Everything you need to know about cultivating pineapple! Learn about: 1. Botany of Pineapple 2. Origin of Pineapple 3. Climate and Soil 4. Orchard Cultural Practices 5. Propagation 6. Planting Operation 7. Manuring 8. Irrigation 9. Flowering and Fruiting 10. Harvesting and Handling 11. Diseases and Pests 12. Varieties.
Botany of Pineapple:
Pineapple belongs to the family Bromeliaceae. It is separated from other genera of this family largely on the basis of syncarpous type of fruit which is not found in the rest of the family. Earlier, Ananas was considered as a monotypic genus including many cultivars but with only one species. Later on two genera Ananas and Pseudananas were established. In Psendananas syncarp at maturity bears a minute inconspicuous coma of bracts and produces elongated stolon and no slips.
In Ananas syncarp bears conspicuous coma of foliaceous bracts and plants produce slips but never produce stolon. In Ananas comosus, syncarp is well over 15 cm long at maturity, floral bracts are relatively inconspicuous and soon exposing the tops of the ovaries and the flesh is palatable.
Fruits are normally seedless and the ovules abort and only traces of them can be found in mature fruits. The genera Ananas has important species like Ananas bracteatus, Ananas ananassoides, Ananas fritzmuelleri, Annas comosus and Ananas erectifolius. The genera Pseudananas has one species Pseudananas sagenarius.
Origin of Pineapple:
It is a native of Brazil and had reached India by 1548. In the mind of an ordinary person, the name pineapple is associated with Hawaii and Singapore, but its cultivation in these places developed around the turn of the century.
It is one of the most popular fruits of the tropical and subtropical regions. It is easy to cultivate, gives quick returns and adapts itself to a wide range of soil and climatic conditions.
It is one of the most juicy fruits containing about 85% moisture, a good source of vitamin A, B and C, contains about 13% sugar, 1.4% titrable acidity, T.S.S 12.5% and rich in minerals like potassium, calcium, iron, phosphorus and boron etc. Pineapple is eaten as fresh fruit and for processing as juice, squash, jam, jelly, tidbits and in tinned slices. Like peaches it is more popular in the processed form, because the fresh fruit does not develop good quality.
This is due to the fact that the fruit which has a little starch in the unripe condition does not ripen properly after harvesting, which is required for long distance transport to the markets.
Pineapple is the other major fruit covering an area of 0.77 lakh ha with total production of 11.82 lakh tonnes. It contributes to 2.7% of the country’s total fruit production and ranks 5th among major producing countries in the world.
Climate and Soil Required for Pineapple Cultivation:
The pineapple is a plant of humid tropics but is known to adapt well in subtropical areas. The fruit grows well near the sea coasts as well as in the interior, so long as the temperatures are not extreme. The optimum temperature range for successful pineapple cultivation is between 22 to 32°C.
Leaves and roots grow best at 32°C and 29°C respectively and their growth practically ceases below 20°C and above 36°C. A high temperature at night is deleterious and a difference of at least 4°C between day and night temperatures is desirable.
Pineapple can be grown upto an elevation of 1,100 metres above sea level. It is sensitive to frost. A mildly cool winter improves fruit quality. Pineapple shows a remarkable ability to grow and produce crops under a wide range of rainfall conditions, although the optimum annual rainfall for commercial production ranges from 100 to 150 cm.
It grows in Golaghat in Assam with annual rainfall of 75 cm and in Khasi hills with 500 cm. In the areas where the rainfall is less, supplementary protective irrigations are necessary during dry season. The localities facing strong winds should be avoided as ends of leaves get bruised.
The pineapple plant comes up well in any type of soil except on very heavy clay soil. Sandy and loamy soils or laterite soils on hill tops are best for pineapple. The soil should be 45-60 cm in depth without hardpan or stones. Low lying areas with high water table should be avoided.
The plant prefers the soil pH of 5.0 ― 6.0. Alkaline soils are not considered suitable. Light soils produce fruits of good quality whereas yield is comparatively higher in heavy soils. High manganese-ferrous ratio in soil is considered injurious.
