Weed Control
INTEGRATED MANAGEMENT OF WEEDS
Weeds pose a serious problem in the South African sugar industry and, in extreme cases, can lead to complete crop failure. Weeds are normally grouped into the three categories, namely, Broadleaf Weeds, Grasses and Sedges. The effect that these weeds have on cane yield will depend on crop growth vigour and the type of weed. Weeds are less of a problem in a fast-growing crop.
SASRI advocates an integrated pest management (IPM) approach to weed control, i.e. a sustainable approach which combines biological, cultural, physical and chemical tools in a way that minimises economic, health and environmental risks.
Anushka Gokul
Details
Agrochemical Scientist
Tel: 031 508 7400 (Switchboard)
Tel: 031 508 7447 (Direct)
Email: anushka.gokul@sugar.org.za
Role & Overall Purpose
Co-ordination and facilitation of research into promising new agrochemical and biological products including those with insecticidal, nematicidal and herbicidal activities, with the aim of contributing to strategic and sustainable management of the industry’s major pests.
Expertise
Plant pathology, Molecular biology, Microbiology, Biological control and Chemical pathology.
Research Intersts
- The safe, practical and sustainable application of agrochemical and biological compounds to reduce yield losses caused by pests, diseases, nematodes and weeds.
- New agrochemical and biological compounds or agents for application and registration in sugarcane agriculture.
Focus Areas
- To contribute to the development of agrochemical management strategies to minimise yield losses due to pests, diseases, nematodes and weeds.
- Assessing efficacy of new chemical compounds (nematicide, herbicide and insecticide) against sugarcane pests.
- Conduct field trials and glasshouse trials towards agrochemical product registration.
- To compile information generated from agrochemical research into outputs and recommendations.
Key Publications
Lamprecht, S.C, Spies, C.J., Phasoana, T and Gokul, A. 2020. Seedling diseases lead to poor establishment [Online]. Available: https://sagrainmag.co.za/2020/08/05/seedling-diseases-lead-to-poor-establishment/
Beukes, A. Gokul, L.J. Rose, A. Viljoen, B. Flett and G. van Collar. 2020. Investigating the identification and host-specificity of Fusarium graminearum species complex members in South Africa. Proceedings of: The 1st African Symposium on Mycotoxicology. Livingstone, Zambia.
Gokul, A., Beukes, I., Viljoen, A. Rose, l. 2015. Abstract “Evaluating MALDI-TOF MS and PCR RFLP for the accurate identification of Fusarium graminearum species complex members in South Africa”. EFS13/13th European Fusarium Seminar. Martina Franca, Italy.
Gokul, A., Beukes, I., Viljoen, A. Rose, l. 2015. Abstract “Chemotype determination and mycotoxin production of Fusarium graminearum from wheat and maize in South Africa”. EFS13/13th European Fusarium Seminar. Martina Franca, Italy.
Qualifications
- MSc. Plant Pathology (Stellenbosch University).
- BSc. (Hons) Chemical Pathology (Stellenbosch University).
- BSc. Molecular biology and Biotechnology (Stellenbosch University).
INFORMATION SHEETS
Watergrass Control
Watergrasses are weeds which are vigorous competitors of sugarcane. The two main species are Cyperus rotundus and Cyperus esculentus. Identification guides and control measures are detailed in this information sheet.
Water Quality for Herbicides
Growers often overlook the importance of water quality when applying herbicides, and this may lead to poor weed control and contribute to economic losses. There are several reasons why water may be unsuitable for pesticides and one or more of these may be responsible for the herbicide failures that growers sometimes experience. Water for weed control is derived from many sources such as dams, boreholes, springs, rivers, municipal supplies, etc, which increases the problem, as quality and suitability vary throughout the industry. There are a number of factors that influence water quality and growers should know how to rectify them.
Alien Plant Control
legislation and guidelines for control.
According to the Conservation of Agricultural Resources Act, alien plants now fall into three categories. The term ‘control’ means to combat Category 1, 2 and 3 plants by using the prescribed methods to the extent necessary to prevent or contain the occurrence, establishment, growth, multiplication, propagation, regeneration and spreading of such plants.
