| Autor: |
R. E. Price, H. D. Brown, E.T. Butler, Roy Bateman, E. J. Müller |
| Rok vydání: |
1997 |
| Předmět: |
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| Zdroj: |
Crop Protection. 16:345-351 |
| ISSN: |
0261-2194 |
| Popis: |
A large micro-light aircraft fitted with Micronair AU7000 atomisers was used to apply Metarhizium flavoviride isolate IMI 330189 to brown locust ( Locustana pardalina ) populations (mostly Vth instar nymphs) in the Richmond District of the Karoo in South Africa. Dry conidial powder was formulated in a paraffinic oil mixture to apply approximately 2.0 × 10 12 conidia per hectare with volume application rates of 1.0 and 2.5 l/ha. Three different droplet size spectra were produced by setting the pitch of the atomiser turbine blades to 25, 35 and 45 °. A total of ten hopper bands were treated on three separate days. Samples consisted of insects kept in cages under field conditions and sections of hopper bands maintained in open-topped field enclosures. All treated bands showed significantly greater mortality than the controls, with up to 98% mortality in samples maintained in enclosures after 3 weeks. Mortality in caged samples was often faster than with hoppers maintained in field enclosures. The relative efficacy of the various methods of aerial application will need confirmation in further trials; a volume rate of 2.5 l/ha appeared to give more consistent results than 1 l/ha applications. Mortality was probably related to droplet impaction, affected primarily by the wind-speed at the time of spraying. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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Full Text from ScienceDirect