Photo: Laura Watilo Blake
Dr. Paul Fisher
Headshot photo courtesy of UF/IFAS

To determine the best formulas for their crop inputs, it’s important that growers read the labels of the products they’re using.

However, not all labels’ measurements are standardized, so sometimes, growers either turn to industry publications for specific ratios, they may inherit a recipe from those who came before them, or simply follow the instructions of their supervisors. It’s not often that they’re crunching the numbers on their own to obtain a ratio.

“It’s really important to know the why behind what they’re doing,” says Dr. Paul Fisher, a professor and extension specialist in the environmental horticulture department at University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS). So in order to guide growers to the right measurements, he and his team created two interactive tools within UF/IFAS’ Back Pocket Grower website,

The site, funded by the Floriculture Research Alliance, includes tips and tools ranging from production issues to economics. Two free tools were added in October 2014, called “ppm to Recipe” and “Recipe to ppm.” The first tool helps growers if they know the target ppm (parts per million) concentration, and they need to calculate the amount of solid or liquid fertilizer or chemical to add to a solution, and the second helps with the opposite — if they know the product that needs to be added, but need to determine the target ppm. So far, more than 1,000 users have utilized the tools.

Fig. 1 - ppm to Recipe
Screenshot taken from

“There are a lot of reasons why it’s very important that we get these calculations correct,” Fisher says. One is to determine that you’re applying the product will be effective, and not overdose your crop, which can cause phytotoxicity. “It’s also important for worker safety, of course,” he says, adding that residues from a chemical may affect the health of a worker or end-consumer, and excess runoff may harm the environment.

The tool is user-friendly, as it’s a simple plug-and-play. Growers may choose the tool that corresponds with what measurement they’re looking for, then fill in the information boxes based on what they know, including what units they’re working in (U.S. or metric), tank volume units, active ingredient percentages, and dilution ratios. Using the label information and specifics of the tanks and injectors that they’re using, they’ll be equipped with everything they need to fill in the blanks. Then, they may click “Calculate” at the bottom of the module, and the tool will generate the appropriate ppm or product recipe. See Fig. 1 and Fig. 2 for examples.

Fig. 2 - Recipe to ppm
Screenshot taken from

There is a new button at the top right corner labeled “Sp” that was added in May of this year that allows users to translate the tool and its information into Spanish if desired.

Visit to access the UF/IFAS tools and try them out for yourself.