Gary W. Moorman, Professor of Plant Pathology
|CUCUMBER MOSAIC VIRUS||Leaves are small and distorted. Bright yellow line patterns form on the leaves.||Cucumber mosaic virus||Destroy affected plants. Propagate from plants free of the symptoms. Maintain good aphid control in the greenhouse.|
|HELMINTHOSPORIUM LEAF SPOT||Small water-soaked leaf spots yellow and die. Spots merge and become large, irregular tan areas with a yellow halo.||Drechslera setariae (formerly Helminthosporium)||Avoid overhead watering. Apply a fungicide to protect plants.|
|ROOT KNOT NEMATODE||Plants are stunted. Normally tuberous roots appear beaded and galled.||Meloidogyne||Discard infected plants. Or, take top cutting and discard the roots and soil. Plant in pasteurized mix.|
|TIP BURN||Leaf tips and margins turn brown and die. There may be a yellow between the dead and live tissue.||phosphate fertilizer or fluoride toxicity or high light intensity.||Water and fertilize moderately. Avoid using superphosphate and perlite since they contain excessive fluoride.|
|YELLOWING||Young leaves are yellowed.||Lack of fertilizer, iron deficiency.||Maintain soil pH near 6. Use micronutrients or iron chelate to avoid iron deficiency.|
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Warning! Pesticides are poisonous. Read and follow all directions and safety precautions on labels. Handle carefully and store in original labeled containers out of the reach of children, pets, and livestock. Dispose of empty containers right away, in a safe manner and place. Do not contaminate forage, streams or ponds.
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