A couple of weeks ago I went to visit our friends at York Timbers, an industry partner of the Tree Protection Co-operative Programme (TPCP). This was my first field trip as the new TPCP Field Extension Officer or Plant Doctor on call (something I hope catches on). As an extension officer, I am the intermediary between the research and our foresters. I operate as a facilitator and communicator, providing foresters with the appropriate knowledge to assist in their decision-making so that they obtain the best results.
I have worked alongside the South African forestry industry for almost ten years; most of that time I spent working as the manager of the TPCP plant or diagnostic clinic (plants get sick too). Over the last decade, I have seen a great deal of change in the industry; especially in the way they breed, plant and utilize trees. Today, they understand – even more – the importance of keeping trees healthy; the result of a nearly thirty year old relationship with the TPCP. A tremendous amount of work, time and money has been poured into this partnership to better understand the pests and pathogens that threaten tree health.
Progress towards growing healthier plants is advancing all the time; not only in our research at the TPCP but also within the industry. During my visit to York, I was pleasantly surprised to find that their nursery is being upgraded; upgrades that will significantly improve both the quality and quantity of plants they produce. Designed with ergonomics, efficiency and plant health in mind, this is a major leap toward producing healthier trees and a welcome change for the company and industry.
Progress does not happen without trial and error and for our forestry industry there are many trials. The main purpose of this trip was to help York figure out why some of their newly established pines were dying. Among the sites affected there were trials established to investigate the feasibility of a new plant insert/pot. Trees, whether they were produced in these new inserts or not, were dying.
Our visit to the nursery prior to our field visit was the first step in figuring out where the problems might have originated. The cuttings being produced in the nursery looked healthy; however, after spending a few months in the ground, the picture changed. The newly established cuttings started showing symptoms of wilt and root rot and, within in a couple of weeks, began to die. This is a serious problem that appears to have no answer as yet.
At the time of our visit, the TPCP hadn’t confirmed whether or not a pathogen was involved, which led to a discussion with the foresters and breeders about the other factors that could cause these trees to die. We discussed weather conditions, site quality, planting preparation, planting operation and cutting quality and agreed that a combination of these factors are likely to blame for the unusually high mortality. The hunt continues.
After a day of pathogen hunting with York, we turned our attention eastwards to one of the most iconic mountain passes in the Mpumalanga province, the Long Tom Pass. Here we would be hunting for a different kind of organism; a group of bacteria that help black wattle (Acacia mearnsii) grow here. This pass gets its name from the Long Tom cannons used during the Anglo-Boer war and , like the cannons, was quite dangerous for early pioneer wagon drivers that used the pass to transport goods from Mozambique to Lydenburg. Today, the pass is tarred, safe and quite popular amongst tourists looking to climb up the Drakensberg escarpment. The pass cuts between a number of beautiful nature reserves and gives travelers a bird’s-eye view of some of South Africa’s incredible landscapes… or a place for scientists to collect some samples.
Black wattle was introduced into South Africa from Australia for its timber and natural tannin production. Since the early 20th century, the amount of black wattle planted across South Africa has decreased. Outside of wattle plantations, you will often find clumps of these trees that have escaped and found refuge along roadsides, national parks and velds all over South Africa. Acacia mearnsii is considered a weed outside of its native range because of how fast it grows, how quickly it adapts, and how easily it replaces naturally occuring flora.
Where some see a problem, there is a solution.
Its ability to rapidly colonize different areas and soil types comes from a relationship that exists between the tree’s roots and the bacteria we are hunting. These bacteria are able to fix nitrogen which enables trees, such as black wattle, to grow in nitrogen poor soils. Studying these organisms has many benefits; for example, we could develop an agricultural product using the bacteria that will help reduce a farmers dependence on expensive nitrogen-based fertilizers. Now, we just need to find them.
My position within the TPCP as the doctor on call is quite special as it allows me to do something that is crucial for our relationship with industry, government and society; I get to interact. Every time I go to the field, I take a wealth of new knowledge and understanding with me – information that has been generated through our research and collaborative networks – so that I can share it with our stakeholders. In return, we learn where our efforts are helping; where we need to do more; and where we need to start.
Keeping plants healthy, whether it is in forestry, agriculture or in our national parks, is in everyone’s best interest. The threat to plant health from climate change and our increased dependence on healthy plants and their products to sustain a growing population has presented us with a number of challenges that may leave some perplexed; however, we needn’t fear because a doctor (many, actually) is near. Scientists, both locally and internationally, are continuously making strides toward overcoming these challenges. Together, with industry, society and government, we can leave a world future generations would be proud of.
Loosely Translated 
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