By Alani Janeke
Slugs and snails have eaten away thousands of hectares of young winter grain crops in the Southern Cape and Overberg in particular in the past few weeks, with farmers having to spend millions of rands buying tonnes of slug pellets.
Farmers in the Southern Cape and Overberg regions of the winter rainfall region are fighting a fierce battle against slugs and snails eating away at their young crops this year.
Rossouw Swart, Grain SA regional representative for the area from Swellendam to Mossel Bay, says greenhouse slugs and dune and tower snails – as they are commonly known – are causing major problems this year. The greenhouse slugs and tower snails are widespread, while the dune snail is found in areas closer to the coast.
Swart says farmers throughout his region are experiencing severe problems. As in previous years, gerbils are once again causing problems and damage in fields where they eat young crops.
“Some of the farmers are quite worried,” says Richard Krige, chairman of Grain SA who himself farms in the Overberg. “The snails and slugs are found all the way to the border of the Rooi Karoo.”
More than R21 million worth of snail pellets
Swart says according to a quick survey he conducted among companies selling snail and slug pellets in the Swellendam district, farmers have already purchased 370 tons of snail pellets worth about R21 million. He himself has had to replant 220 ha of canola due to snail and slug damage.
The snails and slugs mainly feed on canola and barley, and to a lesser extent wheat. The cost of planting canola, for example, is about R1 200/ha just for the seed, while snail and slug pellets cost about R460/ha.
“These are all additional costs on top of the input costs a farmer has already incurred to plant. But the biggest loss comes when you harvest and your yield is not what you planned or hoped for.”
Henk Aggenbach, a farmer from the Bredasdorp district, says snails and slugs are just as big a problem in this area. “No one has been spared. All you can do is put your head down and scatter slug and snail pellets.”
Aggenbach says before planting time arrived for him, they had already noticed the snails and slugs. “We had already started scattering slug and snail pellets before planting time. They delivered another load today. At least I haven’t had to replant any grains. The gerbils are also causing us problems.”
André Kirsten, a farmer from the Darling district in the Swartland, says because this region has experienced a dry summer, they are not experiencing problems with snails and slugs.
Problem worse than previous seasons
Swart says apart from ploughing or burning fields, there is no other way to combat the snails other than scattering slug and snail pellets. With farmers who have mostly already planted their crops, it is not desirable to plough or burn fields. This will also counteract the conservation agriculture practices that farmers in the Western Cape apply.
He says it is precisely these conservation agriculture practices and the fact that fewer farmers in the region keep livestock that are worsening the appearance of the snails and slugs. The snails and slugs thrive in a no-till environment and where farmers leave plant material on fields to conserve moisture and nitrogen in the soil.
According to Rossouw, the problem usually only occurs for a period of a few weeks to a month during planting time, until the winter grain plants are strong enough to continue growing when the snails feed on them.
Corné Louw, senior agricultural economist and head of member services at Grain SA, says according to feedback from farmers, the incidence of snails and slugs is exceptionally severe this year. Grain SA is conducting a survey among farmers to determine the extent of the problem. Farmers are asked to contact Louw (corne@grainsa.co.za) or Mike Ellis (mike@grainsa.co.za), manager of research coordination and the Nampo Academy at Grain SA, to participate in the survey.
