Growth Products, Ltd: Horticulture

Tips for Better Fruit Size and Set

February 2019

The biggest problem that citrus growers are facing is still HLB disease (greening). Fruit size has declined ever since the Asian psyllid took deadly aim at citrus trees in Florida, Texas, and elsewhere. Once infected with HLB, a tree usually loses 30% to 50% of its root mass before any signs of the disease are visible above ground. With such a severe a reduction in root mass, a tree can’t produce the big, juicy citrus fruit that we all once took for granted.

To fight greening, growers should stay up-to-date on the latest HLB research and news. University of Florida’s IFAS’s monthly podcast (“All In For Citrus” -- is a great way to start. Growers can also counter the ravages of greening disease by applying several key foliar sprays and root injections, as suggested below.

Top to Bottom Nutrition and Health

Mark White, a plant nutritionist for G.P. Solutions and Growth Products, recommends a pre-bloom spray application of KPhos 3-18-18 in February – March, followed by a post-bloom spray in April, with each spray at a rate of 4 gallons per acre. With its Dipotassium Phosphate (DKP), KPhos utilizes dual modes of action for delivering phosphorus, and helps improve fruit size and fruit set.

Furthermore, the Growth Products nutrition specialists suggest tank-mixing the 4 gallons of KPhos with 1 gallon of MicroTech Bloom 5-0-0 and 1 gallon of Nitro-22. The MicroTech Bloom contains an agronomically correct array of micronutrients (Calcium, Magnesium, Boron, and Molybdenum) as well as humic and fulvic acid to increase nutrient uptake. The Nitro-22 has 40 percent methylene (CH2-N), Growth Products’ proprietary slow-release nitrogen.

When applied as a foliar spray, Nitro-22 coats the leaf tissue with a clear glossy film. Some of its nitrogen goes to work to give the plant an immediate nitrogen boost, while the methylene’s strong CH2-N bond is gradually broken down by UV radiation, heat and microbial activity. As this break-down happens, nitrogen is released one molecule at a time to provide the tree with a perfectly timed, slow and steady source of nitrogen.

Like all of Growth Products’ Nitro-based liquid fertilizers, Nitro-22 resists volatilization, leaching and run-off. It also and carries an exceptionally low salt index, making it very environmentally friendly.

Extra Care for Needy Roots

With roots so badly damaged by greening, and the normal flow of nutrients from roots to leaves disrupted, foliar fertilizers take on an increasingly important role in citrus health. But growers know that they dare not neglect the roots if they want a viable harvest.

For root health, Growth Products’ citrus nutrition specialists suggest applying 1 to 2 gallons of “TKO” per acre, as well as 1 to 2 lbs. BioNutrients per acre, applied either through irrigation or injection in February, May, June and August.

TKO Phosphite 0-29-26 and BioNutrients both have strong biostimulant properties. “TKO” has been a customer favorite for many years, thanks to the fast-acting and systemic nature of the phosphite molecule and the liquid’s ability to quickly correct any phosphorous or potassium deficiency. TKO encourages root growth and effectively fights soil-borne plant pathogens such as foot rot. Through the years, TKO has been shown to increase fruit size, increase tree vigor, and increase the yield and quality of a harvest, all while maintaining a very safe profile and having remarkable ease of handling.

Likewise, BioNutrients Soluble AG has proven to be a tremendous hit with growers since its introduction several years ago. BioNutrients Soluble has only pure organic ingredients and is loaded with minerals and naturally occurring soil bacteria (PGPB). These soil-dwelling microorganisms work to significantly increase root volume and root branching and to suppress pathogens.