The floral biology of the olive - II. The effect of inflorescence load anddistribution per shoot on fruit set and load

The effect of inflorescence number and distribution along the shoot on the level of fruit-set was studied using 'ON' year olive trees with a high leve l of floral differentiation. Reduced levels and different inflorescence dis tribution patterns were created artificially by hand inflorescence thinning . In most cases, removal of up to 50% of the inflorescences had either no e ffect on the total amount of fruit load per shoot or increased it significa ntly Thus, the percentage of fruit set increased with the reduction in infl orescence number due to both, a higher percentage of fruitful inflorescence s and higher numbers of fruits per inflorescence. Inflorescences on the dis tal half of cv. Barnea shoots were less fruitful than on the proximal half. With cv. Manzanillo no such difference was found. Single inflorescence dis tribution significantly raised the level of both, the fruit load and fruit set compared with distribution of the inflorescences along the shoot in pai rs, although the amount of this increase varied with the different thinning levels. The actual percent of fruit set on a flower number basis increased in parallel with the reduction of their number in response to inflorescenc e thinning. (C) 1999 Elsevier Science B,V. All rights reserved.