Tissue Culture – strategic step forward

By Elise-Marie Steenkamp

Five years ago, there was a shortage of difficult-to-root rootstocks and a need to improve the quality and health status of trees in the pome and stone fruit industries. Tissue culture (TC) provided a solution to addressing this need.  This led to a process to land a technology in the industry to raise the level and selection of rootstocks available to the South African grower.

Since then, many things have changed in the world and there were many challenges for the Tissue Culture Facility (TCF) that was launched in 2020. It was still a strategic step forward and has developed as a centre of excellence with know-how and a well-equipped facility to serve to industry in the future. Last year an accredited TC quarantine facility was also added to facilitate the importation of plant material.

TCF’s main purpose is to ensure clean high-quality rootstocks, and uniform plant material, and to make it readily available to the industry at a cost-effective price.

At a recent information day, attended by more than 100 stakeholders, Anton Rabe, TCF Chairperson said: “Things are currently tough, but I believe the industry is on the verge of a new growth phase.

“Yes, we have many industry challenges such as problems at our harbours and we need to open more markets, but the fact remains that tissue culture, done correctly, offers clean plant material without phytosanitary risks.”

Rabe said that nurseries were industry allies and important portals to ensure quality, clean plant material. “There is huge growth potential at TCF, and we need commercial participation. It is heartening to see so many interested people here today. Let’s unlock this potential.”

Kootjie Viljoen, a deciduous fruit grower from Greyton, who has experience with tissue culture apple rootstocks, said that quality plant material, specifically rootstocks. “I am a grower and a businessman. So, I asked myself, what do I have to do to make my investment work for me? In pome fruit, profit is high-class pack outs.”

Viljoen said that tissue culture has a role to play. “There are many building blocks in the makings of a successful orchard – rootstocks are one of the puzzle pieces. Yet, it is the one thing that is often overlooked. The selection of a rootstock is extremely important.”

Viljoen said that he decided to invest in tissue culture rootstocks and has seen marked differences compared with conventional plantings. “We had lower mortality rates, better uniformity, and better young tree growth. Of course, this has not been tested scientifically, but it is my observation.”

A key driver for Viljoen was to get clean plant material. If you planted 2000 trees per hectare at a cost of between R30 000 to R40 000 extra per hectare, it translates into 3 – 4% of the total establishment cost. “Was it worth it to use TC rootstocks? From what we have seen thus far, yes it was. Are we making money earlier? Yes, we are. We are earlier in production.”

Viljoen pointed out that many factors play a role in making an excellent orchard and every grower must decide for him/herself. “For me, TC is the way to go.”

Hortgro Technical General Manager, Hugh Campbell, said tissue culture forms part of a risk management strategy of ensuring that one starts and ends with clean planting material.  As shown in the presentations of Dr Nigel Cook and Frederick Voigt, virus-infected material reduces the yield and growth of trees – particularly in the early stages of development.  This, in turn, impacts the cumulative yield and profitability of an orchard.

• If you are interested in the presentations or TCF, please contact: Charmaine Stander at charmaine@tissue-culture.co.za or Leander Gagiano at leander@tissue-culture.co.za

Caption: Charmaine Stander, Dr Nigel Cook, Hugh Campbell, Rachel Kriel, Frederick Voigt, Prof Lizel Mostert and Kootjie Viljoen