The Australian perennial fodder crop, Sorghum Silk was introduced to South Africa during the severe drought of the nineteen eighties.
It was first planted on a farm near Potchefstroom in 1984. In spite of the prelonged drought it performed well and has since gained considerable popularity.
This variety is similar to Columbus in appearance but has been considerably superior in trails in Australia. It is late flowering and has good resistance to leaf disease.
Its life expectancy varies from three to six years under normal conditions. It has been observed in Australia and South Africa that Silk is better adapted to heavier soils with a clay content of 205 and over. Silk has survived for up to ten years in Australia.
Silk performs best in subtropical areas of 400 to 900mm rainfall. Dry matter yields of 13 ton per ha have been recorded in field trials in the Western Traansvaal. It has been laboratory analyzed for feed value and found to have a protein content of 15& at the soft dough stage.
Ten years ago Advance Seed introduced Silk to South Africa. Today our company is the only local producer of basic seed and are therefore responsible for the maintenance of the genetic purity of the variety. Certified seed is produced from basic seed. This is done under strict supervision of SANSOR, resulting in better quality seed for the farmer.
Silk is easy to establish! Plant in rows approximately 100cm wide on a fine, well cultivated seed bed. The planting depth must not exceed 3cm. Planting can take place throughout the summer as long as care is taken to avoid extreme cool or hot periods.
The sowing rate is calculated according to the row-width. A sowing rate of 5kg per ha (100cm row-width) should result in a plant population of approximately 20 plants/m2. When broadcasting, the sowing rate should be approximately 20kg per ha. Maize and small grain planters can be used after the necessary adjustments have been made.
The fertilizer requirements of Silk are similar to that of maize. Failure to supply the plant with its nutritional requirements will have a reverse effect on its life span.
Silk stands up well to weed competition but in extreme cases chemical herbicide is recommended. Atrazine 2.4.D or Turbo is suitable for forage sorghums.
Delay grazing until plants are 60cm tall. Avoid grazing plants that are wilted by drought, heat or frost. Do not graze or cut to less than 15cm to stimulate better regrowth and improve conservation of the plant
Cut when in medium to hard dough stage for optimum yield and quality. Molasses can be added to supplement the energy content.
Drying of material can be a problem. Crush or crimp to speed curing. A high sowing rate will result in finer stems which would cure more rapidly. Best quality hay is produced when the crop is cut at the early flowering stage. Silk can be utilized for foggage as well.
Green chop plants before heads emerge to assure high quality forage.
Silk develops short underground rhizomes which give rise to erect shoots.