Aw. Wangai et al., Effects of sowing date and insecticides on cereal aphid populations and barley yellow dwarf virus on barley in Kenya, J PHYTOPATH, 148(1), 2000, pp. 33-37
Citations number
9
Categorie Soggetti
Plant Sciences
Journal title
JOURNAL OF PHYTOPATHOLOGY-PHYTOPATHOLOGISCHE ZEITSCHRIFT
The effects of the date of sowing and insecticide sprays on aphid populatio
ns and barley yellow dwarf virus (BYDV) incidence in barley was studied in
Mau Narok, Kenya. Rhopalosiphum padi (L.) and Metopolophium dirhodum (WLK.)
were common aphid species, but other cereal aphids present were Rhopalosip
hum maidis (Fitch), Stiobion avenae (F.), Schizaphis graminum (Rond.) and H
ysteroneura setaria Thom. The incidence of BYDV was significantly decreased
in plots sown with seed that had been treated with imidacloprid (NTN-33893
, Gaucho) and subsequently sprayed with foliar insecticide (Cypermethrin).
Yield loss due to BYDV was also significantly different between the treatme
nts and between the early-planted and the late-planted crop (P < 0.05). Gra
in yield and 1 000-grain weight were not significantly different among inse
cticide treatments in the early-planted crop. In the late-planted crop, the
yield increase with seed treatment alone was highly significant (P < 0.001
), with a yield increase of 36-43 %, more than that of the untreated contro
l. Grain yield was significantly (P < 0.05) negatively correlated with the
total number of cereal aphids, as well as with the numbers of R. padi alone
.