To achieve needed tree structure, pruning needs to start in the first year and continue regularly throughout the tree’s life.
Trees should be fertilized with nitrogen annually. However, the optimum nitrogen rate will vary depending on the soil type, orchard floor management, crop load, etc. Soil nitrogen leaches more readily in sandy soils than in heavier types. Thus, nitrogen rates may need to be increased slightly on sandy soils.
Deer not only browse chestnuts, but bucks also often rub all the bark off trees during late summer and early fall. Deer protection must be put in place when chestnut trees are small and vulnerable to damage.
Adults feed on chestnut foliage until nut kernels enter the dough stage in mid to late August. Although they can lay eggs any time after kernel filling, most eggs are laid after the bur begins to open. The female weevil uses her long proboscis to drill a hole through the shell before turning around and placing her ovipositor into the nut and laying five to seven eggs. Eggs hatch in about 10 days and larval development is completed two to three weeks later. Mature larvae chew a small round hole through the shell, exit the nut, and then burrow into the ground under the chestnut tree. The insect remains in the soil for two to three years before re-emerging as an adult.
Because of their larger size, large chestnut weevils are more successful in laying eggs in nuts before burs open. The long proboscis of large chestnut weevils enables females to drill oviposition sites among the spines of the bur. Eggs hatch in five to seven days producing large, legless grubs. The life cycle of the large chestnut weevil is similar to that of its smaller cousin, but the larger weevil spends only one to two years in the soil.
This curculio is primarily an acorn pest but has been observed to invade chestnut orchards when the acorn crop in nearby forests is low. The nut curculio is related to chestnut weevils and the damage inflicted to chestnut kernels is similar. Curculios have a much shorter proboscis and must wait until the burs open to lay eggs inside the nut. The nut curculio has a one-year life cycle.