Articles
OLD BELGIAN CULTIVARS OF APPLE AND PEAR AS A SOURCE OF RESISTANCE TO DISEASE
Since 1975, Populer has been collecting these cultivars and evaluating them for resistance to fungal and bacterial diseases and also for yield, fruit quality and keeping ability.
By the end of 1981, 650 apple and 680 pear cultivars had been collected for evaluating at the Plant Pathology Station.
These cultivars were found either in collections at horticultural schools or in gardens and old standard-tree orchards.
Most of this material originated in Belgium and was obtained by well-known amateur breeders of past times or by the anonymous activity of rural people.
The cultivars introduced in the evaluation orchard are budded or grafted on dwarfing rootstocks.
The time from grafting to the end of the evaluation is approximately 10 years for apples and 12 years for pears.
The first evaluation results are expected to be published in 1984–85.
As a complementary line to this programme, a research was initiated by Maroquin in 1977 to detect possible resistance genes to viruses and mycoplasma-like organisms in a choice of apple and pear cultivars collected during the first two years.
These cultivars were heat-treated and tested on a range of indicator plants in an indexing nursery.
Up to now, 101 apple and 100 pear cultivars have been heat-treated and have entered the testing procedure.
Of these, 66 apple and 16 pear cultivars have been completely tested.
These virus-free cultivars will be compared ulteriorly to the initial material to screen out the cultivars with resistance or tolerance to diseases caused by viruses and mycoplasma-like organisms.