Posts Tagged ‘Problem Solvers’
Most Un-Wanted: Cedar–Apple Rust
Sunday, August 8th, 2010
Wanted For: defoliating apple leaves & for just being gross!!
Description: bright yellow-orange-red spots on apple leaves and orange galls with ‘horns’
Hangout: juniper (eastern red cedar) & apple trees including crabapples
Kryptonite: Lime –Sulfur Spray, Home Orchard Spray
The fungus that causes this disease moves back-and-forth between Eastern red cedars (actually junipers) and both fruiting & ornamental apple trees. In order to complete its life cycle this fungus must spend part of its life on both. Therefore, it is possible to eliminate the disease by eliminating the cedars within the given area of the apple tree. However, the spores can be wind borne up to 2-3 miles, so eradication of the disease is often impossible or impractical. Nonetheless, if cedars are not too numerous on your property, the removal of junipers around the immediate apple tree can certainly reduce the spores reaching the apple foliage & fruit.
The spores drift through the air mostly at night and early morning. If it lands on the apple’s leaves & fruit and remains wet for 4-6 hours, the spores infect the leaves of the apple tree. After several weeks, yellow spots develop on the infected apple leaves and fruit. By mid-summer the spots appear slightly raised and light-colored & are visible on the underside of the leaf. Spores are released and the wind carries them to nearby junipers. Infected juniper needles and twigs show no symptoms of infection initially. Inspect them closely the next spring for small, green swellings (immature galls). The galls reach full size by the end of the next growing season but do not mature and develop the orange gelatinous tendrils until the following spring (about 20 months after infection.) This bizarre-looking structure is actually the fruiting stage of the fungus. The “horns” release the spores that infect the apple trees.
Many sulfur fungicides are effective against rust. Begin spraying in spring and repeat throughout the summer as needed. Spraying the juniper is not recommended because cedar-apple rust rarely causes significant damage to this host. Prune dormant galls from juniper during the fall, winter and early spring before the orange tendrils begin to erupt from galls.
planting for the future.
-By Maggie Oldfield Thayer Nursery
Most Un-Wanted: Lily Leaf Beetle
Sunday, August 1st, 2010
Wanted For: an invasive species that dines on & destroys ornamental lilies, also exhibits an interesting habit of personal hygiene – covering themselves with their own excrement
Description: beetle has bright scarlet body & black legs, head, & antennae and the Larvae resemble slugs with swollen orange, brown, yellowish or even greenish bodies and black heads
Hangout: asiatic lilies
Kryptonite: Neem, Spinosad, Pyrethrins
The adult beetles stay alive throughout the winter and emerge early in the spring, when they begin looking for food and a mate. The adult females lay their eggs on the underside of lily leaves and the females produce between 250 and 450 eggs. The eggs appear in April or May and hatch within eight days.
The young larvae feed on the underside and the upper surface of lily leaves and sometimes on lily buds. This feeding period, which lasts 16 to 24 days, is the most destructive. From there, the beetles drop to the soil and pupate, emerging as adults about 16 to 22 days later & feed throughout the rest of the growing season.
And their personal hygiene leaves something to be desired: they secrete and carry their excrement on their backs. While they feed, the lily leaf beetles cover their bodies with their own excrement, giving them a grotesque appearance. It is some sort of defensive mechanism – it makes them look like a bird dropping, warding off predators and parasites.
If you only have a few plants in your garden, hand-picking adults and eggs can be effective (we prefer not to handle larvae, although there is no danger in doing so). Neem is most effective – it will repel beetles and kill young larvae, but must be applied every 5 to 7 days after the eggs hatch. Spinosad will kill the larvae.
planting for the future.
-By Maggie Oldfield Thayer Nursery
Keep an Eye out for Two Tomato Trouble Makers
Monday, July 26th, 2010
Blossom End Rot
Blossom end rot looks like the bottom of the tomato is rotting away. The bottom is shrunken and black.
Blossom-end rot is a physiologic disorder associated with calcium. Calcium is required for normal cell growth. When a rapidly growing fruit is deprived of necessary calcium, the tissues break down, leaving sunken lesion at the blossom end. Blossom-end rot is induced when demand for calcium exceeds supply. This may result from low calcium levels, drought stress, excessive soil moisture fluctuations as well as rapid, vegetative growth due to excessive nitrogen. This reduces uptake and movement of calcium into the plant.
