Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 5, 1999
Publication Date: N/A
Interpretive Summary: Efforts to implement integrated pest management (IPM) strategies for pecan are handicapped by insufficient knowledge of how orchard cultural practices influence damage by pests. It was determined that practices such as thinning of crop load, irrigation, and supplemental application of nitrogen result in both positive and negative effects on damage to foliage and fruit by pests. The effectiveness of IPM efforts to control pecan pests are likely to be influenced by any one of a variety of cultural practices.
Technical Abstract: The effectiveness of pecan [Carya illinoinensis (Wangenh.) K. Koch] integrated pest management (IPM) is potentially influenced by the interaction of cultural practices with host-pest interactions. Standard cultural inputs, such as irrigation (+W), supplemental nitrogen fertilization (+N), and crop thinning (+T), affects damage to Cheyenne pecan by several pests. Feeding damage to late season foliage by black pecan aphids [BPS; Melanocallis caryaefoliae (Davis)] was reduced by +W and +N, but enhanced by +T treatments. Foliage damaged by pecan leaf scorch mite [PLSM; Eotetranychus hicoriae (McGregor)] increased with +W and +N treatments, while being largely unaffected by +T. Shuck decline also increased in severity because of +W and +N supplements. Each of the three cultural practices increased the frequency of second flush shoot growth. Trees receiving all three cultural supplements (i.e., +W+N+T) exhibited a high frequency of second flush shoot growth, shuck decline affected fruit, and PLSM damaged foliage, but little foliar damage by BPA. Conversely, trees deprived of these cultural inputs (i.e., -W-N-T) exhibited relatively little foliar or fruit damage. Cultural inputs caused both positive and negative side effects and therefore require consideration in development or selection of IPM strategies.