Effect of long days and high temperatures in the nursery on the fruit production pattern of the short-day strawberry cultivar 'Gariguette'

This research was carried out to assess the effect of long days and high temperature in the nursery on the spring fruit production of a soilless heated crop. After non-inductive conditions until September 10, 2009 and September 6, 2011, trayplants of the 'Gariguette' cultivar were placed until chilling (a) under outside natural Mediterranean climatic inductive conditions (NC), (b) exposed in a glasshouse to long days, photoperiod 22 h, and semi-controlled high temperatures, minimum 22°C (LDHT). Architecture prior to chilling was determined. Among the fifteen-plant samples exposed to long days and high temperatures, only three plants in 2009 and one plant in 2011 showed an initiated terminal apex, which was at the earliest development stages in both years. Plants exposed to natural climatic conditions all bore an initiated terminal apex and most of them exhibited one or two initiated branches in terminal position. Fruit production with NC plants exhibited two flushes: a) from March to early May in 2010 and to the middle of April in 2012 and b) from late May until the end of harvest around mid-June. The fruit production with LDHT plants was delayed until the beginning of April but showed a continuous flush afterward. The two flushes of fruit yield with NC plants were superior to the continuous but late production of the LDHT plants. These results also indicate that the fruit production before mid-April could be related to initiations during the nursery period, whereas initiation after planting is responsible for subsequent fruit production.