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Studies on the ecology and disease transmission of the psyllid vectors of the citrus greening disease, with special reference to the South African vector, Trioza erytreae [Del Guercio] [Homoptera : Psyllidae]
(Potchefstroom University for Christian Higher Education, 1970)
A comparatively new virus-like disease called greening has become a very
serious threat in many citrus producing countries of the world. The disease
is transmitted by two insect vectors belonging to the Psyllidae ...
Die meting van lugbesoedeling deur stof by 'n misstofnywerheid
(North-West University (South Africa), 1970)
The extent of air pollution by dust was determined
at the granulation plant and the mill section of a fertilizer
industry. During all the tests at the granulation plant
superphosphatic fertilizers were produced. The ...
'n Ekologiese studie van gifblaar, Dichapetalum cymosum [Hook] Engl. in die Pretoria-omgewing
(North-West University (South Africa), 1970)
Although Gifblaar (Dichapetalum cymosum (Hook)Engl.) has been extensively
studied from a biochemical viewpoint, comparatively little is known of the ecological
relations of the plant, which is of considerable economic ...
'n Ondersoek van die hoërdinamiese funksies van die konynhart
(North-West University (South Africa), 1970)
The higher dynamic _functions of the heart are related to the work power
and force of contraction of the myocardium. The rate of volume-,
pressure- and flow changes is closely related to the higher dynamic
functions. ...
'n Taksonomiese ondersoek van die Laelapinae [Acari : Mesostigmata] van die Etiopiese wyk
(North-West University (South Africa), 1970)
The history of the Dermanyssidae is summarized in the first
chapter. This is followed by a brief discussion on the material
methods and techniques employed in the investigation. The nomenclature which is adopted by the ...
Die deuteronaktivering van die eerste oorgangsreeks
(North-West University (South Africa), 1970)
In hierdie ondersoek is twee moderne skyfmaaktegnieke
nl. molekulere platering en elektrosproei bestudeer en gebruik
vir die bereiding van skywe in die molekulere vormo Die metodes
kan veral suksesvol toegepas word by ...
Die chemiese beheer van Pachystigma pygmaeum [Schltr.] Robyns
(North-West University (South Africa), 1970)
A comparative investigation of the influence of the herbi
cides Tordon 22K, Tordon 22K + 1.0 percent DMSO,·Tordon 101, 2,
4-D and 2, 4, 5-T on Pachystigrna pygmaeurn (Schltr.) Robyns was carried out in order to establish ...
'n Ondersoek na die veredeling van laegraadse mangaanerts met besondere verwysing na die reduseerbaarheid
(North-West University (South Africa), 1970)
The possibility of upgrading low grade manganese ore from
Mamatwan was investigated . The main purpose of the ivestigation
involved the removal of lime and silica from the ore (be it before
or after the partial reduction ...
Die organiese voeding van drie algsoorte van die Belmontrivier naby Grahamstad
(North-West University (South Africa), 1970)
The diatom Achnanthes pseudohungarica is capable of
utilizing urea and a large number of amino acids as its
only sources of nitrogen. This. diatom can also assimilate
and utilize urea and a large number of amino acids ...
Physiological changes during prolonged work on a bicycle ergometer
(North-West University (South Africa), 1970)
"No abstract"