General Recommendations for the Post-Harvest Treatment of Citrus

Post-harvest rot is the main cause of losses and claims in citrus fruits. To minimize these losses, the problem must be addressed comprehensively, with actions taken at all stages of the process, from harvesting and handling to cleaning and disinfection, and of course, in post-harvest treatment. HarvestingMost wounds occur during harvesting, caused by either scissor damage, micro-wounds from impacts, or skin injuries from poorly cut peduncles. Minimizing such damage during harvesting and transportation will significantly reduce the incidence of post-harvest rot. HandlingProper temperature and relative humidity (RH) management are key to ensuring good fruit quality. Avoid subjecting the fruit to extreme temperatures, direct sunlight, or abrupt RH changes during its transport and handling. Additionally, it is important to note that refrigerated storage and transportation conditions vary depending on the type of citrus, variety, fruit conditioning, and storage time. Defining the optimal parameters in each case will help minimize losses. Cleaning and Disinfection (C+D) of the packhouseAs mentioned in the previous CITROPOST, it is of vital importance to start the campaign with a clean and properly disinfected warehouse and maintain hygiene conditions throughout the campaign. CITROSOL offers a wide range of C+D products and provides diagnostic, evaluation, and specialized technical advisory services. RPAT The time elapsed between harvesting and treatment application is technically known as RPAT (Permissible Delay Before Treatment). As a general rule, for post-harvest treatments based on Imazalil (IMZ), the application should be performed within 24 hours after harvesting. However, it should be noted that not all fungicides have the same RPAT, so this time may be reduced depending on the active substance used. On the other hand, for residue-free or ecological treatments, this time should be reduced to below even 18 hours. Post-Harvest Treatment Proper application of the treatment in a drencher or pre-calibrated line will guarantee high efficacy in rot control. Regardless of the application method, it is crucial to completely wet each and every fruit to be treated. The choice of active ingredient(s) to use will depend on the treatment's objectives. CITROSOL offers a range of treatments tailored to the customer's specific needs at any given time (see Tables). To ensure maximum and consistent effectiveness of the fungicidal treatment, minimize the occurrence of resistance, and maintain good control of sporulation, it is essential to maintain the recommended fungicide concentration constantly and ensure the correct hygiene of the treatment solution at all times. This, in turn, allows for the safe reuse of the treatment solution. In this regard, the CITROSOL VERTIDO CERO® System enables efficient and sustainable management of the treatment solution, ensuring its effectiveness at all times thanks to its sophisticated dosing system and the strict monitoring carried out by the CITROSOL Technical-Commercial team. CITROSOL also offers a resistance monitoring service that allows for the rapid detection of strains with reduced sensitivity to any fungicide. This way, corrective measures can be quickly taken, such as increasing the intensity and frequency of C+D tasks, changing the drencher treatment, or reinforcing it to control the widespread occurrence of resistance. Table 1: Objective: Treatment with an active substance. The product and function are presented. Table 2: Objective: Resistance control, preservation, and long-distance shipments.