Articles
RESULTS OF FIVE YEARS OF POLLINATION EXPERIMENTS ON SWEET CHERRIES.
Some of them are economically very important (Poolse, Krakers, Brabanders). These varieties are self incompatible but nothing is known about the possible occurrence of cross incompatibility.
From 1978 on, hand pollination experiments were carried out on the local as well as on the more internationally used varieties.
The purpose of these experiments was to investigate if any feature of cross incompatibility occurred and if differences in fruit set could be related to the varieties which were used for pollination.
Cross incompatibility occurred with the varietes Hedelfinger Riesenkirsche x Blauwe Bigarreau and Büttners späte rote Knorpelkirsche x Poolse.
Using Büttners späte rote Knorpelkirsche as a pollinator for Early Rivers did not result in fruit set unlike fruits were formed when Early Rivers served as a pollinator for Büttners späte rote Knorpelkirsche.
No fruit set occurred in the crossings Early Rivers x Bigarreau van Piringen and Lambert spur x Bigarreau Napoleon, but nothing is known about the reverse combinations.
Important differences in fruit set appeared for some of the examined varieties.
These differences were persistent during the years of investigation.
As far as other varieties are concerned, in the years when fruit set was important only small differences were found between the pollinators; in years of a low fruit set however, differences between the pollinators were more accentuated.
Finally, it was concluded that with other varieties, all the pollinators led to a comparable fruit set, unless some symptoms of incompatibility occurred.
For all the examined varieties, the Vroege Krakers can be regarded as a (very) good pollinator.
Sour cherries can pollinate sweet cherries as well, although the result is not usually good.