Le Nord : revue internationale des Pays de Nord - 01.06.1939, Page 328
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those of hay leys and pastures have increased considerably, where-
as the areas of rye, barley, legumes, and fallow have decreased;
oat and potato areas are nearly unchanged. It is obvious that
some of these displacements of the crop relations at least partly
are due to the raised yields of e. g. wheat and root crops caused
by plant breeding. The marked increase of crop yields is due to
many factors such as improved drainage, field technique, manu-
ring a. s. o. and also to improved varieties introduced by the bree-
ders. This last factor differs, however, from all others in that it
does not, or nearly not, cause the farmers any extra expenses.
An effort has been made to estimate the yearly value of the
increase in crop yields caused by the breeding. In self-fertilizing
cereals old regional land varieties are still kept and yearly tested in
yield trials together with the best new varieties. In this case a
rather good estimate of the progress as to yield can be obtained.
In winter wheat it is considered to be about 30 %, as an average
of the whole country, in spring wheat 15, in rye 25, in oats 15»
and in barley 12 %. On the basis of these estimations the value
of the increase in all cereals was calculated, resulting in a yearly
value of about 60.000.000 Sw. crowns. In other crops, in which
either regional varieties never have existed or in which they in
the course of the years have disappeared or changed their com-
position, estimations of this kind are very difficult. As however
these crops together represent twice as many nutritional units
harvested as the cereals and the breeding of these plant species
obviously has been successful, it is concluded that, notwithstanding
raised quality, the increase in yield due to the breeding is in all
worth up to 100.000.000 Sw. crowns a year.
Plant breeding has been of great value to agriculture in still
many other ways. As most valuable should be mentioned the
raised quality and uniformity of the crops harvested. The high
baking quality of modern Swedish wheat varieties made it pos-
sible for the government to stipulate that for milling purposes only
10 % of foreign hard wheat is to be mixed into the Swedish. A
few years ago about 40 was the most common percentage. In bar-
ley special varieties of different chemical composition of the grain
were bred for malting, respectively feeding purposes. Also in oats,
peas, potato, sugar beet, and other root and forage crops quality
breeding has been successful. Earliness, resistance to lodging and
shedding and decreased straw production in new varieties of
cereals as well as unbranched and more or less above the soil