Changes And Relationships Of Yield And Quality Of Potato Varieties Used For French Fry Processing

At present,lack of varieties that are suitable for French fry processing is the most urgent problem in China. Introducing foreign varieties that are qualified for French fry processing is an effective method to solve the problem. In this study,three French fry varieties. Russet Burbank. Kennebec and Shepody. from foreign countries were tested on the performance of growing and storage,and the changes of yield and quality during growing season and storage period were followed. The relationship between French fry color and tuber quality was analyzed as well. The results are as following.The content of N03-N in leaf stalk was increased significantly when the additional fertilizer was applied during the tuber swelling stage. Total yield and marketable \ield increased by 11% and 17% respectively,and the marketable tuber percentage increased by 4.5%. Starch content decreased to some extent,but Russet Burbank,a high starch content variety,only showed less decreasing in starch content.In multi-stages harvest trial. Kennebec increased rapidly in yield with high marketable tuber percentage and relatively low starch content:whereas Russet Burbank and Shepody were low in yield but high in starch content. The marketable yield of Russet Burbank,Kennebec and Shepody increased rapidly during 52-60 d and 77-96 d. 52-96 d . and 69-96 d. respectively,after emergence. All three varieties could be harvested in 85 d after emergence for French fry processing.There were obvious differences in the contents of starch,dry matter and reducing sugar of tubers,and French fry quality among three varieties stored in different temperatures. Tubers of Kennebec both stored for 17 d in 3-5"C and recondition for 21 d at 14-16 C after stored for 134dat3-5C were in 3.5 grades or less for French fry processing. Tubers of Russet Burbank reconditioned for 21 d at 14-16"C after stored at 3-5"C for 134 d were also in 3.5 grade. Stored at 14-16C. the appropriate processing period for Russet Burbank. Kennebec and Shepody was 17- 134 i 17-100d and 45 - 100 i respectively. In this period,French fry grade for the three varieties was 3.5 or less.hi storage at low temperature and then recondition,positive correlation was showed between reducing sugar contents and French fry color grades. Negative correlation was found between starch contents and French fry color grades when potatoes were stored at high temperature.Postgraduate:Teng Weili. Crop genetics and breeding Supervisor:Professor Chen Yili...