The content is just an excerpt from the complete note for SS 2 Second Term Agricultural Science Lesson Note – Diseases of Major Crops: Important Diseases of Major Crops are Explained. Check below to download the complete PDF
DISEASES OF MAJOR CROPS: Important diseases of major crops are explained in tabular form below.
| S/N | Name of disease | Causal organism | Mode of transmission | Symptoms of disease | Prevention/control |
| CEREALS | |||||
| 1 | Maize smut | Fungus (Ustilago maydis) | Through affected seeds
Spore on leaves |
Grains with mass of black spores | Plant healthy seeds, treat seeds with fungicides e.g. thiram, carboxin etc. |
| 2 | Maize rust | Fungus (Puccinia polysora) | Wind or insect deposit spores on leaves | Brown spot on leaves | Use resistant varieties, use fungicides |
| 3 | Rice blast | Fungus (Pyricularia oryzea) | Airborne, spores deposit on leave. | Grains do not fill, dead areas on leaves which may lead to death, low yield | Use resistant varieties, dress seeds with Bordeaux mixture |
| 4. | Rice leave spot | Fungus (Cercospora oryzae) | Wind or rain splash | Reddish brown on leaves | Use resistant variety, burn crop residues |
| 5 | Maize streak | virus | By piercing and sucking insects like leaf hoppers | Chlorosis on leaves, shortened internodes | Plant early, use resistant varieties and burn affected plants |
| LEGUMES | |||||
| 6 | Fusarium wilt | Fungus (Fusarium solani) | Air | Rottening of roots, yellowing of leaves and wilting of plants | Use resistant varieties, plant clean seeds |
| 7 | Cowpea leaf spot | Bacetrium (Xanthoomonas phaseoli) | Infected seeds, wind and rain drops. | Angular leaf spot, stem and pod lesions | Use resistant varieties, plant clean seeds |
| 8 | Root knot | Nematodes | Infected soil and tools | Galls or knots on roots few fruits. | Plant resistant varieties, practice crop rotation |
| 9 | Groundnut rosette | Virus | Through aphids | Mottling of young leaflets and chlorosis, leaf distortion with marging rolling inward, green patches on leaves, reduced flowers formation | Early planting, use resistant varieties, crop rotation, destroy insect vectors, regular weeding |
| ROOTS AND TUBERS | |||||
| 10 | Cassava mosaic | Virus | Through white flies, infected cuttings | Yellowish and mottling of leaves. Leaf distortion, reduced photosynthetic activities |
Use resistant varieties, spray insecticides, burn infected plants |
The table consist of diseases of root and tuber (contd.), fruit, vegetable, spice, fibre etc. Click on the download button to have a complete file.
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