Maturity, Yield, and Quality Modeling for Processing Carrots

Abstract

Carrot processing demands a continuous supply of uniform root grades for various product lines. Consequently, producers frequently harvest carrots with disregard to optimum maturity and quality, resulting in reduced yields, recovery, and profits. Beyond management inputs, weather conditions influence carrot growth and maturity through their intrinsic processes connected with carbon fixation and utilization. Establishing the relationship between the weather parameters and crop maturity, bulking, and quality of various processing carrot varieties would help in predicting crop growth, maturity, yield, and quality; thus leading to better harvest planning. Accordingly, experiments were conducted during the growing seasons of 2002–04, using seven carrot varieties in commercial plots at various locations in Nova Scotia. Weather stations were installed at each location to constantly record air temperature, rainfall, solar radiation, relative humidity, soil temperature, wind speed and direction, from which degree days and evaporation were calculated. Crop measurements included plant stand, leaf biomass (top growth), root girth and length, and gross yield. Recovery of marketable grades was arrived after the final yield was determined. Cumulative data was compiled for all of the weather parameters measured to coincide with the sampling dates. Multiple regression analyses were performed to quantify the association between cumulative weather parameters and maturity traits. All varieties, in all locations, showed strong correlations between bulking and various cumulative weather parameters. Field trials were repeated at three adjacent locations for all varieties during the 2005 growing season and the data obtained will be used to validate the fitness of the proposed model.