg L-1, 400 mg L-1, and 500 mg L-1) 30 days after full bloom (DAFB) and compared to an unsprayed control. Yield components (number of fruit per tree, yield, fruit weight, and estimated yield) and fruit quality attributes (fruit firmness, total soluble solids and starch-iodine index) were evaluated in both seasons. Return bloom (percentage of flowering spurs and 1-year-shoots) was assessed only the year following the application. Our results show that ethephon increases return bloom and yield of ‘Fuji Standard’ apple trees, without affecting fruit quality attributes.

Resumo: O objetivo deste trabalho foi avaliar o efeito de diferentes técnicas para modificar a arquitetura de cachos de uva sobre a incidência e a severidade de podridão cinzenta, bem como sobre o desempenho vitícola da videira (Vitis vinifera) 'Sauvignon Blanc'. Associados aos fungicidas, quatro tratamentos foram testados: controle, 30 ppm de ácido giberélico aplicados por pulverização na plena florada, 1.000 ppm de prohexadiona de cálcio aplicados por pulverização na plena florada e raleio de bagas durante a compactação dos cachos. O experimento foi realizado nas safras 2015, 2016 e 2017. Os cachos foram tratados com fungicidas durante os estádios de plena florada, compactação do cacho, veraison e aproximadamente 15 dias antes da colheita. O raleio de bagas não causa perdas na produtividade e na qualidade de 'Sauvignon Blanc', e, embora tenha pouco efeito na arquitetura do cacho, é eficaz na redução da incidência e da severidade de Botrytis cinerea. A prohexadiona de cálcio melhora a maturação fenólica das uvas, é eficaz na redução da incidência e da severidade de B. cinerea e reduz a compactação do cacho ao diminuir o diâmetro das bagas. A aplicação de ácido giberélico por pulverização na plena florada não é recomendada por reduzir a produtividade e a fertilidade das gemas e aumentar a suscetibilidade das bagas à infecção por B. cinerea.

Abstract: The objective of this work was to evaluate the effect of different techniques to modify grape cluster architecture on the incidence and severity of botrytis bunch rot, as well as on the viticultural performance of the 'Sauvignon Blanc' grapevine (Vitis vinifera). Associated with fungicides, four treatments were tested: control, 30 ppm gibberellic acid sprayed at full bloom, 1,000 ppm prohexadione calcium sprayed at full bloom, and berry thinning at the stage of beginning of berry touch. The experiment was carried out in the 2015, 2016, and 2017 vintages. Clusters were treated with fungicides during the stages of full bloom, beginning of berry touch, veraison, and around 15 days before harvest. Berry thinning does not cause losses in the yield and quality of 'Sauvignon Blanc', and, despite having little effect on cluster architecture, is effective in reducing the incidence and severity of Botrytis cinerea. Prohexadione calcium improves grape phenolic maturation, is effective in reducing the incidence and severity of B. cinerea, and reduces cluster compactness by decreasing berry diameter. The application of gibberellic acid spray at full bloom is not recommended because it decreases yield and bud fertility and increases berry susceptibility to B. cinerea infection.

ABSTRACT: The incorporation of organic matter to the soil not only improves nutrient content, but also reduces the survival of Stenocarpella, the causal agent of stalk rot, Diplodia ear rot, and grey leaf spot, in maize stubble. We evaluated the effect of organic waste incorporation on Stenocarpella survival in maize stalks, the activity of suppressiveness-related enzymes, and nutrient contents. We conducted the assays in the municipalities of Lavras and Sete Lagoas, Minas Gerais State, Brazil. Maize stalks infested with Stenocarpella were kept in field conditions for three months after poultry litter, swine manure, fish hydrolysate, compost sewage sludge, and urea application. Infested stalks, without residue amendment, were kept on surface or incorporated into the soil, representing negative and positive controls. Stenocarpella concentration in stalks was assessed using qPCR expressed as cycle threshold number. Sewage sludge, buried stalks, and stalks retained on the surface showed reduction of pathogen inoculum. Swine manure and urea did not reduce the quantity of DNA. In the experiment conducted in Lavras, poultry litter stimulated β-glucosidase, urease and hydrolysis of fluorescein diacetate activities when compared to the negative control. Sewage sludge, poultry litter, and swine manure increased Ca in the soil by 44 %, 38 % and 36 %, respectively, in the experiment conducted in Lavras. Poultry litter increased Ntotal three months after application. The results indicate that organic wastes are promising in improving nutrient content, activity of hydrolysis-related enzymes, but Stenocarpella inoculum dynamics should be taken into consideration when deciding on the specific organic amendment.