The effectiveness of Solanum panduriforme (Mey) based extracts on the cabbage aphid, Brevicoryne brassicae (Linnacus) on brassicas

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dc.contributor.advisor Kunjeku, E. C.
dc.contributor.advisor Addo-Bediako, A.
dc.contributor.advisor Blair, B.
dc.contributor.author Mhazo, Mary Louis
dc.date 2018
dc.date.accessioned 2018-05-24T13:00:31Z
dc.date.available 2018-05-24T13:00:31Z
dc.date.issued 2018-05-18
dc.identifier.uri http://hdl.handle.net/11602/1070
dc.description PhD (Agric) (Plant Production)
dc.description Department of Plant Production
dc.description.abstract Brassicas are important vegetable crops grown for home consumption and market gardening in eastern and southern Africa. However, productivity is affected by aphids, through both direct feeding and disease transmission. Botanical insecticides have potential to control the aphids, but so far few plants have been evaluated for use on brassicas. This study was conducted to evaluate the effectiveness of Solanum panduriforme to control aphids on brassicas. Botanical extracts from three parts of S. panduriforme were assessed for their insecticidal effects on the cabbage aphid, Brevicoryne brassicae. The extracts from leaf powder (LP), ripe berry powder (BP), fresh ripe berries (RB) and fresh unripe berries (UB) were extracted with four solvents; water, ethanol, hexane and diethyl ether, using homogenisation, maceration and solvent-assisted / sequential extraction methods. The effectiveness of the extracts was determined by laboratory bioassays as well as by plant assays in the screen house and under field conditions. The experiments were replicated three or four times depending on the assays and the design used was completely randomized design (CRD). The immature (LP and UB) plant parts were generally more effective than the mature (BP and RB) plant parts, with mortalities ranging from 100 % down to 40 % respectively depending on assays. Ethanol extracts were more effective than aqueous extracts (LP 96% and 63%; BP 96% and 64%; RB 100% and 64%; UB 100% and 90%). The dried crude extracts from hexane were more effective than di-ethyl ether extracts. The group chemical analysis indicated presence of alkaloids in the berries (BP, RB and UB), which were absent in the leaves (LP). Phenolic compounds and flavonoids were present in all the extracts (LP, BP, RB, and UB). Saponins were present in the fresh parts (RB and UB). The results show how the locally available S. panduriforme plants can be used as an aphicide to control aphids on brassicas. Farmers can directly prepare an easy and cheap botanical en_US
dc.description.sponsorship NRF en_US
dc.format.extent 1 online resource (xii, 158 leaves : color illustrations, color maps)
dc.language.iso en en_US
dc.rights University of Venda
dc.subject Aphicide en_US
dc.subject Biossays en_US
dc.subject Brassica en_US
dc.subject Brevicoryne brassicae en_US
dc.subject Effectiveness en_US
dc.subject Extracts en_US
dc.subject Mortality en_US
dc.subject Solan panduriforme en_US
dc.subject.ddc 635.340968
dc.subject.lcsh Brassica -- South Africa -- Limpopo
dc.subject.lcsh Cabbage -- South Africa
dc.subject.lcsh Cabbage aphid -- South Africa
dc.subject.lcsh Cabbage -- Diseases and pests -- South Africa
dc.title The effectiveness of Solanum panduriforme (Mey) based extracts on the cabbage aphid, Brevicoryne brassicae (Linnacus) on brassicas en_US
dc.type Thesis en_US

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