ABSTRACT
The length of the vegetation period of poppy depends on the ecotype, cultivar characteristics, climatic conditions and sowing time (although both the so-called ‘autumn-sown’ and ‘spring-sown’ ecotypes can in fact be sown at various terms as a consequence of the adaptability of these species (Bemáth and Tétényi, 1982)). According to their morphological and physiological features, both types produce an optimum yield only under appropriate climatic conditions and with the use of appropriate agrotechnical methods. However, ‘autumn-sown’ and ‘spring’ poppy belong to the same species and they have similar characteristic developmental phases during ontogenesis. The main difference is found in the length of the vegetation period under European conditions. The vegetation period of spring poppy lasts 120-160 days and that of the winter poppy 250270 days. However, the actual length of the vegetation period shows large differences country by country, as shown in the crop calendar compiled by Gordon (1994) which lists 120-165 days in India, 135-250 days in Afghanistan and 178-205 days in Pakistan. Such differences are also observed in other regions of the world, for instance 150 and 240 days are reported to be necessary for the vegetation period in Mexico.
