Underground drip irrigation is efficient in controlling the giant borer in sugarcane

Sugarcane is affected by several pests and many of them can cause significant damage to the crop and also economic damage. Among these pests, the giant sugarcane borer (telchin licus) is one of the most important due to the consequences that affect farming.

In Brazil, the incidence has increased significantly, and the lack of control options worries sugarcane producers, especially in the Northeast region. Its presence was observed in the states of Acre, Alagoas, Amazonas, Bahia, Goiás, Maranhão, Mato Grosso do Sul, Minas Gerais, Pará, Paraíba, Pernambuco, Rio de Janeiro, Rio Grande do Norte and Sergipe.

The caterpillars bore into the sugarcane stem, causing considerable weight loss and, eventually, the death of the plants. Due to the numerous damages caused by this pest, the reduction in productivity can reach alarming rates, with a drop of up to 65% being observed in some areas (Mendonça 1973).

The control methods used are, for the most part, ineffective or aggressive to plants. The most commonly used method in infested areas in the Northeastern States of Brazil is the physical destruction of caterpillars and pupae after manual harvesting, with the aim of reducing their population.

Chemical control of this pest has not been effective until now due to limited insecticide penetration into the sugarcane clusters where the caterpillars are located.

In recent years, a new and innovative use of subsurface drip has been developed to deliver a wide range of materials directly to the root zone. The first being the biological control of the borer through the inoculation of the fungus Beauveria bassiana through the drip system, where it proved to be successful in doses of 4, 6 and 8 kg / ha and maintained the number of giant borer samples in half the untreated level.

This success is due to the fact that part of the pest's life cycle is in the soil. As the adult borer lays its eggs in the soil, application of spores beauveria bassiana through the drip system directly into the soil effectively put the pest in contact with the disease inoculant. It may be even more effective to treat B. bassiana with lower infection rates (Garcia 2012).

Another method of controlling this pest can also be carried out with the application of chemical molecules. The figure below shows the performance of Chlorantraniliprole at 450 g/ha for 120 days after its application. This graph shows its maximum residue at 83 days after application (87,6%), decreasing up to 120 days (74,5%). This reinforces its efficiency in reducing the pest population, allowing it to be harvested and present at this time with 91,2% control.

From the above, it can be seen that the drip irrigation system is an excellent tool for controlling the giant borer.