Introduction of Weed and Rice Weed Identification - PowerPoint PPT Presentation

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Introduction of Weed and Rice Weed Identification

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It is part of sustainable and environment friendly weed management training organized by CIMMYT – PowerPoint PPT presentation

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Updated: 27 July 2015
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Why and how: Weed collection from field, identify it by taking reference from national or international level publication

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Title: Introduction of Weed and Rice Weed Identification


1
Cereal System Initiative for South Asia Nepal
(CSISA-NP)
Program- Environment friendly and sustainable
weed management in rice production
Presentation Title- Rice weed identification
and characterization
Himalaya Subedi Research Associate CIMMYT
International CSISA-NP
Regional training center ADBL, Dhangadi,
Nepal Date - 25-26July, 2015
2
Presentation outline
  • Weed and its definition with example
  • Weed crop competition
  • Weed classification
  • Identification and characterization of weeds
  • Major weed of Rice

3
Definition of weed
  • A plant that is growing where it is not wanted
    Roberts et al. 1982
  • A plant out of place Blatchley . 1912
  • A plant that is growing where it is desired that
    something else growth Georgia, 1916
  • Those plants with harmful or objectionable
    habits Muenscher , 1946

Thus, The weeds are those unwanted plant species
which is grown in unwanted place and time causing
competition for cultivated crop and economic loss.
4
How many weed species are there?
5
What makes a plant, a weed?
  • Long seed life in the soil
  • Quick emergence
  • Rapid early growth
  • No special environmental requirements for
    germination
  • Ability to survive and prosper under disturbed
    conditions
  • Source- Holm, 1978

6
  • Dubo or Hariali (Cynodon dactylon)
  • Tori or Mustard (Brassica juncea)
  • Jalkumbi or water hyacinth (Eichhornia crassipes)
  • What happen if
  • Cynodon dactylon grow in rangeland
  • Eichhornia crassipes in aesthetic pond
  • Brassica juncea in maize field

7
Weed crop competition loss
  • Loss
  • Competition
  • Yield loss due to weed depends on types of weed,
    density, crop stage for infestation etc.
  • Yield 17-47 TPR, 14-93 DSR and 9-70 wheat
    (Ranjit and Bhattarai, 1988)
  • Increase cultural operation cost
  • No germination of crop due to allopathic effect
  • Nutrient
  • Light - Weed grow faster than crop causing
    shading (50reduce light intensity)
  • Water - higher transpiration ratio (813 Dubo vs
    430 Junalo)
  • CO2- C4 (mostly weed) can survive under higher
    level of CO2 and drought

Particular N P K Ca Mg
Maize 30 5.5 62.8 14 6
Weed 55 9.7 297.5 43 40
 Different 25 4.2 234.7 29 34
  higher in weed 83 76 374 207 567
8
Weed classification
9
Weed classification
Narrow leaf Broad leaf Sedges
Round/flattened steam Leaves in group of two Leaves are narrow Parallel leaf vein Prominent node Wide leaves Net like vein in leaves Leaves in cluster bunch with one or more leaflet Mostly dicot Solid angular stem Three leaf in group Semi-acquatic More problem in warmer climate
10
What make difficult to identify weed
  • Difficulty in identification
  • Growing stage of weeds
  • Soil types and environment
  • Growing season
  • Easy way of identification
  • Season of Growing weed
  • Morphological part (Leaf, stem, root, phyllotaxy
    etc)
  • Reproductive stage with flower and fruit

11
  • Majors weeds on Rice

12
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13
Botanical NameCyprus
  • Sedges types
  • Perennial
  • Propagated by seed, tuber, rhizome etc.
  • Problem in both upland and lowland
  • Nepali- dy, 5ltof

C.rotundus
C. difformis
C. iria
14
  • Fimbristylis miliaceae
  • Annual weed
  • Sedges leaf
  • Commonly found in low land

15
Scirpus maritimus
  • Annual weed
  • Sedges leaf
  • Commonly found in low land
  • Propagated by seed

16
The Cyperaceae Family
  • Cyperaceae or the Sedges include 17 different
    genera
  • Those species most commonly viewed as troublesome
    weeds are found in the Cyperus genus.
  • Of the 45 Cyperus species in the Southeast U.S.,
    29 are perennials
  • 1 tuber then 10 tubers then 1000 tubers

