More than Just Lines on a Map: Best Practices for U.S Bike Routes
Weeds control in sugarcane
1.
2. What is a Weed?
Definitions:
- Any plant or vegetation, excluding fungi,
interfering with the objectives or
requirements of people (EWRS)
- A plant growing where it is not desired
(WSSA)
5. CLASSIFICATION OF WEEDS
- botanical
- ‘agronomical’
- Botanical classification:
- Weed identification – importance for control
- more convenient to scientists than farmers
- Agronomical : more friendly for farmers
6. Vernacular namesBotanical names
Mauritius Reunion Other countries
Cynodon dactylon chiendent Petit-chiendent
Chiendent fil de fer
Bermuda grass
Couch grass
Elusine indica Chiendent patte poule C. patte poule
Gros chiendent
Digitaria horizontalis Gros meinki Chiendent caille Crab grass
Cyperus rotundus Herbe à oignons Oumine/zoumine Nut grass
Bidens pilosa Villebague Piquant –noir/ sornette Cobler’s pegs
Blackjack
Solanum nigrum Brede martin Morelle/Morelle noire Blackberry/nightshade
Panicum maximum Fataque Herbe fataque Guinea grass /Barby
Sataria barbata H. bambou/ bassine millet
21. Botanical name: Ipomoea nil L.
Common name: Liseron
Family : Convulvulaceae
Characteristics : Perennial;
produces large amount of seeds;
widely distributed
22. Bot. name: Paederia foetida L.
Common name: Lingue
Family : Rubiaceae
Characteristics : Perennial;
reproduces mainly by
rhizomes; widely distributed
23. • Weeds compete with crops for environmental
resources available in limited supply
• Three essential elements which have a great
influence on growth:
•water
•light
•mineral nutrients
• Competition defined as the tendency of
neighbouring plants to utilise the same quantum of
light, ion of mineral nutrient, molecule of water, or
volume of space. As a consequence, weeds may
reduce yield significantly and impair crop quality.
24. WEED COMPETITION
- Global or World-wide basis, 10% crop yield reduction by weeds
(Zimdahl, 1980: Froud-Williams, 2002)
- In tropics, crop loss may exceed 15%
- Crop losses depend on many factors
- In s. cane, no weed control may result in total loss of crop in plant
cane whereas a maximum yield loss of 60% may be recorded in
ratoon cane
25. Economic importance
- Weed control represents an important proportion of the total
expenditure in crop production
- Costs of weed control affect profitability of a crop
- Costs for crop protection (chemicals only) world-wide: US $ 30
billions
- In Mauritius, herbicide imports : Approx. 300 millions MUR
- Costs for weed control in sugar cane estimated at MUR 425
millions
26. An arbitrary rating scale ranging between 1 and 8 has been established for that purpose by
Rochecouste (1959) as follows :-
1- very rare
2- rare
3- occasional
4- fairly frequent
5- frequent
6- common
7- abundant
8 very abundant
FREQUENCY ABUNDANCE METHOD