USING WEED FOR ORGANIC FARMING

1. SUBMITTED TO:
Prof. (Dr.) THOMAS ABRAHAM
DEPARTMENT OF AGRONOMY
ALLAHABAD SCHOOL OF
AGRICULTURE
SUBMITTED BY:
GROUP NO # 13

2. What is WEED….????
“Plant whose virtues are yet to be
discovered”
“A plant out of place”
Weeds are unwanted or undesirable
plants that compete with crops for water,
soil nutrients, light and space (i.e. CO2)
and thus reduce crop yields. Weeds
account for 33% loss in agriculture
alone.(Jethro Tull, 1731)

3. Successful Management Requires
Multiple approaches
Continual effort
Knowledge of the biology of weeds
species
Reproduction, lifecycle,
establishment annual, perennial,
wandering perennial, broadleaf,
grass.
Weed : Top issues for Organic
Farmers

4. Principles Involved:
Eco Friendly :- i.e. it should cause no harm to
our environment.
Break the survival mechanism of the weed in
soil.
Easily acceptable by the progressive farmers.
Crop husbandry ( Crop Rotation, Mulching
etc.)

5. Multiple Prevention and
Elimination Strategies
(Practices):
Cultural
Biological
Physical
Mechanical
“Many hammers approach.”
Liebman and Gallandt, 1997

6. Cultural Strategies
Buy quality crop seed with low/no weed seeds
present.
Do not allow weeds to form seed.
Improve crop competitiveness
Improve soil tilth, aeration, and fertility to
optimize crop growth
Increase crop density through narrow
row spacing and increased seeding rate
Use transplants, rather than seed, when possible

7. Cultural Practices
Reduce weed numbers
Mulch (wood chips, mow and blow, paper,
living, plastic, etc)
Use weed-suppressive cover crops
Quick germinating, high biomass
Field with high weed pressure may warrant full year of
cover cropping and fallow to reduce weeds
Crop rotations
altering narrowly spaced crops with closely spaced
crops, shallow rooted/deep rooted crops, cold/warm
season crops
Intercrop
Clover underseeded in sweetcorn.

8. Mulches
Wood
chips
Shredded
paper
Leave
s
Stra
w

9. Cover Crops
Field pea-oat-
mustard cover crop
Red Clover

10. Crop Rotations
• Weeds tend to infest crops with similar
life cycles.
• Change crop ecology: shallow/deep
roots, cold/warm season, row/drilled
crops, foliage density, and heavy/light
feeders.
Change cultural practices: cultivation,
mowing, fertilization, herbicide
application, and planting/harvest dates

11. Biological Control Practices
Insects: may consume
large numbers of weed
seeds or feeding injury to
plant or vector virus
Phyllocoptes fructiphilus has
been shown to transmit rose
rosette disease on young fast
growing roses
Selective grazing
Sheep: clean fields after
harvest
Weeder geese: useful against
grass weeds and in perennial
systems
Biofumigation
Use of Brassica species
(canola, Indian
mustard) as cover crop
or in rotation
May be incorporated or
left as residue
Brassicas produce
glucosinolates, which
may by converted to
cyanate compounds
during decomposition.
Sustainable Vegetable Production from Start-Up to Market, Grubinger, 1999

12. Allelopathy
Allelopathy is the direct or indirect chemical effect
of one plant on the germination, growth or
development of neighboring plants.
Species of both crops and weeds exhibit this
ability. Allelopathic crops include barley, rye,
annual ryegrass, buckwheat, oats, sorghum, sudan
sorghum hybrids, alfalfa, wheat, red clover, and
sunflower.
The alleopathic effect can be used to an advantage
when oats are sown with a new planting of alfalfa.

