. Insect and disease conditions in the United States, 1979-83 : what else is growing in our forests?. Forest insects United States; Trees Diseases and pests United States; Plants Disease and pest resistance. Nursery Pests Figure 4. Chronic, pest-caused mortality in southern nurseries—1980 ED Diseases O Insects Cause of Mortality Nematodes Preemergence Damping-off Postemergence Damping-off Fusiform Rust Insects Nematodes Millions of Seedlings Killed 0 10 15 Total: million seedlings killed Source: Chart based on data in article by Boyer and South entitled "Forest Nursery Prac
. Insect and disease conditions in the United States, 1979-83 : what else is growing in our forests?. Forest insects United States; Trees Diseases and pests United States; Plants Disease and pest resistance. Nursery Pests Figure 4. Chronic, pest-caused mortality in southern nurseries—1980 ED Diseases O Insects Cause of Mortality Nematodes Preemergence Damping-off Postemergence Damping-off Fusiform Rust Insects Nematodes Millions of Seedlings Killed 0 10 15 Total: million seedlings killed Source: Chart based on data in article by Boyer and South entitled "Forest Nursery Practices in the ; Southern Journal of Applied Forestry. Volume 8. No. 2; 1984. management, an entire crop could be lost. The cost of such a catastrophe in a single nursery could reach $500,000. Pest-Caused Seedling Losses A successful planting program depends on the availability of reasonably priced, high-quality seedlings. Many diseases cause damage that results in undersized or otherwise poor-quality seed- lings that must be discarded. More insidious and costly are cases where infection goes undetected in the nursery, only to damage or kill the seedlings later, after they are planted on a site. Tracing the exact cause of losses attributed to nursery pests is seldom simple. Pests are part of a complex of environmental con- ditions; two or more types of pests can occur simultaneously. Pest-caused losses are usually attributed to diseases, insects, and nematodes. In 1980, nematodes and insects killed about one-fifth of the seedlings lost. Nematodes are ubiquitous, parasitic root pests that damage nearly all tree species. Insects that damage nursery stock include tip moths on southern pines, cutworms on most conifer species, and white grubs on the roots of conifers and hardwoods. Diseases, however, especially preemergence damping- off, postemergence damping-off, and fusiform rust, accounted for most of the damage (fig. 4) (Boyer and South 1984). Diseases of tree seedlin
Size: 2269px × 1101px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
