Rit Landbúnaðardeildar : A-flokkur - 01.05.1967, Blaðsíða 185

stand up to frost, has not proved to be any better than other varieties witli
similar grass growth.
The best varieties and most popular ones are: Golden eye, Icel. red.
and Bintje.
17. As a result of trials at Sámsstaðir with increasing doses of N-
fertilizer the flavour of the potatoes was found to depreciate as the fertilizer
was increased.
Trials with increasing doses of N P K (10 — 12 — 15) fertilizer on
potato fields show, that the proper amount for good soil is 1600—2000
kg/ha but where the soil is poorer 2400 kg/ha give better results.
18. The use of STAM as weed killer in potato fields (4—6 liters/ha)
has proved to be very good, when sprayed at a time when the weed has
between 4—-6 leaves. It can be used after the potato grass begins to show.
It does not seem to have any effects on yield.
ARESIN has also proved effective. It destroys the roots of young
weeds and should be sprayed before the seed take root. The effects lasts
for some weeks.
IS0-C0RN0X works much the same way as Stam but it is stronger
and damages the leaves of the potatoes grass. It has proved effective when
used before the leaves begin to show.
19. The copper compound PERINOX has proved to be effective against
Phytophora intestans.
AAZIMAG and DITHANE have been used for the same purpose at
Sámsstaðir with good results. Phytophora infestans is only to be found in
Skaftafellssýslur and South- and South-west Icelar.d.
20. The most promising types of Kale are: Silona rape, Rape kale and
English Giant rape.
Spreading 7 kg/ha of seed has proved to be most economical.
Trials at Hvanneyri show that for Kale in peat soil the best ratio of
phosphor and potash with 200 kg/ha of N-fertilizer are 150 kg/ha P2O5
against 200 kg/ha K^O.
21. A combination of Kale and annual rye grass or winter rye has been
found to be a good mixture for grazing.
22. Many different species of barley and oats have been tested at Sáms-
staðir. The yield of the most promising ones is given below:
183