Saturday Magazine

Do not worry - No Virus disease Papaya Cultivation in Home gardens

by Suranimala Wirasinghe, Rtd Director of Agricultural, Extension and Training, Department of Agriculture

During the recent past due to non-availability of virus disease resistant varieties and miss identification of the ring spot virus and mosaic virus cultivation of papaya in the wet zone has come down. Even in the dry zone in some areas this has happened.

How ever recent experience of growing "Red Lady" Hybrid papaya variety in the Mahaweli Areas has given solutions to these problems.

The perennial problem with papaya growing were identified to be this disease problem and cultivators getting very high percentage of "male" or non bearing trees.

The other problem associated with papaya is fruit uniformity, taste and bans portability. The hybrid variety "Red Lady" is an answer to all these provided one follow the simple scientific technologies recommended.

Varieties of papaya: There are many varieties cultivated in Sri Lanka

(1) Ratna

A variety recommended by Department of Agriculture. This is self-pollinated composite variety. Fruit quality is good, but no unfortunately of fruits. No assurance of 100% fruit baring trees, not resistant to virus diseases. This is the first papaya variety farmers got after a long time.

(2) Known You Number One

This is a hybrid papaya variety, resistant to ring spot virus, Plants are thick sturdy, early and heavy yielding, fruit is large weighing about 1.6 - 3 kgs per fruit with yellow flesh, sweet and good taste.

A fruit from bi-sexual plant is oblong with slightly pointed end. Hard skin, good transportability.

(3) Sun rise

This high quality papaya was selected and released by the Fengshan Tropical Horticultural Experiment station Hawai, fruit is small, pear shaped with slightly pointed blossom end, red fleshed with very high sugar content and aromatic.

Each fruit weight average of about 400 gms. Good for home Consumption, Not very good for transport.

This variety has similarity to "Solo Hawai" old verity. Sun Rice is not a hybrid variety.

(4) Solo Hawai

This is similar to Sunrise but the flesh is yellow. Not a hybrid variety. Of this variety is difficult to obtain seeds in Sri Lanka.

(5) Red lady

Hybrid variety. This variety is extra dwarf, early bearing and vigorous and productive, tolerant to ring spot virus. Plants begin to bear at 60-80 cms height and could yield over 30 fruits per plant in each - fruit bearing season. Fruits are short - oblong on female plants and rather long shaped on bi-sexual plants, weighing about 1.5 - 2 kgs. In Sri Lanka fruits weighing 2-5 kilos are commonly obtained. Flesh is thick red, hard, with brixvalue of about 13% just, little below run rise, Arromatic, this variety is ready for eating when the fruit out side is fully yellow and soft to the fingers on touching. Cut Red Lady papaya could be kept in the fridge for over 5-7 days. Does not became watery when mixed in the fruit salad. The best papaya variety for transport. Unlike local papaya varieties should be harvested when there are at least 2 inches long two yellow patches on the fruit. At this stage there will be yellow patches all around the fruit covering about quarter of surface area. For better taste it is better to peal the fruit using a peeler and cool in the fridge for at least one or two hours before eating. Ideal for any processing such as de - hydration. Seeds produced by Known You Seed Company, Taiwan.

Nutrition value of Papaya

Papaya ranks as one of the most nutritious and healthy fruits similar to banana and oranges. It is very high in calcium, carotin, thiamin, riboflavin, and vitamin c, phosphorous, niacin. Papaya is good for digestion, bowel movement, high blood pressure, heart conditions, cancer etc. Papaya is considered the a "King of Fruits".

Climatic requirements and soil

Papaya thrives in dry climates but could be grown in the wet zone an well, up to elevation of 2000 feet above sea level. The soils should be perfectly drained. Thrives on gravel and rocky soils. Papaya plant has evolved in gravel and rocky soils in the South American continent near the equator.

Fruiting and Non Fruiting Trees

This is the biggest problem in papaya cultivation if any one is using stray seeds or seeds obtained from un-certified sources, the trees will not give fruits. There is a scientific method of producing high percentage of fruit bearing trees by pollination of identified specific type of trees. For small-scale growers this technology will be too difficult to adopt. There are three types of fruits. The first type is a male or non-bearing trees. The second is the female type in which the flower and the fruit will be round or oval shape. The central cavity is large. The third type is the bi-sexual fruit, where the shape is long and the flower is thin and long, central cavity is smaller. All types taste the same. Some time one will find both types of female and bi-sexual fruits on the same tree. In addition to this there are fruits where in one side of the fruit has a protruded surface or ridge from the stalk end to the distil end of the fruit. This is due to the stamens also becoming carpaloid and produce ridged or irregular shape fruits. These fruits taste the same as others. This is also called "cat face" fruits.

Planting papaya

Select land where there is no shade or shade. The soil should be well drained. Heavy or clay soil not good. In the wet zone the planting hole should be two (2) feet by two (2) feet and at least three feet deep. In high lands where there is no water retention the depth can be two feet. The soil taken out and two handfuls of lime powder (calcium caborate) and the pit filled back to the top mixed with 2-3 baskets of well decomposed compost and the center section to be about 6 inches higher than the edge. Keep it for about two weeks and allow the soil to settle down. If the center goes down below the surrounding land level fill the center with soil to raise the center above ground level to about 6 inches. Plant at least 6 inches tall plants by making a small hole at the center. Tie a small thin stick so that plant will not get damaged due to wind. Water the plants if there is dry weather. If it is very sunny shade plants with dry branches of plants.

