Current heat wave will be devastating to agricultural yield – MUT Agriculture expert

Dr Eric Mthembu

An Agriculture expert at MUT pointed out that the recent heatwave will have more dire consequences on agricultural yield. Dr Eric Mthembu, the Head of the Department of Agriculture, has pointed out that the heat wave has started “ravaging” plants and livestock, and will “continue to have devastating effects on plants and animal productivity”.

Dr Mthembu said it was because high temperatures have negative effects on various production factors.

“It is important to remember that physical and chemical processes are controlled by temperatures which in turn control biological reactions in plants and animals,” said Dr Mthembu.

He added that heat stress from high temperatures suppressed seed germination. Dr Mthembu said the plants that will mostly be affected are those that are planted at this time of the year. He added that it was important to remember that most of the small-hold farmers plant dry beans in January, which is the second part of the growing season.

“Therefore, the heat wave will have a negative impact on legume productivity such as dry beans, a staple food crop,” said Dr Mthembu.

Dr Mthembu added that high temperatures negatively affect pollen viability and silks receptivity, leading to a high reduction in maize yield and grain quality.

Livestock are also affected by heat. He said the heat waves arising from current high temperatures reduce production in livestock and their reproductive performance, and that feed intake was reduced because of heat stress experienced by animals. This reduction in feed intake results in poor growth rates in animals.

“Heat stress might cause high mortality rates leading to income losses by farmers,” he said.

Dr Mthembu said the heat wave has persisted for more than 10 days and is a “clear indication that climate change” arising from global warming was real. Climate change through rainfall variability patterns (such as 2022 flooding in various parts of South Africa) and current high temperatures, poses great threats to South Africa’s food security and is catastrophic to the country’s ecosystems and humans.