Minimising post-harvest losses in radish through an understanding of pre and post-harvest factors that influence root splitting

Rainfall, temperature and relative humidity during growth and/or at harvest all affect the rates of splitting in commercially grown radishes. Splitting rates at harvest were correlated with substrate moisture content at the radish growth stage 41.

Post-harvest splitting susceptibility can be decreased by reducing hypocotyl water content and increasing temperature during handling.

Growers of radish encounter frequent problems with splitting which can have a significant commercial impact in terms of product wastage, additional handling/selection costs and depot rejections.  These problems appear to be linked to crop maturity and conditions immediately before and after harvest.  This project studied the effect of environmental conditions during crop growth, particularly soil water status and the effect of variation in soil water status; the consequence of the timing of foliage removal before harvesting and the effect of post-harvest treatments, such as washing and storage conditions. 

UK radish producers encounter frequent problems with post-harvest splitting in radish which has a significant commercial impact in terms of product wastage. Identification and removal of splits is both time consuming and wasteful and is not always successful which results in depot rejection and further cost.  The direct impact on the consumer is not known, but is thought that the split roots and drying/deterioration of the split surfaces may also deter sales.

The work undertaken by the student focused on 4 main areas:

1. Irrigation impacts
   1. Effect of soil water potential
   2. Timing of irrigation stress
2. Post-harvest storage environment
   1. Effect of temperature
   2. Effect of humidity
3. Harvesting
   1. Timing of foliage removal
   2. Temperature of root at harvest

4. Post-harvest washing
   1. Temperature differential between root and wash water
   2. Duration of washing
   3. Timing of washing