Orchard Cultural Practices for Pineapple Cultivation:
i. Irrigation:
In India, pineapple is mostly grown under rainfed conditions. Supplementary irrigation can help in production of good sized fruits in areas having optimum rainfall. Irrigation can also be helpful in the establishment of off-season plantings with a view to maintain the year round production of fruits for feeding the canning factories. At Hessaraghatta, it was observed that 20 per cent available moisture is as good as 80-100 per cent available moisture in the field, without affecting the size, yield and quality. Therefore, 4-6 irrigations in hot months at 20-25 days interval ensure good crop.
ii. Earthing Up:
Earthing up is most important operation in pineapple culture. The operation gives better anchorage to the plant. This becomes more important in ratoon crops. Earthing up should be done after each fertilizer
to be effective in controlling weeds in pineapple plantation and in bringing down the cost of weeding considerably. The weeds can be effectively controlled by spraying a combination of Bromacil and Diuron @ 2 kg a.i./hectare each as pre-emergence herbicides as soon as the pineapple suckers are planted. In established pineapple plantation, the weeds have to be removed before the spray is given as these herbicides do not kill the established weeds very effectively.
Simazine and Diuron @ 4 kg/ha as pre-emergence herbicides are very much effective against, grasses and sedges. Bromacil alone @ 3 kg a.i./hectare can be as effective against motha (Cyprus rotundus). Diuron @ 2 kg a.i and Bromacil @ 3 kg. a.i/ha applied at an intervals of 6 months effectively reduced both dicot and monocot weeds and increase the yield by 18 per cent as compared to control.
Bromacil and Diuron work every effectively in sandy and clay loam soils. In areas where the density of weed flora is heavy, the effect of herbicides may break down after one year and a second spray consisting of half the concentration of the first spray may have to be given.
iii. Manuring and Fertilization:
Pineapple requires nitrogen and potash for better yield and fruit quality. Nutritional removal from pineapple plantation yielding 400 quintals of fruits per hectare is nitrogen 123 kg, phosphorus, 33 kg and potassium 308 kg. At Bangalore, it was concluded that 12 g N per plant is ideal under irrigated conditions. Under rainfed conditions, a dose of 16 g N per plant was found to be necessary for getting higher yield. Potash @ 12 g per plant is recommended for irrigated as well as rainfed crops.
No response to phosphorus was observed. For Kew pineapple 600 kg N per hectare is considered optimum for a plant population ranging from 43,500-63,500 plants per hectare. In West Bengal, it was reported that nitrogen at 12-16 g, phosphorus at 2-4 g and potassium at 10-12 g per plant should be the optimum for a plant density of 51,000 per hectare. However, the highest yield with N, P and K @ 600,400 and 600 g per hectare, respectively was reported in plant density of 64000 and 72,727 per hectare.
Application of organic manure is done a fortnight before planting. The fertilizers are applied in two split doses, once at the onset of monsoon (May-June) and again at the end of rains (September-October) after the fruits are harvested and slips and suckers are removed.
The ammonium sulphate is considered the best source of nitrogen when applied to soil and was far superior to both calcium ammonium nitrate and urea. It resulted into highest fruit weight, yield and sucker production.
Foliar application of urea at 4 – 5 per cent in dry season and 10 per cent in wet season are useful.
Propagation of Pineapple:
Pineapple is mainly propagated by vegetative methods. It can be propagated by shoot suckers, ground suckers, slips, crown, stem-bits and from splitted crowns. However, suckers, slips and crowns are the three important types of materials used for planting. Suckers arise from the axils of the leaves just below the ground level and the slips are found on the fruit stalk below the fruit.
Suckers and slips are usually preferred for planting since they flower comparatively earlier than the crowns. Suckers produce the first crop in 15-18 months after planting while the slips take 20-22 months for the first crop. Crowns take more than 24 months for the first crop. Suckers weighing around 450 g and slips weighing about 350 g are the best planting material for Kew pineapple.
Small sized suckers, slips and overgrown suckers may be used only in case of non-availability of the ideal plant material. Fresh suckers and slips should be left to dry and should not be stored for more than 14 days. In shy suckering varieties, sucker production can be increased with high dose of nitrogen, more moisture and application of maleic hydrazide.
When there is shortage of planting material, the leaf cuttings from the crowns can be used for multiplication of planting material. From each crown, ten to fifteen leaf cuttings are made. Cuttings are dipped in 0.3% solution of Dithane Z-78 (3 g in 1 litre of water) for about 5 minutes and then planted. These cuttings will take even more time for flowering than crowns. Thus, they are only recommended where planting material is not available and more area is to be covered under this crop.
The root primordia are present in the basal portion of the planting material which are covered by scaly leaves. After removing scaly leaves, the planting material should be treated with Ekatox (0.05%) and Dithane Z-78 (0.3%) on Difolatan (0.4%) solution to protect against mealy bugs and heart rot, respectively. If the plants are to be stored, these should be arranged up-side down under shade instead of heaping them.
