| PINEAPPLE TECHNICAL | |||||||||
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Introduction
variety is mostly grown in Tripura and partly in Assam and Meghalaya. The flesh is deep golden yellow, less juicy than Kew. The crop has pleasant aroma and flavour. ‘Mauritius,’ a mid-season variety from Queen group is grown in some parts of Kerala. Fruit is medium in size. And the variety is exclusively grown for table purpose. ‘Jaldhup’ and ‘Lakhat’ are 2 indigenous varieties under Queen group grown in Assam. The choice of planting material is crucial as the performance of the plants developed depends on the materials planted. It is always advisable to use uniform size material of monotype for getting uniform growth of the plants, enabling uniform cultural operations and getting harvest at 1 time from such a field. Hence selection of right type and size of planting material is essential for commercial planting. Pineapple is commonly propagated from suckers or slips. Suckers arising from the underground parts of the plant are commonly used. Slips arise from the fruiting stem and from the crown on top of the fruit. After the fruit is harvested, stalks are cut into discs and used for propagation. Plants grown from suckers produce fruits in about 18 months, whereas those from slips and suckers propagated from disc cuttings take over two years. Studies carried out at Basti and Bangalore have indicated superiority of slips over suckers, which in turn were better than crowns. Both in suckers and slips, larger planting material resulted in more vigorous plants. Among the types and sizes of propagules tried, slips and suckers weighing around 350 and 450 g respectively were found best for yield and quality for Kew pineapple. Mass multiplication of propagation material is vital to bring fresh area under cultivation. This is possible only when a number of plantlets can be obtained from a single mother plant, unlike a few suckers or slips. It has been found possible to use leaf cuttings from the crowns of Kew pineapple for multiplication of planting material. Total 10-15 leaf cutting is made from each crown. However, these cuttings will take even more time than crowns for flowering and thus are only recommended where planting material is not available. Suckers or slips are first cured by stripping off the lower leaves, followed by drying in the sun, or in partial shade for three to four days before planting. They are planted either in flat beds, where there is no danger of water stagnating, or in shallow trenches, which are filled as the suckers grow and develop. Care should be taken to see that they grow and develop. Care should be taken to see that the bud or `heart’ of the suckers does not get buried. A planting density of 43,500 plants per hectare can be followed, keeping a distance of 30 cm between plant and plant, 60 cm between rows and 90 cm between beds. The rainy season is the best time for planting. The system of planting will vary depending on the topography of land and rainfall. There are 4 planting systems in vogue, viz. flat-bed planting, furrow planting, contour planting and trench planting. Plant spacing or density depends on the growth of the plant and system of planting. Adoption of low-planting densities has been the major constraint in India, causing high cost of production per tonne of pineapple. One of the ways to reduce cost of production is to increase yield per unit area by following high-density planting. According to the Department of Agricultural Research and Education, ICAR, Government of India, the population density of 44,444 plants/ha with a spacing of 30cm x 60cm x 90cm was best for getting more yield under rainfed conditions in north Bengal. Pineapple is a shallow feeder with high nitrogen and potassium requirement. Since these nutrients are prone to heavy losses in the soil, practices relating to time of application and the form of fertilizer determine their efficient usage. Experts based on research trials conducted at a number of locations advise to give N and K2O at 12 g each per plant. There is no need for P application. However, if the soils are poor in P, 4 g of P2O5 /plant can be applied. Nitrogen should be applied in 6 split doses. The first dose of N can be given 2 months after planting and the last dose 12 months after planting. Potash should be given in 2 split doses. Entire P and half the dose of K can be given at the time of planting and the remaining K, 6 months after planting. Application of fertilizer under rainfed conditions has to be done when moisture is available. Ammonium sulphate was found better nitrogenous fertilizer than urea or calcium ammonium nitrate, as it resulted in the highest fruit weight and sucker production. There were no differences due to application of potassium as potassium sulphate or as muriate potash. Earthing up is an essential operation in pineapple cultivation aimed at good anchorage to plants. It involves pushing the soil into the trench from the ridge where trench planting is a common practice. As the pineapple roots are very shallow, the plants are eventually lodged especially under conditions of flat-bed planting in heavy rainfall areas. Lodging of plants when the fruits are developing would result in lopsided growth, uneven development and ripening of fruits. This operation becomes more important in ratoon crops, as the base of the plant shifts-up, crop after crop. High-density planting would minimize the necessity of this operation, as the plants prop each other preventing lodging. Weeds could be effectively and economically controlled by application of Diuron 3 kg/ha or a combination of Bromocil + Diuron 2 kg/ha each as pre-emergent spray and repeated with half of the dose, 5 months after the first application in field. Water containing 2 kg of each herbicide @ 1,000 litres/ha would be sufficient to give satisfactory spray coverage. Mulching is one of the cultural practices aimed at weed control and soil-moisture conservation. Though mulching is not a common practice in India, use of dry leaves or straw is in practice in some areas of south India. Preliminary studies at Bangalore revealed that mulching with black polythene and saw-dust resulted in better growth of plants than that with white polythene and rice-straw mulching. Suckers start growing with the emergence of inflorescence and slips grow with developing fruit. According to some of the studies, fruit weight increase with increasing number of suckers/plant, whereas the increased number of slips delayed fruit maturity. Crown size has no bearing on fruit weight or quality. Hence desuckering can be delayed as much as possible, whereas the slips are recommended to be removed as soon as they attain the required size for planting, Partial pinching of crown in Kew pineapple consisting of removal of the inner most whorl of leaflets along with the growing tips 18 months after fruit set gave better fruit size and shape. Pineapple crop suffers considerably from the infestation of pests and diseases, though a few of them have been observed to infest it. Some of the more common disease and their recommended remedies are given below:
