Calculate the Quantity of Herbicide Required for Rice
A farmer wants to apply butachlor (50% EC) to rice at 1.5 kg active ingredient per hectare. Calculate the quantity of herbicide required for one hectare.
Given:
- Recommended dosage = 1.5 kg a.i./ha
- Active ingredient in commercial formulation = 50%
Formula:
Quantity of commercial formulation = (Required dosage / Percentage of active ingredient) × 100
= (1.5 / 50) × 100
= 3 litres/ha
Final Answer: 3 litres of commercial formulation per hectare.
Calculate the Quantity of Atrazine Required for Maize
A farmer wants to apply atrazine to maize at 0.5 kg a.i./ha in the form of Atrataf 50% WP. Calculate the quantity of herbicide required for one hectare.
Given:
- Recommended dosage = 0.5 kg a.i./ha
- Active ingredient = 50%
Quantity of commercial formulation = (0.5 / 50) × 100
= 1 kg/ha
Final Answer: 1 kg of commercial formulation per hectare.
Calculation of the Quantity of Herbicide Required
The quantity of herbicide (commercial product, Q) required per hectare is calculated as follows:
Formula:
Q = [Dosage in kg a.i./ha ÷ Percentage of active ingredient in the product] × 100
Example: If the recommended dosage is 2.5 kg a.i./ha and the herbicide formulation contains 50% active ingredient:
Q = (2.5 / 50) × 100
Q = 5 kg/ha = 5,000 g/ha
Quantity of Spray Liquid Required per Hectare
The quantity of spray liquid required per hectare depends on the type of sprayer, nozzle discharge, operator, and extent of weed infestation. Calibration can be performed by spraying a measured area of 100 m² with water and converting the quantity used to a hectare basis.
Given:
- Test spray area = 100 m²
- Water required for the test area = 7 litres
- One hectare = 10,000 m²
Water required per hectare = (7 / 100) × 10,000
= 700 litres/ha
Final Answer: 700 litres of spray liquid per hectare.
Calculate the Quantity of Herbicide Solution Required per Tankful
The quantity of herbicide required per tankful is calculated using the area covered by one tankful and the recommended herbicide dosage per hectare.
Formula:
Quantity per tankful = (Quantity of herbicide required per hectare / 10,000) × Area in m² covered by one tankful
Where:
- Q = Quantity of commercial herbicide formulation required per hectare
- q = Quantity of commercial herbicide formulation required per tankful
- a = Area covered by one tankful, in m²
Calculate the Quantity of Herbicide Required for 150 m²
If a herbicide is recommended at 2.5 kg a.i./ha and the commercial product contains 50% active ingredient, calculate the quantity of commercial product required for a tankful that covers 150 m².
Step 1: Calculate the commercial product required per hectare.
Q = (2.5 / 50) × 100
Q = 5 kg/ha = 5,000 g/ha
Step 2: Calculate the quantity required for 150 m².
Quantity = (5,000 / 10,000) × 150
= 75 g = 0.075 kg
Final Answer: 75 g of commercial product for 150 m².
Precautions:
- Calibrate the sprayer before application.
- Follow the herbicide label and recommended dosage.
- Wear suitable gloves and a protective mask.
- Avoid spraying in windy conditions.
- Prevent spray drift onto neighbouring crops.
Calculate the Area Covered by Available Herbicide Formulation
A farmer has 20 litres of fluochloralin 45 EC and wants to control weeds in cumin by applying the herbicide at 1 kg a.i./ha. Calculate the area that can be covered by the available formulation.
Given:
- Available formulation = 20 litres
- Formulation concentration = 45%
- Required dosage = 1 kg a.i./ha
Assuming the formulation is treated as 45% active ingredient by the calculation convention used in the source:
Area = (Available quantity × Percentage of active ingredient) / Recommended dosage
Area = (20 × 45) / 100
Area = 9 ha
Note: The source’s calculation assumes a direct percentage-based conversion. For a liquid formulation specified in % w/w or % w/v, use the label concentration and density where required to convert litres into kilograms of active ingredient.
Calculate the Quantity and Cost of Herbicide Required for 5 Hectares
A farmer has been advised to control weeds in a 5 ha field using one of the following herbicides:
- Fluchloralin: 45% a.i., recommended dose 1.25 kg/ha, cost ₹500/kg
- Pendimethalin: 30% a.i., recommended dose 1.00 kg/ha, cost ₹450/kg
- Oxadiazon: 50% a.i., recommended dose 1.00 kg/ha, cost ₹650/kg
Calculate the commercial product required and suggest the most economical herbicide.
