Experiment - 1
COMMON WEEDS
About 30,000 species of weeds have been listed in the world, out of which nearly 18,000 cause
serious damage in different ways resulting in considerable losses to agricultural production.
Eighteen weeds identified as the most serious in the world are listed here under.
Table. Eighteen most serious weeds in the world.
Common name Scientific name Growth habitat and kind of plant
Sr. Common Name Scientific Name Growth habit Kind of plant
No.
1. Smooth pig weed Amaranthus viridies Annual Broad leave
Spiny amaranth Amaranthus spinosus A-B
Wild oat Avena fatua A-G
Common lamb’squarters Chenopodium album A-B
Field bind weed Convolvulus arvensis P-B
Bermuda grass Cynodon dactylon P-G
Yellow nut sedge Cyperus esculentus P-S
Purple nut sedge Cyperus rotundus P-S
Crab grass Digitaria sanguinalis A-G
Jungle rice Echinochloa colonum A-G
Barnyard grass Echinochloa crusgalli A-G
Water hyacinth Echinochloa crassipes P-G
Goose grass Elusine indica A-G
Cogon grass Imperata cylindrica P-G
Sour paspalum Paspalam conjugation P-G
Common purslane Portulaca oleracea A-B
Itch grass Rottboellia exaltata A-G
Johnson grass Sorghum halepense P-G
A= Annual, P= Perennial. B=Broad leaved, G= Grass, and S = Sedge.
Experiment 2
Environment ideal for crop growth is also ideal for weed growth. Hence, any attempt to improve
the crop productivity without weed control is a futile exercise. The most common weeds in cop
fields in India are given here under.
Most common weeds in crop fields of India (Sankaran and Mudaliar 1991)
Annuals
Sr. Common Name Scientific Name Kind of plant
No.
1. Barnyard grass Echinochloa crugalli Grass
Goat weed Ageratum conyzoides
Crab grass Digitaria sp
Pig weed Amaranthus sp
Foxtail Setaria sp
Black jack Bidens pilosa
Sandbur Cenchrus sp
Cox comb Celosia argentina
Wild oat Avena fatua, Lambsquarters Chenopodiu, album
Goose grass Eleusine indica Wild carrot weed Parthenium spp
Torpedo grass Dactyloctenium aegyptium
Horse purslane Trianthema portulacastrum
Perennials
Sr. Common Name Scientific Name Kind of plant
No.
1. Bermuda grass Cynodon dactylon grass
Canada thistle Circium arvense Broad leaved
Bermuda grass Cynodon dactylon ,
Thatch grass Imperata cylindrica , Day flower Commelina benghalensis
Johnson grass Sorghum halepense, Field bind weed Convolvulus arvensis
Quack grass Agropyron repens, White horse nettle Solanum elaegnifolium
Nut grass Cyperus rotundus
Experiment 3
Date:
Identification of weeds
S.No. Common name Scientific, Family
Sr. Common Name Scientific Name Family
No.
1. Quack grass Agropyron repens
1. Quack grass Agropyron repens
2. Parrot amaranthus Amaranthus viridis
3. Wild oat Avena fatua
4. Wild safflower Carthamus oxycantha
5. White cock’s comb Celosia argentea
6. Lamb’s quarter Chenopodium album
7. Canada thistle Cirsium arvense
8. Field bind weed Convolvulus arvensis
9. Salt grass Chloris barbata
10. Blue daisy Chichorium intybus
11. Day flower Commelina benghalensis
12. Dog pea Crotalaria verrucosa
13. Bermuda grass Cynodon dactylon
14. Purple nutsedge Cyperus rotundus
15. Eclipta Eclipta alba
16. Jungle rice Echinochloa colonum
17. Phyician’s spurge Euphorbia hirta
18. Foxtail weed Pennisetum purpureum
19. Little seed canary grass Phalaris minor
20. Cat green gram Phaseolus tribolus
21. Sweet grass Poa annua
22. Johnson Grass Sorghum halepense
23. Mexican daisy Tridax procumbens
24. Common Vetch Vicia sativa
25. Dog mustard Cleome viscose
26. Carvelle Gynandropsis pentaphylla
27. Thatch grass Imperata cylindrica
28. Wild sage Lantana camera
29. Dog basil Ocimum canum
30. Lady’s sorrel Oxalis corniculata
31. Kans grass Saccharam spontaneum
32. Prickly brinjal Solanum xanthocarpus
33. Sow thistle Sonchus oleraceus
34. Wild indigo Tephrosia purpurea
35. Cocklebur Xanthium strumarium
36. Spiny amaranth Amaranthus spinosus
37. Spreading hog weed Boerhavia diffusa
38. Negro-coffee Cassia occidentalis
39. Egyptian crowfoot grass Dactyloctenium egypticum
40. Lippia Lippia nodiflora
41. White sweet clover Melilotus alba
42. Touch-me-not Mimosa pudica
43. Yellow foxtial Setaria glauca
44. Indian acalypha Acalypha indica
45. Prickly-chaff Flower Achyranthes aspera
46. Goat weed Ageratum conyzoides
47. Ass betelvine Aristolochia bracteata
48. Mexican Poppy Argemona mexicana
49. Para grass Brachiaria mutica
50. Dog chilli Croton Sparsiflorus
51. Rat’s ear Merremia emerginata
52. Holy basil Ocimum sanctum
53. Prickly pear Opuntia dellenii
54. Indian purslane Portulaca oleracea
55. Small caltrop Tribulus terrestris
56. Wetland amaranth Alternanthera sessilis
57. Fire feaf Ammania baccifera
58. Giant swallow wort Calotropis gigantean
59. Jimson weed Datura stramonium
60. Carrot grass Parthenium hysteroporus
61. Dodder Cascuta Spp
62. Broom rape Orobanche cernua
63. Witch weed Striga Spp
64. Common rag weed Ambrosia artemissifolia
65. water lettuce Pistia lanceolata