Planting Operation for Pineapple:
Double row method of planting is considered best for pineapple. The spacing of 30, 60 and 90 cm between plants, rows and beds respectively in a double row planting system accommodates 43, 500 plants per hectare. Little less spacing between plants i.e. 25 cm and 60 and 90 cm spacing between rows and beds accommodates 53,000 plants per hectare.
But plant to plant distance of 22.5 cm, row to row 45 cm and trench to trench 90 cm accommodates 63,500 plants per hectare. The plant density of 64,000 with a spacing of 25 cm x 35 cm x 90 cm in double row system is considered most suitable under North Bengal condition. Further increase in plant density to 25 x 35 x 75 cm, accommodates 72,727 plants per hectare.
The population density ranging from 53,000 to 63,500 plants per hectare could be easily accommodated yielding 85 to 105 tonnes per hectare without adversely affecting the fruit size, quality and canning recovery. In rainfed, high fertile and hilly areas, a lower planting density of 43,500 plants per hectare is recommended. High planting density gives more profits apart from other advantages like less weed infestation, protection from sun burn, increased production of suckers and slips per unit area and non-lodging of plants. Close planting saves the cost of providing shade to the fruits and results in uniformly coloured lustrous fruits.
In wider spacing, 20-25 per cent of the fruits get sun- burn. Close planting also helps in moisture conservation of soil, as the transpirational loss is much less when compared to evaporation from soil. It was also been possible to take atleast two crops under high density planting. Hence it is recommended to plant pineapple as close as possible ensuring sufficient space for carrying out the cultural operations.
Usually planting is done during monsoon season to take advantage of soil moisture. The planting in the month of July-August is considered best for establishment and growth of plant. The best months for planting in the North Bengal districts are October and November and in the other districts June-July. Planting should be avoided during heavy rains to prevent heart rot. Where irrigation facilities are available, planting could be taken up all around the year.
Manuring in Pineapple Plants:
Pineapple requires heavy manuring. Application of 10 to 20 tonnes of cow dung manure per hectare is recommended before planting. For high density (64000 plant/ha) planting in pineapple 600 kg N, 400 kg P and 60 kg K per hectare is recommended. Half of nitrogen and the whole of phosphorus and potassium should be applied three months after planting. The remaining amount of nitrogen should be applied 10 to 12 months after planting.
Sometimes zinc deficiency showing leaf chlorosis appears, which can be prevented by spraying 0.5% zinc sulphate. Spray of micro-nutrient mixture of zinc, boron molybdenum and copper at the concentrations of 0.2% after 5th month of planting and one month before flowering improves the fruit yield and quality.
Beside, spraying of fruits after 120 days of flower emergence with ethrel (0.50 ml/L) considerably increases the fruit size, weight and quality in West Bengal.
A pineapple plant generally flowers after 12 months when the plants attain 40 to 50 functional leaves. Most of the commercial cultivars of pineapple usually flower from February to July and maximum flowering takes place from February to April. Flowering of pineapple may be induced by using growth regulators and chemicals.
Growth substances like NAA (20 mg/L), ethrel (0.02 ml/L) or calcium carbide (20 g/L) are effective in flower induction. However, Ethephon at the rate of 25 ppm with 2% urea and 0.04% calcium carbonate has been considered suitable for all the pineapple growing regions of the country. About 50 ml of the solution is applied in the heart of the plant in the evening.
It is also to be sprayed when the plant has produced at least 40 to 50 functional leaves. It will hasten the flowering by 30 to 45 days with uniform flowering. In a uniform climate throughout the year as in Hawaii, flowering is staggered over a long period. Under such conditions it is especially important to induce uniform flowering at one time by using chemical means so that the fruit can be harvested in one given season.
Fruit harvesting in different seasons of the year is possible by using different types of planting materials, sequential planting and chemical flower induction. Planting of slips from July to November and applying calcium carbide (20 g/ 1) after 365 to 420 days from planting makes the pineapple available throughout the year in West Bengal.
In most countries the pineapple ripens in summer- and the crop ripening in winter is tart. In India the first fruit crop ripens in winter or spring, 15 to 20 months after planting, which is done in the rainy season. Therefore, the fruit ripens mainly in July-August from the flower appearing in February-March.
The fruit is harvested when it turns greenish-yellow and the leaf like scales around the eyes on the surface of the fruit dries up at the ends. Harvesting for local market should be done at full maturity when the fruits turn orangish- yellow, the bracts turn loose and brown while for the distant markets at about the 70-80 per cent maturing stage.
