Title: The effect of time of whitefly infestation and plant nutrition on the development of tomato irregular ripening disorder Authors
Submitted to: American Society of Horticulture Science Meeting
Publication Type: Abstract Only
Publication Acceptance Date: March 28, 2007
Publication Date: March 28, 2007
Citation: McKenzie, C.L., Albano, J.P. 2007. The effect of time of whitefly infestation and plant nutrition on the development of tomato irregular ripening disorder. American Society of Horticulture Science Meeting. http://ashs.org/annualmeeting/conference/index.lasso. Technical Abstract: Tomato irregular ripening (TIR) is a physiological plant disorder caused by Bemisia tabaci biotype B feeding on foliage and resulting in incomplete ripening of longitudinal sections of fruit.Our objective was to determine the effect of time of whitefly infestation and plant nutrition on the development of TIR. Healthy tomato plants were introduced to whitefly infestations at different developmental stages of plant growth: 1) 5-7 true leaf, 2) flower, 3) green fruit, 4) breaking red fruit and compared to uninfested control plants of the same age. Plants were fertilized weekly (exp 1) or bi-weekly (exp 2). All fruit (98 to 100%) produced by tomato plants infested with whitefly at stages 1 and 2 (78 and 56 days of whitefly exposure, respectively) developed TIR. Plants infested at stage 3 (35 days of whitefly exposure) had 77 to 84% of the fruit develop TIR. Surprisingly, 57-60% of fruit from plants infested at stage 4 (14 days of whitefly exposure) also developed the disorder indicating that tomatoes may need to be protected from whitefly until harvest to avoid this disorder. Seed germination was not affected by TIR. Regardless of time of infestation or fertilizer regime, plants infested with whitefly had higher foliar nutrient levels than uninfested control plants at final harvest. On average, whitefly infested plants had foliar macronutrients (N, P, K, Ca, and Mg) and micronutrients (B, Cu, Fe, Mn, Mo, and Zn) 1.6- and 2.1-times greater, respectively than uninfested control plants. The foliar macronutrient and micronutrient most affected by whitefly infestation was P and Zn, respectively. At final harvest, the mean foliar level of P and Zn in whitefly infested and uninfested control plants was 0.46 and 0.26 % P and 45.87 and 13.33 '.g-1 Zn, respectively.