What are pesticide and how does they work?
Ans. Pesticide are the toxic chemicals that are used to control any pest population through their contact systemic or gasseous (fumigant) action. They are used for preventive or corrective purpose and are classified into various groups on the basis of hazards e.g. extremely highly, moderately and shortly hazardous. Moreover, pesticides are classified are OC, OP, Carbamate, Pyrethroids on the basis of chemical structure.
Are there any ill hazards of pesticide application on human and environment?
Ans. Pesticides are classified according to either toxicity level into various groups. All the pesticides are toxic and their application is required to be carried out following the recommendation of manufacturers. Over dosing of pesticides in any crop may result into severe health hazards like disturbance of CNS, disordering reproductive system and produce cancer. Poisoning may be due to direct exposure of through food chain (indirect exposure) followed by medical symptoms like nausea, vomiting, headache and unconsciousness. Extensive, ill planned and improperly applied pesticides cause soil & water contamination ad air pollution.
What is the toxicity level of insecticides?
Ans. The nature of toxicity of different pesticides vary from each other. Some of them are cancer producing, others are liver damaging or nervous poisons. The toxicity level of various pesticides is different for various crops and the environment. International bodies have set Maximum Residue Level (MRL) for various pesticides on various commodities. Residue beyond these limits is not acceptable and may result on health and environmental problems.
How can we ensure that the sprays are carried out properly?
Ans. The spray should be carried out keeping in view the dose recommended by the manufacturer. The spray equipment must not be substandard and the nosels calibrated for spraying. Frequent spraying and the use of same pesticide for consequent sprays should be avoided as much as possible.
What are the other precautions of spray?
Ans. Spray should not be carried out by untrained personnel. The applicator must ensure his protection by using necessary tools viz. gloves/masks etc. Spray should be done on target material and keeping in view the air direction to apply it on specific area and also to protect the environment.
What is PARC’s role in pesticide research?
Ans. PARC is playing a key role in pesticide research through development of application techniques and its extensive research to determine the pesticide residues in agricultural products and the environment. By now thousand of samples have been analyzed for pesticide residues in fruits, vegetables, human blood and the environment.
What are the common diseases of Melon in Sindh and how it can be controlled?
Ans. Root rot and wilt disease capable of destroying 40-50% crop. Two species of Fusarium viz. F. oxysporum Schlelt. and F. solani (Mert.) Sacc., Macrophomina phaseolina (Tassi) Goid. and Rhizoctonia solani are responsible for these economically important diseases of melon in Sindh. Because of the persistence of the pathogen in soil, the disease is very difficult to manage. The most commonly grown cultivars are not resistant to root rot and wilt disease complex. These soil-borne root infecting fungi have a wide host range in Pakistan. Macrophomina phaseolina is reported to produce charcoal rot, seedling blight, root rot, stem rot and pod rot on more than 72 hosts. Rhizoctonia solani exist as active mycelium in soil, 63 hosts have been reported to produce seed rot, damping off of seedling, wilt and root rot. Fusarium solani andF. oxysporum are common in agriculture fields and cause root rot, stem rot and wilt disease.
Symptom complexes included vascular wilt, dead and drying vine, dry collar and root rot, cortical collar and root necrosis, yellow stunt, longitudinal splitting and oozing of brownish at the collar region.
To control root rot and wilt in melon seed treatment with 0.2% Baytan, Cake (2 ton/hec) prior sowing and soil drenching with Carbendazim (125 gm/hec) twice an interval of 25 days after fruit setting to harvesting is most effective for combat root infecting fungi viz. Fusarium solani, F. oxysporum, Macrophomina phaseolina and Rhizoctonia solani.