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The Plant Protection Service of the Ministry of Agri-
culture is also using aerial photographs for the de-
tection of plant diseases. Under the conditions pre-
vailing in this country the aerial photographs made at
a flying height below 400 m proved to be most suitable,
when taken from a helicopter with a manual camera, using
Kodak Ektachrome-X and MS films, and completing the
procedure with infrared observation through an AGA
Thermovision equipment.
In the aerial photographs, the fungus, virus, and other
diseases attacking the agricultural plant stocks have
been evaluated partly by stereoscope and interpretos-
cope, and partly by densitometry. For the latter a new
mathematical evaluation method has been developed.
Analysis by aerial photographs was supplemented by
random in-site observations. Results prove that a number
of plant diseases can be detected and surveyed this way.
Intensive vegetation mapping started by the Ungarian
Academy of Sciences several years ago has successfully
employed aerial photographs. The rich contents and
precise data of these maps greatly facilitate the vege-
tation cartography work. The accuracy of these maps
could meet the most stringent requirements even in the
case of vegetation mosaics (such as forest-prairie
vegetation). Thus aerial photographs rendered excellent
results in mapping the vegetation of the basalt capped
monadrocks over the Balaton lake highland, or that of
the limestone and dolomite hills of the Transdanubian
Range.
In addition to that of the land vegetation, the aerial
photo interpretation of the river and lake vegetation
was similarly started with great anthusiasm, under the
supervision of the Department of Botany, College of the
Agricultural Sciences, Keszthely. The survey used
1:10000 and 1:5000 transformed photo maps produced by
a special surveyor camera. Detailed analysis of the
underwater vegetation employed black-and-white as well
as coloured aerial photographs taken at a flying height
of 200 to 500 m by manual camera. In plotting these
vegetation maps, the plants illustrated by the photo
maps could be readily identified on the basis of their
coenological features. The phytomass production, too,
was calculated and a number of biotechnical problems
associated with the water have been solved by this
method.
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