Diseases In Crops SS2 Agricultural Science Lesson Note

ii. Galls on ears, leaves and tarsals which later turn black

ii. Use resistant varieties.

iii. Seed treatment.

ii. Reduced yield

ii. Avoid heavy use of nitrogen fertilizers.

iii. Use resistant varieties

A leaf spot of cowpea

ii. Lesions on leaves

iii. Chlorosis

ii. Spray with fungicides

iii. Crop rotation

iv. Plant resistant varieties.

ii. Reduced yield

ii. Early planting

iii. Crop rotation 

iv. Use resistant varieties.

ii. Stunted plant with curled leaves.

iii. Wilting and death of plants.

iv. Shortening of the internodes.

ii. Crop rotation

iii. Use insecticides

iv. Uproot and burn infected plants.

v. Use resistant variety.

(Bemisia nigerensis)

ii. Infected plant cutting

ii. Distortion of leaves and stems.

iii. Vein clearing

Stunted growth

iv. Development of yellowish-pale areas alternating with green patches on the leaves or mosaic patterns on the leaves

ii. Uproot and burn infected plant 

iii. Spray with insecticide to kill vector

iv. Use disease-free stem cuttings 

v. Farm sanitation.

Xanthomonas manholes

ii. Rain splashing

iii. Insects

iv. Tools

ii. Wilting of plant

iii. Falling off of leaves

iv. Reduced yield

v. Canker of stem

vi. Die-back of stem

ii. Use disease-free cuttings

iii. Early planting

iv. Practice crop rotation

ii. Insects

ii. Rotting of pods

iii. Entire pod turns black 

iv. Low yield

ii. Regular weeding

iii. Spray with fungicides eg Bordeaux mixture

iv. Avoid overcrowding of cocoa plants.

ii. By rain splash

ii. Orange powdery mass on the leaf

iii. Reduction in yield

iv. Dropping of leaves

ii. Use resistant varieties.

iii. Spray with copper fungicides.

ii. Stems near the ground

iii. Angular spot on leaves

iv. Boll rot

ii. Retarded growth and death of plants.

ii. Uproot and burn infected plants

ii. Knotting or galling of roots

ii. Early death of the plant

Reduction in yield

ii. Crop rotation

iii. Use resistant varieties

iv. Uproot and burn infected plants

ii. Cells become waterlogged

iii. Gradual wilting of plant

iv. Death of plant

ii. Use resistant varieties 

iii. Sterilization of soil

ii. Water splash

iii. Infected bulb

ii. Gray patches on leaves

iii. Reduction in yield

iv. Death of plant

ii. Use resistant varieties

iii. Spray with fungicides

iv. Early planting 

ii. High humidity

iii. By Soil

ii. Pungent smell.

iii. Sour taste

iv. Decay of seeds and fruits in store.

ii. Spray with 

iii. Maintain low humidity in store

iv. Remove contaminated seeds before storage.