Plant Physician, Pesticides & Environment

Plant physician or plant doctor plays the same role for treating plant ailments, as a physician for treating human ailments. What a irony! No one asks the doctor as to why lots of chemical medicines are being prescribed? If the patient reports of insomnia like condition, the doctor prescribes sleeping pills. If the patient consumes more than the recommended dose, it becomes fatal? Are you not aware of fatality due to over-consumption of sleeping pills? Should we ban sleeping pills? Do medicines not have side effects? Yet the doctor will prescribe medicine and hardly in few cases recommend yoga, meditation and exercises depending upon the condition of the patients.

Same holds true for plant ailments too. Why so much of hue and cry against pesticides when these are recommended by plant doctor? Like medicines, pesticides are the handy tool in the hands of plant physician? He cannot practice without pesticides. It does not mean that in all eventuality pesticides need to be recommended as a matter of rule. When a farmer visits the plant doctor, he is first interested in saving the crop. And truly speaking at that moment of time only pesticide can offer some respite. The wisdom of the plant doctor lies in recommending safe eco-friendly pesticides. Most of the hazards are due to lack of wisdom and foresightedness of the doctor. I have no hesitation in expressing that many pest advisors are not well versed with so called Materia Medica of plant pests. It is worth mentioning that there are many recent generation pesticides which are effective in very small quantity and besides being effective and have least impact on biodiversity. We should be realistic and should not have blinkered vision and make unnecessary hue and cry against pesticides.

I am not against environmentalists, nor I am an advocate of pesticides, but discovery of pesticides might not have progressed after publication of Silent Spring by Rachel Carson in 1962. But it did not happen. Scarcity of food due to outbreaks of epiphytotics led to development of wide range of fungicides. Today we have specific fungicides which can control, downy mildew, powdery mildew and a variety of diseases as listed in the Table 1.  Bordeaux mixture, copper oxychloride, Sulphur discovered in 19th century still hold the ground. Discovery of dithiocarbamates as potent fungicides marked the beginning of second generation fungicides, which include very widely used fungicides like zineb and mancozeb. The other important fungicides considered to be part of 2nd generation are captan, captafol, dinocap etc. The first systemic fungicide carboxin and oxycarboxin made their debut in 1966 and marked the beginning of third generation fungicide. Carbendazim, a benzimdazole fungicide appeared two years later. Subsequently phenylamides, and fosetyl-Al aimed at controlling Oomycetous fungi were discovered. In spite of outbursts against pesticides by Rachel Carson in 1962 the process of discovery continued and unbelievable, effective and safer fungicides such as, SBIs,  MBIs (tricyclazole pyroquilon etc.), strobilurins etc. were developed. Today with the availability of relatively safe and effective fungicides of 4th generation including novel fungicides, most of the diseases can be effectively controlled and crop yields can be improved. While phenylamides and fosetyl-Al have revolutionized control of downy mildews and phytophthoras, SBIs have offered control of diverse group of fungi, MBIs to rice blast and strobilurins unusually wide array of crop diseases from all four classes of plant pathogens, namely the Ascomycetes, Basidiomycetes, Deuteromycetes and Oomycetes. In view of specifically effective fungicides, farmers do not want to take risk of going the other way.

Fungicides or for that purpose pesticides are poisonous entities and hence need to be used with caution and overdependence should be avoided, and greater emphasis should be laid on integrated pest management, what in common parlance is known as holistic control. But this is a system approach which needs to be planned and is to be practiced from sowing or planting stage, the same way as a child is nurtured. If this is followed in real earnest, pesticide usage can be minimized or avoided to save man and environment. It is for this reason, a knowledgeable practitioner always advises to avoid use of pesticides as for as possible as is evident from a prescription given below:

It is therefore concluded that pesticides are major component of management strategy, but need to be used with care and can be used in diseases outbreak, but otherwise as for as possible lay greater reliance on Integrated Pest Management for prevention of hazards to man and environment.

For more information, please contact Dr M. P. Srivastava,  E-mail : mpsrivastava28@gmail.com; Web portal: www.xsgrowth.com; Mobile: +91 98183 98655