MINISTRY OF EDUCATION

SECONDARY ENGAGEMENT PROGRAMME

NOVEMBER 2020

GRADE 8

SUBJECT: AGRICULTURAL SCIENCE

WEEK 9

LESSON 1

TOPIC: Cultivation of Crops (Coconut)

SUBTOPICS: Fertilizer Application and Major Pest and Diseases of Coconut.

OBJECTIVES:

Students will:

Describe in detail the different fertilizers that are recommended for coconut

cultivation correctly.

Identify and discuss signs and symptoms of pests affecting coconut accurately.

Identify and diseases affecting coconut without hesitation.

Fertilizer ApplicationThe regular manuring and chemical fertilizers should be carried from the first year of

plantation for proper vegetative growth, early flowering and fruit bearing.

The first application of in-organic fertilizers should be carried after 3 months of coconutplantation.

In case of lateritic and acidic soils, Rock phosphate is recommended as source ofphosphorus.

Usually fertilizers should be applied in 2 split doses during May to June and Sep to Octmonths for rainfed trees.

In case of irrigated palms, 4 or more equal split doses should be carried to avoid heavyrainfall period.

In case of sandy soil with acidic nature, 1 kg of dolomite should be supplemented duringApril to May in the plant basins and should be forced into the soil. This application is inaddition to regular fertilizers.

Fertilizer Application

Pest of Coconut Major insect-pests found in coconut plantations are:

Mealy bugs and Scale insects

Termites

White grub

Coconut Moth Borer

Coconut Caterpillar

Rhinoceros Beetle

Red Palm Weevil

Black headed caterpillar

Rats.

Pest of Coconut

Coconut Caterpillar (Brassolis sophorae)

The adult butterfly is large brown in colour and has a diagonal orangeband on the forewing.

As the caterpillar gets older the defoliate the coconut palms leaving onlythe mid rib.

Large caterpillars make nest up to 90 cm long by webbing the leaflets.

Control

Keep fields free of trash, weeds and bushes

Drill holes of 7.5cm depth and squeeze monocrotophos

60% to fill the hole.

Pest of Coconut

Coconut Moth Borer (Castnia daedal us)

The adult moth is dark brown with a whitish crescent shaped mark onthe forewings and two rows of spots on the hind wings.

The larvae are whitish and 10-12.5cm long when fully grown.

They tunnel the trunk shallowly under the base of the leaves and trussesbearing nuts in the crown region and continue vertically upwards.

As a result trusses drop prematurely.

When young seedlings are attacked, they wither.

Control

Drill 3 holes each 7.4cm deep in the trunk of coconut palm about ameter high from the ground level and squeeze Monocrotphos 60% EC tofill the holes.

Pest of Coconut

Coconut Beetle (Strateous glopus)

It attacks young palms between 6mths and 3 years and kills them in a shortperiod.

The adult is a large black beetle and on emergence attack young palms.

They enter large holes they make on the stem and eat into the heart of theplant and kill it.

Control

Burn to destroy their breeding ground like rotten coconut trunks to kill allstages of insects which may be prevent in it or spray the breeding placeswith Aldrin (1/4 pint in 2 gallons of water).

Diseases of Coconut Major diseases found in coconut farming are:

Bud rot

Leaf rot

Stem Bleeding

Root (wilt) disease

Lethal Yellowing

Mahali

Crown chocking

Leaf blight or Grey Leaf Spot

Tatipaka Disease.

Diseases of Coconut

Lethal yellowing

Causes great damage to tall varieties.

It is caused by a mycoplasma.

Nuts are shed prematurely from the affected plants.

Leaves turn yellow starting from the distal part of the old leaves and moving to the

young ones.

The heart leaves collapses, and inflorescence opens prematurely.

Control

Use resistant varieties.

Diseases of Coconut

Bud rot

The disease is caused by the fungus phytophthora palmivora.

The fungus causes the young unfolding leaves to wither and collapsefirst followed by surrounding leaves in succession.

Brown spots also appear at the base of the young leaves.

The central bud rots and produces a foul smell.

Control

Several infected plants should be cut down and burned.

Spray the crown of healthy plants with copper fungicide to reduce

the incidence.

Diseases of Coconut

Cedros Wilt

The disease is caused by flagellate protozoa.

In the affected plants leaves droop, nuts fall early, roots die andeventually the tree dies dies within one month of the first sign of thedisease.

Sometimes some leaves may still appear green and wilted.

The disease spreads to coconut palms by insects living in milk weedwhich acts as a vector.

Control

Cut the affected palms at once and burn leaves and trash.

Get rid of the milk weed from the field that act as alternate host to themilk weed bug.

Review

Answer the following questions.

Identify any 4 pests of coconut and describe any one identified.

Explain how a farmer can control coconut beetles.

Discuss how fertilizers should be applied in coconut production.

Name and discuss 2 diseases of coconut.

References

Book

Weever, et al (1993), Agricultural Science for Secondary Schools in Guyana, BK 2,

Ministry of Education National Center for Educational Resource Development,

Georgetown, Guyana. Chapter 2, pages 73-78.

Internet

http://agritech.tnau.ac.in/horticulture/horti_pcrops_coconut_nursery.html

http://pca.da.gov.ph/coconutrde/images/gen5.pdf

https://www.plantationsinternational.com/coconuts/

https://www.youtube.com/watch?v=KchM1j6IXt8