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Reginaldo Gonçalves Mafia

Suzano's Forest Management Technology Manager


The new era of forest protection

In Brazil, eucalyptus plantations reached 7.53 million hectares last year. Despite the more accelerated growth recently, the availability of wood is still a factor that makes it difficult to increase the productive capacity of the pulp and paper industry, as well as the production of new products from forest biomass. Additionally, climate change, the emergence of new pests and diseases, expansion into new regions, where naturally there is less knowledge of the environment, are limiting factors for increased productivity and, consequently, for wood supply.

In this context, the protection of eucalyptus plantations against losses becomes even more relevant. Forest protection has undergone a great evolution in recent decades. In a didactic way, we can separate this progress into three periods. The first, between the 1980s and 2000s, comprised the phase of discovery, characterization and studies of bioecology and control of pests, diseases and weeds.

Then, between 2000 and 2020, protocols were developed to evaluate the resistance of eucalyptus clones to pests and diseases, as well as the use of biological control intensified. In the same period, the introduction of integrated weed management took place. As of 2020, it is possible to distinguish a new phase, in which the use of biotechnology will assume an even more important role, with the use of genetically modified eucalyptus, which may confer characteristics of increased productivity, resistance to pests and tolerance to herbicides.

In addition, considering the current scenario, in this third phase, it is essential to invest in the selection of clones and in the adjustment of management to form forests that are more resilient to climate change. Genetic transformation is an excellent tool for adding desirable characteristics to increase productivity and wood quality, either directly or through more efficient use of environmental resources and/or increased plant resistance. Normally, to obtain direct growth gains, as it is about quantitative traits, the process involves more genes and is more complex.

On the other hand, to add a qualitative attribute, for example, resistance to a pest or tolerance to a certain herbicide, the process is comparatively simpler, involving one or a few genes. This difference in complexity and potential gain, as well as the way to synchronize advances in the conventional breeding program and genetic transformation, needs to be considered when defining a good eucalyptus clonal development strategy.

Genetically transformed eucalyptus clones already exist to increase wood productivity and to tolerate the herbicide glyphosate. Other genetically modified events for resistance to insect pests are under evaluation by the National Technical Commission on Biosafety. Although these technologies are already safely used in agriculture, due to forest certification barriers, genetically modified eucalyptus plantations are still being carried out on an experimental pilot scale.

This reality needs to be changed in view of the potential gains. In the case of glyphosate-tolerant eucalyptus, in addition to the lower risk of loss of productivity caused by phytotoxicity from drifts, it is expected to increase work safety, as it will be possible to use fully mechanized applications, with greater efficiency, lower cost and exposure to workers.

From an environmental point of view, there is an opportunity to optimize the use of herbicides, as it will be possible to better position the moment of application. Another interesting example is the development of eucalyptus with resistance to pests. In this case, in addition to reducing control costs, it is worth mentioning the elimination of losses and the use of insecticides for control, representing a big step towards reducing the use of pesticides.

It is important to mention that these technologies are part of integrated management as an additional tool. It is worth remembering that the best way to increase environmental sustainability, for plant production, continues to be to achieve greater productivity, as this way we will be even more efficient in the use of resources and with less demand for area for cultivation.

Until a certain time, the possibility of profit from the use of genetically modified eucalyptus seemed a distant reality, as there were no proven efficient events, and certifications did not allow planting on a commercial scale. This reality has changed and, currently, there are already effective and approved events, proven to be safe for human health, animals and the environment.

On the other hand, there has not been an evolution in the policy of forest certifications, which still do not consider the advancement of science and the worldwide evolution of regulatory systems. To make a comparison, for the main agricultural crops, the use of transgenic cultivars has been a reality for over 20 years, and food from these crops is consumed daily.

It is important to mention that the National Biosafety Law and the Normative Resolutions of the National Technical Biosafety Commission are careful and efficient to evaluate, monitor and regulate the use of genetically modified organisms. Not recognizing this competence on the part of the certifying agencies and making the use of safe biotechnologies more flexible is, at the very least, a contradiction, with impacts on the competitiveness of the forestry sector and on obtaining environmental gains.

In another important area for forest protection, knowledge bases on assessment have been developed against biotic agents. These evaluations aim to determine and select resistance phenotypes against pests and pathogens, a process called “phenotyping”. From now on, however, considering climate change and more significant climate variations, it becomes essential to develop methodologies to select clones that are more resilient to abiotic factors. Among these factors linked to the environment, resistance to water deficit seems to be the most relevant, since, in the main eucalyptus growing regions, drastic drought events have become a cyclical constant.

Therefore, we are investing in the characterization of physiological markers and in techniques for selecting clones that are more tolerant to water deficit and more adapted for planting in sandy soils. The growth of eucalyptus or any other plant is conditioned to the effect of the genotype, the environment and the interaction of these factors. Considering that the environment is increasingly variable in space and time, it is important to rethink the way of carrying out genetic improvement and management of eucalyptus plantations. Otherwise, we will not be able to reach higher levels of productivity and minimize losses caused by harmful agents, whether biotic or abiotic factors.