McLean Family Farms Controls Citrus Canker with KeyPlex

KeyPlex 350 OR helped control citrus canker and citrus greening in organic orange trees when paired with copper-based fungicide

Two environmentally friendly and sustainable products have emerged to help citrus growers fight two of the industry’s most threatening diseases, particularly in oranges, when used together in the same spray tank.

The two products – KeyPlex 350 OR and Magna-Bon CS 2005 – were recently used by Clermont, Fla.- based McLean Family Farms and its Uncle Matt’s Organic orange juice business to combat citrus canker and citrus greening in an orange grove. McLean Family Farms, which grows organic citrus, peaches, and vegetables in central Florida, has specialized in organic farming since 1999. The McLean family has farmed in Florida for more than 100 years.

KeyPlex 350 OR is a micronutrient that aids in the prevention of plant diseases when applied as a foliar spray, such as post-bloom fruit drop and greasy spot diseases of citrus, and bacterial leaf spot of tomatoes. Magna-Bon CS 2005 is an OMRI-listed copper sulphate pentahydrate bactericide fungicide that offers disease control on a range of specialty fruits, vegetables, citrus, and tree nuts.

Earlier this year, Benny McLean Jr. and his son Ben McLean III decided to combine the products in one spray tank to treat citrus canker on a five-year-old organic grove of Sugar Belle oranges at their fourth generation-owned family farm, which supplies product to make orange juice for Uncle Matt’s Organic. They had tried other organic products to treat the citrus canker but could not find anything that offered control to improve the trees’ lackluster growth and substandard leaf coloring. So beginning last April and lasting through the end of September, they tried something new: The trees were treated with 1 quart of KeyPlex 350 OR and 100 parts per million of Magna-Bon’s CS 2005 (25.6 ounces). The mixture was sprayed 100 gallons an acre of mature trees.

While the two products did not cure the oranges from citrus canker (no products exist to cure the disease), McLean III says they provided “significant benefits” in helping to reduce its symptoms, including the bacterial canker infection on leaves and a reduction in micronutrient deficiencies. As a bonus, the two products also helped control citrus greening, which has ravaged the citrus industry in Florida with yellow spotting on leaves and misshapen and bitter fruit since its onset in 2005.

“Overall, what we saw was an increase in the health and productivity of the grove,” says McLean III, the Head of Research for Uncle Matt’s Organic. “There was a significant visual improvement in the health and color of the grove.”

McLean Jr., who heads the family farm and is also Production Manager of Uncle Matt’s Organic (headed by his other son, Matt) says he noticed a difference in “the look” of the grove after only two days of the first application. “The leaf color was the biggest thing that stood out,” he adds, noting the farm has used KeyPlex 350 OR numerous times over the years in other growing areas, but this was the first time it was ever used in this orange grove.

“We’ve always liked it,” he adds about KeyPlex 350 OR. “It’s a good nutritional, and we’ve always seen a good response in our crops from it.”
McLean Jr. and McLean III wonder – and would like to see further study on – if there’s a synergy between the two products, particularly the micronutrients and peptides in KeyPlex 350 OR and the copper component in Magna-Bon CS 2005, that causes the trees to “turn on” their immune systems.

KeyPlex says its micronutrient and biocontrol products are part art and part science and can unlock the complexity of plant health. Even though they have been farming for decades, McLean Jr. and McLean III are always looking to learn more than they have already learned, especially when it comes to controlling diseases that have no cure.

While they realize they haven’t found a cure for citrus canker and citrus greening, they’ve found hope in controlling the diseases through KeyPlex 350 OR and Magna-Bon CS 2005.
At one time, McLean Family Farms oversaw about 1,200 acres of organic citrus. But because of citrus disease and real estate development, that number has dropped to about 100 acres.

Thanks to products like KeyPlex 350 OR and Magna-Bon CS 2005, however, McLean Jr. and McLean III are confident that they can greatly increase their citrus acreage once again.