Mysterious tree disease of the 70s and 80s unmasked
Farmer's Weekly|November 17, 2023
A mystery disease hit South Africa's pine trees 40 years ago. New DNA technology has found the killer, say Andi Wilson, postdoctoral fellow at the University of Pretoria, Brenda Wingfield, previous vice-president of the Academy of Science of South Africa and DSI-NRF SARChI chair in Fungal Genomics and professor of genetics at the University of Pretoria (UP), and Prof Michael John Wingfield, adviser to the executive at UP.
Mysterious tree disease of the 70s and 80s unmasked

In the 1970s and 1980s, pine trees growing in various forestry plantations in the Western Cape began to die in patches. These trees succumbed to a mysterious root disease and the patches expanded gradually. Spontaneous regrowth of seedlings in the patches died dramatically.

As in many other true-crime dramas, the finger was initially pointed at the most likely suspect: the root-infecting Phytophthora cinnamomi. Its name – plant (phyto) destroyer (phthora) – reveals its power to cause harm; the pathogen is known to cause disease in almost 5 000 different plants.

After further investigation and the collection of many samples, tree pathologists shifted the blame onto the fungus Leptographium serpens (now known as Leptographium alacre). This fungus is well known to be transported by insects and was previously only known in Europe. It was visually identified from the roots of the dying trees. Now it was the prime suspect.

Doubts lingered, though. Most Leptographium species are not known to act as primary disease agents and so L. serpens was most likely not able to cause the disease. Other fungi were also found within the roots of the diseased trees but could not be identified at the time due to a lack of more advanced techniques.

Knowing that the then-available technologies could not provide the complete answer to this mystery, the pathologists took more samples from the dead and dying pine trees, and stored them carefully. The hope was that one day they would have a better idea of the cause of this disease outbreak.

هذه القصة مأخوذة من طبعة November 17, 2023 من Farmer's Weekly.

ابدأ النسخة التجريبية المجانية من Magzter GOLD لمدة 7 أيام للوصول إلى آلاف القصص المتميزة المنسقة وأكثر من 9,000 مجلة وصحيفة.

هذه القصة مأخوذة من طبعة November 17, 2023 من Farmer's Weekly.

ابدأ النسخة التجريبية المجانية من Magzter GOLD لمدة 7 أيام للوصول إلى آلاف القصص المتميزة المنسقة وأكثر من 9,000 مجلة وصحيفة.

المزيد من القصص من FARMER'S WEEKLY مشاهدة الكل
Syngenta Seedcare celebrates a decade of innovation
Farmer's Weekly

Syngenta Seedcare celebrates a decade of innovation

Syngenta's ambition is to enable their customers' investments to grow in healthy soil from treated seeds to young plants through innovation and collaboration, writes Magda du Toit.

time-read
3 mins  |
November 22, 2024
Agri workers shine at Western Cape awards
Farmer's Weekly

Agri workers shine at Western Cape awards

Lindie-Alet van Staden, a garden and olive orchard manager at L’Ormarins Wine Estate in Franschhoek, was crowned as the Western Cape Prestige Agri-Worker of 2024 at a gala event recently held near Paarl.

time-read
1 min  |
November 22, 2024
Small and large farmers recognised at grain awards
Farmer's Weekly

Small and large farmers recognised at grain awards

The annual Grain SA/Syngenta awards ceremony bears testimony to the quality of farmers in the grain industry.

time-read
1 min  |
November 22, 2024
Growing partnerships: Fedgroup's flexible and innovative approach
Farmer's Weekly

Growing partnerships: Fedgroup's flexible and innovative approach

Janine Ryan spoke to Warren Winchester, general manager of impact investing at Fedgroup, about why the company became involved in agriculture, and what it offers farmers and their immediate communities.

time-read
6 mins  |
November 22, 2024
Why fish farms fail, and how to avoid becoming a statistic
Farmer's Weekly

Why fish farms fail, and how to avoid becoming a statistic

The popularity of launching fish farms is not matched by their success. Leslie Ter Morshuizen, owner of Aquaculture Solutions, explores the factors that cause most of these businesses to go under.

time-read
3 mins  |
November 22, 2024
Where history and modernity meet in a luxurious setting
Farmer's Weekly

Where history and modernity meet in a luxurious setting

Brian Berkman kept his eyes peeled for ghosts in the oldest continuously run hotel in South Africa, but all he found was a fabulous two-night stay.

time-read
4 mins  |
November 22, 2024
THE HITCHING POST
Farmer's Weekly

THE HITCHING POST

I'm a stylish elderly lady with a radiant glow and a good sense of humour that keeps me young at heart.

time-read
2 mins  |
November 22, 2024
Cutworms: check the weeds on your fields!
Farmer's Weekly

Cutworms: check the weeds on your fields!

Zunel van Eeden explains why understanding the ecological interplay between cutworms and weeds is crucial for effective pest management. Producers should disrupt the life cycle of cutworms to minimise crop damage.

time-read
5 mins  |
November 22, 2024
Does high-density grazing mimic grazing patterns of game?
Farmer's Weekly

Does high-density grazing mimic grazing patterns of game?

In their paper on high-density grazing in Southern Africa, professors Angelinus Franke and Elmarie Kotzé from the Department of Soil, Crop and Climate Sciences at the University of the Free State say high-density grazing systems may not accurately reflect natural ecosystems. Roelof Bezuidenhout reports.

time-read
5 mins  |
November 22, 2024
Global grain outlook: 2024/25 marketing season
Farmer's Weekly

Global grain outlook: 2024/25 marketing season

In its latest summer crops report, the Crop Estimates Committee says South African farmers intend to plant 4,47 million hectares of summer grains and oilseeds in the 2024/25 season, up 1% from the previous season. As South Africa exports maize and soya bean, Annelie Coleman reports on the latest trends in the international grain and oilseed markets, amid fluctuations in weather conditions and ongoing armed conflicts.

time-read
5 mins  |
November 22, 2024