Monitoring of Aphid Fauna in Passionfruit Orchards in Kenya
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Date
2013Author
Kilalo, D C
Olubayo, F M
Ateka, E M
Hutchinson, J C
Kimenju, J W
Type
ArticleLanguage
enMetadata
Show full item recordAbstract
Passionfruit woodiness disease viral pathogens limit passionfruit
production and are non-persistently transmitted by aphid vectors. The
study was conducted to identify aphid species and assess the population
dynamics of potential vectors in the orchards for purposes of developing
viral disease management tactics. Field trials laid out in a randomized
complete block design with four replicates, were conducted in Kabete
and Embu and aphid populations monitored weekly in passionfruit
orchards for a year using yellow water pan traps under natural
conditions. Aphid transmission tests using commonly found aphids Aphis
gosypii, A. fabae, Brevicoryne brassicae, Ropalosiphum maidis, and
Sitobion avenae and a CABMV isolate from the field were also carried
out in the greenhouse. These tests would establish the ability of the
aphid species to transmit CABMV. Twelve species of aphids were
captured but the most abundant were Aphis gosypii, Ropalosiphum
maidis, Acyrthosiphon pisum and Brevicoryne brassicae accounting for
97% and 95 % of the total aphids collected in Embu and Kabete,
respectively. The species diversity was rich and abundant at 0.79 and
0.7 for Kabete and Embu, respectively. The aphid population in Kabete
(8000) was significantly (p< 0.05) higher than that collected in Embu
(2900) whereas the population collected during the long rains season
was significantly (p<0.05) higher than that which was collected in the
short rains. Individual species populations were higher in Kabete than in
Embu but only A. gosypii, Macrosiphum euphorbiae, Myzus persicaeand R. maidis had significantly (p<0.05) higher populations in Kabete.
About 70% of the total aphids were collected during the peak period in
both sites indicating greatest aphid dispersal and flight activity. The
aphids were present in the orchards throughout the year with one major
seasonal peak in June, a time period when food crops and other
vegetation such as weeds grow vigorously. The occurrence of aphids in
the orchards throughout the year with the peak population density
coinciding with the cropping season has serious implications in the
management of the pest and spread of viral diseases of passionfruit.
URI
http://www.uonbi.ac.ke/openscholar/dchao/files/monitor_passionfruit_orchards.pdfhttp://erepository.uonbi.ac.ke:8080/xmlui/handle/123456789/35490
Citation
International Journal of Horticultural & Crop Science Research Volume 3, Number 1 (2013), pp. 1-18Publisher
University of Nairobi Plant Science and Crop Protection department