The Ministry of Agriculture, Water, Livestock, and Fisheries, together with the Valencian Institute of Agricultural Research (IVIA), has disseminated an updated set of recommendations to strengthen the control of mites in citrus fruits, in light of the increase in their presence, particularly affecting the regions of the Plana de Castellón.
These measures combine practical guidelines aimed at the citrus sector with new lines of scientific work, in order to adjust control strategies to current conditions, as the Generalitat has pointed out in a statement.
The General Director of Agricultural and Livestock Production, Mª Àngels Ramón-Llín, has stated that "the evolution of this pest requires continuously adapting control strategies to provide citrus growers with the most effective tools against an increasingly conditioned scenario by high temperatures and environmental dryness."
The red spider (Tetranychus urticae) has established itself as one of the most relevant phytosanitary pests for citrus fruits in the Plana de Castellón. The clementine and lemon tree are the varieties most vulnerable to its attacks, which cause discoloration and leaf desiccation, strong summer defoliation, and damage to the fruits, with the appearance of diffuse rusty spots on the skin of the ripe fruit and, in cases of intense infestations, a dirty gray tone.
Ramón-Llín has emphasized that "the collaboration between IVIA, the Plant Health Service of the Ministry of Agriculture, and the technicians working on the ground allows us to convey recommendations based on scientific knowledge and anticipate the new challenges affecting the plant health of our citrus fruits."
Among the main guidelines is to intervene only when the established action thresholds are exceeded, avoiding indiscriminate treatments based solely on the presence of leaves with symptoms, and applying products with authorized acaricides, alternating the ten existing modes of action to reduce the likelihood of resistance development.
Similarly, the need for correct application of phytosanitary products is emphasized, using well-calibrated equipment and low-drift nozzles, and ensuring a homogeneous wetting of the canopy so that the treatment reaches the underside of the leaves and the interior of the colonies, where the pest concentrates.
Regarding preventive and cultural measures, it is recommended to maintain regular irrigation to avoid water stress, ensure balanced fertilization, and form canopies that facilitate the entry of the treatment solution, as well as to assess the use of cover crops between the rows that favor the presence of phytoseiids.
The actions contemplated also include the review of the integrated pest management strategy for mites in citrus, through the updating of monitoring systems and intervention thresholds, defined years ago and now considered susceptible to being adjusted to the current reality.
There will also be a deeper analysis of how climatic conditions influence the expansion of mites, the possible emergence of resistance to the main registered acaricides, and the evaluation of the effectiveness of currently available treatments.