Blossoms damage

Wind has the obvious effect of damaging branches. Less obvious is the fact that pollinating insects cannot visit blossoms in blustery weather, and this will affect the size of the harvest. Some gardens are naturally sheltered. If not, thought needs to be given to creating shelters against the wind. 

Pears enjoy warmth and an early start to the season. Choose a sunny, sheltered spot, or train them against a warm wall. Blossoming occurs several weeks earlier than with apples, which means that the cooler the climate, the more likely It Is that flowers will be damaged by frost and the crop will suffer. If you live In a cold area, you will find that your choice of cultivars is much more limited. Pears need the same soil conditions and soil preparation before planting as apples (see pp.296-297). 

Plums grow best in sunny conditions, sheltered from frost and high winds. The blossoms open early in spring, so avoid sites where frosty air collects. North-facing slopes are ideal because they warm up later and delay flowering for a few days, reducing the chance of frost damage. 

Black currants, rich in flavor and full of vitamin C, are hardy and reliable, although late frost can damage blossoms and reduce the crop. The berries can be eaten raw, cooked, or pressed for their juice they freeze well, and make excellent preserves. Black currants are always grown as bushes. You will harvest a moderate crop after two years, and a full crop after three or four years. 

Fig. 2.8. Anti-frost irrigation prevents damage to blossoms from frost.

INSPECTION AND DAMAGE THRESHOLDS. First flowering 15-20 colonies/100 blossom clusters (blossoms and rosette leaves). 

Both moths emerge rather later in spring than the summer fruit tortrix. Like the latter they migrate up to the blossoms and rosette leaves and start to feed there. The damage caused is similar to that caused by C. reticulana. 

DAMAGE CAUSED BY THE TORTRIX MOTHS. Damage due to feeding can be seen on the blossom clusters and rosette leaves around flowering. There is usually a cocoon in the immediate vicinity. 

The damage threshold at this point is 8-10% of blossom clusters attacked. 

NATURE OF DAMAGE. The typical holes or damage at the edge can be seen in the leaves. Blossom clusters are also attacked, but no cocoon is found there. 

After flowering, the damage threshold is 5% of blossom clusters infested. 

INSPECTION AND DAMAGE THRESHOLD. Winter moth Caterpillars are detected by visual inspection, with 100 blossom clusters being examined. The damage threshold is 10-15% of blossom clusters infested. 

The damage threshold is 5-8% of blossom clusters infested in the case of Spilonota ocellana and 10—15% of blossom clusters infested in the case ofHedya nubiferana. 

NATURE OF DAMAGE. The holes bored by the beetles are visible in the blossom buds at budburst. 

INSPECTION AND DAMAGE THRESHOED. The apple blossom weevil is monitored mainly by means of the knockdown test. 

The widely held opinion that the apple blossom weevil is a welcome blossom thinner is not applicable to modern organic fruit production. The blossom weevil cannot be controlled and can thus cause damage even when there is abundant production of blossom buds. 

These beetles overwinter as larvae in the soil. Around apple blossom time the beetles emerge from their winter hiding-places and feed on the leaves and petals. The leaves are eaten from the margin inwards. These beetles can cause considerable damage, especially in nurseries and young orchards. 

NATURE OF DAMAGE. The leaf and blossom buds do not open in the spring. These buds are still closed while the other buds are already coming into flower. The bud scales are not completely closed but rather lacerated. 

The damage caused can be seen as a small red dot where the slit has been made for oviposition in the calyx region of the blossoms. 

INSPECTION AND DAMAGE THRESHOLD. First flowerffig visual inspection of the blossom trusses for leaf suckers and anthocorid bugs at any stage of development. 

INSPECTION AND DAMAGE THRESHOLD. Flight and oviposition should he monitored on the blossom clusters. There is no known damage threshold. 

Disadvantages Not biodegradable There should not be any frost for 2-3 days after spraying (otherwise there is phytotoxic damage or in susceptible varieties, such as Gala and Braeburn, the blossom trusses and leaves fall)... 

Causes Excessive heat mechanical injury zinc deficiency. Hot days (85°F or more) or mechanical damage caused by heavy rains or strong water sprays can cause flowers to drop. Wait for new blossoms. 

Avoid planting in frost pockets where late spring frosts may damage blossoms and early fall freezes may shorten the harvest season. Frost pockets develop because cold air tends to sink and collects in depressions. Frost pockets occur at the bottom of valleys and on the uphill side of woods or buildings on slopes. If your whole property is a frost pocket, try training trees taller so they can blossom above the frost pocket, and try planting hardier cultivars. 

Peonies prefer full sun and moist, well-drained, richly organic soil, although light shade is tolerated and may prolong bloom in the South. A protected site limits wind damage to blossoms. Most are hardy to Zone 5 and do best in cold-winter climates. 

Damage Larvae chew blossoms and vines and bore into fruit of cucurbit plants, especially cucumbers, cantaloupes, and squash. A serious pest of summer squash. 

Prevention and Control Plant resistant cultivars. Prune trees to provide for good air circulation. Prune out and destroy damaged shoots. Pick off and clean up rotted and shriveled fruit. Spray with sulfur just before blos-.soms open and again after blossoming to protect the fruit. Another spray, just before harvest, will protect fruit from brown rot during storage. 

Prevention and Control Blossom end rot is commonly from calcium deficiency. This often occurs when hot, dry weather or rapid growth (due to excess nitrogen, for example) draws extra water and nutrients to the leaves, starving fruit for this nutrient. Root damage can also interfere with calcium uptake. 

To avoid blossom end rot, keep the soil evenly moist by watering regularly and putting down a thick layer of organic mulch. Cultivate carefully to avoid damaging roots. 

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