3/30/2023 - By Dr. Tom Reed

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

POLYON® Fertilizer and Watermelon Production

Researchers at the University of Florida Institute of Food and Agricultural Sciences  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, a multiple-application program (preplant application, fertigation throughout season), to a single preplant application of a POLYON® fertilizer blend. In both years, the POLYON® fertilizer program had greater yields at first harvest. In 2019, the first harvest fruit number from the POLYON® fertilizer application was significantly higher (60%) than the conventional program (Figure 1).

POLYON® vs Traditional Program Yields

In 2020, the CRF treatment had a 20% greater marketable fruit weight at first harvest, which resulted in a 22% total yield per acre increase compared to the conventional (Figure 2). The trials demonstrated that a single application of Harrell’s POLYON® fertilizer produced a similar or greater yield when compared to a grower’s standard program of nine or more applications. This allows growers to optimize other aspects of their operation.

POLYON® fertilizer can provide greater early-season yields when the market for produce is on the side of the grower. This may limit growing season risks from production pressures as well. To further confirm these findings, large-scale grower trials in 2020 and 2021 provided similar results.

Researchers looked at replacing a conventional nitrogen preplant 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 applications 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.

Harrell’s POLYON® fertilizer can go as far as being the total fertilizer program for a watermelon grower, or even the primary source of nutrients, allowing growers options for nutrient supplementation throughout the season. 

Harrell's POLYON® fertilizer 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.