Abstract
A citrus seedbed was established August 1984 on the west coast of Barbados. Before being planted and inoculated with vesicular-arbuscular mycorrhizal (VAM) fungi, one-half the seedbed was fumigated with methyl bromide; the other half was untreated. Four weeks after fumigation, four treatments, Glomus intraradices, G. mosseae, indigenous VAM fungi, and a noninoculated control were established in each half of the test. Early vigorous plant growth in the nonfumigated half of the plot suggested that indigenous VAM may have colonized and stimulated plant growth earlier than the treatments in the fumigated portion. Three months after inoculation, plants in both portions of the plot were growing well. In the fumigated area, application of two Glomus species, which were introduced from Florida, resulted in a significant improvement in plant growth over the control. This occurred in spite of the fact that infection levels in control roots were similar to those in inoculated roots. This study suggests that, when possible, alternative pesticides not harmful to VAM fungi should be used in place of methyl bromide fumigation to conserve these fungi in agricultural soils.