Rainy weather may delay frost but slow crop maturity

By Alani Janeke

Initial forecasts suggested that the first frost of the season could occur around mid-April, but the persistent wet conditions across parts of the summer rainfall region may act as a buffer against early frost.

Weather models now indicate that parts of the summer rainfall region may get almost daily rainfall until  20 April. While earlier predictions pointed to the possibility of frost from mid-April onwards, current conditions tell a different story.

“The rain and cloud cover predicted for the coming weeks will reduce daytime temperatures, but they will also help to prevent extreme overnight cooling,” says independent agricultural meteorologist Johan van den Berg. “Minimum temperatures in April are not expected to drop to freezing. It’s more likely that real cold will set in only from May, once the rainy weather clears.”

The real concern, Van den Berg says, is that limited sunshine and low temperatures can slow down crop growth and development. Many of the late plantings have not yet reached maturity, and there will be very few heat units available during most of April, especially in Mpumalanga and the Eastern Free State.

Danie Bester, a farmer from the Balfour district in Mpumalanga, says they are hoping for another three to four weeks of warmer days and sufficient heat units before the cold sets in to ensure a good maize harvest, as they only planted very late in the season. 

Making hay before winter

The wet conditions are also creating challenges for farmers who need to bale livestock feed before winter sets in. Crops such as teff, lucerne and cowpea require at least five to seven consecutive days of warm, dry weather with full sun to dry properly before they can be baled for feed.

Van den Berg says the persistent wet conditions and high humidity will significantly extend the drying period. “It doesn’t look like there will be a suitable window for making hay before at least 10 April in the western parts, in the region of Jacobsdal, Douglas and Vaalharts. In the central to eastern parts of the country, it will likely only be possible in the final week or last 10 days of April.”

This delay could cause further difficulties for farmers hoping to get in another round of baling before the onset of winter.

Also read:

• Chances slim for an overly wet harvest period

• Above-normal autumn rainfall, dry winter forecast for parts of SA