Scientists practising in the agricultural sector have issued a rallying cry to the Federal Government, NGOs (Non Governmental Organisations), and farmers associations to interfere with immediate effect in the control of risky usage of corrosive agro-chemicals (especially herbicides), so as to minimize life threatening cases of water contamination and food poisoning in the country.
In reaction to the recent disturbing concerns over the effects of chemicals on foods coming from pests preventive cultivation system and safety of the foods for human consumption, an extension specialist and Regional Coordinator of Bill and Melinda Gates Foundation-sponsored Cassava, Professor Kolawole Adebayo cited Adding Value for Africa (C:AVA), as he talked about dangers inherent in the indiscriminate use of herbicides.
He warned that when herbicides are overused on agricultural farmlands, as they have implications for farm productivity and quality of farm products. The implications he talked about may be positive or negative.
He said one of the major reasons why farmers consistently make use of herbicides is to cut down weeding costs and achieve better returns in terms of profits on farm investments.
He pointed out that where herbicides are properly used, following specific instructions and guidelines for safe use, problems to human health and natural ecology are usually contained. “Problems arise,” Prof. Adebayo added, “with misuse of herbicides. Wrong use, use of wrong dosages, non-adherence to prescriptions, among others, make chemicals to become adverse factors in the environment and the food systems.”
Prof. Adebayo also explained that diseases of the internal organs or even tumors of varying dimensions had been as a result of indiscriminate and wrong usage of herbicides which have a negative effect on local ecosystems and when these chemicals find their ways into water bodies.
On the other hand, Adeniyi Aremu, the Managing Director of the Lower Niger River Basin Development Authority, Ilorin, in Kwara State said humans warned that humans who expose themselves to herbicides through oral, skin, eye contacts or inhalation are faced with the danger of being victims of eye problem, respiratory damage, irritation, fatigue, vomiting, skin problems, dizziness, cancer, and severe damage to body’s immunity system.
“Herbicides also contaminate surface and ground water through runoff, spills, leakages and leaching,” Aremu added, saying, “In soil ecosystems, herbicides disrupt natural processes within the soil structure by killing some soil micro flora, altering biochemical processes and reducing microbial activities.”
An Ilorin based land preparation specialist and agricultural business consultant further gave an enlightenment on the classification and the application of herbicides, stating that the effect of herbicides on ecosystems and human health could not be overemphasized, especially in rural areas in dere need of education and technical competence in handling them.
Ayodele shared similar notions with Aremu also stressing that poor handling and use of herbicides could get humans prone to be faced with several dangers ranging from ill health, contamination of water bodies and undue accumulation of salts in the soil. Therefore, it is necessary for farmers to be properly trained on safe handling and appropriate application of herbicides to avoid misuse and death.
Noting that herbicides are toxic chemicals used in the control of weed, there are several classifications that should be reckoned with such as selectiveness, non-selectiveness, post-emergence or pre-emergence.
Selective herbicides are used for weed control where crops are unaffected but weeds are wiped out. A chemical that is maize-selective, for example, would destroy all other weeds except the grass family, which maize belongs. Maize-like grasses would also be spared in this case. Non-selective herbicides wipe off both crops and weeds.
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Pre-emergence herbicides are sprayed after land preparation and planting but before the seeds and weeds germinate. Some pre-emergence herbicides are sprayed on prepared land before the seeds or crops are planted or transplanted to retard emergence of weeds. Post-emergence herbicides, on the other hand, is applied after the weeds and seeds/plants have emerged. Selective post-emergence herbicides will, therefore, leave the seedlings or crops undamaged, while the weeds would be wiped out.
Stressing further, Ayodele talked about four major routes through which herbicides reach usable water. He firstly stated the possibility of the herbicides drifting outside of the intended area when it is sprayed; it may percolate, or leach through the soil; it may be carried to the water as runoff, or it may be spilled accidentally or through neglect caused by poor knowledge of use and handling.
However, different organic researchers hawe proven that the practice of organic agriculture was the answer to many challenges associated with synthetic agriculture, as they’ve persistently waved away misconceptions about organic agriculture with a scientific proof that the it does not mean you cannot use fertiliser, high-yielding varieties or insecticides.
Moreover, what organic agriculture promotes is the encouragement of agriculturists to use organic fertiliser, pesticides, and improved seeds that have been done in natural ways.