13. Physical and Mechanical
Practices
Mowing
Prevents seeding
Depletes storage reserves
Better control for broadleaves
Soil solarization
Effective control of winter
annuals
Limited control of perennials
Cost prohibitive on large
acreages
Avoid tillage deeper than 3”
after solarization
Hand weeding
Cultivation
( done with
cultivators)
Flaming

14. Flaming
Intense heat sears the leaf,
causing the cell sap to
expand and disrupt cell
walls
seedlings are most
susceptible
Broadleaf weeds are more
susceptible than grasses
May be used in wet soil
conditions Sustainable Vegetable Production from Start-Up to Market, Grubinger, 1999

15. Crop Map Of Jharkhand:

16. Weed Management of RICE
( Major crop ) In Jharkhand.
Few weed species are
Echinochola crus-galli
Echinochloa colona
Eclipta alba
Monochoria vaginalis
Cynodon dactylon
Cyperus iria
Cyperus difformis
Cyperus rotundus
If these weeds are not
controlled from very
beginning the
reduction in rice
yield may be as high
as 12-98%.
Critical Period :
30 t0 70 DAS

17. Control:
Cultural control :
Keeping a layer of water (7 cm -15cm) on rice is said to
suppress germination of weeds completely.
Biological control :
Very little is known about natural enemies of this
sedge; the fungi, Corticum sasaki , and the
nematode Meloidogyne graminicola, may be considered
for biological control.
Mechanical Control:
Hand picking is the most commonly used process
practiced for weed management in Jharkhand.

18. Weed Management of POTATO(
Major crop ) In Meghalaya.
Most common weed associated are:
 Witchgrass-Panicum capillare
Dense hairs cover the leaf blades on both
sides and the sheath
Leaves are rolled in the bud and lack
auricles
Leaves have a white mid-vein
Its is a nuisance in lawns and gardens
It has a fibrous root system
Mature plants are 1 to 2’ tall
A.K.A. ‘ticklegrass’

19. Control:
Prevention:Learn to identify plants; start
monitoring early in the season.
Cultural Weed Control:
Plant competitive grass or other cover
crops. Witchgrass does not compete well with
perennial grasses.
Mechanical Weed Control
Cultivation or mowing before seed develops will
control this plant. Witchgrass can also be hand
pulled.
Biological Control :
No known biological control in our area.

20. Weed Management of SUGARCANE
( Major crop ) In Uttar Pradesh.
Most common
weeds associated
are:
 Sorghum halepense
 Cyperus rotundus
 Eleusine indica
 Saccharum
spontaneum
 Digera arvensis
 Eclipta alba
 Cynodon dactylon
If these weeds are not
controlled from very
beginning the
reduction in
sugarcane yield may
be as high as 10-70%.
Critical period for
weed competition
is 4 months after
sowing.

21. Control:
Cultural Weed Control:
 Selection of cultivars that have quick canopy closure.
 Seed cane from clean fields.
 Trash mulch at 45 DAP @ 7-10 t/ha,10 cm thick is
effective against many weeds.
 Mechanical Weed Control
Plant cane-scratchers are used over the top of the
cane and tines are removed as the can gets larger.
Ratoon cane-disk cultivators are used for weed
control in row middles.
Biological Control : Not practiced in Uttar Pradesh.

22. Weed Management of PINEAPPLE
( Major crop ) In Nagaland
Matricaria matricarioides ( Pineapple weed ):
the most common associated weed.
 Plant stems grow erect up to 1’ tall
 Heads are cone-shaped and a yellowish green colour
with each head surrounded by overlapping bracts with
no ray petals
 Crushed heads give off an odour likened to pineapple.
 An annual plant reproducing by seeds
 It is a nuisance in lawns and gardens and is also found
in croplands and along roadsides.

23. Control:
Prevention – Learn to identify plants; start monitoring
early in the season
Biological – No known biological control in our area
Cultural –
 One hand weeding in May/June.
 For the treatment involving mulching, non-decomposed
coffee husk was uniformly applied at a rate of 20 tons ha-
1 as per the schedule & mulched treatments significantly
out- yielded treatments without mulch and the clean
weeding with 100% weed control efficiency.

24. Conclusion
Using multiple approaches (“many
hammers”) to manage weeds will yield
greater impact than relying on a few
practices.
Develop a weed management strategy
that is designed for the needs of your
farm.
Although weeds can serve as host plants
for pests, they can also serve as hosts to

25. Conclusion
Today, however, with the increase in organic
farming and the decrease in the use of
herbicides, breeding for weed suppression
has become a higher priority.
Instead of eradicating weeds, farmers
especially organic farmers-- are learning to
manage weeds.

26. THANKING YOU
GROUP NO # 13