Wheat is one of the most cultivated and consumed cereals in the world, playing a key role in human nutrition and in the global economy, thus being responsible for basic food and national and international food security.
The presence of the El Niño phenomenon this year sparked an alert for wheat growers in Rio Grande do Sul, because rainfall will be above normal for this time of year, thus favoring the spread of diseases in wheat, such as scab, a disease caused by the fungus Gibberella zeae.
Headache is characterized by the development of infections in the spikes or panicles of plants, especially during periods of high humidity and mild temperatures. In this way, the fungus invades the flowers or grains in development, resulting in symptoms such as discoloration, wilting of spikelets, edges of infected spikelets that deviate from the direction of others that are not infected, as well as the formation of fungal structures of pink color or reddish (CASA et al., 2007).
Infection by the fungus that causes scab occurs at the time of anthesis, which is characterized by the opening of the ovary of the plant for the formation of anthers, thus presenting itself as a period of vulnerability to the arrival of the disease. That said, it is possible to state that a moment of great importance for the chemical application in the culture, for the control of the scab, must occur in the moment before the extrusion of the anthers, reducing the susceptibility of infection to the fusarium fungi, responsible for the development of the disease (MAIS SOJA, 2019).
At the same time, another moment of application can occur throughout its development as a whole, that is, the crops must be monitored throughout the crop cycle, thus analyzing whether there are the three pillars for the development of the disease, namely the host, pathogen and environment. Therefore, by monitoring these factors and verifying the possibility of aggravation of the disease in the crop, it may be a good time for a new fungicide application that, preferably, is broad-spectrum carboxamides, and that occurs before a rainy period , given that such a climatic factor will make the disease inoculum carry to the ear. (MORE SOJA, 2019).
Finally, continuous monitoring of the crop is extremely important, paying attention to the climate issue and the history of the disease in the cultivation area, so that proper care can be given, also counting on the monitoring of a technician. It is worth noting that, when carrying out such an analysis, we must take into account the cost of these phytosanitary management operations.
Text written by Lucas Silva Bormann and Márlon Ribeiro Feldens, members of AGR Jr. Consultoria Agronómica, Junior Company of the Agronomy course at UFSM Campus Frederico Westphalen, under the guidance of professor Gizelli Moiano de Paula.