Simply, it is a lack of calcium & a watering problem. The plant needed calcium at some point in its development of the fruit and there wasn’t enough water to transport the calcium up to the fruit. So this condition develops.
The solution is to fertilize with Calcium (FOLI-CAL) and be consistent with your watering.
Monterey FOLI-CAL
Tomato Cracking
Cracking of the skins is mostly a problem of inconsistent watering or water availability. The plants take it up and grow too quickly for the skins to expand. It mostly seems to happen when you water after a dry spell.
The solution is to water more thoroughly and more consistently. You will get more consistency and far fewer cracks.
-By Maggie Oldfield Thayer Nursery
Most Un-Wanted: Aphid
Sunday, June 27th, 2010
Wanted For: sucking the life out of innocent rose bushes with their needle-like mouth
Description: pinkish, greenish white; 1/16″ long & soft-bodied
Hangout: rose bushes; especially on stems, buds and young leaves
Kryptonite: Saf-t-Side Horticultural Oil, Bt & Lady Bugs
So Long, Suckers!
There are almost as many kinds of aphids as there are kinds of plants –rose aphid is just one example. Rose aphids prepare for next spring’s assault by laying hundreds of eggs on the branches of the rose bush. After the young aphids hatch, they spend their entire lives gorging on their victim’s life juices and producing more criminals. Too many on one bush can force some aphids to move and begin attacking another rose bush. Unless winters are mild, adults will die and only the eggs will survive until the next spring.
Not only should you learn about aphids, but you should also get to know the squadron of beneficial insects covering the area. Many hunt down aphids, restoring law and order.
However, aphids aren’t just sitting ducks-they have ants for bodyguards. Ants will tend aphids for their honeydew and protect them from aphid-eaters, so look for ways to deter ants, too.
Aphids reproduce quickly, actually giving birth to females that are already pregnant, so keep good records of changes in population size and tactics you used to control them.
CAUTION
aphids let diseases hitch a ride on their backs to new plants & then puncture plants for them so watch out for a fungus popping up at the same time as an aphid infestation
Planting for the future.
-By Maggie Oldfield Thayer Nursery
This Spring’s Most Un-Wanted: Winter Moth
Tuesday, April 6th, 2010
Wanted For: defoliating & weakening trees ultimately causing death after several years
Description: young are 1” green inchworms with white stripes on sides; adult males are grayish brown with 1″ wingspans and appear hairy; females have no wings
Hangout: ornamental trees (crabapples, cherries & birch), fruit and shade trees (oaks & maples)
Kryptonite: Horticultural Oil, Bt, Spinosad
Research from UMass Amherst is indicating that Winter Moth is expected to be in very large numbers this spring and the potential for defoliation this year might surpass last year. Begin peeling the buds open and start inspecting for the presence of tiny larvae, which wriggle into swelling buds to feed.
Horticultural oil spray should be applied now when temperatures are above 45°f. Hort oil is an organic control that works by suffocation. Eggs that are protectively hidden within crevices and under lichen will not be covered by the spray thus will not be killed.
Winter moth eggs hatch anytime between late March and early April. This is the time when the most damage occurs. There is great potential of injury when the buds stay swollen but unopened. Winter moths will enter both leaf and flower buds.
Once the buds open, the caterpillars are known as “free-feeders” given that they are now on the foliage and free to move easily from one area to another. Winter moth will be in this stage until late May or early June. While still on the plant, however, they are exposed and very treatable with Bt or Spinosad.
Bacillus thuringiensis, Bt, is a bacterium which must be ingested to be effective. Bt produces proteins that paralyze the digestive system of the winter moth. The infected insect stops feeding within hours thus starving to death in a couple of days. Bt works best on the younger stages of caterpillars; older ones are much less affected.
Spinosad is another organic control that is derived from a naturally occurring soil bacterium that was collected from soil in an abandoned rum distillery in the Caribbean by a scientist on vacation. Spinosad kills damaging insects by causing rapid excitation of the nervous system. Spinosad is fast acting – the insect dies within 1 to 2 days after ingesting. It works well as both a contact spray as well as by ingestion. Spinosad products work well on caterpillars of all ages.
The winter moth will then be out of sight until adults emerge in late November or early December when they are seen fluttering in your headlights or by your back door light.
-By Maggie Oldfield Thayer Nursery
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