Bragantia
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9887
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Item Physical and chemical attributes of beans damaged by the coffee berry borer at different levels of infestation(Instituto Agronômico (IAC), 2024-05-09) Silva, Sabrina Alves; Pereira, Rosemary Gualberto Fonseca Alvarenga; Chalfoun, Sara Maria; Teixeira, Alexandre ResendeThe physical and chemical attributes of coffee beans have a direct relation with the sensory quality of the beverage and the commodity’s market value. The coffee berry borer is a pest that causes a worldwide harm, and its infestation compromises bean health and composition. The objective of this study was to analyze the effect of infestation levels on beans physical and chemical parameters. Coffee samples were collected, and the damaged beans present in the samples were classified as to infestation level. The centesimal composition, color, quantification of bioactive compounds, and organic acids were evaluated. The L* and b* parameters of the CIELab color system were found to be significantly different between infestation levels. For chemical parameters, beans with major levels of infestation were found to differ from the others in the content of sugars, lipids, soluble solids, total titratable acidity, electrical conductivity, potassium leaching, succinic acid, and acetic acid. The presence of pests did not affect the bioactive compounds present in the coffee beans.Item Factors influencing the performance of phosphites on the control of coffee leaf rust(Instituto Agronômico (IAC), 2021) Honorato Júnior, Jaime; Debona, Daniel; Zambolim, Laércio; Rodrigues, Fabrício ÁvilaThis study investigated the effect of different phosphites on the control of coffee leaf rust (CLR) caused by Hemileia vastatrix, considered the major disease affecting coffee yield worldwide. Three-month-old coffee plants were sprayed with two doses each of the phosphite solutions (standard and double), as follows: K (40% P2O5; 1.5 and 3 mL·L-1), K (30% P2O5; 3 and 6 mL·L-1), Cu (2.5 and 5 mL·L- 1), Mn+Zn (3 and 6 mL·L-1) and Na (3 and 6 mL·L-1) 24 h before being inoculated with H. vastatrix. Leaves were not washed or washed with deionized water after the foliar phosphites spray. Plants sprayed with water served as the control treatment. Inoculation was performed on the abaxial side of the first pair of expanded leaves using a camel hairbrush with a suspension of urediniospores (1 mg per leaf). All phosphites applied at the standard doses (from 1.5 to 3 mL·L-1) reduced the total number of pustules (TNP) per leaf by 28-69% regardless of washing treatment. The biggest reductions were observed for Cu phosphite, which decreased the TNP per leaf by 60 and 69% without and with leaf washing, respectively. A similar trend was observed when the double doses of phosphites (from 3 to 6 mL·L-1) were used, though Na phosphite without leaf washing and Mn/Zn phosphite without and with leaf washing were not efficient to reduce the TNP per leaf. Without leaf washing, only Cu and Na phosphites decreased CLR severity at the standard doses (53-61%), whereas all phosphites, except the Mn/ Zn phosphite, reduced CLR severity at the double dose. The CLR severity was decreased using K 30%, K 40% and Cu phosphites When applied at the standard doses with leaf washing (41-59%). With double doses, only Cu and Na phosphites decreased CLR severity by 55% for both treatments. In conclusion, the efficiency of the phosphites for CLR control varied according to the accompanying cation, dose and washing conditions. The Cu phosphite resulted in the best CLR control regardless of the dose used and the washing conditions.