Call to prioritise weed management
AS farmers race to make up for the time lost during the dry spell that characterised the first half of the 2023/24 season, it is crucial to make sure they manage weeds properly to avoid compromising their potential yields.
A recent post on X (formerly twitter) by the Agricultural Research and Development and Advisory Services (ARDAS) urged farmers to weed properly and timely management saying that would the desired plants had resources like water, sunlight and nutrients that they needed to grow. Weeding also helps prevent problems with pests and diseases to increase productivity.
“Put on the armour, get on to the battle field to fight against weeds,” urged the post.
ARDAS Mashonaland Central provincial director Mr Nhamo Mudada added that weeds were a significant component of the biotic constraints to agricultural production.
“Weeds are economically important on the significant losses they cause on crop yields apart from other pests in the form of pathogens, insects and animal pests,” he said.
He further observed that weeds not only competed with crops for essential resources such as sunlight, water, nutrients and space but also harboured pests that attack crops. The extent of damage caused by weeds depends on various factors that include type of the weeds, weed density, weed emergence time and the crops being grown.
Mr Mudada explained that the consequences of failing to control weeds could be disastrous as weeds like Striga spp can result in 100 percent yield loss. On average, depending on crop varieties, weeds cause 10 to 80 percent crop yield losses apart from being a nuisance on product quality and causing health and environmental hazards.
He urged farmers to combat weeds as a critical step towards achieving food security because by reducing grain losses due to weeds, there can be significant increase their grain production.
“To win the battle against weeds, it is essential to adopt integrated weed management (IWM) strategies that employ multiple tactics. These tactics include enhancing crop competitiveness through techniques such as crop rotations and reducing weed emergence by controlling weed seed populations.
“Various methods can be used to remove weeds. These are hoeing, use of cultivators and hand pulling. In orchards, thermal weed management techniques, such as direct flaming, solarisation and microwaves, can effectively to disrupt the physiological functions of weeds.
“Proper application of herbicides is an effective weed management approach. It is crucial to use correct application techniques, full herbicide rates, herbicide mixtures and herbicide rotations to reduce the risk of weed resistance,” he explained.
He also added that mulching can also be employed for weed management in smallholder farming systems. Mulch not only suppresses weed germination but also conserves moisture and reduces insect populations by removing the food sources for pests.
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