Exercise 9 - Effect of Crude Leaf Extract

Question 1

Name of Exercise 9:

Answer 1

Effect of Crude Leaf Extract of Gliricidia sepium (Jacq.) Walp on the Seed Germination.

Question 2

_____ also known as ____ is a small thornless, semi-deciduous tree known for its _____ and ____ property.

It is also used as fodder for cattle and has medicinal uses too.

Answer 2

Gliricidia sepium
“Madre de Cacao”

rodenticide
mosquito repellent property

Question 3

The secondary metabolites moderately present in stem, leaves, and roots (7)

Answer 3

Anthraquinone
Alkaloids
Phenol
Saponin
Tannins
Polyoses
Polyuronoids flavanols

Question 4

The toxicity of some plant species are due to ____ which inhibit the germination and seedling vigor of plants

Answer 4

allelochemicals

Question 5

Examples of allelochemicals (4)

Answer 5

tannins

wax

flavonoids

phenolic acids

Question 6

_____ can result from competition and allelopathy

Answer 6

Interference

Question 7

Examples of interference occuring (4)

Answer 7

One plant species fails to germinate

Grows more safely

Shows symptom of damage

Does not survive in the presence of another plant species

Question 8

_____
Ability of plants to inhibit or stimulate growth of other plants by exuding chemicals

This has lead to decline in crop yield in cropping and agroforestry system.

Allelopathic substances are most commonly found in _____ and in _____ However, some are found in ____ and as ____ liberated from leaves and rhizome

Answer 8

Allelopathy

plant extracts and in plant residues of soil

live plant exudates and as volatile gases

Question 9

The exercise will be carried out to evaluate the effects of the crude leaf extract of ____ on the germination of selected plants to determine if it has allelopathic potential

Answer 9

Gliricidia sepium

Question 10

Procedure:

1. Collect fresh leaves of _____ and ground with mortar and pestle
2. Collect the sap and filter using cheesecloth and _____
3. Store the filtrate in amber bottles and refrigerate as a stock solution
4. Prepare five different concentrations (5) Make three replicates using ___ seeds per treatment

Answer 10

1.Gliricidia sepium

2. Whatman filter paper (No. 1)
3. (30, 35, 40, 45, and 50%)
   10 seeds

Question 11

Procedure:

5. Soak the seeds in distilled water as a control group and in the crude plant extract for ____ h.

You need ____ layers of paper towels in the covered clean plastic containers. Keep the seeds moist with their respective liquid.

The radicle of the seeds in the control group need to be ____-_____ cm which will then be your time 0.

Afterwards, continue to keep under mlist conditions for _____ days this is so we can ensure seeds that did not germinate is due to the extract.

Answer 11

6h

2 layers

1.0-1.5 cm

5 days

Question 12

Test for toxicity:

1. Determine the toxicity of the crude leaf extract of ____ by counting the number of germinating seeds after 5 days (96 h)
2. To get the ____ you need to divide ____ by ____ then _____. This is to ensure that the seeds that did not germinate are considered dead attributed to the ____ present in the plant extract.

Answer 12

1. Gliricidia sepium

2.percentage Morality (%M)

divide number of seeds that did not germinate by the total number of seeds used then multiply by 100%

bioactive compounds

Question 13

Test for toxicity:

3. Determine the ____ ( as established at a concentration where_____ after the whole duration of the treatment.)

Answer 13

LC50

50% of the population germinated