El Neoclasicismo y las Edades literarias: Edad Augusta,

Three to fi ve well-developed branches 50–80 cm from the soil, with wide angles, are allowed to develop on carambola. The annual pruning removes narrow-angled, low-hanging and overlapping branches. All side shoots up to 1 m are also removed. Pruning aims to retain recently maturing shoots and generate new shoots that bear the highest fruit yield; new shoots have smaller fruit. Flowers on main branches are also less productive. Bilimbi trees can be Fig. 3.6. Production practices for carambola. (A) Trellises are used in Taiwan, with (B) the bagged fruit hanging under the trellis. Wind can cause severe damage to fruit that rub against the stem and other fruit, necessitating protection with either a tree or screen wind-break (C). Birds can be a problem in some areas, requiring protective structures (D).

pruned and trained to various shapes. Heavy pruning of bilimbi suppresses fl owering since fl owering occurs on thicker branches.

In more intensive production systems, the tree height of carambola is maintained at less than 2.5 m to allow fruit bagging, if practiced, and harvesting from the ground. Trellis pruning of trees at 1.8 m is used to assist in maintaining tree height in an inverse conical shape. Alternatively, trees are tied down to achieve a weeping willow structure for ease of harvesting from the ground (Fig. 3.6A and B).

In Taiwan, heavy pruning at the end of the cool season is used to induce fl ower-bud initiation 7–15 days later. This heavy pruning reshapes the tree, reducing its height as well as removing slender and senescent branches. Lighter pruning at about 3-month intervals can then be used to develop further fl owering and fruiting (Fig. 3.7), giving three harvests a year. Light pruning removes dry, slender and senescent branches to open up the canopy, produce new shoots and fl ower buds and prevent fruit drop. Any water shoots that develop between regular prunings are removed.

Flower and fruit thinning are frequently used to increase fruit size, reduce the occurrence of misshaped fruit and prevent interference of fl ower cycling.

Thinning to three fruit per cluster 3–4 weeks after fl owering has been recommended. If out-of-season fl owering is required, all or most fl owers and fruit from the previous cycle are removed. Where fruit thinning is practiced, the individual fruit are often bagged when they reach about 6 cm in diameter. This bagging avoids mechanical damage and insect stings. The bags can be made of white paper, newspaper or polyethylene. Commercial bags of 20 u 10 cm with a wire tie at the open end are available, and can be tied on the fruit with one hand.

Fig. 3.7. Management practices utilized to induce three harvests per year in southern Taiwan. Double fertilization is carried out 1–2 months before the fi rst pruning in every year during the cool dry season and then every 2 months. The time of pruning are varied to achieve year-round production. Other essential management practices include maintaining the water supply and fruit thinning (T) to improve fruit size and reduce the length of the harvest period.

Fertilization

Animal manure or organic matter should be dug into each planting-hole site for carambola, 4–6 months before planting. Fertilizer (NPK) is mixed with top soil at transplanting. Organic matter or manure, 10 kg/tree/year for young trees and 10–25 kg/tree/year for older trees, is applied in a single application in some production systems. The fertilizer is applied in a 1 m ring around the tree base or along the drip-line. There are no reports of fertilizer recommendations in the literature for bilimbi.

In more intensive production systems, young bearing carambola trees receive 0.4–0.8 kg/tree/year of NPK (ratio 11:12:17–15:15:15), depending on soil analysis results. Older trees (8 years) may require 6–25 kg/tree/year. The fertilizer can be applied at intervals of about 3 months during fruit production, though limited during fl owering. An application is made after the last fruit harvest of the year, followed by irrigation to stimulate new growth. The trees are pruned heavily when growth slows 1–2 months later.

Each 1 t of carambola fruit can remove 1.02 kg nitrogen, 0.12 kg phos-phorous, 1.58 kg potassium, 0.1 kg magnesium, 0.1 kg sulfur and 0.05 kg calcium from the soil. Leaf analysis from non-bearing trees has found leaves contain 1.4% nitrogen, 0.12% phosphorous, 0.12% potassium, 0.98% calcium, 0.64% magnesium and 0.24% sulfur. These fi gures are given as guides and may not directly relate to yield.

Pest management

Diseases

Leaf spot (Cercospora averrhoa Petch.) can cause serious loss of carambola leaves and can also aff ect the fruit. The small chlorotic spots (up to 5 mm) are at fi rst brown, then turn grayish-brown and lead to premature leaf loss. Cupric fungicides and Difolatan provide control. Leaf spots caused by Phomopsis species, Phyllosticta species and Corynespora cassiicola have been reported in diff erent areas.

Fruit rot or blemishes caused by Botrytis, Ceratocystis, Colletotrichum, Aspergillus, Dothiorella, Alternaria, Phoma and Phomopsis species also occur. Fruit blemish can lead to rejection on the packing line. Symptoms of anthracnose (Colletotrichum spp.) include thin, light-brown patches that enlarge and coalesce into salmon-colored patches, which then blacken. There are no recommendations for postharvest disease control. Precooling and refrigeration do reduce the disease development rate.

Fusarium decemcellulare can cause serious infl orescence growth disorder of bilimbi, with Penicillium reported as pathogenic to the fruit. Leaf spots have been seen, but the causal organism is unknown.

Insect pests

Fruit fl ies such as Dacus dorsalis (the Oriental fruit fl y) in Asia are major commercial pests of carambola and a reason for fruit bagging. This and other fruit fl ies are also a quarantine restriction for export from tropical countries to some markets. Several moths, including Othreis species, pierce nearly mature to mature fruit and suck the juice, with the area subsequently rotting and fruit falling prematurely. This is particularly a problem in south-east Asia and Australia. Control measures are limited in their eff ectiveness.

Various other beetles, fruit borers, thrips, mealy bugs and scales can attack the branches, fruit and fl owers of carambola. Citrus red mite (Panonychus citri) is a severe problem, especially in the dry season in southern Taiwan. Ants are sometimes found around the peduncle depression at the end of the fruit, collecting honey dew produced by tree hoppers (Membracidae spp.) that feed on the peduncle.

No serious insect pests have been reported for bilimbi.

Non-pathogenic problems

Browning and rotting of the area between the ribs has been reported from Florida. This should not be confused with the surface browning frequently found in cooler months or following moisture loss. Chilling injury leading to brown patches has also been reported for carambola. This, however, may be related to dehydration and not low temperatures. Bird and bat damage can be a major problem (Fig. 3.6C and D). Cultivars with sharp rib edges are more susceptible to bruising and discoloration than those with rounded edges. This bruising and rubbing is frequently caused by wind damage.

Weed management

Trees are not good competitors when small, and weed control is essential.

Organic or plastic mulches are used to maintain a 1 m diameter weed-free area around the base of the tree.