How to control kweekgras in croplands

Couch grass, commonly known as kweekgras, can rapidly take over a land, leading to serious crop losses. Here’s how to beat this weed.

Cynodon dactylon (couch grass, more commonly known in South Africa by its Afrikaans name, kweekgras) is a creeping perennial weed that spreads mainly through runners on the ground (stolons) and rhizomes below the surface. Approximately 85% of the rhizomes are located in the top 20cm of the soil, and a few will be found deeper than 30cm.

When temperatures start increasing in spring, new runners grow longer and new shoots (stems) sprout. Seeds start germinating when daily temperatures rise above 18°C. In summer, the weed grows laterally in concentric circles from the original rhizome. Significant growth takes place at temperatures above 24°C, while maximum growth rates occur at 38°C.

Seeds can survive and remain vigorous under field conditions for three to four years.

Kweekgras grows better in heavier clay soils than in sandy soils in dry regions. It can also survive long periods of waterlogged conditions.

Although it can grow in a wide range of pH soils, it tolerates alkaline soils better than acid soils. Applying lime to soil with a pH of 5,5 promotes growth of the weed.