Research determines susceptibility and efficient use of copper in cancer control in Tahiti acid lime

Research carried out by Fundecitrus, in partnership with Embrapa, evaluated the susceptibility period of Tahiti lime to citrus canker and the efficiency of the optimized use of copper in managing the disease in fruit orchards. As with oranges, copper is the most efficient measure for managing canker in this fruit.

For the study, experiments were carried out in the field with fruits not protected with copper and inoculated by spraying with the bacteria that cause citrus canker. After application, the researchers found lesions in 90,7% of young fruits with a diameter between 1 and 1,9 cm and in 70,9% with a diameter of 2 to 2,9 cm.

Injuries

In files with intermediate diameters, between 3 to 3,9 and 4 to 4,9 cm, the probabilities of developing disease lesions decreased to 41,9% and 19,1%, respectively. In fruits with a diameter greater than 5 cm, the chance of developing a symptom was only 1,1%. The same occurred in relation to the number of injuries. Fruits that were 1 to 1,9 cm and 2 to 2,9 cm in diameter when infected showed, on average, 3,4 and 3,5 lesions, respectively. In those measuring 3 to 3,9 cm and 4 to 4,9 cm in diameter, the average number of lesions fell to 2,2 and 1,3, respectively.

Finally, the average number of symptoms in limes with a diameter above 4,9 cm was 0,3 lesions per fruit – for this size of lemon, only one lesion was observed in one of the almost one hundred fruits evaluated. “The results demonstrate that the susceptibility of the Tahiti lime to citrus canker decreases in the same proportion as the growth of the fruit, which, like the orange, becomes resistant when it reaches 5 cm in diameter. The study also revealed that the fruits take around four months to reach this size in spring and summer, a period in which control must be rigorous”, observes Fundecitrus researcher Franklin Behlau, coordinator of the work.

Driving

Fundecitrus research also demonstrated that the dose and volume of copper syrup can be the same as those recommended for the management of citrus canker in orange orchards. The research results also showed that citrus canker can be managed successfully and sustainably in Tahiti acid lime, as long as control measures are appropriately employed.