Chemical approaches to manage coffee leaf rust in drip irrigated trees

Abstract

The purpose of this study was to assess the efficiency of chemical approaches to manage coffee leaf rust (CLR) in drip-irrigated coffee trees. Coffea arabica plants of the Catuaí Vermelho IAC 144 cultivar were subjected to applications of protective and systemic fungicides . Foliar application of the systemic fungicide epoxiconazol was performed at predefined dates (calendar) and after ascertaining that CLR was present in 10% of plants. A fungicide + systemic insecticide (cyproconazol + thiamethoxam) was applied on the soil at the beginning of the rainy season. The results showed that a strategy based on two foliar application calendar for epoxiconazol at pre-determined times in December (0.6 L c.p.ha −1 ) and March (0.4 L c.p.ha −1 ) controlled CLR more effectively than four foliar application calendar for the protective fungicide copper oxychloride applied in December, January, February and March, at 3.0 kg c.p. ha −1 , application on the soil of fungicide + insecticide (cyproconazol + thiamethoxam) at the beginning of the rainy season and sampling and decision-making with foliar application of the systemic fungicide epoxiconazol at 0.6 L c.p.ha −1 after ascertaining a 10% disease incidence. There was no significant difference in yield among the different strategies of fungicide applications across the six studied crops. The averages of coffee berry yield of all the treatments with fungicides either protective and or systemic were 30.80 (60-kg bags of processed coffee per hectare) which is 22.4% higher than the control treatment. In conclusion all the strategies can be used to control CLR including application of systemic fungicide after ascertaining a 10% disease incidence. The number of application of systemic fungicide epoxiconazol at 10% disease incidence was approximately 40% less than in a calendar system. This is the first report of the effective control of CLR with systemic fungicide epoxiconazol either spraying on the plants (performed at predefined dates or after ascertaining a 10% disease incidence) or through the application of cyproconazol on the soil in drip irrigation trees.

Current status and management of coffee leaf rust in Brazil

“…As to the use of calcium and potassium silicates, results showed that application was not efficient either as foliar spray or to the soil (Carré-Missio et al 2009Lopes et al 2013). On the other hand, treatment with Viçosa mixture and Bordeaux mixture have reduced rust incidence by 75 % due to the effect of copper sulfate (Souza et al 2011;Carvalho et al 2012).…”

“…Among systemic fungicides, triazoles are applied alone or in mixtures with QoI (strobilurin) fungicides, and are applied either on the leaves or in the soil (in this case, together with systemic insecticides for control of leaf miner). The combined use of copper-based fungicides with systemic fungicides has the additional advantage of providing copper to the plants, besides reducing the risk of selecting fungicideresistant rust populations (Souza et al 2011). Various rules can be used to aid the decision of when to start fungicide applications.…”

“…One of the advantages of systemic over protectant fungicides is their ability to act curatively (after the infection is established). However, their curative efficacy is greatly reduced if rust incidence is greater than 10 % in years of high fruit load (Souza et al 2011). In this case, systemic fungicides should be used alternated with cupric fungicides to avoid the selection of fungicide-resistant strains.…”

Effect of foliar application of potassium silicate on the progress of coffee leaf rust

“…Rust control in Brazil is routinely performed with the use of systemic fungicides sprayed on the leaves (two applications) or applied to soil (one application), and/or copper fungicide (4 to 5 foliar applications) Souza et al, 2011). Due to increasing concern regarding the environment and health of the consumers, the search for high quality coffee without pesticide residues has been a constant demand (Rodrigues, 2007).…”

Drying Time of Systemic and Protectant Fungicides on Coffee Leaves Exposed to Artificial Rain for the Control of Leaf Rust

“…The disease causes early leaf fall, resulting in a die-back of productive branches and fruits. Consequently, in the following year, the plants have a low fruit load (Souza et al, 2011). The most important strategy for the control of the coffee leaf rust is the use of resistant varieties.…”