Respiratory response of healthy and diseased potatoes (Solanum tuberosum L.) under real and experimental storage conditions

This study investigates respiration rate of potatoes (Solanum tuberosum L.) under real and experimental storage conditions. Real storage conditions were obtained by building a small-scale storage facility equipped with two independent storage bins including all controls. Each bin was filled with 2.5 metric tons of potatoes and these were stored for five months. Temperature, relative humidity, air flowrate and other operational parameters were collected. Also, mass loss and CO₂ analyses were performed.; A heat and moisture balance was applied to quantify heat and moisture rates produced by potatoes and were converted to respiration rates as CO ₂ produced (ml.kg−1.h−1). Evaporation rates were also determined (g.kg−1.h −1). The balance was mainly applied on data collected from specific periods in which steady conditions were imposed; heaters and humidifiers were turned off and fans were operated to circulate air at a given flowrate for more than 8 h/day over a two month period. Respiration rates were determined as rates of heat produced (W) with stability and acceptable accuracy for a relatively large facility. Respiration rates were converted to CO₂ production (ml.kg−1.h−1), and these agreed fairly with ranges reported in the literature. Simultaneously, respiration rates were measured by in-store CO₂ analysis, and later they were measured under laboratory conditions using a closed gas analysis system. Comparing these with rates obtained by the heat and moisture balance, the later were slightly higher. Mass losses were also obtained by both weight losses and moisture balance; results from the two methods were quite similar and comparable with those reported in the literature.; Under experimental conditions, respiration rates were measured for healthy, diseased and sprouted tubers using a gas analysis method. This experiment demonstrated the need for a more extensive investigation of disease development and its relation to respiration rates, and the need for a faster and more convenient gas analysis system. (Abstract shortened by UMI.)...