South African dairy farmers should start planting fodder radish to support and improve our milk production during the dry winter and spring. Locally bred varieties are perfect for our needs, and will improve milk production in the country, argues Patrick Rakau, a PhD candidate in crop science at the University of KwaZulu-Natal.
Fodder radish is an annual tuber crop with the shortest cycle among other vegetables and it belongs to Brassicaceae plant family. Despite it being used widely across the world as a supplement for livestock during winter, fodder radish is relatively underutilised in South Africa.
This underutilisation is very unfortunate because considering the strides that have been made towards the developing cultivars that were selected for flowering late in the dry season under the South Africa conditions.
To give a short history, the Agricultural Research Council (ARC) has been breeding and evaluating forages at Cedara Research Station in Pietermaritzburg for the past 70 years. Since 1993, this forage breeding and evaluation unit has been awarded Plant Breeders Rights (PBR) for 62 new forage cultivars of different forage species. Among the species that are targeted as the focus of breeding programmes at the ARC-API Cedara is fodder radish, often referred to as Japanese radish.
In the late 90s, several conventional fodder radish cultivars such as Samurai, Star 1650 and Star 1654 were released. These were followed by some soft-leaved fodder radish cultivars, like Sterling and Geisha and Lomo, a cultivar that was characterised by a red root.
While these varieties did well in the market, their full market potential was limited by the fact that they tend to go reproductive (flowering stage) early in spring and the bulbs start bolting (rotting) too soon. Efforts were later directed towards developing varieties with a large dual-purpose type with hairless, soft leaves and large, aboveground roots. Some of the leaves could be used even for human consumption.
Recent work looked at fodder radish with a longer growth duration and bulb quality retention. To achieve the latter, the ARC joined forces with a New Zealand Company called PGG Wrightson Seeds (PGGW). The ARC Cedara team top-crossed their radish cultivars Geisha and Sterling onto a very late-flowering fodder radish line supplied by PGGW and after about eight consecutive years of selection of individual plants displaying desirable traits and culling of those showing undesirable traits, a new variety was produced. This was called Endurance and is now inscribed in the South African Variety List.
Among the many good traits, Endurance only starts flowering approximately six weeks later than the above-mentioned varieties. This gives the farmer an extended grazing by over half the yield of conventional cultivars. Late flowering, hairless, biennial type traits in the newly bred cultivar and large productive bulb type are solutions to most dairy farmers for spring feeding.
Fodder radish is suitable for regions that receive more than 350mm per annum and thus could be planted in most parts of South Africa. It requires well-drained, fertile soils and is established in January or February. Dryland sowing rate is 3kg to 5kg per hectare and under irrigation 5kg to 7kg per hectare.
Other desirable features of Endurance include minimal ripening required, large bulb size that give a very high % of aboveground biomass that is highly palatable, drought and heat tolerant. Leaf retention, bulb keeping ability and yield potential is high and the leaves are smooth.
These are the reasons why we need to start planting fodder radish to support and improve our milk production during the dry winter and spring. This will improve milk production in the country.