66. water fern Salvinia molesta
67. Alligator weed Alternanthera sp
68. Mile-a–minute weed Mikania micrantha
69. Noble cane. Saccharum spontaneum
70. Algae Chlorella pyrenoides
71. Hariyali grass Cynodon dactylon
72. Buffel grass or African foxtail grass Cenchrus ciliaris
73. Marvel grass Dichanthium annulatum
74. Bringraj Eclipta alba
75. water hyacinth Eichornia crassipes
76. wild mustard Brassica kaber
77. Chick weed Stellaria media
78. Prickly Pear Opuntia dellini
79. Dronapushpi Leucas aspera
80. Cogon grass Imperata cylindrica
81. Common vernonia )) Vernonia cinera
82. Dock Rumex spp
83. Goose grass Eleusine indica
84. wild poinsettia Euphorbia geniculata
85. Indian acalypha Acalipha indica
86. Joe Pye weed, boneset, snakeroot Euphatorium spp
87. American mint / pignut Hyptis suaveolens
88. Johnsongrass Sorghum halepense
89. Canada thistle Circium arvense
90. Chicory Cichorium intybus
91. Swine cress Coronopus didymus
92. Mesquite Prosopis juliflora
93. Wild plum Zizyphus rotundifolia
94. Red sorel Rumex acetosella ,
95. Bracken fern Pteridium spp
96. Drop seed grass Sporobolus diander
97. Digera Digera arvensis
98. Yellow fox tail Setaria glauca
99. Vetches Vicia spp
100. Wild carrot or Bishop's weed Daucus carota
101. Wild onion and garlic Allium vineale
102. Dandelion Taraxacum officinale
103. Lilac tassel flower Emilia sonchifolia.
104. Horse weed Erigeron canadensis L
105. Arrow weed Pluchia lanceolata
109. Annual sow thistle Sonchus oleraceus
110 Baloon vine Cardiospermum halicacabum
111 Mauritian Grass Apluda mutica
Experiment No. 4
Survey of weeds in crop fields
Sr. Common Name Scientific Name Propagation
No.
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Experiment No. 5
Survey of weeds in non crop land
Sr. Common Name Scientific Name Propagation
No.
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17.
Experiment 5
Herbarium preparation of weeds
Herbarium is a collection of plants that are dried, pressed and preserved on herbarium sheets and
arranged in sequence in accordance of specific purpose for future reference, record and study.
1. How to collect weed specimens.
2. Steps in preparation of herbarium.
Materials required
1) Sharp knife / scalpel – for cutting
2) Vasculum – It is a container made up of wood having a lid to keep the specimen in turgid
ondition.
3) Plant press
4) A weed note book
Herbarium collection
1) Collect the plant material at flowering stage
2) It is desirable to maintain all the plant parts intact (leaf, stem, flowers, fruits)
3) Collect fresh part of the plant but not diseased preferably apical part.
Herbarium pressing and drying
The wooden press board consist of 2 wooden plates of 12”x13” each which are
tighten with nuts on bolts for pressing. Placing each of the collected specimen in between the
folds of the newspaper for blotting. Ensure that plant is maintained. The specimen in newspaper
folds are to be arranged on the lower part of the pressing board. Place upper plate on the top and
tighten upper and lower parts with nuts and bolts. Keep the specimen for 24 hrs for sweating of
moisture. This is called as Sweating period. Ensure that the specimen is spread in the newspaper
folds and if necessary the top portion should be bent during pressing. The large specimens are to
be cut in 2 to 3 parts according to convenience the cut parts are to be arranged on separate sheets.
If the specimen can’t be directly dried they have to be preserved by preservatives. If the foliage is
very thick, it has to be pruned assuring that the portion of the cut parts are identified. If the leaf is
large, cut it vertically into 2 halves use one of the portion as specimen. The newspaper/bolting
paper changed after 12 hrs in first incidence and these after 24 hrs, 48 hrs and 72 hrs is done till
the specimen is dried completely. This is called Natural drying. In artificial drying, after
sweating period specimens are direct in hot air oven by maintaining 62 0C.
Herbarium mountings
Thick herbarium sheets of 11 ½” x 16 ½ “ are used for mounting.
Keep the specimen in centre and spread properly.
Fix the specimen to the mounting sheet with glue / gum / tape.
Herbarium labeling
Label the specimen in the space provided 4 ½ x 3 ½ on lower right side of the herbarium sheets.
The label information should have details of botanical name, local name, family, habit, habitat
and name of the student. Arrange the herbarium by group into terrestrial and aquatic weeds, sub
group them into monocots and dicots and further into annuals, biennials and perennials.Number
the herbarium sheets, serially on the top right corner of the sheet. Write the index for it.
Things to do
1) Collect 65 weeds.
2) Collect seed samples in 10 weeds for identification, study and record.
3) Select well spread specimen with natural color and all parts intact.
4) Reject discolored, folded, wrinkled specimen which are unfit for herbarium.
