Effects of Color to Deter Thrips and Reducing the Incidence of Tomato Spotted Wilt Virus

Abstract

A field study was conducted to evaluate the influence of colored mulch plastic on thrips ability to locate tomatoes (Lycopersicon esculentum Mill.). Mulch colors were selected based on ultra violet reflectance which has been shown to repel thrips. Specially manufactured colored mulches (Pliant Corp, Washington, GA) were: silver, red 1, red 2, black, and violet. Thrips population counts and plant yields were taken weekly. Enzyme-linked immunosorbent assay (ELISA) tests were completed early-season and mid-season to test for tomato spotted wilt virus (TSWV). Statistical anaylsis revealed that the colored mulches did effect thrips counts measured by cup and flower sampling, marketable weight, marketable count, and TSWV incidence. The silver colored mulch was consistently lower in cup counts of thrips than all other treatments and black mulch had the highest cup count of thrips. The silver mulch had the least number of flower thrips than any other treatment and the violet mulch had the highest flower thrips. Silver mulch had higher marketable weight and marketable fruit count then all other treatments followed by the violet mulch, but the violet mulch had less incidence of TSWV than the silver. The standard black mulch had the lowest marketable weight and marketable fruit count than all other treatments. In the later test for TSWV, red 1 and violet colored mulches similarly had the lowest percentage of TSWV incidence and black mulches had the highest percentage of TSWV incidence. A field study was conducted to evaluate the influence of Blue-X Growtube Shelters on the ability of thrips to locate tomatoes (Lycopersicon esculentum Mill.). Blue-X Shelters (BLUE-X® Enterprises, Inc., Sacramento, CA) with varying tube sizes were selected for this study: 13”x9”, 13”x6”, 18”x9”, and 18”x6”, along with a non-treated control. Thrips population counts, yields, and height measurements were taken weekly. Enzyme-linked immunosorbent assay (ELISA) tests were completed early-season and mid-season to test for tomato spotted wilt virus (TSWV). Statistical anaylsis revealed that the Blue-X growtubes did lower thrips cup counts in the early season. No difference was seen in the flower counts taken later in the season. The marketable weight and marketable fruit counts were effected by the treatments. The non-treated control plots had the highest marketable fruit weight and marketable fruit counts over all the tube treatments. The 18”x6” and 18”x9” had the lowest marketable fruit weight and marketable fruit count. TSWV was highest in the 18”x6” tubes in the early season test than any other treatment. In the later testing 13”x6” tubes had the highest amount of TSWV incidence of any other treatment. Plant height was effected by the treatments. All tube treatments were taller than the control plots.