Abrie de Wet recently won the Southern Cape Canola competition with a yield of 2,1t/ha and a gross income of R2 237/ha – at a time when many other farmers in the region suffered huge losses due to insects, heavy rains and weed problems. Abrie talks to Glenneis Erasmus about how he managed this.
Canola production is almost like raising a child, as it requires a huge amount of attention and time,” says thirty-something farmer Abrie De Wet, while trying to control his three preschool boys running excitedly around his sitting room. U nlike wheat and other grain crops, canola is very unforgiving. “You must do the right thing at the right time and you have to be alert at all times to prevent losses,” he elaborates. “Otherwise you won’t have success with canola.”
Getting results
Abrie’s success with canola on his farm Kwartelrivier, just outside Caledon in the southern Cape, proves that he knows what he’s talking about. While most producers in the area are still struggling to maintain production between 1,3t/ha to 1,5t/ha, Abrie won this year’s Cape Canola competition with a land that yielded an astronomical 2,1t/ha and a gross income of R2 237/ha. His long-term production average is around 1,8t/ha. Canola is a significant crop on Kwartelrivier and an essential part of Abrie’s crop rotation. His rotation programme currently consists of six years cash crops with consecutive years of wheat, barley, canola, wheat, barley, lupins or oats. Around 160ha of the 1 300ha sown each year is under canola. The cash crops are followed by six years of lucerne, primarily used as animal feed for Abrie’s 3 000-odd Dohne Merino sheep and 50 Hereford beef cattle. brie uses selected conservation farming methods. He doesn’t have a planter, but uses a pneumatic airseeder, and sows crops in crop residues from the previous year.
The ripping debate and weeds
Towards the end of February, before planting, Abrie slightly rips the soil as part of his soil preparation. “It’s true that most pure conservation farmers might frown on this practice, but loose soil is imperative for a good canola stand as canola has to penetrate the soil more deeply than other grain crops,” he explains. He adds that one year’s ripping every five or so years definitely isn’t going to destroy all the benefits gained through conservation farming methods. Charl van Rooyen of the Western Cape Department of Agriculture, who is also the organiser of the Southern Cape Canola competition, adds that instead of ripping, farmers can loosen the soil with the primary tooth of the planter, which can rip much deeper than they think. “The primary tooth can be set deeper than usual to loosen the soil,” explains Charl. “The tractor must have sufficient power to maintain the planting implement at the correct depth and required speed. The amount of power needed will be determined by the type of soil, water content and soil slope, as well as the weight of the planter implement.”
Ripping also has other advantages. It helps destroy eggs of pests that are usually located in the first 6cm of the soil, and loosens the weed seed bed, thereby encouraging weed seeds to germinate. Glyphosate is far more effective applied to weeds that are starting to show substantial leaf growth than to ungerminated weed seed. Abrie sprays glyphosate about two or three days before planting. Because he uses Thunder TT, which is triazine resistant, he can apply atrazine around four to six weeks after planting to further reduce weeds and eliminate competition between weeds and canola seedlings. Ryegrass is a particular problem.
Timely planting and sowing
Abrie firmly believes that success with canola can only be obtained by planting or sowing at the right time. “I always sow early – preferably after the first rains from 1 April right up to 20 April, but never after that, because it would result in uneven ripening,” he explains. “Sowing early also results in good plant establishment before June and July, when drought patches usually occur. I will sow in dry ground if it doesn’t rain before 20 April.” The importance of planting time is evident from results obtained by other producers in the Southern Cape Canola competition. Charl points out that most participants who planted before 20 April in 2007 achieved higher yields than those who planted later. Plant densities in this year’s competition varied from 2,25kg/ha to 4,8kg/ha. Abrie plants between 3kg/ha to 3,5kg/ha of canola seed at a depth of around 2cm. He has planted as little as 2,5kg/ha with good results in the past, but prefers planting around 3kg/ha. This provides a high enough plant density to suppress weeds, while still regulating competition between the canola plants. Planting low seed densities could be risky, as many plants may be lost due to unfavourable weather conditions, insects, diseases and so on. “Once plants start emerging and they’re too thinly spread, there’s nothing you can do to increase yield,” Abrie says.
Both Abrie and Charl complain about the difference in the seed sizes of cultivars as well as between years. “Because of variable seed sizes, the number of plants per hectare don’t have any correlation with the plant density,” says Charl. “A seed density of 3kg/ha yielded 80 plants per square metre at some farms, while only 30/m² were obtained on others at a seed density of 4kg/ha,” Charl says. He adds that while it’s true that this phenomenon can be attributed to various factors, variable seed sizes definitely have an impact and seeding companies could help reduce variability by indicating the thousand-kernel mass on seed bags, as is done with wheat. Abrie overcomes this problem by calibrating his sowing equipment more often to ensure the plant densities between cultivars remain constant.
Effective fertilisers and insecticides
Abrie treats seed with a Guacho and Soygro mixture before planting – the mixture helps to kick-start plant growth and suppresses diseases and insects, especially after the first two weeks after planting. “There has been a significant improvement in plant health and our yields since I started using this mixture in 2005,” Abrie says. Some 15kg/ha of phosphate and 30kg/ha of nitrogen is applied to fertilise the soil during planting. Another two nitrogen applications are administered: 30kg/ha around a month after plant emergence, and 20kg/ha during stem elongation. “Many producers apply a once-off treatment of 80kg/ha, but this is risky as high amounts of nitrogen can scorch seed,” explains Abrie. “Some of the nitrogen can also wash away with rain and become unavailable to the plants.” Abrie adds that all the nitrogen applied during planting is used for vegetative growth, while two later nitrogen applications help to ensure that some of it also goes into the pods. Abrie’s nitrogen fertiliser contains sulphur to address shortages. He doesn’t apply microelements during or after planting unless leaf analysis has proved there’s a shortage. The microelements he used in the past didn’t significantly improve yields or plant quality.
Insects can decimate a harvest, especially during the flowering stage. Abrie explains that aphids suck the juice out of the canola flowers, reducing the size of the pod or causing it to drop off. Farmers have to be alert at all times to prevent such losses. Abrie physically monitors the canola lands at least twice a week for insects, weeds and other problems. He sprays insecticides such as Dematox or Supermetrine if insect problems are observed, especially during the flowering stage. “You need to walk through the lands as problems can be isolated. A land might seem clean on the outskirts, but there could be a spot that’s severely infested,” Abrie explains.
Preventing shattering
Canola ripens unevenly and pods are prone to shatter. Abrie usually swathes his land after more than 70% of the grain has changed from green to brown. During swathing, pods are thrown into windrows and left to ripen for about three days before harvest. Canola is only harvested in cool, moist conditions at a moisture level of 11% to 12% to prevent pods from shattering. “Farmers can lose up to 40% of their yield if they harvest in dry conditions,” Abrie says. All Abrie’s canola is sold to SOIL, which is a canola oil processing company. “Canola production has always been like the stepchild of the grain industry as it doesn’t yield returns as high as wheat or barley, considering canola production’s high inputs and low yields,” Abrie says. “However, this year’s prices rendered canola just as profitable as barley and will definitely inspire farmers to plant more.” Contact Abrie De Wet on (028) 254 9756 or e-mail [email protected].
