Imidacloprid for Aphid Control on Banana in Hawaii
: Banana is cultivated on nearly 2,000 acres in Hawaii. Banana bunchy top virus (BBTV) was discovered on the island of Oahu in 1989 and has spread to the islands of Hawaii and Kauai. Diseased plants do not produce marketable bananas. The banana aphid, Pentalonia nigronervosa, transmits the disease. Diazonon is currently registered under a 24(c)Special Local Needs label. However, the insecticide is an organophosphate that is currently being reviewed under the Food Quality Protection Act. The project evaluated the use of the low risk pesticide, imidacloprid, for aphid control on bananas. Three different application methods were tested: drench, drip and spray. Treatments were made to young banana plants, about three to five weeks old. For each test, treated (diazinon) and untreated checks treatments were included as comparisons.
Project goals and objectives
Demonstrate the efficacy of the low risk insecticide, imidacloprid for apphid control on banana.
Imidacloprid proved very effective in controlling the banana aphid. However, effectiveness took longer to achieve in banana suckers that were treated by drench or drip irrigation methods. In other crop systems, control was observed within seven days after treatment with imidacloprid but in banana, complete control took as long as 43 days when the product was applied by drench or drip irrigation. Placement in the root zone may have been a factor. Improper application deposits the insecticide above or below the root zone, resulting in poor uptake by the roots. Also, the size of the plants may have been a factor in delaying control. Larger plants may require more time to distribute the product within their system. Foliar sprays, in contrast, allowed suckers immediate uptake of the product so quick control was observed. More research is now underway to determine the proper application of imidacloprid in drip irrigation and drench application practices.