Growth Products, Ltd: Horticulture

Manganese Research is Revealing Sweet New Benefits

April 2018

Research agronomists have recently focused on the “two spoonfuls of sugar are better than one” phenomenon when it comes to manganese. Growers have long known that applying plenty of manganese helps reduce the incidence and severity of patch diseases on turf. Now, the latest research out of the citrus world indicates that providing mega-doses of manganese to HLB-infected citrus groves may increase yield, boost the trees’ leaf nutrient concentration, and perhaps fend off further HLB infection.

Manganese Basics

Manganese (Mn) is a micronutrient with a powerful punch. Without sufficient amounts of Mn, a plant cannot adequately create chlorophyll, metabolize nitrogen, produce amino acids, activate required enzymes, or otherwise support plant life. Although Mn is relatively abundant in the earth’s surface as a metallic, rock-like substance, it’s not always readily available for plant uptake, particularly in alkaline or sandy soils.

Manganese and HLB in Citrus

For the last year or more, industry groups and researchers from the University of Florida’s Institute of Food and Agricultural Science (UF/IFAS) have zeroed in on the role of manganese in citrus tree health and productivity. Buzz has been building about the experimental application of three to four times as much manganese as is normally called for in citrus groves that are infected with greening disease.

In a video interview ( that can be found in a March 2018 Citrus Industry This Week newsletter, University of Florida professor Dr. Kelly Morgan said that applying three times the amount of historically recommended levels of Mn and twice the amount of recommended Zinc to infected trees seems to produce optimal yields in citrus test plots.

Dr. Morgan explains that leaf nutrient concentration is reduced in all HLB infected trees, but for optimal yield, growers need to keep nutrients within the recommended sufficiency scale. Dr. Morgan is not alone in this assessment: others in the citrus industry are coming to realize that “more than a spoonful of manganese” makes groves more productive.

To assist growers in achieving optimal nutrient levels in citrus and elsewhere, Growth Products’ recently introduced Manganese Inject 10%. Concentrate Liquid Nitrate with Fulvic Acid. An easy-to-handle liquid with a pH of 2.2 to 2.8, Manganese Inject provides a convenient and affordable way to quickly correct manganese deficiencies in citrus trees. Manganese Inject usually needs to be applied three to four times a year, ideally at flush for maximum uptake.

Manganese for Turf and Ornamentals

As mentioned above, manganese is critical to all plant life, not just to citrus. Ornamentals and other plants with a manganese deficiency usually show chlorosis (yellowing) on new leaves, mainly between the veins. However, the initial sign of manganese deficiency in turf is an overall lack of vigor and an increased susceptibility to disease. Conversely, turf grown with adequate levels of Mn tend to be healthy and to have low levels of patch disease damage.

A simple, liquid solution to Mn deficiency in turf and ornamentals is Manganese Chelate 5% with 2% Sulfur. This organic chelate contains Mn in a form that’s ideal for plant uptake. It can effectively be applied as a soil drench because its negatively charged ions do not bind to the negatively charged particles in high pH soils, as many other Mn forms do.

Manganese Chelate 5% also excels as a foliar spray to correct manganese deficiencies. Manganese is largely immobile in plants, so sprays are most efficient for getting manganese to the parts of the plant where it is most needed. As an added benefit, Manganese Chelate 5% can also be tanked mixed with most non-phosphate fertilizers to reduce total spray time.

To learn more about our Manganese products along with our other Liquid Solutions, please call (800) 648-7626 or email us here.