While harvesting, the fruit stalk should be cut about 5-7 cm below the fruit. To keep the fruit for a long period the crown should be detached. The fruit yield is 50-60 tonnes per hectare with a planting density of 45000 to 50000 in a well maintained field.
Pre-harvest application of Ethepon (500-2000 ppm) leads to faster and more even orange colour development in the fruits. The yellow colour development of fruit could be delayed by treating the fruit with GA-3 at 100 ppm.
Irrigation for Pineapple Cultivation:
Pineapple needs light and frequent irrigation due to its shallow roots. Irrigation is done during dry months from January till the break of the monsoon. Weeds are a major problem in pineapple cultivation particularly in high rainfall areas.
Manual weeding is expensive. Weedicides like Bromacil (3.0 kg /ha) and Diuron (2.0 kg/ha) are effective in controlling weeds. It should be applied twice, once before planting as pre-emergence of weeds and again six months after planting.
Mulching in pineapple reduces weed population, minimizes the requirement of water and also increases size of the fruit. A mulch of leaves or straw or polythene sheet is spread on the soil between the plants. A pineapple plantation is retained from one to ten years in different countries but in India for not more than three years.
Flowering and Fruiting in Pineapple Plants:
After attainment of certain vegetative growth and ripeness-to- flower stage, pineapple plants flower 11-12 months after planting and formation of atleast 40 leaves. A pineapple plant produces only one fruit during its life time. It is often observed that even after 15 to 18 months of growth under optimal nutritional and environmental conditions only 40 to 50 per cent plants come to flowering. Irregular flowering behaviour of pineapple is one of the limiting factor in its cultivation. Flowering in pineapple may be induced if the stems are kept in horizontal position, due to geotropism. In this way, accumulation of auxin induces bud initiation.
The fruit growth of pineapple in terms of length, breadth and weight follows a pattern of sigmoid growth. In Kew pineapple, pre-maturation stage covered 0-120 days, early mature 120-150 days and late mature covered 150-165 days and the fruits ripened after 165 days. Fruit growth increased continuously upto 120 days but the rate of increase was less pronounced from 120 – 150 days. The increase in fruit weight was maximum between 30 – 90 days.
The juice content increased from 30 – 60 days. Total soluble solids and sugars showed a rise till harvest but rate of increase was more between 60 to 120 days. Starch contents declined during 90-100 days and increased thereafter.
Harvesting and Handling of Pineapple Fruits:
Pineapple is non-climacteric fruit and should be harvested ripe. It usually flowers from February to April and ripens in July to September. In Kew variety off-season flowering occurs about 10-15 per cent and such fruit ripens from September to December. The fruits mature in winter are more acidic and not considered for table purpose. In Andhra Pradesh, the fruits are harvested from June to August. The fruit ripens from April to June in West Coast. For local market harvesting should be done at full maturity stage.
However, for distant markets, the fruits should be harvested at 75-80 per cent maturity stage. At maturity, the lower most eyelets in the cultivar Kew show orange-yellow colour and eyes get flattened in the centre and bulge on the sides. The bracts become loose and turn brown. The fruits of Kew pineapple harvested between 115 to 130 days after flowering are better suited for canning. Harvesting should be done with a sharp knife severing the fruit stalk with a clean cut and retaining 5-7 cm of the stalk.
Crown should be retained otherwise its removal quickens the ripening process and thus reduces the life of the fruit. The fruit should be protected from mechanical injury on the skin to avoid fruit rot. The cut end of the fruit stalk may be dipped in 10 per cent solution of benzoic acid in alcohol to check attack of fungus.
Ethrel treatment was found effective in enhancing uniform ripening in pineapple. Pre- harvest treatment of mature green pineapple cv. Perola with ethrel at 500-2000 ppm resulted in the development of uniform yellow colour in 8 days.
The yield is recorded about 65 tonnes from a population density of 43,500 plants per hectare. The yield goes higher i.e. 80 to 100 tonnes when density of plants ranges from 53,000 to 63,500 plants per hectare. In South India, average yield of 125 quintals per hectare has been recorded. Higher yield upto 200 quintals per hec, has been observed in Kew variety. The fruit size and yield decreased considerably with the age of plantation. Thus, plantation should be renewed after every 4-5 years.
The fruits should be handled carefully after harvest. Mechanical injury on the skin can cause fruit rotting during transit or in storage. The fruits are graded on the basis of size, shape and colour. Normally fruits are graded into 5 grades on the basis of weight.
