FLORAL INITIATION IN PEAR TREES
Analysis of several thousand spurs of 'Williams Bon Chrétien' (syn. 'Bartlett') pear showed clearly that leaves promote, whereas fruits - or, more specifically, seeds - inhibit floral initiation in the terminal buds. On spurs with a low leaf number, chlormequat and SADH have a promoting effect on floral initiation, but GA3 is inhibitory. On long shoots the major factor controlling floral initiation appeared to be the pattern of growth, the relative growth rate of shoots during the month before growth·finally ceased being inversely related to the average number of fruit buds per shoot. The results suggest that flower initiation on spurs is controlled mainly by factors acting within each individual spur system.
Huet, J. (1973). FLORAL INITIATION IN PEAR TREES. Acta Hortic. 34, 193-198