VEGETATIVE STAGE OF STRAWBERRY DURATION DETERMINED BY THE CROP YEAR

Abstract

ABSTRACT Over the years, strawberry growth has shown alterations in its phenology, involving mainly the beginning of flowering and fruiting. The aim of this study was to verify whether the growth years influence the duration of strawberry vegetative and reproductive stages in protected environment. The development of the Camarosa strawberry cultivar was observed between 2007 and 2014. The crops were settled in a greenhouse in the Horticulture Sector at the University of Passo Fundo, RS. Data like transplant date, in the beginning and end of the fruits harvest; temperature data (maximum, average and minimum) were recorded in the growth environment. These data were used for the thermal sum calculation (daily, accumulated). The data analyses were carried out in a descriptive manner, relating the temperature data with the phenological stage of each year. The accumulated thermal sum that is necessary to begin the harvest was variable throughout the years, where it was between 383 and 438 degrees days-1 for plants with interval between transplant and harvest of 73 days (2008 and 2009) at 816 degrees days-1, where the interval was 111 days (in 2014). In the first case, it accumulated 5.2 ºC/day, in 2008 and 6 ºC/day, in 2009. In the second case, it was 7.3 ºC/day, in 2014. Seedlings which were transplanted in the first fortnight of May began fruiting in the beginning of August and September. Seedlings transplanted in July 2011 and 2012 began fruiting in similar periods, that is, in the first and second fortnight of September. It was found that, because of the temperatures recorded in different periods of growth and transplant time, there is alteration mainly in the strawberry vegetative stage.