NATIONAL CULTIVAR RECOMMENDATIONS FOR COTTON – 2019/20

Cotton cultivar recommendations are made by Cotton SA in conjunction with experts in the cotton industry. The cultivars recommended for the different areas are legally registered for planting in the RSA. In compiling the recommendations, the following aspects were taken into account:

- Yield
- Fibre length
- Fibre strength
- Micronaire
- Fibre percentage
- Good adaptability and tolerance to disease.

The recommendations were made after considering these factors per area. The regions are classified according to temperature and altitude. The recommendations per area include the following:

- Cultivars with acceptable potential
- Planting dates for each cultivar
- Optimal plant population per cultivar.

Dr. M.C. DIPPENAAR

Planting time

Irrigated cotton One of the most important factors determining the planting time for cotton is soil temperature. Cotton should not be planted before the top 30 mm of the soil has maintained a temperature of 16 to 18 °C or higher for approximately 10 days. This means that the second half of October to mid-November can be considered the best planting time for all the cotton-producing areas of the Republic. If the soil temperature is too low, germination is slow. Together with the severe incidence of seedling diseases ("damping-off") at low soil temperature, this causes a poor stand, which is one of the most important disadvantages of too early planting. With early planting there are advantages of higher yields and better fibre quality. Since red bollworm and red spider usually occur later in the season, these pests can be partially avoided. When ...

Dr. C. G. THERON

Temperature

Although cotton of origin is a tropical or sub-tropical plant, the majority of cotton is produced outside the tropics. The temperature factor is therefore of vital importance when considering areas suitable for economical cotton production. Yield and fibre quality are to a great extent determined by air temperature during the growing season. With a normal growing period of 200 days, the cotton plant requires a relatively high temperature over a long growing season. Temperatures under 20oC have a slowing down effect on the growth of the plant, especially during the flowering and boll phases. In practice, low temperatures just after planting time, when germination occurs, as well as low night temperatures during any stage of growing can be potentially harmful to the plant. To ensure good germination, the soil temperature in the seedbed should at least be 18oC. In ...