Evaluation of Tempera Paints to Reduce Occurrence of Tomato Spotted Wilt Virus

Abstract

Thrips occur in lower numbers on certain colors of flowers and with the use of certain reflective mulches. A series of experiments was conducted to evaluate the potential of foliar application of selected colors of tempera paints on tomato [Solanum lycopersicum L. (syn.: Lycopersicon esculentum Mill.)] plants as an alternative to plastic mulches for reducing numbers of thrips and incidence of tomato spotted wilt virus (TSWV). Two preliminary greenhouse experiments were conducted in Winter/early Spring 2005 and Fall 2005 to evaluate possible adverse effects of selected tempera paints on growth and early yield of tomato in Auburn, Alabama. Brilliant red, cerise, crimson, jazz orange, or purple tempera paint was applied weekly to foliage of container-grown plants until first harvest. Paint treatments did not significantly reduce plant height in comparison with nontreated plants in either the winter/early spring or fall experiment; fruit yield was reduced on plants treated with purple paint in the spring experiment and all paint colors (except cerise) in the fall experiment. Four subsequent field experiments were conducted in 2006 and 2007 in Shorter and Auburn, Alabama, to evaluate the effects of the same foliar-applied paints on tomato yield, occurrence of thrips, and incidence of TSWV. Plants sprayed with jazz orange paint exhibited reduced yield of marketable fruit in only one of the four crops; otherwise, total weight of marketable fruit from paint-treated plants showed no significant reduction compared with nontreated plants. There was an indication of reduction in thrips numbers on painted plants when evaluated prebloom but not postbloom. Paint treatments did not significantly reduce occurrence of TSWV.