Weed Science Important Study Point
Subject:- Weed Science
Weed Science Important Table
1.Some Harmful Weeds of Field Crops
| Name of Crop | Harmful Weeds |
| Paddy | Sanva, Wild rice |
| Wheat and Barley | Phalaris (gulli-danda, Gehu ka mama), Goose foot, red Chick weed, wild oat |
| Pea, Lentil, Mustard, linseed, gram | Goose foot, Red chick weed, Lathyrus |
| Clover | Common chicory |
| Mustard, Tobacco | Orobanche (Parasitic) |
| Green-gram, Black-gram, Pegionpea, cotton, groundnut, Soybean | Stone breaker, Spider weed, Safed murg. |
| Maize, Sorghum, Pearl millet | Stone breaker, Gumba wild, Amaranths |
2.WEED AND SUITABLE HERBICIDE
| Name of Weed | Suitable Herbicide |
| Wild carrot | Simazine, Atrazine, Alachlor |
| Wild Oat | Trilare, Trifluralin, Barban |
| Java grass (Motha) | Atrazine |
| Wild rice | Alachlore, EPTC, Trifluralin |
| Goose foot | Metachlore, Alachlore |
| Field bind weed | MCPA, 2,4-D |
| Blade grass (Thatch grass) | MSMA, Dalapon |
| False cane | Paraquate ,Diquate |
| Hyacinth | Paraquate |
| Canary grass | Isoproturon |
| Hypomia | 2,4-D |
| Striga (Witch weed) | Finake, Simazine, Atrazine |
- MCPA:- 2-methyl-4-chlorophenoxyacetic acid
- MSMA:- Monosodium Methanearsonate
- 2,4-D:- 2,4-Dichlorophenoxyacetic acid
- EPTC:- S-ethyl dipropylthiocarbamate
3.Classification of Herbicides
Which are divided into two group
- Selective herbicides
- Non Selective herbicides
(1) Selective herbicides:- Such herbicide kills only target weeds or plants. These are also divided into two parts
- A. Foliage application
- B. Root application
(A)Foliage application:- These are used for spray on plants leaves. These are also divided into two classes.
- i. Contact herbicide
- ii. Trans located/Systematic herbicide
(i) Contact herbicide:- A contact herbicide kills only those plants parts. Which comes in direct contact.
(ii) Trans located / Systematic herbicide:- The systematic or trans-located herbicides are those chemicals which kill the plants after their absorption by accelerating or retarding the metabolism of plants.
| Contact herbicide | Trans located herbicide |
Example:-
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Example:-
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(B) Root Application:- These chemical are mixed into soil before sowing.
| Root Application Herbicide |
Example:-
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(2) Non-Selective herbicides:- These are also divided into two parts
- A. Foliage application
- B. Root application
A. Foliage application:- It is also divided into two types.
| Contact herbicide | Trans located herbicide |
Example:-
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Example:-
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B. Root application:- It is also divided into two types.
| Soil fumigants | Soil Sterilants |
Example:-
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Example:-
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4.Formulation of Herbicide
| Formulation of Herbicide |
| Emulsion Concentration (E.C.) |
| This is a liquid form of herbicide |
Example:-
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| Wettable Powder (WP) |
| It is a powder form of herbicidal chemical. The particle size is less than 3 micron. It is available in market in 50-80 % WP form. It’s used as a water solution |
Example:-
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| Granules |
| Herbicides are available in granules form which contains 1-20 % active ingredient. |
| Fumigants |
| It releases some gases which are harmful to weeds. |
Example:-
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| Dust |
| It is used in dust form |
Example:-
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5.Weed dormancy
It is a stage of suspended development
| Types Of Dormancy | Cause of Dormancy |
| Enforced | Due to deeper placement of seeds |
| Innate dormancy | Genetically controlled dormancy |
| Induced | Due to sudden physio changes like water logging. |
Note:- Wild oat (A. fatua) exhibits all three kinds of dormancy, reported by Thurston, 1959
6.Weed Name & Their Family
| Weed Name | Family |
| Prickly chafflower | Amaranthceae |
| Bill goat weed | Compositae |
| Wild safflower | Compositae |
| Chicory/Blue daisy | Compositae |
| False daisy | Compositae |
| Garden spurge | Compositae |
| Pill pod spurge | Compositae |
| Congress grass/Wild carrot grass | Compositae |
| Wild mint | Compositae |
| Mexican daisy | Compositae |
| Cocklebur/Bur-weed | Compositae |
| Spiny amaranths | Amaranthceae |
| Slender amaranthus | Amaranthceae |
| Mexican prickly poppy | Papaveraceae |
| Wild oat | Gramineae |
| Bermuda grass | Gramineae |
| Marvel grass | Gramineae |
| Crab grass | Gramineae |
| Jungle rice | Gramineae |
| Goose grass | Gramineae |
| Wrinkle grass | Gramineae |
| Wild rice | Gramineae |
| Knot grass | Gramineae |
| Canary grass | Gramineae |
| Tiger grass | Gramineae |
| Green fox tail | Gramineae |
| Johnson grass | Gramineae |
| Barnyard grass | Gramineae |
| Spreading hog weed | Nyctaginaceae |
| Wild mustard | Cruciferae |
| Giant swallow wort | Ascletiabaceae |
| Buffalo gram | Leguminasae |
| Lathyrus | Leguminasae |
| White sweet clover | Leguminasae |
| Yellow sweet clover | Leguminasae |
| Mimosa | Leguminasae |
| Common vetches | Leguminasae |
| Vetches | Leguminasae |
| White cock’s comb | Amaranthceae |
| Lambsquate/Dog tooth grass | Chenopodiaceae |
| Bind weed | Convolvulaceae |
| Dodder | Convolvulaceae |
| Swamp morning glory | Convolvulaceae |
| Wild jute | Tilliaceae |
| Purple nutsedge | Cyperaceae |
| Yellow nutsedge/Rice flat sedge | Cyperaceae |
| Umbrella sedge | Cyperaceae |
| Thorne apple | Solanceae |
| Ground cherry/Hog weed | Solanceae |
| Black night shade | Solanceae |
| Prickly brinjal | Solanceae |
| Jimson weed | Solanceae |
| Water hyacinth | Pontederiaceae |
| Prickly lantana | Verbenaceae |
| Haory basin | Labiatae |
| Prickly pear | Cacaceae |
| Broom rape | Orobanchaceae |
| Sorrel | Oxalidaceae |
| Indian sorel | Oxalidaceae |
| Purslane | Portulaceae |
| Corn spurry/Niruri | Euphorbiaceae |
| Sida | Malvaceae |
| Witch weed | Scrophulariaceae |
| Typha (Cattail) | Typhaceae |
| Wild ber | Rhamnaceae |
Weed Science Important Study Point
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