Introduction
Abiu or Caimo (Pouteria Caimito) is native to Brazil and Peru. It has been introduced to other countries including South-East Asia. Abiu in the Philippines was brought from Australia in 1987, and is now fast becoming popular.
The fruit is usually eaten fresh, It is usually sliced longitudinally in four parts and the seeds removed . It tastes best when chilled and flavored with Calamansi juice.
Description
The small to medium-sized, evergreen tree grows up to 16 m high with upright or spreading branches. The leaves are dark green, 26 cm x 6 cm, oblong to elliptic and pointed at the tip.
The flowers are small, greenish-white and are borne in clusters at leaf axils. The fruits are oboivoid-globose, 6-8 cm in diameter and golden yellow when ripe. The flesh is white, soft, juicy and sweet. Each fruit has 1-3, large and flattened seeds.
The fruit and the tree resemble that tof tiesa (Canistel) but the flesh is similar to the taste, softness and sweetness of Caimito (Starapple).
Variety
"RCF GOLD" is the only registered variety of Abiu in the Philippines. Its fruit is round, large (weighs 300 grams) and golden yellow when ripe. Its flesh is translucent white, soft and melting, moderately juicy, sweet (19 Brix total soluble solids) and has high edible portion (63%). It has 1-2, oblong, black, large seeds. Other varieties have been identified but are not yet registered with the National Seed Industry Council.
Climatic and Soil Requirements
Climatic Requirement. Abiu thrives best in the open in places well-distributed rainfall. However, it can also be planted in areas with a distinct dry season if partial shading is provided.
Soil Requirement. Slightly acidic (pH 5.5-6.5), deep, loam soil with good drainageand rich in organic matter is favorable for raising Abiu. It can be planted in flat or slightly sloping areas.
Propagation
Abiu may be propagated by seeds but asexual propagation through Cleft grafting and inarching is recommended. Grafted plants fruit as early as two years while plants propagated by seeds fruit in three years or more.
To prepare the seeds, remove the slimy covering by macerating in fine sand or coir dust. Wash thoroughly in clean water and air-dry.
Sow the seeds horizontally in individual containers (such as perforated black plastic bags) containing good soil, or in a seedbox containing fine river sand or coir dust. Position the seeds with their hilum (large scar) down. Cover with a thin layer of germinating medium. Water and keep the soil moist all the time.
Transplant seedlings established in the seedbed in individual containers mentioned above as soon as the first pair of leaves has expanded and the roots are still short. This is also to check early if the roots are infested with aphids.
With proper care Abiu seedlings grow fast and are ready for field grafting or inarching when they are about a year old.
Planting
Abiu is planted during the start of rainy season, from May to June, with a planting distance of 4-5 m between trees. Prepare holes 30 cm in diameter and 30 cm deep. It is recommended to place a handful of complete fertilizer (15-15-15) before planting. Cover the fertilizer with a layer of soil. Remove the plastic bag from the plant and set the plant at the center of the hole. Cover the hole with soil. Water after planting.
Training and Pruning
Unlike other fruit trees, Abiu branches at an early stage. For easier management of the trees, prune branches growing lower than 50 cm from the trunk. Maintain the treeheight at 2 meters by cutting excess branches. Pruning is done regularly to remove dead. weak or interlocking branches.
Irrigation
During summer months, Abiu trees should be watered especially when the leaves start to wither. Mulching with leaves and grasses around the tree is recommended to conserve moisture in the soil.
Fertilization
Apply compost and manure if available. Mulching also conserves the nutrients stored in the soil. Application of inorganic fertilizers is recommended if Abiu trees exhibit low fruit yield. Apply 200 grams complete fertilizer on newly bearing Abiu trees at the start and end of rainy season. Five-year old trees and above should be fertilized with 500 grams complete fertilizer twice a year.
Harvesting
Plants propagated from seeds start to fruit in three years while grafted plants start to fruit in tow years. Abiu is available all-year-round but the peak of the fruiting season is from December to February. When the fruits turns golden yellow, it is ready for harvesting. A five to seven year old tree usually yields 50-70 fruits.
Abiu is harvested by twisting or pulling from the stem. It usually has a storage life of two weeks.
Reference: Growers' Guide on Abiu Production by Dr. Roberto Coronel
