What is the cost (US$) of rust control failure? What is the economic impact? How much is the country losing? Do we have time to waste? The longer you wait, the greater the losses will be? Considering the amount of losses, is there a need for immediate action to reduce losses for the next harvest? Is it possible to recover control efficiency?
Take as an example Brazilian soybean production in the 2013/14 harvest, estimated at 90 million tons.
Considering rust, if the efficiency of chemical control was 100%, the damage (reduction in production) would be zero, and, therefore, 90 million tons would be harvested.
The data generated by the Fungicide Cooperative Trials in the 2003/04 to 2004/05 harvests pointed to a maximum efficiency of 90% (maximum value) and, consequently, resulting in 10% damage, or 900 thousand tons. In this case, 9 million tons would be harvested.
Due to the reduced sensitivity of Phakopsora pachyrhizi, the current control efficiency is 60% (Godoy et al., 2013), with a damage of 30% or 2,7 million tons. As a result, 87,3 million tons would be harvested.
Given this amount of damage (US$ 507.00/t, Paranaguá, PR) there is an urgent need to seek solutions aimed at recovering control efficiency. In this sense, a strategy to reduce damage has already been identified (experiments conducted in two harvests 2012/13 and 2013/14) which consists of the addition of multisite fungicide, commercial fungicide mixtures.
This article was presented by the author during the SEMINAR ON FUNGI RESISTANCE TO FUNGICIDES IN WINTER CEREALS AND SOY,organized by OR Melhoramento de Sementes Ltda and held on December 16, 2015, at the University of Passo Fundo.
Receive the latest agriculture news by email
Receive the latest agriculture news by email