The fruits weighing above 1500 g are placed in A grade, 1100 – 1500 g in B grade, 800 – 1100 g in C grade, 550 – 800 g in D grade and less than 550 g in E (baby) grade. The fruits are packed into fibreboard or wood containers for distant transport. A fixed number of fruits are either placed horizontally or vertically in the boxes.
Healthy fruits can be stored well for 15-20 days under ordinary conditions. The mature and ripe fruits can be stored at 11-13°C and 85-90 per cent relative humidity for about 5-6 weeks. Shelf life of fruits can be extended upto six weeks in good condition after treating with 500 ppm NAA or 100 ppm GA.
Diseases and Pests of Pineapple:
The common disease of pineapple is storage rot caused by Ceratostomella paradoxa, which can be controlled by smearing the cut ends with an antiseptic.
The common insect pest is mealy bug (Pseudococcus bromeliae), which can be controlled by cutting and destroying the affected shoots and spraying 0.05% Dichlorvos or 0.1% Malathion.
Varieties of Pineapple:
The most important variety in India is the Giant Kew or Smooth Cayenne. It has ash-grey leaves, well spread, little trough-shaped with straight smooth margin. The leaves commonly have spines on the tips and on the base near its attachment to the stem. Upper side of the leaves is dark metallic green and lower side ash-grey in colour.
Fruits are cylindrical in shape slightly tapering towards the crown. Eyes are broad and shallow, making the fruits suitable for easy trimming as required in canning. It is suitable for canning as well as for dessert purposes.
The colour of fruit when unripe is brownish green and turns to yellow when completely ripened. Fruit pulp is almost fibreless, juicy with characteristic flavour. It is shy in producing suckers. Average fruit weight is 1.25 to 3.0 kg.
Queen is another important variety. It has sharply serrated leaves and a small fruit of excellent quality as fresh fruit. Its fruit weighs from 1.5 to 2.5 kg each. The fruits are almost cylindrical in shape; eyes are smaller but deep, thus not suitable for canning. The colour of the fruit is dark green and turns completely yellow when fully ripe.
Ripley Queen and Red and Green Ripley are also related to this variety and are found in some parts of India. Simhalchalam is another small fruited variety found in coastal Andhra Pradesh. Jaldhup is a similar variety found in Assam. Lakhat is a wild type found in Assam and has small, acidic fruit with an alcoholic flavour. Baruipar and Haricharan vita are other varieties of West Bengal.
Mealy bug (Dy. smicoccus brevipus) is major pest of pineapple in India. Reddish white mealy bug infests roots, crown and fruits and sucks sap. Severely infested plants become stunted and bear small fruits. To avoid the incidence, plant healthy suckers and dip suckers in Phenthoate (0.05%) emulsion for 15 minutes.
Apply Phorate granules @ 1.75 kg/ha, three months after planting. Fruit eating beetle (Carpophilus dimidiatus) feed inside ripe fruits. The damaged fruits later rot due to pathogen infection. Do not allow the fruits to ripen in the field. Termite infestation is noticed in plantations in sandy soils.
Regular irrigation and drenching the field with chlorpyriphos (0.1%) minimizes infestation. Among its diseases the basal rot, caused by the fungus Ceratostomella paradoxa, is serious in Assam. The fungus can live on the trash in the soil and is easily spread through the planting material, insects and wind. The fungus can cause leaf spot and fruit rot.
Smearing the cut ends with 0.5% benzoic acid reduces the incidence of disease. Heart rot of the stem caused by Phytophthora parasitica which attacks citrus trees can also cause damage in patches.
It can be controlled by good soil drainage and dipping the suckers into 1-1-50 Bordeaux mixture before planting. Rotting of the roots is caused by another strain of the same fungus. Its symptoms are similar to those caused by Phytophthora cinnomoni in Queensland.
Among its diseases the basal not caused by the fungus ceratostomella paradoxa, is serious in Assam. The fungus can live on the trash in the soil and is easily spread through the planting material insects and wind. The fungus can cause leaf spot and fruit not. Smearing the cut ends with 0.5y benzoic acid reduces the incidence of disease.
Heart rot of the stem caused by Phytophythora parasitica, which attacks the citrus tree, can also cause damage in patches. It can be controlled by good soil drainage and dipping the suckers. Rotting of the roots is caused by another strain of the same fungus. Its symptoms are similar to these caused by phytophthora cinnomoin in Queensland.