Causal Agent:
Abiotic(Genetic mutation)
| Characteristic Symptoms: | |
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Spontaneous genetic mutation in plants causes changes in color or shape of melon leaves. |
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Typical symptoms of chimera are variegation or distortion of leaves resembling with those caused by viruses or herbicide injury. |
| Conditions for Disease Development: | |
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Chimeras are caused by spontaneous genetic changes in the plant. |
| Control and Management: | |
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Use the best quality of seeds available. |
| References: | |
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Pepper and Eggplant Disease Guide by Seminis |
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Aphids |
| Common Species: | |
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Aphis gossypii - cotton aphids |
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Myzus persicae - green peach aphids |
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Aphis fabae - bean aphid |
| Common Name: | |
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plant lice |
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greenflies |
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blackflies |
| Damaging Stage: | |
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Adults and nymphs |
| Crops Affected: | |
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Cucurbits, solanaceous, legumes, papaya, cotton |
| Characteristic Damage: | |
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Initial damage includes yellowing of leaves. |
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High aphid population causes downward curling of leaves, stunted plant growth and wilting. |
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Aphids produce honeydew, a sticky exudate that serves as substrate for the growth of sooty mold. It also interferes with the leaves’ photosynthesis and transpiration. |
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They are known vectors of different groups of viruses including Potyvirus (PRSV, ZYMV, ChiVMV), Luteovirus (CAYV/NMK) and Cucumovirus (CMV). |
| Management and Control: | |
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Monitor the area regularly. |
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Remove weeds and volunteer plants that may serve as alternate hosts for the aphids. |
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Regulate use of nitrogen fertilizer, excessive nitrogen fertilization favors aphid reproduction. |
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Use yellow sticky traps to minimize aphid population. |
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Use plastic mulch to repel the aphids. |
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Use botanical extracts like neem, kakawate and hot pepper and canola oil. |
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Apply imidacloprid, acephate, thiamethoxam, acetamiprid, azadirachtin, dinotefuran, acetamiprid, spinosad, pymetrozine when necessary. |
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