Understanding the label on herbicide containers
The herbicide container label provides essential information about the purpose and safe and effective use of the herbicide. Product container labels are usually made up of three panels with the centre or sales panel flanked by two ancillary side panels for precautions, instructions, etc. To cater for illiterate people, pictograms (illustrated instructions) are included on product labels to communicate key safety information.
Spraying Herbicides With Low Volume
Controlled droplet application (CDA) systems.
The CDA system uses centrifugal force to deliver pesticide by means of a spinning disc. The most commonly used models are battery driven and the chemical is delivered to the disc by gravity. The term ‘controlled droplet application’ refers to the size of the drops that are ‘thrown’ off the edge of the disc as it rotates. These drops, unlike those delivered from hydraulically operated nozzles, are relatively uniform in size.
BOOKS/BOOKLETS
SASRI Herbicide Selection Guide
Information in this guide must be used in conjunction with herbicide label instructions. Users specify weed types and weed stages and then take note of the active ingredients suggested as treatments. These active ingredients are then linked to a list of specific commercial products. While some additional information is provided for each active ingredient, users must consult the label of the selected products for application guidelines and restrictions.
Weeds of the South African sugar industry
The objective of this book is to provide the South African sugarcane grower with the means to identify weeds without the complication of botanical keys. It will also help the grower make better choices regarding weed control measures. All the weed species that appear in the book were collected from canefields throughout the South African sugar industry and, in most cases, each is shown at the seedling and mature stage of development. It must be appreciated that the list of weeds included is by no means complete and further species will appear in subsequent editions.
Integrated weed management of creeping grasses in sugarcane
Creeping grasses pose a serious problem in the South African sugar industry and, in extreme cases, can lead to complete crop failure. This booklet describes sixteen control tactics for creeping grasses, with a description of the circumstance where each tactic is suitable. These are summarised for easy reference in tables having different weed densities. These tactics are more effective when employed in selected combinations. An Integrated Weed Management (IWM) programme uses appropriate combinations of cultural, mechanical and chemical control tactics which are important for successful weed management.
Understanding the FAS Report: Water Quality
The FAS Agricultural Laboratory undertakes routine irrigation water quality analysis focusing on determination of excess salt and the suitability of the water source for irrigation. In addition, some growers may use this water for agrochemical mixing. Using good quality water is important to optimise the efficacy of chemicals.
Uhlelo oludidiyelwe Iwamasu okulawula utshani obenabayo emobeni
isiZulu version of ‘Integrated weed management of creeping grasses in sugarcane’ described above.
Alien Plants
Ziyini izifikanamthwalo noma izinhlaseli?
(Alien plants)
Weed Control
Ukuqwanda kokhula emobeni
(Weed Control)
Parthenium Biosecurity Alert
Qaphela ubungozi: Ukhula i-Parthenium
(Parthenium Biosecurity Alert)
DECISION SUPPORT TOOLS
HERBICIDE SELECTOR
SASRI has developed a herbicide selection tool, available as an MS Excel application. The tool takes into account weed spectrum, weed growth stage and clay% and suggests a range of active ingredients that will work for the chosen criteria. Users can also see a list of commercial products that are available for each active ingredient. Notes are also provided for each active ingredient.
The information is also available as a PDF file.
Download Herbicide Selector (MS Excel) | Download Herbicide Selection Guide (PDF)
Videos
Knapsack calibration
Ukugcina amathuluzi okufutha ekhipha isilinganiso esifanele
(Calibrating Spraying Equipment)
Yini edlala ukuthi izibulala khula zingasebenzi?
(What influences efficacy of herbicides?)
Kungani ukhula lungafuneki
Ensimini (Controlling weeds)
Services
Biosecurity
SASRI’s Biosecurity staff work together with Local Pest, Disease and Variety Control Committees to prevent or minimise loss and damage caused by pests and diseases.
Extension and Biosecurity Service
SASRI Extension Specialists located throughout the South African sugar industry are available to offer advice and support on crop nutrition and all other aspects of sugarcane farming.
Special Advisory Requests
Service to investigate new products on behalf of commercial companies to facilitate registration. Investigations can include testing of herbicides, fungicides, ripeners, fertilisers and pesticides.
RESEARCH
Research on weed control develops integrated management strategies that minimise the effects of weeds on crop production in a sustainable manner. Visit CROP PROTECTION for more information.
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