11/1/2021 - By Dr. Tom Reed

Conclusion:

The trial evaluated POLYON® controlled release fertilizer (CRF) 17-5-11 (6-month) and 17-6-11 (1-year) blends applied to young orange tree (Hamlin on Cleo) compared to blends from Citriblend (17-5-12, 1-year and 18-6-12, 6-month), Diamond R (8-4-8, 3-month and 12-8-6, 6-month), and Florikan (13-4-9, 1-year and 14-4-10, 6-month). The first applications were on 7/12/13 with objective of 0.22 lb N/tree applied the first year, 0.45 lb N/tree the second year, and 0.67 lb N/tree the third year for each blend and program. There were approximately 294 trees per treatment with five trees in the center of the treatment row measured monthly. Grower had great results with trees responding well to Harrell’s blends early with greater rootstock and scion growth than other CRF blends.

Figure 1: Rootstock and scion measurements on January 24, 2014.