pesticide calculation and the methods to handle them

pesticides calculations

1. Pesticide Calculations

2. Formula : N 1 V 1 = N 2 V 2 N 1 : Concentration of commercial formulation in percent or grams N 2 : Desired concentration of spray fluid in percent V 1 : Volume or amount of commercial formulation required in milliliter or grams (desired) V 2 : Volume or amount of spray fluid required (In milliliter) (recommended dose ) Note : The above formula is used only to calculate the formulations like EC,SL,SC or WP

3. Problems: 1. How much quantity of Chlorpyriphos 20EC required to spray @0.05 % for control of yellow stem borer in paddy and the spray fluid recommended for spraying is 150 l/ha.

4. Problems: 1. How much quantity of Chlorpyriphos 20EC required to spray @0.05 % for control of yellow stem borer in paddy and the spray fluid recommended for spraying is 150 l/ha. Solution Given N 1 = 20% N 2 = 0.05 % V 1 = ? V 2 = 150 l/ha (150 *1000= 1,50,000ml) i.e 1litre = 1000 ml Formula N 1 V 1 = N 2 V 2 V 1 = N 2 V 2 / N 1 = 0.05 *1,50,000/ 20 = 375 ml

5. 2. How much quantity of Indoxacarb 14.5 SC for one acre required to spray @0.02 % for control of Helicoverpa armigera in cotton and the spray fluid recommended for spraying is 200 l/ha.

6. 2. How much quantity of Indoxacarb 14.5 SC for one acre required to spray @0.02 % for control of Helicoverpa armigera in cotton and the spray fluid recommended for spraying is 200 l/ha. Solution Given N1 = 14.5% N2 = 0.02 % V1 = ? V2 = 200 l/ha (1 ha = 2.5 acre; 200/2.5 = 80 l/ha; 80 *1000 = 80,000 ml) Formula N1 V1 = N2 V2 V1 = N2 V2 / N1 = 0.02 *80,000/ 14.5 = 110.34 ml

7. 3. Monocrotophos 36SL is recommended to control aphid in cotton measured 250 ml and is added to 125 litres of water spray fluid. Calculate the percentage concentration of the insecticide in the spray fluid

8. 3. Monocrotophos 36SL is recommended to control aphid in cotton measured 250 ml and is added to 125 litres of water spray fluid. Calculate the percentage concentration of the insecticide in the spray fluid Solution Given N 1 = 36% N 2 = ? V 1 = 250ml V 2 = 125L (125 *1000= 1,25,000 ml) Formula N 1 V 1 = N 2 V 2 N 2 = N 1 V 1 / V 2 = 36 *250/ 125000 = 0.072%

9. 4. How much spray fluid of 0.5% concentration can be prepared from 300 gram of malathion 25 WP?

10. 4. How much spray fluid of 0.5% concentration can be prepared from 300 gram of malathion 25 WP? Solution Given N 1 = 25% N 2 = 0.5 V 1 = 300 gram V 2 = ? Formula N 1 V 1 = N 2 V 2 V 2 = N 1 V 1 /N 2 = 25 *300/ 0.5 = 15000 ml = 15000/1000 = 15 liter

11. Formula which is used to calculate the quantity or amount of toxicant for Dusts and granular formulations is N1 V1 = 100* R*A N 1 : Concentration of commercial formulation in percent (%) V 1 : Quantity of commercial formulation required in grams or kilogram R : Recommended rate of pesticide application ( active ingredient/ha ) A : Area to be treated in hectares

12. Problems: 1. How much quantity of commercial formulation of phorate 10 G is required to treat 7000 m 2 area of paddy field when the recommended rate is 0.5 kg a.i /ha?

13. Problems: 1. How much quantity of commercial formulation of phorate 10 G is required to treat 7000 m 2 area of paddy field when the recommended rate is 0.5 kg a.i /ha? Solution Given N 1 = 10% V 1 = ? R = 0.5 Kg A = 7000 m 2 = 7000/10,000 = 0.7 ha ( I ha=10,000 m 2 ) N 1 V 1 = 100 RA V 1 = 100 RA/ N 1 V1 = 100 *0.5 * 0.7/10 = 3.5 kg

14. 2.Calculate the quantity of Fenvalerate 0.4 % dust applied @ 0.2 kg a.i . for three hectare area?

15. 2.Calculate the quantity of Fenvalerate 0.4 % dust applied @ 0.2 kg a.i . for three hectare area? Solution Given N1 = 0.4% V1 = ? R = 0.2 Kg A = 3ha N 1 V 1 = 100 RA V1 = 100 RA/ N1 V1 = 100 *0.2 * 3/0.4 = 150 kg

16. 3. How much quantity of commercial formulation of carbofuran 3 G is required to treat 2500 m 2 area of sorghum field to control stem borer when the recommended rate is 0.35 kg a.i /ha?

17. 3. How much quantity of commercial formulation of carbofuran 3 G is required to treat 2500 m 2 area of sorghum field to control stem borer when the recommended rate is 0.35 kg a.i /ha? Solution Given N1 = 3% V1 = ? R = 0.35 Kg A = 2500 m 2 = 2500/10,000 = 0.25 ha N 1 V 1 = 100 RA V1 = 100 RA/ N1 V1 = 100 *0.35 * 0.25/3 = 2.916 = 2.92 kg