Kleffmann’s study shows that correct use of refuge comprehends only 20% of Summer Corn total area.

Majority (61%) of those who use Bt seeds do not use refuge and 14% of who claim to adopt the practice, do it inappropriately.

A new unpublished study by Kleffmann Group sets the alert on reduction, year by year, of the adoption index of refuge on summer cornfields. In 2016/17 harvest, from the total of 4,2 million hectares planted with the crop, farmers properly adopted refuge to preserve the seed technology (GMO caterpillar resistant) only on 20% from the total of 4,2 million hectares of this crop. According to Daniel Holzhausen, Kleffmann’s research manager for Latin America, the margin of error is set on 2,2%. This research was composed by 2.034 interviews with producers from Bahia, Distrito Federal, Paraná, Rio Grande do Sul, Santa Catarina and São Paulo states, in the last summer harvest.

Based on Kleffmann’s historical data, the past six harvests showed that Bahia state is the most committed area when it comes to the use of refuge – 48% of the area were conducted the right way. However, there has been a significant decrease comparing to the last year, when appropriate refuge area was adopted by 69% of crop area. In Rio Grande do Sul and Santa Catarina states, the practice adoption are 29% and 26% respectively, and were kept the same when compared to the last two harvests. In Minas Gerais and São Paulo states, the share has not changed from one harvest to another, staying at 16% of the area in both states.

This study brought up another important information. Considering the number of producers that practice refuge area, there is this tendency of growers who do it incorrectly. Meaning that they make at least one mistake in one of the basic rules of this practice. One of them is keeping the maximum distance of 800 meters between Bt corn and conventional one. Another common mistake is about respecting the maximum usage area on each property (90% of total). However, the number of farmers who do 8% or 9% of the area is so high that we cannot consider them not committed, but there are a few more improvements to make, such as better planning and more control of the sowing process.

“In our historical data, we saw that 2014/15 harvest showed the most adoption of correct practice of refuge. Meantime, new technologies of varieties resistant towards caterpillar were launched to the market, which made the companies intensify the campaign on how important the correct practice is”, says Daniel Holzhausen.

This article demonstrates how important it is to intensify the campaign to convince producers, given that the low ratio of adhesion to the practice could compromise the technology by creating resistant descendants to Bt protein and consequently shortening the useful life of its applicability. “This scenario should be improved, so we can guarantee effectiveness and the maintenance current and for new field technologies”, Daniel confirms. Having this on mind, the research showed that from the nine mentioned brands, five presented above average results on adhesion to the good practice.


Isabela Colagrossi

Kleffmann Group Brazil