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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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