Pesticide-Free Production of Tropical Maize in Hawaii and Western Pacific: Varietal Identification and Distribution
Maize has been a secondary crop to sugarcane on prime lands in tropical Pacific islands. However, with the decline of sugarcane, large acreages are now available for irrigated row crops. However, the production of corn silage and grain using temperate hybrids in Hawaii and the Western Pacific is difficult. As a result, the livestock industry in the Pacific areas has been greatly restricted since importing grain is expensive and importing silage is not practical. The islands represent such a small market that commercial seed companies have not bothered to breed hybrids specifically adapted to this region. Insects are particularly a problem for temperate hybrids and include leafhoppers, the corn earworm, the rose beetle, thrips, aphids and spider mites. Control can require from eight to 14 insecticide applications per crop. This project identified and developed maize varieties that have been adapted to the tropics and can be grown without insecticides and fungicides. In previous work, the five best Hawaii-bred tropical hybrids produced 186 bushels per acre compared to the two best temperate hybrids with 85 bushels per acre. The project tested elite, Pacific-adapted, 3-way corn hybrids under pesticide-free conditions at four locations during two seasons in each of two years. Open-pedigree inbred parents of these hybrids derive from Australia, Colombia, India, Nigeria, Philippines, Thailand and Hawaii. The Hawaii Foundation Seed Facility then increased parental inbreds of the three superior 3-way crosses and Hawaii was able to once again produce silage (1,500 acres of hybrids in 2002).
Project goals and objectives
Reduce pesticide use on corn in the Pacific Islands by:
1) Demonstrating productivity of hawaii-bred corn hybrids under pesticide-free management
2) Producing foundation seedstocks of eleite parent lines
Hawaii's silage production has been re-initiated using the CTAHR hybrids, 1,500 acres in 2002, and is being grown without the use of pesticides.