Alternative Methods for Harvesting and Field-packing Mandarin (Citrus reticulata Blanco) Fruits in Tanzania

Tanzania ranks second after Kenya in production of citrus fruits in East Africa. The Tanga, Morogoro and Pwani regions are the major citrus producing regions in the country. Mandarin and sweet oranges are among the major economic crops in the regions. Compared to developed countries, where the majority of fresh fruit losses tend to occur at the consumer level, most losses in Tanzania occur during harvest, shipping and marketing. Despite the delicate nature of mandarin fruits, harvesting is traditionally done by the pick-drop-catch (PDC) method after which the harvested fruits are bulk-loaded onto grass cushioning in a flatbed truck for shipping. This study compared fruit quality of 1) fruit harvested using the PDC, Ladder Plus Bag (L+B) or Cutting Pole (CP) harvesting methods, and 2) three field-pack methods: bulk (BULK), bamboo-baskets (BAMB) and stackable, plastic crates (SPCR). Fruits harvested using the PDC method were packaged and shipped by truck to simulate local shipping conditions. Additional fruit harvested using the three harvest methods were packed in foam cushioned SPCR for storage evaluation. At harvest, fruit culls were lower using L+B (4.4%) and PDC (6.4%) than with CP (19.6%). Fruit stem plugging was >6% higher with CP than with PDC and L+B methods. CP required 30 minutes more than the other methods to fill a 300-fruit capacity SPCR. CP-harvested fruit also had >4% more decay than L+B or PDC during subsequent storage at ambient temperatures. Fruit decay after 9 d of storage was higher with BAMB (32.4%) than SPCR packaging (24.5%); decay with BULK was not different (29.6%). Most of the decayed fruits with SPRC were located on the top while for BAMB most were from middle position of the package. L+B and SPCR show promise as alternative harvest and packaging practices for reducing postharvest loss of  mandarin fruit along the value chain in Tanzania.