Organic Methods to Save Your Grape Plants From Pests | Reader's Digest

Organic Methods to Save Your Grape Plants From Pests

gardening tips organic garden garden maintenance

Robert Goyette from The Canadian Illustrated Guide to Green Gardening

CANE GIRDLERS

Symptoms: Adult Beetles come into vineyards when new shoots are about 1 foot (30 cm) long. Eggs are laid inside shoots about 6 inches (15 cm) from tips. Larvae tunnel inside shoots, destroying them.

Cure: Inspect canes and cut off about 4 inches (10 cm) below girdling area.

GRAPE BERRY MOTHS

Symptoms: Moth larvae feed inside fruits. Grapes are often webbed together. Wormy fruits result.

Cure: Set out pheromone traps to know when to spray with organic Bacillus thuringiensis var. kurstaki.

LEAF ROLLERS; LEFT TIERS

Symptoms: Larvae of moths feed on foliage of new shoots, chewing them badly. They may also feed on fruits.

Cure: Spray with organic neem in early summer. Repeat 2 weeks later.

ROSE CHAFERS, JAPANESE BEETLES and ORIENTAL BEETLES

Symptoms: Adult beetles feed heavily on foliage during day, causing severe skeletonizing of leaves.

Cure: Handpick adult beetles. Spray vines with organic neem to deter beetles from feeding. Place pheromone traps downwind away from the vines.

BLACK ROT

Symptoms: Fungus attacks leaves in early summer and later appears on fruits that are half grown. Entire grape shrivels to dry, black, raisinlike fruit.

Cure: Infection occurs during bloom period. Apply copper spray just before bloom, after bloom and every 10 to 14 days thereafter up to early fall. Remove mummified fruit and destroy.

DEAD ARM

Symptoms: Fungus, one of most destructive of all grape diseases, first attacks leaves and canes; later it infects young shoots. Dead arm phase results from infection through wounds caused by pruning or winterkill.

Cure: Remove infected vine at ground level during winter pruning. Spray with Bordeaux mixture when new shoots are about 1.2 inches (3 cm) long and again when they are 4.7 inches (12 cm) long.

DOWNY MILDEW

Symptoms: First appears as small yellow spots on top of leaves. Later, downy white mats appear on lower surfaces. Complete defoliation may occur. Grapes are attacked, harden and turn off-color.

Cure: Same program as for black rot (above).

Grapes with mold© iStockphoto/ThinkstockCommon grape ailments are easy to treat.

POWDERY MILDEW

Symptoms: Mildew occurs on foliage in early summer and fall, producing white powdery growth on leaves and fruits.

Cure: Organic sulfur sprays should be applied as needed.

  • Republished from:

    The Canadian Illustrated Guide to Gardening

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