EFFECTS OF LATITUDE IN MORPHOLOGICAL AND PHYSIOLOGIC PARAMETERS AND PLANT HARVEST INDEX IN FRESH PLANTS OF STRAWBERRY CV. 'CAMAROSA'

The production of early strawberries in Argentina is situated in the north of the country under a humid subtropical regime. Fresh plants are being grown at nurseries located both at high and low latitudes. The purpose of this study was to determine the effect of latitude on plant development and Plant Harvest Index (PHI) = (dry weight root + dry weight crown)/(total dry weight) x 100 strawberry cv. ‘Camarosa’. The nurseries were located in low latitude (Tafi of Valley, 2200 m a.s.l.) and high latitude (Esquel, 789 m a.s.l., 42°56’S.L., and Los Antiguos 46°35’20”S.L). The plants were grown in 2005/2006 and were harvested in the first week of April 2006. Under low latitude conditions dry matter weight, petiole and leaflet were higher; PHI was higher (49.223; 47.314) in high latitude compared with low latitude (34.877). Latitude had no effect on crown dry wt expressed as % of total plant dry wt, but root dry wt expressed as % of total plant dry wt was significantly reduced (24.1%) at the low latitude site compared to either high latitude site (37.5% and 35.7%), respectively to low latitude (24.1%). A correlation was found between PHI and root dry matter weight. A non-significant correlation was found with the dry matter weight in the crowns. These results suggest that factors such as photoperiod and temperature are determining the physiological maturity of the plants. The study revealed that the latitude, existing out of the temperature and photoperiod component, contributes significantly to the increase in dry matter in the roots.