Spacing

Seeds from Red Lady papaya fruit, will not give you the original Red Lady variety, as it is a hybrid variety. You should obtain fresh seeds fot this purpose. The papaya plants should be planted at 3 meters by 3 meters spacing. If plants are too close to each other the plants will grow too tall very fast. At this spacing there will be 1111 plants per hectare or 450 plants per acre. 10gm pack of Red Lady seed will have 650-750 seeds.

Staking of trees

When plants are growing always fix stakes to prevent the tree from falling during heavy rains due to the loose soil and bending. Heavy wind can cause trees to fall. The Red Lady papaya trees start bearing very early and good healthy trees would carry about 10-15 kilos of fruits making it too heavy. At the early stage a single stake will be sufficient. Later on there is a need to fix three stakes. The cross bars can be thinner sticks tied to the stake by using G.I wire. The cross bar should be tied to the top most part using old bicycle tyre strips or old car tube strips to prevent any damage to the stem. The cross bar and the place of tie should be raised every three months. See diagrams.

Stage of bearing - Red Lady papaya will start flowering in three months and the fruit picking in about seven - eight months. It takes about 2-3 months for each fruit to mature. In order to prevent bird damage and sun scorch it is better to cover older fruits with thick paper (do not use polythene) or jute material or old cotton cloth material.

Fertilizer Recommendation - For one plant

At planting urea 60 gms, Thriple super phosphate 40 gms, muriate of potash 130 gms, borate 5 gms, zinc sulphate 5 gms. Repeat this every two to three months.

Application of borate and zinc sulphate is very critical if the two fertilizers are not applied you get yellow crinkled chlorotic leaves which most identify as ring - spot virus disease. If zinc sulphate is not applied the leaf get deformed and appear as mosaic virus. Boron deficiency cause bumpy fruit or hard small lumps on the fruit surface and the fruit will be hard even after ripening and poor taste. These fertilizers are available in the fertilizer cooperation and other companies in one- kilogram packs. One may buy and keep as these fertilizers need to be applied to your other fruit trees, vegetables etc.

These nutrients are coefficient in our soils. There are liquidfrtilizers containing boron and zinc but they are expensive. One kilo of borate is about Rs. 85.00 and one kilo of zinc sulphate is Rs. 40.00.

After some time the soil around the papaya tree became compact and some of the zinc and borate becomes not available to the papaya tree. As such when applying fertilizers along with zinc and borate using a large fork make fork holes about 3 feet away from the base of the tree and loosen the soil without damaging the roots. Apply compost to the holes always keep the base of the tree exposed and dry. Papaya thrive under dry conditions. It is better to watch papaya tree growth and production and apply fertilizer.

Diseases

When plants are small during wet weather fungus diseases such as antracnose, phytophthora and pithium can cause death of plants. May apply a common fungicide such as Benlate Homai Champion. May apply calcium carbonate - copper sulphate - mixture called Bordeaux.

Bordeaux Mixture

Mix 1 lb of copper sulphate with 1 1/2 lbs of calcium sulphate in one gallone of water. Apply this solution to infected places.

Boron defficency Zinc defficency

Yields

Red Lady papaya yields about one to two fruits per week after 6-7 months. Each fruit will weight about 1-2 kilos. This weekly production of 3 kilos for about four months yielding about 48 kilos. Then there will be a break of about one month, depending on the rain and dry months apply fertilizer.

During the second year each tree will yield about 120 kilos and the third year about 120 kilos. Total yield to about 188 kilos, the cost of production for plants, fertilizer etc. will be about Rs. 6.00 per kilo. One can now calculate the profits per tree for three years.

Post harvest Handling

Fruit after plucking wash the fruit in normal cold water. Then dip in hot water at 49`B0c Celsius. This is the water one can put your hand for few minutes with out burning your hand. Keep for 2-4 minutes. Ensure that water temperature does not drop or increase. Allow fruit to dry. Store in a well ventilated boxes by keeping the stalk down wards. May wrap with clean old newspaper to prevent damage due to fruits touching each other. If one wants to hasten ripening spray with 0.1% ethral solution till the entire fruit is well moist and cover with a polythene sheet. Ethral treatment would ensure - ready to eat in 48 hours if a 25% yellow fruit is harvested, by mixing one milk litre of ethral in one litre of water this solution could be made. Using a small PVC hand sprayer ethral solution could be applied. Ethral is available in Agrochemical shops.

How to get Red Lady Papava Plants

Most Mahaweli Systems farmers are raising plants for their own cultivations. Nursery men in cities could arrange to get down plants and sell. There are seed importing companies importing small quantities of seeds for sale. Contac your Agriculture Extension officers for Red Lady papaya plants. May be a good business for Nurseries.

Important

Never plant papaya without borate and zinc sulphate. Do not apply these fertilizers more than recommended amounts. Too much of it can cause toxic effects.

It is nice to see home gardens with beautiful Red Lady papaya trees.

Grow Papaya and eat it and be healthy. Reduce your medical bills. A detailed book on cultivation will be available soon.


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