What Could Be The Problem With My Hop Field?

Are there blackened and water-soaked areas on the roots, leaves are yellowing and stems wilting?

Do the leaves have pale areas on upper surfaces and "downy" patches underneath?

Are there cankers on the base of the climbing stem, which may wilt suddenly in high temperatures?

Are there lesions on the tips of leaves associated with the cones turning tan to dark brown, gray fuzzy growth on the tip of the cones is present?

Are the leaves covered with white powder?

Is there a yellowing of leaf tissue between the veins, climbing vines are swollen with brown discoloration of the inner tissue?

Are there any water-soaked lesions on the stem just below the soil line, tan to gray lesions develop out of the water-soaked region?

Are there any yellow-green mottling of the leaves, plants may be stunted?

Are the parts of leaves withering and turning brown in a V-shape, plant growth is reduced?

Are the leaves skeletonized?

Are the leaves distorted and yellow, clusters of small insects are present?

Your hop field has been affected by Blackroot rot. The only control is to plant new plants in well-drained soil at a new site as black root rot fungus can survive up to 10 years in the ground.

Pale areas on upper surfaces of the leaves and "downy" patches underneath are caused by Downy mildew. This fungus spreads quickly during cool, wet nights and warm, humid days. Leaves will wilt and die. Remove and destroy all affected plant parts and encourage good air circulation around plants by thining them. Water plants early in the morning to make sure they dry before nightfall.

Fusarium canker (Cone tip blight) is a fungal disease that causes these symptoms. Infected plants should be removed. Avoid injury to hop plants. Avoid wetting the crown while watering. Increase soil pH above 7 by using lime.

These symptoms indicate a fungal disease - Botrytis blight (Gray mold)). Prevent Botrytis blight by planting in areas with good air circulation. Water plants sparsely. Infected plants should be removed. Spray weekly with a copper fungicide until the disease is under control.

White, powdery patches on the leaves are caused by a fungal disease Powdery mildew. Powdery mildew usually appears in damp places. Encourage good air circulation around the affected plants by thining them and any surrounding plants. Water plants from bellow to keep foliage dry. Any affected leaves should be cut off and removed.

A soilborne fungus Verticillium causes a disease called Verticillium wilt. There is no way to save a plant once it has this problem. Don't plant hop in soil that has sustained other Verticillium-susceptible crops such as tomatoes, peppers, and eggplants. Solarize the soil for 1-2 months over the summer before planting Verticillium-susceptible plants.

Sclerotinia wilt (white mold) is a fungal disease that causes these symptoms. Wet weather conditions favor this disease. The disease is usually introduced to non-infected areas by infected seed. Plant only certified seed. If the disease is known to present rotate crops with non-hosts such as cereals.

Hop mosaic virus is transmitted by aphids. There is no known cure for viral diseases. Prevent problems by planting resistant cultivars, controlling aphids, and using virus-free seed from a reputable nursery.

Potato leafhoppers are tiny insects that feed on leaf undersides, giving the foliage a finely mottled look. Use water or insecticidal soap sprays to dislodge nymphs. Encourage enemies such as big-eyed bugs and parasitic wasps. For control of severe infestations, spray plants with neem or pyrethrin.

Skeletonized leaves are caused by Japanese beetles. Handpick adult beetles into a can of soapy water but make sure to wear gloves as Japanese beetles are blister beetles. Apply parasitic nematodes to the soil to limit beetle grub populations. Use pyrethrin powder or neem oil as a last resort.

Distorted, yellow leaves are caused by aphids. These tiny insects cluster under leaves and on growing tips where they feed on plant sap. Leaves, stems, and buds get distorted, and later leaves and flowers drop from the plant. You can control them by washing them off the plant with water spray. Insecticidal soap should be used with severe infestations.

If there are small light colored spots on leaves that later turn brown and shrivel the culprits are Two-spotted spider mites. Spider mites are small spiderlike insects that are hard to see with the naked eye. You can control spider mites by spraying plants thoroughly with water 2-3 times a day for several days. For severe infestations, spray plants with insecticidal soap or pyrethrin.