Map monitors the occurrence of corn stunting in the field

Continuing with the assessment of the occurrence of the corn stunting complex, the Ministry of Agriculture, Livestock and Supply (Mapa) began measures in March to carry out monitoring activities for the disease in areas where the crop is grown during the year 2022. The measure aims to diagnose the occurrence of agents causing the disease to support possible measures that can reduce or avoid losses for corn producers.

Stuntings are caused by bacteria from the Mollicutes class and are classified into two types: pale stunting and red stunting, caused by Spiroplasma kunkelii (spiroplasma) and Maize bushy stunt phytoplasma (phytoplasma), respectively. Both pathogens are transmitted by the corn leafhopper Dalbulus maidis.

This year, seeking to improve the systematization of data and the preparation of disease occurrence maps, the Department of Plant Health and Agricultural Inputs of the Secretariat of Agricultural Defense made adjustments to the monitoring protocol, sent to the Federal Superintendencies of Agriculture and State Agencies of Agricultural Defense of the main corn producing states in the country. 

Among the guidelines is a list of information that must necessarily be recorded during monitoring, such as geographic coordinates, crop development phase, management practices used to control leafhoppers and stunting, damage levels, among others.

Furthermore, as in the previous year, sampling will be carried out in two stages, starting with the collection of the insect vector, if detected at the time of monitoring, and, subsequently, corn leaves, regardless of whether the plants show symptoms.

“To expand the collection of information on the occurrence of the disease among corn producers, the Secretariat of Agricultural Defense also hopes to count on the participation of the productive segment, through some of its representative entities, formally invited to participate in the actions at the beginning of the month”, reports the general coordinator of Plant Protection, Graciane de Castro.

In 2021, Mapa, in partnership with state agricultural defense agencies and research institutions involved in the topic, carried out phytosanitary surveys that allowed the mapping of the occurrence of red stunting and pale stunting in the main corn producing regions of the states Bahia, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Paraná, Rio Grande do Sul and Santa Catarina, in addition to the Federal District.

The maps are available for consultation at Ministry of Agriculture website.