Weed Science Section

Weed Section

1. To  identified of weed and to maintain of weed in herbarium . Making weed sample card and photo recording.

2. To read and check the submitted herbicide and plant growth regulator documents to PRB.

3. To supervise the efficacy test of  new herbicide trials for experimental registration.

4. Technolgy transfer to  extension workers and farmers to  distribute the knowledge  of weed and their control measures, safety use of herbicide and farmer training.

5. Conducting training and certified pesticide applicator about weed classification , weed control ,herbicide and plant growth regulator.

6. Survey weed species associated with crops.

7. Conduct the Pest risk analysis for quarantine pest.


Precaution of using herbicides

1. Selection of correct herbicide. ( It must be suitable for both crop and weed species)
2. Must be appropriate dosage according to label.
3. Must be correct application time.
4. Suitable environment condition.Generally it must spray under sunlight condition but it should not be sprayed too hot condition. Do not spray against wind direction. It should not be sprayed under windy and rainy condition.
5. It is need to free from rain after application within half hour to six hours.(Eg.Paraquat –half hour).Must be free from rain.
6. The soil must be leveled and drainage and irrigation must be correct.
7. Clear water must be used.
8. Use appropriate nozzle. (Use fan-type nozzle for systemic and soil applied herbicide, Use hollow comb nozzle for contact herbicide)
9. Repeating use of one kind of herbicide may cause herbicide resistant and troublesome weeds may come out so herbicide should use alternate to reduce for this problem.
10. Some kind of mixture herbicide can control all kinds of weeds and other weeds that are difficult to control with low rate and low cost but do not tank mixed with herbicides by yourself because it has phytoxicity and incompatibility.
11. Wash sprayer thoroughly with soup after and before application.
12. The distance between nozzle and soil surface or weed must be 1 feet
13. Moisture is needed for soil apply herbicide . If dry condition, irrigate or light rain after application within one week.
14. It is need to put organic fertilizer for example ,EM Bokashi, Cow dung and Green manure to avoid soil depletion by herbicide.


Safety use of herbicide

  1. Always read the label of container before using control.
  2. Wear protective clothing or masks. Basic protective clothing includes rubber boots, long trousers, long-sleeved shirt and rubber-gloves. When opening herbicide containers or pouring and mixing herbicide, goggles should also be worn.
  3. Avoid inhaling vapors, dust or spray mist.
  4. Do not eat, drink or smoke while applying herbicide. Wash hands, face and other exposed skin thoroughtly with soap and water after using herbicide.
  5. Clean sprayers thoroughly with soap and water, drain completely.
  6. Store herbicides in their original label containers in a well ventilated place that can be locked.
  7. Do not store herbicides near food, water, planting materials, fertilizer or other farm chemical and supplies.
  8. Do not poor excess herbicides near water ways of canals.
  9. Empty containers should be deposited in disposal pits and puncture or broken until they are unfit for further use.
  10. Do not burn containers.

What is a weed ?

  • Any plant or part of a plant interfering of the human and live stock environment
  • A plant out of place
  • A plant not sown


Negative and Positive effects of weed
Weed Classification
Herbicide(Active Ingredient ) use in crops