Herbicide application

Factors that may influence the efficacy of the applied herbicide

• Type of weed and density• Choice of product

1. Formulation2. Rate of application3. Mode of action

Timing of the treatment1. Early preplant (EPP)

2. Preplant foliar (PPF)

3. Preplant incorporated (PPI)

4. Pre-emergence (PE)

5. Post emergence overtop (POT)

6. Post emergence directed (POE-DIR)

Factors that may influence the efficacy of the applied herbicide-Contd.

Water management

Equipment inspection and maintenance

Calibration and calculation dose to apply

Application techniques

1. Aerial application

2. Ground

• Tractor mounted boom

• Knapsacks or Backpatch

i. Broadcast

i i . Band

ii i . Spot

iv. Directed

Factors that may influence the efficacy of the applied herbicide-Contd.

Weather condition

Safety

Calibration of Spray volume rate and herbicide concentration

Timeliness in herbicide application

This is crit ical to the effectiveness of the herbicide and

to the efficiency of the operation. Herbicide application

should be made when the weeds are most susceptible

and when environmental conditions are suitable for

effective and safe application. Herbicides therefore,

should be

applied under the following conditions:

When the energy reserve in the weeds are low

When they are some fully expanded soft leaves

When the weeds are young and are actively growing

When it is not raining but the soil moisture is adequate

General steps for effective herbicide application

1. Read the label 2. Wear protective clothing and equipment mentioned

on the label, such as goggles, gloves, etc. 3. Make certain you have the correct equipment for

herbicide application. 4. Mix herbicide for use according to the label, using

the exact proportions. 5. Choose the best day and time of day for safety in

herbicide application. 6. Apply herbicides in a continuous manner with l i t t le

overlap. 7. Clean up after herbicide application. 8. Store herbicides in original containers in a locked

cabinet away from temperature extremes and away from children and pets.

9. Know what f irst aid procedures are required by reading the "Statement of Practical Treatment" on the herbicide label ahead of t ime.

Three Common Nozzles

• Cone nozzles• A fan nozzle • A Floodjet

• flat fan • deflector

• Low volume(LV) • Very low Volume

TABLE: 2. Deflector nozzle: LV nozzle with lance at 50 cm above ground

(L/ha)

Nozzle

colour

code

Flow rate

(L/min)

Swath

(cm)

Rate

Yellow 0.6 50 200

Green 1.2 100 200

Blue 1.8 150 200

Red 2.4 200 200

TABLE: 3. Deflector nozzle:VLV nozzle with lance at 50 cm above ground

Nozzle

colour code

Flow rate

(L/min)

Flow Swath

(cm)

Rate

(L/ha)

Orange 0.24 110 35

Green 0.40 144 50

Yellow 0.47 170 45

Blue 0.68 160 70

Thank you….