17
Patch Expansion 6 months of growth from a
single tuber
Purple Nutsedge Cyperus rotundus
Yellow Nutsedge Cyperus iria
Patch Area 7.85 m2 518 Purple Nutsedge
Shoots Max. Density 280 shoots/m2
Patch Area 0.18 m2 177 Yellow Nutsedge
Shoots Max. Density 7000 shoots/m2
18
Preliminary Conclusions
  • Purple nutsedge (Cyperus rotundus) produced
  • Similar number of shoots at 3 months
  • 2-fold more shoots than did yellow nutsedge
    (Cyperus iria) at 6 months
  • Purple nutsedge (Cyperus rotundus) expanded to a
    patch size 31-fold greater than yellow nutsedge
    (Cyperus iria)
  • Yellow Nutsedge (Cyperus iria) does not
    distribute itself far from the mother tuber

19
Botanical NameUnknown
  • Broadleaf

20
Commelina diffusa
  • Annual Weed
  • Broadleaf
  • Common in DSR
  • Nepali- sGo

21
Echinochloa colona
  • Annual weed
  • Narrow leaf
  • Commonly found in maize and rice
  • Very fast grow than rice and seed without awn
  • Nepali- aGf

22
Echinochloa crusgalli
  • Annual and narrow leaf weed
  • Maize and rice field
  • Seed with awn
  • Major rice problematic weed
  • Nepali- fdf

23
Alternanthera sessilis
  • Broad leafs
  • Perennial Weed
  • Problem in low land
  • Nepali-

24
Unidentify
  • Found in low land at DSR

25
Marsilea minute
  • Broad leaf
  • Rainy season
  • Vegetative propagated

26
Eclipta prostata
  • Annual weed
  • Broad leaf
  • Commonly found in lowland
  • Nepali - eunf

27
Sagittaria guayanensis
  • Annual weed
  • Broad leaf
  • Commonly found in lowland

28
Cyanotis axillaris
  • Annual weed
  • Broad leaf
  • Commonly found in lowland

29
Ludwigia hyssopifolia
  • Annual Weed
  • Broadleaf

30
Ageratum conyzoides
  • Annual weed
  • Broadleaf
  • Commonly found in upland
  • Nepali - uGw

31
Monochoria vaginalis
  • Perennial weed
  • Narrow leaf
  • Commonly found in low land

32
Caesulia axillaris
  • Biennial weed
  • Broadleaf
  • Commonly found in low land
  • Nepali- 7flof

33
Unidentify
  • Annual weed
  • Broadleaf
  • Commonly found in upland

34
Paspalum disticum
  • Perennial weed
  • Narrow leaf
  • Commonly found in low land
  • Vegetative ( rhizome) propagated

35
Panicum dichotomiflorum
  • Annual weed
  • Narrow leaf
  • Commonly found in upland
  • Nepali- aGf

36
P-1
P-2
P-3
P-4
37
SUMMARY - 1 (source- V. Sridevi et al, 2013)
  • The dominant weed under puddled condition of
    sandy clay loam soil during rainy season.
  • Grass weed species were Echinochloa
    crusgalli and Echinochloa colona,
  • Sedges were Cyperus iria, C. rotundus and
    Fimbristylis miliacea
  • Broad-leaved weed species were Ammania
    baccifera, Marsilia quadrifolia and Potamogeton
    distinctus
  • The broad leaved constituted 34.1 per cent,
    grasses 42.2 per cent and sedges 23.6 percent of
    the total weed population under weedy conditions
    (Singh et al., 2007a).
  • The wet seeded rice
  • Infested with composite weed flora comprising of
    51.5 grasses, 30.9 sedges and 17.5
    broad-leaved weeds (Ravisankar et al., 2008).

38
SUMMARY - 1 (source- V. Sridevi et al, 2013)
  • Dominant weed species in transplanted rice
    Ramachandra (2010)
  • Grasses weed- Echinochloa crus-galli and E.
    colona
  • Sedges- Cyperus difformis, Cyperus iria and
    Cyperus rotundus
  • broad leaved weeds - Eclipta alba and Ammania
    baccifera.
  • Dominant weed species direct seeded rice Reddy
    (2010)
  • Grasses- Echinochloa crus-galli
  • Sedges- Cyperus difformis and Fimbristylis
    miliacea
  • Eclipta alba and Ammania baccifera under the
    broad leaved weeds.

39
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