Common Weeds Found in Farm

Back to: AGRICULTURAL SCIENCE SS2

WEEK ONE 

Welcome to SS2 Third Term!

We are eager to have you join us in class!!

In today’s class, We will be discussing Common Weed found in Farm. We hope you enjoy the class!

 

CONTENT

• Meaning of Weeds
• Effects of weeds on crops and the Economy
• Various types of weeds and their botanical names
• Methods of weed control

 

MEANING OF WEEDS

A weed is any plant that grows in a place where it is not (expected to grow) wanted

 

ECONOMIC IMPORTANCE OF WEEDS

1. They compete with crops for space
2. Weeds compete with crops for sunlight
3. Weeds compete with the crop for nutrient
4. Weeds harbour crop pests and pathogens
5. Weeds compete with the crop for soil moisture
6. It leads to a loss in crop yields
7. Weeds compete with the crop for soil oxygen
8. They reduce the quality of crops
9. They reduce the income of farmers
10. They cause a reduction in the taste of some grasses
11. Some weeds are toxic to farm animals

 

BENEFITS OF WEEDS TO FARMERS

1. Weeds help in checking soil erosion
2. Some weeds are useful as food for humans
3. Some weeds serve as food for animals
4. Certain weeds have medicinal values
5. They can be used as green manure
6. Some are used for making roots, mats and baskets
7. Weeds are used for mulching
8. Weeds are used for compost making

 

SELF EVALUATION

1. What are weeds?
2. List five beneficial effects of weeds

 

CHARACTERISTICS AND GROWTH HABIT OF WEEDS

1. Production of a large quantity of seeds
2. Some weeds reduced by seeds
3. Some weeds reduced by vegetative propagation
4. Growth of large leaves within a short time
5. Weeds growth is favoured during the rainy season
6. Most weeds are wind-pollinated
7. Production of a large quantity of pollen grains

 

DISPERSAL OF WEED SEEDS AND FRUITS

Most seeds and fruits of weeds are generally dispersed by wind and animals. The mode of dispersal are;

1. Dispersal of seeds by wind

Such weeds have feathery, winged or powdery seeds e.g. Tridax (PWD weed), goats weed, guinea grass, elephant grass and many other species of grasses.

2. Dispersal of seeds by Animal

Animal dispersed weeds usually have sticky, hooked, edible or colourful fruits or seeds. The sticky and hooked types of fruits and seeds adhere to the coats of grazing animals and are carried from one place to another. Examples of such animals are; rabbits, rats squirrels, antelope and man. Pigweed and commelina spp are examples of such weed.

3. Dispersal of seeds by water

Water dispersed weeds have waterproof cuticles, air spaces within the fruit and are lightweight

4. Dispersal of seeds by an explosive mechanism

Few plants and all leguminous weeds are dispersed by explosive mechanism eg waterleaf, Centro, Pueraria, Calapo and mucuna.

COMMON WEEDS FOUND ON FARMS

S/N	COMMON NAME	BOTANICAL NAME
1.	Guinea grass	Panicum maximum
2.	Bahama grass	Cynodon dactylon
3.	Carpet grass	Axonopus compressus
4.	Cogon grass	Imperata cylindrica
5.	Speargrass	Heteropogon contortus
6.	Wild sunflower	Aspilia Africana
7.	Centro	Centrosema pubescens
8.	Waterleaf	Talinum triangulare
9.	Wire/sida weed	Sida acuta
10.	Goat weed	Ageratum conyzoides
11.	Elephant grass	Pennisetum purpureum
12.	Giant star grass	Cynodon plectostachyum
13.	Pigweed	Amaranthus spinosus
14.	Tridax	Tridax procumbens
15.	Calapo	Calapogonium mucunoides
16.	Sunhemp	Crotalaria juncea
17.	Mucuna	Mucuna utilis
18.	Stylo	Stylosanthes gracilis
19.	Northern gamba	Andropogon gayanus
20.	Southern gamba	Andropogon tectorum
21.	Puero	Pueraria phaseoloides

EVALUATION

1. List and explain different weed dispersal method
2. List five weeds and their botanical names

 

We have come to the end of this class. We do hope you enjoyed the class?

Should you have any further question, feel free to ask in the comment section below and trust us to respond as soon as possible.

In our next class, we will be talking about Weed  II as we look into the economic importance of weeds. We are very much eager to meet you there.

School Owner? Looking for ready-made content and tools to save time and grow easily? Book a free demo session now

Get more class notes, videos, homework help, exam practice on Android [DOWNLOAD]

Get more class notes, videos, homework help, exam practice on iPhone [DOWNLOAD]