Valencian kaki growers are concerned about a new whitefly outbreak in their farms, as they are very harmful insects whose impact was so far limited to the citrus industry. They have been detected and caused damage to kaki plantations for the first time this summer, as highlighted during the meeting of the Valencian Growers Association (AVA-ASAJA) devoted to the crop.
Both producers themselves and the technical services of the Valencian Institute of Agricultural Research (IVIA) have confirmed that whitefly species are adapting perfectly to kakis; in fact, they have started colonising them to an extent that has reached alarming proportions. The whitefly identified as Dialeurodes citri is mostly the one that is spreading, although two other whiteflies, called Paraleyrodes minei and Aleurothrixus flocossus, have also been found to a smaller extent.
The attacks of these insects take place through the laying of eggs on the leaves of trees. The larva feeds on the sap and thus considerably weakens the tree while secreting a sweet substance that falls on the fruit and causes the emergence of fungus. The direct consequence is the commercial depreciation of affected kakis. The municipalities where plantations are being hit the hardest by whiteflies are Alginet, Algemesí, Albalat de la Ribera, Carcaixent and Polinyà del Xúquer.
The growing presence of this new pest in Valencia has forced kaki producers, with the advice and support of the IVIA, to start treatments and test various formulas to try to prevent the appearance of fungus during the handling process in the warehouses. A parasite, called Encarsia streneua, has also been found to act as a natural predator of such flies.
The president of AVA-ASAJA, Cristóbal Aguado, said that "it is a reason for concern that a pest that so far only affected citrus has adapted to kakis and that it is colonising one of the few crops that generate acceptable returns to growers. We must remain cautious, be alert, and, with the collaboration of the Council of Agriculture, adopt all preventive measures necessary to stop whitefly populations from continuing to expand."