Effect of foliar‐applied potassium silicate on coffee leaf infection by Hemileia vastatrix

Abstract

Coffee leaf rust, caused by Hemileia vastatrix, is the most devastating disease of coffee. Since limited information is available in the literature on silicon (Si) affecting plant diseases in coffee, this study was designed to investigate foliar application of potassium silicate (PS), a source of soluble (Si), on infection process of coffee leaf rust at the microscopic level. The foliar Si concentration for plants sprayed with water and PS has no significant difference (0.24 and 0.30 dag kg −1 , respectively). X-ray microanalysis indicated that the deposition of Si on the leaves of the plants that were sprayed with PS was greater in comparison to the leaf samples from the plants sprayed with water. Rust severity on leaves of plants sprayed with water or sprayed with PS reached 44% and 32%, respectively, at 36 days after inoculation (dai). Plates of polymerised PS were observed on the leaf surfaces of the plants sprayed with the product, in contrast to its absence on the leaf surfaces of plants sprayed with water. At 36 dai, a greater number of uredia were observed on the leaf surfaces of plants sprayed with water in comparison to the leaf surfaces of plants sprayed with PS. On fractured leaf tissues that were sprayed with PS, less fungal colonisation was observed in comparison to the leaves of plants sprayed with water. In conclusion, the results of this study suggest that the effect of foliar-applied Si on the control of the coffee leaf rust development may be attributed to the physical role of the polymerised PS, its osmotic effect against urediniospores germination, or both.

Effect of Different Varieties and Silicon Fertilizer on the Rooting Efficiency and Productivity of Mini-Cuttings and Powdery Mildew Disease of Eucalypt

“…From the results presented in previous studies [50,51,52,53] it is believed that the absorbed Si doses were too low to have any effect on the incidence of powdery mildew, since absorption of this nutrient in the plants that responded to Si application were those that presented higher leaf contents than those observed in the present study.…”

Dynamics of severity of coffee leaf rust (Hemileia vastatrix) on Coffee, in Chanchamayo (Junin-Peru)

“…In this work, within the dry season, in May and June, the severity was higher than in the other months, reaching from 32 % to 34 %, 20 % to 30 %, and 12 % to 23 % in the lower, middle and upper parts, respectively. About 35-40 % severity of CLR in coffee cv Catuaí Vermelho IAC 81 and Catuaí Vermelho 44 respectively, was reported by Sera et al (2009) and Carré-Missio et al (2013).…”

Role of Silicon in Mediating Salt Tolerance in Plants: A Review

“…In several studies, foliar spray of silicate (e.g., K 2 SiO 3 or Na 2 SiO 3 ), silica nanoparticles, and stabilized silicic acid (sSA) have been found to be effective to increase plant growth [43]. For example, Carré Missio et al [44] reported that foliar application of potassium silicate increased Si deposition on the leaves and reduced coffee leaf rust, which was mainly attributed to the physical role of the polymerized potassium silicate or its osmotic effect against urediniospore germination. Prakash et al [45] found that foliar silicic acid at 2 and 4 mL·L −1 significant increased grain and straw yield.…”