Culturing enquiring minds

Horticulture BTech students got a taste of academic rigour when they recently presented their research on Plant Tissue Culture to lecturers and fellow students.

Not only did they have to defend their presentation choices but also demonstrate whether they could draw on lessons learned in various classes to support particular statements.

Plant Tissue Culture (PTC) is a collection of techniques used to grow plants in a laboratory under controlled conditions on a nutrient medium.

Biotechnology lecturer Dr Lalini Reddy says PTC forms a capstone for the subject and this year she wanted her students to expand beyond a factual assignment to grapple with philosophical questions.

She also encouraged her 9 BTech students to write a letter to the presidency to try to start a conversation encouraging the South African government to take PTC more seriously as a niche industry. They had to concentrate on the conservation of biodiversity and its potential effects on the country’s GDP and employment rates.

“It’s just a start for them,” Reddy told the lecturers and students who had gathered to listen to the presentations.

STERILE ENVIRONMENT: Plants cultivated in a CPUT laboratory in a nutrient medium.

The students recently visited plant tissue culture laboratory Frontier Labs in Brackenfell, which Horticulture BTech student Amanda Mahlungulu described as useful for giving them an idea of what the PTC industry is about.

“Normally when you grow plants, we know the conventional methods. He showed us how you can use technology and that something can come of it,” said Mahlungulu.

Fellow student Ngawethu Ngaka said they have found the industry visits very useful when they have to apply to do their in service training: “It makes it easier because you understand how the different organisations work.”

While Mahlungulu is interested in the concept, she knows that PTC is not yet so popular in South Africa that it would be easy to find a job in the field.

Reddy says the opportunities do exist: “It is up to the students to make themselves known.”

She says assigning the students to write the letter to the presidency and do a presentation to their fellow students and the CPUT community about their findings is one way to do just that.

Written by Theresa Smith

Tea could save indigenous plants

A specially formulated mushroom compost tea may just be what’s needed to save indigenous medicinal plants that are facing extinction.

Horticulturist Timothy Jasson, who heads up operations at the CPUT nursery, is currently exploring the effects of compost tea, which is a brew of compost extract and water, on the growth and nutritional value of the Siphonochilus aethiopicus, commonly known as Wild Ginger, and the Hypoxis hemerocallidea, which is referred to as the African Potato/Inkomfe.

The study is important in the South African context as both plant species are sought after for its medicinal properties and is widely used by traditional healers in the treatment of flu, cancer, headaches, asthma and various other ailments, says Jasson.

However, over-harvesting and a lack of cultivation of these medicinal plants to provide additional stocks have seen both plant species listed on the South African National Biodiversity Institute Red List of Threatened Species.

“These plants are extremely valuable and the demand will not decrease. That is why it’s important to find ways to conserve it,” he says.


Over the past two years Jasson has formulated and experimented with different compost tea brews in order to ascertain if it had any positive impact on these medicinal plants.

To produce the compost tea, compost is brewed in water to extract nutrients, in order to create a biologically rich feed for soil and plants.

“It’s like brewing a cup of tea,” says Jasson.

The finished product is then applied as a soil-drench for seedlings or is either sprayed directly onto plants or soil.

“One can have different formulations of compost tea and each produces a different result because of the nutrient content of that specific compost mixture. For example, mushroom compost tea consists of straw, chicken manure and spent mushroom mycelium extract and will produce a specific result. If I use a leaf waste, cow manure and general soil and brew that, I will get a different result,” he says.


Initial results of the study show that there are advantages to using mushroom compost tea in the cultivation of these medicinal plants. Advantages include an improvement in plant growth as a result of improving nutrient retention in the soil as well as protecting plant surfaces.

The study uncovered potential anti-oxidant activity in both medicinal plants, as a result of compost tea extract being stored in the bulb structures underground.

“Compost tea is linked to organic farming, where organic farmers/ growers attempt to reduce the reliance and cut out chemical fertilizers and their application in general commercial farming operations. Although genetic modification of plants can increase the yield, it can also in some cases reduce the nutrients. Organic farming attempts to create a complete seasonal organic sustainable nutrient cycle, with crops vs animals vs soil requirements vs harvest. This cycle restarts with direct seed sowing or planting for the new season”

Jasson says the Wild Ginger and African Potato plants are a complex species and more research in this area is needed.

Greenhouses go high-tech

Advanced automatic heating and cooling systems, sterile foot baths and automatic solar screens are just some of the impressive features of CPUT’s six new greenhouses.

With the finishing touches added late last year to the two research greenhouses, these high-tech greenhouses are set to open for business this month when students of the Department of Horticultural Sciences start their academic year.

Constructed at the nursery premises on the Bellville Campus, the greenhouses are a welcome addition to the department, which is the only in the Western Cape institution offering a course that focuses specifically on ornamental horticulture.

Head of programme, Dr Chris Daniels says the greenhouses will play a central role in practical teaching and learning activities and serve as the department’s laboratories.

“These are state of the art, world class facilities and all systems are on par with national and industry requirements” he says.

The greenhouses have automatic heating and cooling systems, rain water harvesting systems, artificial lighting systems, automatic solar screens, propagation systems and sterile foot baths.

Each greenhouse came at a price tag of just over R 700 000 with the biggest greenhouse measuring well over 270 square meters.

Daniels says each of the greenhouses have a specific function, with two dedicated for research, while the other four are being  utilised by undergraduate students for various propagation and cultivation processes.

The greenhouse in the courtyard of the design building is known as the display greenhouse and will specifically focus on plant identification. This greenhouse boasts four automatically independently controlled climatic zones and will display plants from different biomes in South Africa.

Daniels says one very important feature of all the greenhouses is the sterile foot baths at the entrances of each greenhouse.

“This will limit the spread of diseases by students and visitors into our greenhouses and teach students the importance of sanitation in horticulture. Greenhouses must be treated like laboratories and improper disease control can have serious negative impacts on plant production” he says.

“The Department of Horticultural Sciences is proud to have these state of the art world class facilities, to give our undergraduate and postgraduate students possibly the best horticultural experience in the country,” says Daniels.