Question 2
Study specimens G, H, I, J and K carefully and answer the following questions.
(a) State the botanical names of each of specimens G, H, I, J and K
[ 5 marks ]
(b) Give one reason why each of specimens I, J and K is difficult to control. [ 3 marks ]
(c) Mention two uses of specimen J. [ 2 marks ]
(d) State five ways in which G, H, I, J and K are of economic importance to farmers. [ 5 marks ]
Observation
This question was fairly attempted by the candidates. In 2(a), majority of the candidates were unable to state the botanical names of specimens G(Goat weed), H(Sida weed), I(Spear grass), J(Elephant grass) and K(Pig weed). More so, most of them could not give reasons why specimens I(Spear grass), J(Elephant grass) and K(Pig weed) are difficult to control as required in 2(b). However, in 2(c-d), most of the candidates were able to mention the uses of specimen J(Elephant grass) as well as state the ways in which specimens G(Goat weed), H(Sida weed), I(Spear grass), J(Elephant grass) and K(Pig weed) are of economic importance to farmers.
The expected answers include:
2 (a) Botanical names of specimens G, H, I, J and KG (Goat weed)
Ageratum conyzoides
H (Sida weed)
Sida acuta/carpinfolia
I (Spear grass)
Imperata cylindrica
J (Elephant grass)
Pennisetum purpureum
K (Pig weed)
Boerhavia diffusa
(b) Reasons why specimen I, J and K are difficult to control I (Spear grass)
J (Elephant grass)
- It produces a lot of seeds- The seeds are easily dispersed
- It has auxiliary buds with scales
- It easily out-competes and smother native plant community
- Resistant to drought
- Can easily re-sprout because of its underground stem
K (Pig weed)
- It has underground storage organ- It has seeds which easily stick to humans/animals for dispersal
- It produces flowers and fruits throughout the year
- Can survive various soil conditions(acidic, alkaline)