Solution
1. Fluchloralin
Quantity = (5 × 1.25 / 45) × 100
= 13.89 kg
Cost = 13.89 × ₹500
= ₹6,944.44 approximately
2. Pendimethalin
Quantity = (5 × 1 / 30) × 100
= 16.67 kg
Cost = 16.67 × ₹450
= ₹7,500 approximately
3. Oxadiazon
Quantity = (5 × 1 / 50) × 100
= 10 kg
Cost = 10 × ₹650
= ₹6,500
Final Answer
Based on these calculations, oxadiazon has the lowest estimated cost among the three products at ₹6,500 for 5 ha.
Use only a herbicide approved for the specific crop and target weeds. The lowest calculated cost does not establish agronomic suitability.
Calculate the Quantity of Paraquat Required for Weed Control
A farmer in Chandauli district has been advised to spray a 0.3% solution of paraquat (10%) to control Cuscuta spp. in lucerne using a spray volume of 1 litre per 10 m². Calculate the active ingredient and commercial product required for one hectare.
Solution
Step 1: Calculate the spray volume per hectare.
Spray volume = (10,000 / 10) × 1
= 1,000 litres/ha
Step 2: Calculate the quantity of a 0.3% solution.
A 0.3% solution corresponds to 3 g per litre on a w/v basis.
Quantity of active ingredient = 3 × 1,000
= 3,000 g = 3 kg/ha
Important safety note: Paraquat is highly toxic and can be fatal if swallowed or absorbed. The original example should not be treated as an application recommendation. Follow current local registration, product labelling, and professional safety guidance.
Calculate the Quantity and Cost of Metaxuron Required
A farmer in Dagampur is advised to spray metaxuron 80 WP at 1.5 kg a.i./ha in a 5,000 m² area, using a spray volume of 800 litres/ha. Calculate the concentration, commercial product required, and cost at ₹450/kg.
Solution
Step 1: Calculate the water required for 5,000 m².
Water required = (800 / 10,000) × 5,000
= 400 litres
Step 2: Calculate the commercial product required.
Commercial product per hectare = (1.5 / 80) × 100
= 1.875 kg/ha
For 0.5 ha:
Quantity = 1.875 × 0.5
= 0.9375 kg
Step 3: Calculate the cost.
Cost = 0.9375 × ₹450
= ₹421.88 approximately
Note: This is a mathematical illustration based on the stated concentration and dosage. Verify the product identity, crop approval, and label instructions before any application.
Calculate the Active Ingredient Required for a 0.2% Solution of 2,4-D
A farmer wants to apply a 0.2% solution of 2,4-D to control weeds along a ditch bank. The estimated spray volume is 1,000 litres/ha. Calculate the active ingredient required to treat a 4 m wide, 3,000 m long ditch bank.
Solution
Step 1: Calculate the area.
Area = 4 × 3,000
= 12,000 m² = 1.2 ha
Step 2: Calculate the spray volume.
Spray volume = 1,000 × 1.2
= 1,200 litres
Step 3: Calculate the active ingredient for a 0.2% w/v solution.
0.2% w/v = 2 g per litre
Active ingredient = 2 × 1,200
= 2,400 g = 2.4 kg
Safety note: Use 2,4-D only where its specific formulation and use are approved. Avoid drift onto susceptible crops and follow the product label.
Calculate the Quantity of Herbicide Required for a Pond
A pond 30 m wide, 100 m long, and 4 m deep is infested with submerged weeds. The source proposes a herbicide concentration of 2 ppm. Calculate the quantity required using the stated concentration.
Solution
Step 1: Calculate pond volume.
Volume = 30 × 100 × 4
= 12,000 m³
Since 1 m³ = 1,000 litres:
Volume = 12,000 × 1,000
= 12,000,000 litres
Step 2: Calculate the theoretical quantity at 2 ppm.
For water, 2 ppm is approximately 2 mg/L.
Quantity = 12,000,000 × 2 mg
= 24,000,000 mg
= 24 kg of active ingredient
Final Answer: The theoretical quantity is 24 kg of active ingredient at 2 ppm.
Important: Do not apply this calculation directly to a pond. Aquatic herbicide use depends on the specific approved product, target weed, water use, environmental restrictions, and label instructions.
Calculate the Spray Volume per Hectare
Find the spray volume (litres/ha) from the following data:
- Distance covered = 150 m
- Swath width = 2 m
- Water required to fill the tank = 15 litres
Solution
Formula:
Spray volume (litres/ha) = (Volume of water used × 10,000) / (Distance covered × Swath width)
Spray volume = (15 × 10,000) / (150 × 2)
= 150,000 / 300
= 500 litres/ha
Final Answer
The spray volume is 500 litres per hectare.