NEW PROMISING SELECTIONS OF APRICOT

Since apricot »varieties« found in Austria are rather populations (mixtures of different, more or less valuable strains) than pure cultivars, the author in cooperation with Dir. J. Falch and numerous extension workers of Lower Austria and the Burgenland in 1957 tried to find especially valuable strains for further testing. The selected trees were either grafted at their place of standing as to their healthiness, resistance, performance and time of ripening (very early and very late types). At the Hochschule für Bodenkultur Wien the essential characteristics of the fruit of these selected trees (in most cases of three successive years) have been determined with laboratory techniques. Finally grafts were made from those 11 selections, which combined very good characteristics of the tree and the fruit. (The vegetative descendants of a single tree are a clone, a uniform variety). Three types of rootstocks have been used: »Millionär«-apricot (seeds from H. Plock, Oppenheim), »Ackermann«-plum and »Brompton«-plum. In the first case the scions were grafted into the main branches of the tree; with Ackermann and Brompton they were budded just above the ground.

In the fall of 1960 seven trees per clone (3 standard size trees od Millionär, 2 high-bushes on Ackermann, 2 high-bushes on Brompton, distance 6 x 5,70 m were planted in the Experiment Station Gerasdorferstrasse, Vienna XXI. The climate there is pannonic; the soil is dry, loamy sand on gravel.

After seven years of observation 4 clones seemed to be very promising. Up to now they did not have dead trees or limbs caused by apoplexy, which generally — as with the 7 remaining clones — is a serious problem in apricot culture already during the first years of production.

Of the two extremely early clones not effected by apoplexy the clone »Marillensämling (seedling) besonders frühreif aus Kittsee« short name »Frühmarille aus Kittsee«, is far superior to the wellknown »Frühe Ungasche Gelbe« in many respects. The yield up to now is very high (The mean per tree of »Frühmarille aus Kitsee« on »Millionär« is 80 kg as compared to 55 kg of the »Frühe Ungarsiche Gelbe« and 64 kg of the average yield of all 11 clones on this rootstock). Grown under the same conditions the fruits of the »Frühmarille aus Kittsee« are bigger and have a higher refractometer-value than the similar »Frühe Ungar. Gelbe«.

The only clone ripening at mid-season, having no dead trees and limbs is the »Ungarische Beste aus Landersdorf«; the yields of which are highest (up to now 99 kg per tree on »Millionär«), the weight of the fruit (more than 50 g) second highest following a clone bearing only one thirs as much.

Also no dead trees have been observed yet with the extremely late ripening »Kecskemeter aus Mautern«, which can be easily sold and brings high