Factors associated with internal damage and bruising in potato tubers

The aim of this project was to determine important factors influencing bruising using data collected from commercial potato production. During 2001, 2002 and 2003 samples of tubers from 187 crops were bruised using a pendulum, and tuber dry matter content and mineral nutrient content were measured. The varieties Cara, Marfona and Maris Piper were used. Maris Piper crops were supplied as either Maris Piper grown for prepacking or for processing. Records of the history of 184 of these crops were supplied by growers. Relationships between bruising susceptibility, tuber characters and features of crop production were explored.

Results

• Bruising susceptibility varied considerably between crops of the same variety
• Dry soil conditions at burning off were associated with greater susceptibility to bruising in Marfona, Cara and Maris Piper
• In Marfona and in Maris Piper, the time between defoliation and lifting was associated with susceptibility to bruising
• In Cara and in Maris Piper, a higher tuber dry matter percentage was associated with greater susceptibility to bruising
• In Marfona there was no relationship between tuber dry matter percentage and susceptibility to bruising
• The influence of K and Mg appeared complex and varied with variety

The final report from a previous project "807/124 improving quality by minimising damage" (1997) is also provided. It includes information on methods used to assess bruise susceptibility and results from trials on irrigation, fertiliser use and bruising.