NATURAL TENDENCY TO PARTHENOCARPY OF PEAR VARIETIES IN HUNGARY

Authors monitored the natural parthenocarpy, i.e. the ratio of seedless (parthenocarpous), empty or embryoless seed containing (stenospermocarpous) fruits on three sites of contrasting ecological conditions for ten years with 87 varieties.
Every time (variety and year) 40 to 150 buds were emasculated radically and isolated without having been pollinated.

According to observations over the three sites and ten-year’s period, 46–48 % of the varieties developed some seedless fruits.
From a total of 25 052 emasculated flowers the rate of fruits considered to be parthenocarpous did not exceed 2.1%. Varieties were classified according to their tendency to develop parthenocarpy into 6 categories: (1) no inclination (0 % of ripe fruits), (2) very slightly inclined (0.1 to 1%), (3) slight parthenocarpy (1.1 to 5 %), (4) intermediate (5.1 to 10%), (5) strong tendency (10.1 to 20 %), and (6) highly parthenocarpous (more than 20 %) varieties.

The major part of varieties, 52 %, did not display parthenocarpy at all, and varieties belonging to the two latter groups with strong and very strong tendency of natural parthenocarpy represented 12 % of the assortment, only.
We attempted the inference to the genetic background of the varieties in three categories, as (1) genetically not prone, (2) seedless fruitlets were shed prematurely, and (3) yearly appearance of parthenocarpous fruits is expected though irregular.

VII International Symposium on Pear Growing

J. Nyéki, M. Soltész, J. Iváncsics

natural parthenocarpy, effect of season and site on the expression of parthenocarpy

https://doi.org/10.17660/ActaHortic.1998.475.43