ARS | Publication request: Impact of barrier crops on arthropod pests immigrating into orchards of sapodilla and banana.

Submitted to: Entomological Society of America Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 7, 2008
Publication Date: N/A

Interpretive Summary: Insects are often impacted by variations in the landscape, including edge effects, crop density and alternate crops. We decided to see if planting a physical barrier consisting of a tall stand of sorghum around an orchard would reduce the number of pests within that orchard. Comparisons of orchards of sapodilla, banana, and papaya with and without a barrier of sorghum revealed that for the vast majority of pests surveyed the barrier crop had no impact. However, for the very important foliage and root pest Phyllophaga vandinei, the barrier crop significantly reduced populations of these beetles in protected orchards to negligible levels. The following year all barriers were removed and P. vandinei was abundant in all orchards, demonstrating that the reduction in P. vandinei in orchards with a barrier crop was not due to the physical location of the orchard. Furthermore, trees in protected orchards also showed increased growth in such parameters as tree height and yield, suggesting there may be advantages beyond pest control for barrier crops.

Technical Abstract: We compared the abundance and damage of several pests in orchards of sapodilla, banana, and papaya that were either surrounded by a border of tall sorghum or without such a border. Almost all pests were present in equal numbers in orchards, despite the presence or absence of a barrier crop of sorghum. However, Phyllophaga vandinei was significantly more abundant in orchards without a sorghum barrier crop than in orchards that did have a barrier crop. In fact, P. vandinei individuals were virtually non-existent in orchards with a barrier crop. Furthermore, papaya trees in orchards with barrier crops grew taller and yielded more fruit, despite the fact that P. vandinei does not attack this crop. This suggests that there may be advantages beyond pest control provided by barrier crops.