With a favorable climate, the psyllid population is high in all regions of the citrus belt

The population of the psyllid, the insect that transmits greening, is high in all regions of the citrus belt of São Paulo and Triângulo/Southwest Mineiro. By means of more than 30 thousand traps spread throughout the park, Fundecitrus monitors the insect's population fluctuation and verified a growth of 204% in July and 337% in August compared to the same months last year, the highest rates verified for the period since the beginning of the historical series, in 2014.

The second half of the year is traditionally the period when the psyllid population peaks and when around 65% of the insects are captured. This occurs due to a combination of favorable climatic conditions: the arrival of rain stimulates the emergence of shoots, which attract psyllids for feeding and reproduction as they are softer tissues. Furthermore, the high temperatures observed at this time of year also favor the development of the insect and the dry weather associated with the wind helps its dispersion. 

According to Fundecitrus researcher Marcelo Miranda, changes in climate behavior in 2020 anticipated the high population of the psyllid. “Population peaks generally occur in August, September and October, but we have been observing a high population of the insect since June because the month had a volume of rain well above the average recorded in June 2019 [+155%] and high temperatures, which caused the anticipation of sprouts”, he explains. 

The recommendation is that citrus growers pay attention to the appearance of sprouts so that, at these times, they can intensify control of the psyllid, regardless of the time of year, adapting, whenever necessary, the pre-established calendar of applications to these critical periods. 

“It is essential to maintain strict control to protect orchards even during the pandemic, to prevent insects from contaminating new plants, which could result in an increase in greening next year,” says Fundecitrus agronomist Ivaldo Sala.

According to a survey by Fundecitrus, greening affects 20,87% of orange trees in the citrus belt. The disease is considered the most destructive of citriculture in the world and has no cure, but since it was identified in Brazil, 16 years ago, management has been improved and much information and mechanisms are available to increase the effectiveness of control. 

One of these mechanisms is the Fundecitrus Phytosanitary Alert, which includes traps that monitor the presence of the psyllid. The free tool identifies the insect's population increase and the presence of sprouts and issues alerts to producers so that they can jointly protect orchards in the same region, increasing effectiveness. Still within the farms, research by the institution showed that most psyllids are captured in the first 100 meters from the border, places where control must be more frequent. 

As the majority of psyllids arrive at commercial orchards from outside the farms, external control is important and, on properties that have combined it with strict internal control, it is possible to see a reduction in insect capture and a reduction in the incidence of greening. The strategy consists of replacing citrus plants and myrtles around properties, in places such as backyards and farms, with other fruit and ornamental species, which are not attractive to the psyllid.