The influence of thermal shock and pre-sprouting of seed potatoes on formation of some yield structure elements

Abstract

Abstract For earlier potato yield formation we used pre-sprouting and thermal treatment which both add to the physiological age of potato. At the same time, pre-sprouting is a very time- and energy-consuming procedure. We investigated if thermal treatment could replace pre-sprouting and how it affects the growth and development of potato haulms and tubers. For that purpose an experiment was conducted in 2000–2002 to examine the opportunities for growing potatoes by using different methods of pre-planting treatment of seed tubers. Early, middle and late maturing potato varieties (two Estonian varieties and one Latvian) were used, each being subdivided into three variant categories: untreated, thermal shock and pre-sprouting. The experiment indicated that one or the other of thermal shock or pre-sprouting shortened the time to emergence by up to 10 days. With pre-sprouting, the formation of tubers started as soon as 45 days after planting and with thermal shock 50 days after planting, i.e., 5–10 days earlier than in the untreated variant. Thermal shock of seed tubers had the greatest effect on the number of tubers per plant, while pre-sprouting increased the average weight of tubers. Both pre-sprouting and thermal shock had a strong effect on the weight of the haulms in varieties with a longer growth period.