3/23/2023 - By Dr. Tom Reed

Watermelon growers throughout Florida utilize POLYON^® controlled release fertilizer (CRF) blends to increase the productivity of their operation. POLYON^® allows for fewer applications, increased nutrient efficiency, and reduced environmental impact compared to traditional fertilizer sources.

UFAS POLYON® and Watermelon Trials

University of Florida Institute of Food and Agricultural Sciences researchers have conducted eight trials that quantified the benefits of POLYON^® fertilizer in watermelon production. A study conducted in 2019 and repeated in 2020 compared a conventional grower standard multiple-application program (pre-plant application, fertigation throughout the season) to a single pre-plant application of a POLYON^® fertilizer blend. In both years, the POLYON^® fertilizer program had greater yields at first harvest.

First Watermelon Harvest

In 2019, the first harvest fruit number from the POLYON^® fertilizer application was significantly higher (60%) than the conventional program (Figure 1). In 2020, the POLYON® fertilizer treatment had 20% greater marketable fruit weight at the first harvest, which resulted in a 22% total yield per acre increase compared to the conventional (Figure 2).

The trials demonstrated a Harrell’s POLYON® fertilizer blend single application produces a similar or greater yield as a grower standard program of nine or more applications. This allows growers to optimize other aspects of their operation. POLYON^® fertilizer can provide greater early yields when the produce market may be more desirable for the grower, this may limit growing season risks from production pressures as well. Large-scale grower trials in 2020 and 2021 provided similar results.

POLYON® Fertilizer Improves Yields Over Time

Harrell’s POLYON^® controlled-release fertilizer can be the total fertilizer program for a watermelon grower or be the primary source of nutrients that allows the grower options for nutrient supplementation throughout the season. Researchers looked at replacing a conventional nitrogen pre-plant application with a short-term CRF source of nitrogen as part of an irrigation rate study. The treatments with POLYON^® fertilizer resulted in 5% and 4% greater total watermelon yield compared to the conventional in the two years of the study.

POLYON^® fertilizer application can improve current grower practices by reducing nutrient leaching compared to vulnerable conventional sources. This provides the environmental benefit of reduced nutrient loading to groundwater and greater nutrient efficiency.

Your Harrell’s Rep is Here to Help

Harrell's POLYON® blends are customized to provide nutrients over time at a predictable rate under specified conditions. To find the right POLYON® controlled-release fertilizer product for you, reach out to your Harrell's Rep.