W. C. PIERCE Entomology Research Division, Agr. Res. Serv., U. S. D. A. Observations and reports by growers and others interested in pecan production indicate that apparently many growers are not obtaining maximum benefits from the measures used to control insect pests and diseases on these pecans. Several workers have published reasons for these failures and have suggested methods of improving results. It is believed that discussion of some ways of making spray applications in pecan orchards more effective may prove helpful to growers at this time. Prior to 1935, very few pecan growers in northern Louisiana and adjoining areas sprayed their trees. Some orchards suffered insect damage but generally not enough to justify a spray program. Since 1935 the pecan phyloxera has become established in many orchards, and it often causes severe damage if not controlled. The pecan nut case-bearer, the pecan weevil, the hickory shuckworm, the black pecan aphid, and spider mites are other pests that may also cause serious injury in some years. The relative importance of these pests varies widely with the pecan variety, the locality, the year, and between orchards in the same general area. It is important, therefore, that each grower become familiar with the pests most likely to cause damage in his particular orchard. The conditions under which pecan growers began to apply insecticides varied widely. Some began to spray to control one or more major pests that cause occasional damage, others to control pests that caused serious damage in most years, and still others as a supplement to their disease-control program. However, many of them ignored the need to control insects until after their orchards had become unproductive or unprofitable. In many of these orchards damage by insects was an important factor contributing to the crop failures. Some growers still produce profitable pecan crops without the benefit of sprays or insect control. Good cultural practices are an aid in this connection. Others obtain good control with but one or two properly timed treatments per year, and still others find it necessary to make five or more applications per year. It is sometimes necessary to apply insecticides alone for the timely control of injurious insects, but more often it is advisable to combine insecticides with fungicides to hold spraying costs to the minimum. To overcome and improve the effectiveness of the program, the following suggestions are offered: 1. Study the problem in your orchard through the season to determine the need for various treatments. Often timely observations will indicate that materials can be combined to control various insects and diseases with a single application. At other times they will indicate the need for a supplementary application for a specific pest. Whenever feasible, combine chemical control with cultural practices, which are often of importance in insect control. 2. Study methods of application to make sure that the sprays are put on as thoroughly as possible. Careful attention to these matters by pecan growers should enable them to obtain increased benefits from pest control programs.
