1. OBJECTIVES
At the end of the topic, the students/trainees must be
able to:
1. Determine the true different meaning of
weeds;
2. Associate the harmful and beneficial effects
of weeds;
3. Identify and Internalize scientific names of
different weeds;
4. Collect different weeds that are present in
the area
3. • Weed is known as “unwanted weeds”.
• Herbaceous plant not valued for use or
beauty, growing wild and rank, and
regarded as cumbering the ground or
hindering the growth of superior
vegetation.
WHAT IS WEED?
4. HARMFUL EFFECTS
• Yield losses due to weeds are more than
those from insect- pests and diseases. Yield
losses due to weeds vary with the crops.
• Weeds compete with crops for water soil,
nutrients, light, and space, and thus reduce
the crop yields.
HARMFUL EFFECTS
5. BENEFICIAL EFFECTS
• Weeds as fodder - Useful as good fodder for
milch animals.
• Weeds as vegetables - Used as green
vegetables and weeds serve as human food.
• Weeds as manure - When weeds are ploughed
in, they add to the soil plenty of humus. Excellent
compost can be made out of many weed plants.
• Weeds as fuel - Notorious tree weed commonly
used as fire wood. People make charcoal out of it
and are marketed.
BENEFICIAL EFFECTS
6. • Weeds as soil binders - Panicum repense is an
excellent soil binder; keeps bunds in position
and prevents soil erosion in high rainfall regions
and hilly slopes.
• Weeds as indicator plants - weeds can also be
valuable indicators of growing conditions in a
field, for example of water levels, compaction
and pH. Weeds are useful as indicators of good
and bad soils.
• Food for wildlife - Weeds can be an important
source of food for wildlife, especially birds.
BENEFICIAL EFFECTS
34. REFERENCES
• Survey and Identification of Common Weeds
Associated with Rice and Vegetable Production in
Rosario, La Union, Philippines by: Angelina T.
Gonzales. College of Agriculture, Cagayan State
University, Lal-lo Campus, Philippines
(https://www.hrpub.org/download/20170830/UJPS1-
10309438.pdf)
• Introduction to weeds, characteristics of weeds, their
harmful and beneficial effects on ecosystem. CSK
Himachal Pradesh Krishi Vish vavidyalaya,
Palampur176062, HP, India.
Email:ranass_dee@yahoo.com
(file:///C:/Users/lenovo/Downloads/1.Introductiontowee
ds.pdf)
35. ACTIVITY NO. 2
COLLECT AND PRESENT TO
ME AT LEAST 5 DIFFERENT
WEEDS AND THEIR SCIENTIFIC
NAME.
