Fertility Influence of the U.S. Midwestern Soils on Yellow Shoulder Disorder in Processing Tomatoes

Abstract

<jats:p>The economics of processing tomato production are driven by soluble solids content, viscosity, color, and color uniformity of the fruit. Ripening disorders that affect color are a major limitation to the economic success of processing whole-peel and diced products. The causes of ripening disorders are not completely understood, although it is clear that soil nutritional status, weather, plant genetics, and interactions among these variables are important factors. We sampled both soil and fruit from fields in Michigan, Ohio, and Indiana and were able to correlate soil fertility properties and fruit color. The correlation between soil properties and fruit color was different for fine- and coarse-textured soils. Fine-textured soils presented more frequent, but weaker, correlations with absolute color and within-fruit color differences when compared with coarse-textured soils. For fine-textured soils, exchangeable K correlated with a measure of within-fruit variation, L* difference (L*<jats:sub>diff</jats:sub>; r = −0.21, <jats:italic>P</jats:italic> &lt; 0.01). Other measurements of K nutrition, K·Mg<jats:sup>−½</jats:sup> ratio, K<jats:sub>act</jats:sub>, and K<jats:sub>%CEC</jats:sub>, all correlated to the same extent (r = −0.29, <jats:italic>P</jats:italic> &lt; 0.01). The highest correlations were identified between soil-available P and L* (r = −0.33, <jats:italic>P</jats:italic> &lt; 0.01) and L*<jats:sub>diff</jats:sub> (r = −0.31, <jats:italic>P</jats:italic> &lt; 0.01). In coarse-textured soils, exchangeable K correlated with L* (r = −0.373, <jats:italic>P</jats:italic> &lt; 0.05), b* (r = −0.49, <jats:italic>P</jats:italic> &lt; 0.01) and Hue° (r = −0.37, <jats:italic>P</jats:italic> &lt; 0.05). K·Mg<jats:sup>−½</jats:sup> ratio and K<jats:sub>act</jats:sub> yielded higher correlation coefficients with absolute color measurements when compared with fine-textured soils. Soil-available P was correlated with L* (r = −0.375, <jats:italic>P</jats:italic> &lt; 0.05), a* (r = 0.49, <jats:italic>P</jats:italic> &lt; 0.01), Hue° (r = −0.46, <jats:italic>P</jats:italic> &lt; 0.01), and C* (r = 0.40, <jats:italic>P</jats:italic> &lt; 0.01). For coarse soils, K·Mg<jats:sup>−½</jats:sup> ratio, K<jats:sub>act</jats:sub>, and available P were important properties when the color of tomato fruit is of value. In all cases, higher exchangeable K and P nutrient status had a positive correlation with fruit color. Our sampling could not detect interactions among weather, genetics, and soil, and further work will be necessary to clearly describe the role of interactions in determining fruit quality in tomatoes.</jats:p>

Optimizing Sampling of Tomato Fruit for Carotenoid Content with Application To Assessing the Impact of Ripening Disorders

“…Although the reduction in lycopene due to YSD was consistent from one year to the other, there was a marked increase in the overall mean of lycopene the second year compared to the first. Environmental influences such as weather, soil fertility management practices, and/or soil properties have been reported to affect the severity of YSD (reviewed in refs and ). In Fremont, OH, there was twice as much precipitation in June 2006 compared to June 2003.…”

“…However, chroma is a poor measure of tomato color quality because high chroma due to high b * values would constitute poor quality while high chroma due to high a * values would constitute good quality. Previous indices to measure fruit affected by YSD incorporated information on the difference between two measurements of L * and hue and the absolute value of L * and hue . The ability to measure color on a pixel by pixel basis using TACT has improved our estimates .…”

“…The causes of YSD are diverse. The incidence of YSD is influenced by soil fertility, especially potassium nutrition and phosphorus nutrition ; environmental factors, including low to high temperature fluctuations , high pericarp temperature, and high relative humidity (reviewed in ref ); and genetic background . Some varieties appear more or less susceptible, though resistance to YSD has not been explicitly reported , .…”