Besides pests and diseases, some fruit abnormalities make fruits useless. Multiple crowns: Generally fruit bears a single crown but in some cases a fruit bears more than 1 or even up to 25 crowns. Consequently, the top of the fruit will be flat and broad and the fruit will be unfit for canning. Such fruits also taste insipid and are more corcky. It is supposed to be heritable character, found mostly in Cayenne group to which Kew belongs. Fruit and crown fasciation: Fasciated fruits are deformed to such an extent, that they are totally useless. In certain cases, the proliferation is so extreme that fruit is highly flattened and twisted with innumerable crowns. Fruit and crown fascination is associated with high vigour of the plants. Such plants took longer time to flower than the normal ones. High fertility of the soil and the warm weather, the conditions highly congenial for vigorous vegetative growth, may favour fasciation. The incidence of fasciation was found increased wit the advancing ratoons. Collar of slips: The collar of slips is typified by the presence of a large number of slips arising the stem close to the base of the fruit, or even directly from the fruit itself. The excessive slip growth is at the expense of the fruit, resulting in small, tapered fruits, often with knobs at the base. High nitrogen fertilization and high rainfall along with relatively low temperature are supposed to be congenial for such an abnormality. The period between planting and harvesting of pineapple is usually two to two and half years. The stage of maturity at harvest is dependent on the required storage or shelf-life and the method of transportation to the export markets. The level of yellow colouration of the "eyes" of the fruit judges maturity. Colour stages are categorised as follows:
Sugar content should be assessed in the field prior to harvesting to ensure
adequate sugar development. A minimum of 10% is generally required although
this may vary with the market. Sugar content is not always related to the
colour stage as agronomic and production factors will affect sugar development.
For the export market where sea-shipment for seven to fourteen days is used,
fruits should be harvested at CS1, where the fruits show no yellow colour
development on the eyes (ensuring that checks have been made on the sugar
content). For air-freighted shipments, although generally cost prohibitive,
harvesting can be carried out at CS2 to 3. Those harvested at more advanced
stages are more susceptible to mechanical damage and over-ripeness. Fruit
maturity can also be assessed on random samples by determination of the
flesh condition. This is carried out by slicing the fruit horizontally at
the point of largest diameter; in fruit for sea-shipment export; the fruit
should show limited development of translucent areas. Where more than half
of the area is translucent, the fruit is considered beyond optimum maturity.
Pineapples harvested by hand are snapped from the stalk using a downward
motion. The fruit should be placed in field crates and while in the field,
left in shaded conditions. Collection in the field and field to pack house
transport using sacks or bags will cause mechanical damage and increase
the level of rejection. On arrival at the packing facility, the stems and
the crowns should be trimmed to 2 cm (0.5") and 10 cm (4") respectively.
Out grading should be made of all fruits which are undersize, oversize,
over-ripe, under-ripe (depending on the market requirements), damaged, bruised
or show fungal or insect damage.
Export Grading and Packing
Packaging A full-telescopic two-piece fibre-board carton with internal
dividers between the fruit; bursting strength 275 lb/in2. Top and bottom
ventilation, in addition to side vents are required, particularly where
sea-shipments in break bulk are used. Where staples are used in carton construction,
care should be taken to ensure complete staples closure to prevent fruit
damage. Carton internal dimensions
Where sea-shipment is to be used, the fruit should be harvested on
the day prior to shipment. Green fruit should be stored at 10°C, 85 to 95%
relative humidity, and under these conditions, should have a storage life
of two to three weeks. This will be dependent on the sugar content and the
agronomic conditions during production, in addition to the handling and
storage procedures. Where exports are made by air with fruit harvested at
more advanced stages of maturity, pre-export storage can be used and the
suitable storage temperature decreases to 7.5°C, 85 to 95% relative humidity.
Losses in pineapples during air-transport are minimal if careful handling
is employed. On sea-shipments and long term storage however, the fruit are
more susceptible to post-harvest losses as a result of increased handling,
control of temperature and disease incidence.
Bruising or puncturing caused by poor handling, dropping or abrasion,
will result in localised areas of softening and development of secondary
microbial infection.
Sensitivity to chilling injury is related to the level of ripeness
of the fruit. Storage of green fruit (CS 1) should be at 10°C, 85 to 95%
relative humidity; storage for extended periods below this temperature will
result in chilling injury shown by incomplete colour development, wilting
and darkening of the flesh and peel. Pineapples with 25% yellow eyes can
be stored for one week to two weeks at 5° to 7°C; critical temperatures
may be dependent on the production area and growing conditions.
Black rot caused by Ceratocystis results in a black watery rot of the flesh
and a thin brittle skin. Infection usually occurs through the cut stem or
through damaged areas, but can generally be controlled by prompt treatment
with either Dowicide A or Thaibendazole. Black spot or brown spot caused
by Penicillium funiculosum and Fusarium moniliformae results in browning
and sinking of the eyes and a browning of the internal fruitlets. Incidence
is not usually detected until the fruit is cut. The diseases are believed
to be caused by mite damage in the field allowing entry of the fungi. Pre-harvest
spraying regimes are required to control the mite population. Endogenous
Brown Spot
Physiological disorder characterised by watery spots, which eventually
coalesce and turn brown. The incidence is found in certain varieties and
production areas and is generally enhanced during long term storage.
Size
Ripe fruit should be stored at 7° to 8°C; lower temperatures will result in chilling injury and higher temperatures will lead to softening and decay. For maximum storage life of unripe pineapples, the fruit should be stored at 10°C and separate from ethylene producing products. |
