Chemical-free ways of wiping out 'witch weed' from farms

Farmers are losing more than 80 per cent of their crops before harvest to deadly striga weed, which is attacking multiple crops yet here are simple non-chemical ways of dealing with it.

Striga, which is nickname ‘witch weed’ attacks rice, maize, millet, sorghum, among other crops in most parts of Rift Valley, Western, Nyanza , Central and Eastern.

This weed is parasitic and it creeps into the holes during planting. The weed is thin, but highly destructive.

Tillage

The weed attacks the root system of the crops and extracts moisture and minerals. This leads to poor development and eventual death due to malnutrition, Caleb Adede of African Agricultural Technology Foundation (AATF) says.

Minimum tillage is one of the leading ways of deadline with this weed. It involves sowing without digging after the previous harvest.

Minimum tillage gives limited disturbance to the soil besides reducing chances of multiple seed germination.

Minimum tillage also reduces soil moisture loss. Dismal or no rain soon after planting does not threaten the crop at its tender age.

At the same time, sufficient moisture gives rise to strong seedlings which can resists impacts of the weed, according to Access Agriculture.

Rotation and intercropping

Crop rotating and intercropping methods would help in reorganising the growing pattern to ensure propagation of less vulnerable crops with susceptible ones. In this case, maize can be grown in one season and be intercropped with legumes such as cow peas, mukuna and other cover crops.

Cover crops not only smoother the weeds when grown with maize which is tall, but also reduce sunlight penetration into the stem and floor areas of the field, therefore, limiting synthesis of food in the weed, leading to death.

Cover crops, being leafy, would increase soil’s fertility after harvesting following decay of the heavy biomass.

If the cover crops manage to smoother most of the weeds before maturity, this would also break the reproduction cycle. Repeated practice would eventually lead to dying out of the witch weed.

Resistant varieties

Use of resistant varieties is a short-lived effective reprieve for farmers. The weed will continue multiplying and affecting vulnerable crops which may not have alternative resistant varieties.

Rice growers can adopt Nerica 2, 3, 4, 8 and 10 varieties, which are highly resistant to the witch. Nerica 5, 9 and 17 are moderately resistant.

For maize, Imazapry Resistant variety can help farmers dodge this deadly witch.