Tuber quality and nutritional components of “early” potato subjected to chemical haulm desiccation

“Early” potato is a typical crop grown in most of the Mediterranean countries, and it is one of the most important horticultural crops exported towards the Northern European markets. In order to improve market value of early potatoes, growers are more and more involved in choosing new potato varieties and constantly looking for methods to improve the commercial quality of tubers. One of the most increasingly used agro-techniques is chemical haulm desiccation, which aims to simplify harvesting and can help to manipulate tuber size distribution and tuber skin-set. Its effect on yield and quality aspects of early potato remains to be better evaluated. This paper resumes results of trials and analysis conducted during 2007 concerning the effect of the application of a chemical desiccant (gluphosinate ammonium) on some relevant nutritional parameters of three early potato varieties (Spunta, Ditta, and Krone) grown in Southern Italy. Tubers from the trials were analyzed for tuber size distribution, flesh and skin colour, dry matter, nitrate, soluble carbohydrates, total and resistant starch, vitamin C, phenol content, and total antioxidant activity. Results indicate that chemical desiccation does not affect the levels of vitamin C and those of other molecules with antioxidant properties as well as those of total soluble carbohydrates. On the other hand, it induces a significant decrease in starch storage and an increase in the percentage of resistant starch (a component of dietary fibre).