Insecticides Defend Florida Avocado Trees from Invasive Species

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The redbay ambrosia beetle is an invasive species that vectors a fungus, Raffaelea lauricola, that causes laurel wilt, a lethal disease of several plant species within the Lauraceae, including avocado… The spread of the fungus has affected large areas of native Lauraceae trees in the southeastern United States and is now threatening the avocado industry in south Florida.

“In February 2012, the first avocado tree in a commercial grove located in the northeastern quadrant of the avocado growing area was diagnosed with R. lauricola. As of July 2013, 90 trees have been diagnosed R. lauricola positive, and >1,900 symptomatic trees have been removed as part of a suppression and sanitation strategy. …Because of the lack of alternative pest management strategies (e.g. biological control, repellants, etc.), private landowners and avocado producers rely on applications of chemical insecticides to complement sanitation practices and protect trees in groves affected by this beetle-disease complex.

The current strategy is based in early detection and removal of diseased trees to eliminate beetle breeding sites and fungal inoculum sources. The diseased trees are uprooted, the stump and roots burned, the trunk and limbs are chipped, and the chips and adjacent trees are sprayed with insecticides.”

Authors: Carrillo, D., et al.
Affiliation: Tropical Research and Education Center, University of Florida.
Title: Potential of Contact Insecticides to Control Xyleborus glabratus (Coleoptera: Curculionidae), a Vector of Laurel Wilt Disease in Avocados
Source: Journal of Economic Entomology. 2013. December.

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Weed from Hell Invades Florida

Tropical Soda Apple

Tropical Soda Apple

Tropical soda apple (TSA) is a weed native to Brazil, Argentina, Paraguay, and Uruguay that has invaded Florida. The pathway of introduction is unknown, but it may have been accidentally introduced with cattle carrying undigested TSA seeds. Currently, more than 404,000 acres are believed infested in Florida. TSA invades pasture, where it reduces livestock carrying capacity. Dense stands of the prickly shrub prevent cattle access to shaded areas, which results in summer heat stress and economic losses from cattle heat stress have been estimated at $2 million. TSA is a reservoir for at least six crop viruses; in addition, major insect pests use TSA as an alternate host. Herbicides are a major management practice for this “weed from hell.”

“Tropical soda apple (TSA) is an invasive weed of agricultural and natural areas in Florida. The plant is native to South America and was first found in south Florida in 1988. Its spiny foliage and stems are unpalatable to livestock, and dense stands of this prickly plant often grow into large impenetrable thickets.

In some areas of central and south Florida, TSA has covered entire pastures, rendering them unusable for grazing livestock. Some have called this weed the “plant from hell”.

The preferred methods of TSA control were chemical herbicides and mowing. On a statewide basis, 20% of cattle producers used herbicides alone, 7% used mowing alone, and 20% used both methods. Triclopyr and glyphosate were the two most commonly used herbicides reported by cattle producers. However, many had begun using amino-pyralid, an herbicide registered for use in pasture and rangeland in 2005, and becoming the new standard for TSA control. With continued TSA spread and the absence of alternative effective control measures, it is likely that the demand for these herbicides will continue to grow.”

Authors: Salaudeen, T., et al.
Affiliation: College of Agriculture, Florida A&M University.
Title: Economic impact of tropical soda apple (Solanum viarum) on Florida cattle production.
Source: Weed Technology. 2013. 27:389-394.

Florida is Great for Growing Sweet Corn in the Winter, Insects Love Florida in the Winter Too

Florida sweet corn, w/o insecticides

Florida sweet corn, w/o insecticides

Florida Sweet Corn Production

Florida Sweet Corn Production

Florida is the #1 state in the production of fresh sweet corn with production occurring in winter months when the crop cannot be grown in states further north. Many insect species survive the winter and thrive in Florida. 98-99% of Florida’s sweet corn would be damaged by insects if insecticide sprays were not made. The importance of insecticides for Florida sweet corn is underscored by the realization that the crop was not grown in the state until synthetic chemical insecticides were introduced in the 1940s.

[1]“Florida ranks #1 nationally in the production and value of fresh market sweet corn, typically accounting for approximately 20 percent of both national sweet corn production and of U.S. cash receipts for fresh sales. A total of 589 million pounds of fresh sweet corn, valued at $189 million, was produced on 42,100 acres in Florida during the 2009-10 season. Nearly 20 percent of sweet corn producers overall total direct expenses are invested in pesticides and pesticide application costs. Florida’s warm, humid climate is ideal for the development of pest populations. Sweet corn grown in Florida is subject to damage from numerous insect, weed, disease, and nematode pests. Pesticide use is high and the crop may be sprayed daily in some cases.”

[2]”The first commercial production of sweet corn in Florida was reported in the 1947-48 season. The establishment of sweet corn as one of the major crops produced in Florida is attributed largely to successful control of insects with the newer insecticides. “

[1]
Author: McAvoy, G.
Affiliation: Regional Vegetable Extension Agent IV, University of Florida
Title: Sweet corn production in south Florida
Source: Proceedings of the 2012 Atlantic Coast Ag Convention & Trade Show, pp 66-68

[2]
Authors: Hayslip, N. C., et al.
Affiliation: Florida Agricultural Experiment Station, Ft. Pierce
Title: Corn earworm investigations in Florida
Source: Journal of Economic Entomology. 1953. 46[4]:574-583.

Disease Management Sprays Have Doubled and Quadrupled in Florida Citrus Groves since 2004 Due to New Exotic Pests

Citrus Canker

Citrus Canker

Before 2004, Florida citrus growers were concerned with only a few diseases. Thanks to hurricanes and tropical storms, new exotic disease organisms have been spread around the state. As a result, Florida citrus growers have had to dramatically increase sprays to manage disease: sprays for processed juice fruit have quadrupled and sprays for fresh grapefruit have doubled.

“The Florida example begins before 2004 when citrus tristeza and blight-decline were the major disease problems. Average annual sprays were two for processed juice fruit and six sprays for fresh market grapefruit. After the 2004-05 hurricanes and the ending of the citrus canker eradication program in 2006, the number of sprays to manage canker and other diseases increased to three or four sprays for processed juice fruit and 10 sprays for fresh grapefruit. With the 2005 discovery of huanglongbing (HLB) in Florida and citrus black spot in 2010, costs continued to increase. Now the annual spray program includes eight or nine sprays for processed juice fruit and 14 for fresh market grapefruit.”

Author: Muraro, R. P.
Affiliation: University of Florida, IFAS, Citrus Research and Education Center.
Title: Evolution of citrus disease management programs and their economic implications: the case of Florida’s citrus industry.
Source: Proceedings of the Florida State Horticultural Society. 2012. 125:126-129.