• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • 1
  • Tagged with
  • 3
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Die insekplaagkompleks op sitrus te Vaalharts

Mathewson, Johanna 03 1900 (has links)
Thesis (MSc)--Stellenbosch University, 2000. / Full text to be digitised and attached to bibliographic record. / ENGLISH ABSTRACT: The cultivation of citrus in the Vaalharts region is a fairly recent development. With the introduction of this crop, an insect pest complex has also developed in this region. The presence of these pests was studied in eleven orchards, planted with three citrus cultivars and of varying ages, distributed in the 300 square kilometer cultivation area. Each orchard was inspected for the presence of pests by making use of two weekly sampling techniques. Ten of the most important insect pests of citrus in the Vaalharts region are briefly described by refering to their general appearance, life cycles, feeding and pest status and economic threshold. For every pest various control options, including operational systems, crop cultivation, biological and chemical control, are discussed and, where applicable, illustrated by means of graphic presentations. The seasonal presence of the cirtrus pests in the Vaalharts region is tabulated and discussed individually. With these details as background, an insect pest management programme for citrus in the Vaalharts region is compiled. / AFRIKAANSE OPSOMMING: Die verbouing van sitrus in die Vaalhartsgebied is 'n redelik onlangse ontwikkeling. Gepaard met die nuwe gewas het daar ook 'n insekplaagkompleks in die gebied ontstaan. Die voorkoms van die plae is in elt .boorde, beplant met drie sitruskultivars en van verskillende ouderdomme, verspreid in die 300 vierkante kilometer verbouingsareaal, bestudeer. Elk van die boorde is weekliks ondersoek vir die aanwesigheid van plae deur van twee moniteringstegnieke gebruik te maak. Die tien belangrikste insekplae van sitrus in die Vaalhartsgebied word kortliks beskryf deur na hulle algemene voorkoms, lewenssiklus, voeding en plaagstatus en ekonomiese drempelwaardes asook die moniteringsmetodes wat gebruik is, te verwys. Vir elke plaag word beheeropsies, wat operasionele stelsels, gewasverbouing, bloloqlese en chemiese beheer insluit, bespreek wat, waar toepaslik, aan die hand van grafiese voorstellings gemustreer word. Die seisoenale aanwesigheid van die sitrusplae word in 'n tabel aangedui en individueel bespreek. Met die gegewens as agtergrond is 'n insekplaagbestuurprogram vir sitrus in die Vaalhartsgebied opgestel.
2

The compilation of indigenous knowledge regarding insect pests in small-scale farming communities in North Eastern South Africa

Netshifhefhe, Shandukani Rudolf 30 June 2005 (has links)
Please read the abstract in the section 00front of this document / Dissertation (M Inst Agrar (Sustainable Insect Management))--University of Pretoria, 2005. / Zoology and Entomology / unrestricted
3

Composition and phenology of insect pests of Capsicum (Solanaceae) cultivated in the Makana District, Eastern Cape Province, South Africa

Hepburn, Colleen January 2008 (has links)
Capsicum baccatum var. pendulum was first grown in the Makana District in 2005. Extremely little was known about best practices for cultivation or the insects and diseases associated with the crop in this area. The study was conducted during the second year of production, November 2005 and November 2006, in an attempt to identify the composition and phenology of insects occurring on C. baccatum. In the more rural parts of the Eastern Cape, and more particularly in Grahamstown, there are very few industries. With the advent of this new agricultural venture, a processing factory has been opened in Grahamstown creating more than 600 seasonal jobs in the factory and 1000 seasonal jobs on farms for local people. This business enterprise has not only brought about the creation of jobs, but also training and skills development and empowerment, generating much-needed income in this area. An extensive literature review yielded limited information on insect pests associated with Capsicum. Data from a pilot sampling trial undertaken were statistically analyzed to establish the number of plants to be scouted per site and the most effective scouting techniques to use. Based on the data available and insects collected during the pilot sampling trial, a surveillance programme was designed. Five different types of monitoring traps were placed in each of the eight study sites. Collection of trap catches and scouting of fifteen individual plants per site was undertaken on a weekly basis over the 52-week study period. The most commonly occurring potential insect pests were African Bollworm Helicoverpa armigera (Hübner), False Codling Moth Thaumatotibia leucotreta (= Cryptophlebia leucotreta) (Meyrick), Mediterranean Fruit Fly Ceratitis capitata (Wiedemann) and several species of thrips. Population densities of these pests and their phenology on Capsicum were determined. Statistical analyses established the efficacy of the monitoring traps for each pest, tested for differences among and between study sites, calculated an estimate of the number of pods damaged and a measure of plant damage.The results show that the majority of damage caused to the Capsicum baccatum cropping system was due to Mediterranean Fruit Fly populations. It was established that, although African Bollworm and False Codling Moth were present during the study period, their numbers were negligible and only nominal damage was caused by these pests. Damage caused by thrips species was apparent but not quantifiable. Intervention strategies using an Integrated Pest Management approach, are discussed.

Page generated in 0.3271 seconds