Mangos, oranges and avocados. It’s the way these fruits, and others, have been growing that could be the vital puzzle pieces for a team of local scientists gauging how climate change is affecting South Africa’s crops.
But to do that, the Ndlovu Node of the SA Environmental Observation Network (Saeon) and Wits University are asking the public to help them go “backwards in time” by providing them with treasured agricultural records to better understand the impact of climate change on the agricultural sector.
Their objective is to compare crop production data, including bud opening dates, full flowering dates, full or partial petal drop rates, spraying dates, harvest dates and yield data, with temperature and precipitation records across southern Africa in recent decades to determine what impact climate change is having on the timing and success of the various reproductive stages, termed phenophases, of crop production and on the eventual yields.
Dr Dave Thompson, a biodiversity scientist at Saeon’s Ndlovu Node, hopes the crop production data gleaned from farmers will encompass at least the past 20 years.
“Obviously, the longer the data record, the more useful it is as a piece of this puzzle.”
Drought, unseasonal cold spells and extreme temperatures all negatively affect farmers, a picture that could be worsened by predicted temperature increases from climate change of between two to four degrees.
“The overall impression is that agriculture as a whole will suffer as global temperatures continue to rise… Africa as a whole could suffer from as much as a 17 percent reduction in agricultural output potential by 2080.”
The researchers say it’s important to understand how climate change can act to reduce yield and profit in agriculture. But the problem is that the current understanding is based mainly on studies undertaken in Europe, with little known about the effect climate change is having on African and southern African crops.
Professor Stefan Grab of the School of Geography, Archaeology and Environmental Studies at Wits, who specialises in climate change, attributes this to poor record-keeping.
Depending on the crop and the severity of the changes in climate, the worst-case scenario will be outright plant death.
“However, the more likely consequences will be more subtle and could include, among others, changes in flowering times, failure to open buds, skewed gender ratios, and inhibited or delayed maturation,” says Grab.
Farmers need to be open to the possibility of planting alternative crops, more suited to the “new environment”.
Grab adds: “Farmers are aware of climate change, but they may not always be aware of the extent to which climate change is impacting on their crops.”
If you can help, contact Thompson at [email protected] - The Independent on Saturday