Cassava

Cssava

Cassava (Manihot esculenta) which belongs to the family Euphorbiaceae is a robust productive starchy root crop that is grown clonally almost entirely within the tropics, grown chiefly as a food. But it is also an important animal feed, and it has several significant industrial uses. Cassava is a perennial crop, originated in Brazil with Central America and introduced to Sri Lanka in the Dutch regime. Since then cassava stands out in the country as the most important source of energy for the calorie deficient low-income population strata. But from the recent past it has now become a major horticultural export commodity earning foreign exchange.
Nutritional Value
Cassava roots combine high energy and high levels of some vitamins, minerals and dictary fibre and contain no trypsin inhibitor, but create a problem due to presence of cyanide which is removed by post-harvest treatments and cooking. The edible green leaves of cassava are a good source of protein, vitamins and minerals and are often used to augment the rural diet.
Nutritional values of Cassava

Component	Root tubers	Leaves
Moisture % Energy (Kg/100g) Protein % Starch % Sugar % Dietary fibre % Ash %	62.8 580 0.53 31.0 0.83 1.40 0.84	74.8 - 5.1 - - - 2.7
Minerals (mg/100g) Ca P Mg K S Fe	20 46 30 302 6.4 0.23	350 56 - - - 218
Vitamins (mg/100g) Vit. A Thiamin Riboflavin Nicotinic acid Vit. C	Trace 0.05 0.04 0.6 15.0	3 0.2 0.3 1.5 200

 
Growing situations
Although cassava is not a nutritionally superior crop, from the agricultural point of view its popularity among resource poor farmers is due to its remarkable hardiness, drought resistance, relative freedom from pest attack and its ability to give acceptable yields under unfavoured conditions with low inputs and attention. It is mainly grown as a rainfed crop throughout the island excluding high elevation areas and mostly concentrating in the wet and intermediate zones. The production systems of cassava have been identified as a backyard crop and large scale open-land cultivation in the wet zone (Gampaha, Colombo, Kegalle, Rathnapura and Matara Districts) as well as in the intermediate zone (Kurunegala district) are mixed cropped with coconut and pineapple cultivations. Chena cultivation in large scale in the dry zone (Putlam, Anuradhapura, Ampara, Hambantota, Moneragala Districts) is viable. Peak production falls during Maha season.

Statistics 
According to FAO estimates, 172 million tonnes of cassava was produced worldwide in 2000. Africa accounted for 54%, Asia for 28%, and Latin America and the Caribbean for 19% of the total world production. In 1999, Nigeria produced 33 million tonnes making it the world’s largest producer.

In terms of area harvested, a total of 16.8 million hectares was planted with cassava throughout the world in 2000; about 64% of this was in sub-Saharan Africa.

The average yield in 2000 was 10.2 tonnes per hectare, but this varied from 1.8 tonnes per hectare in Sudan to 27.3 tonnes per hectare in Barbados. In Nigeria, the average yield was 10.6 tonnes per hectare.

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Dioscorea is a seasonal crop

DIOASCOREA

Dioscorea is a genus of over 600 species of flowering plants in the family Dioscoreaceae, native throughout the tropical and warm temperate regions of the world. The vast majority of the species are tropical, with only a few species extending into temperate climates. It is an important staple food crop in the Pacific, Africa and the Caribbean.

Among the tuber crops cultivated in Sri Lanka Dioscorea plays major roll in food security. Dioscorea is a seasonal crop. It means planting in Yala season and the harvest in the Maha season. Special character of this species is remain dormancy period up to planting time.

Easy management, minimum pest and disease attacks, Less input, less attention, can be cultivate in marginal lands as well as high medicinal value gives high demand for Dioscorea spp.

Time of planting
Recommended planting period is the onset of rain in the Yala season. Sand nursery can be used to get germinate those tuber pieces to obtain planting materials on time.

Planting materials
Usage of healthy seed tubers and tubers divided into pieces of 250g are important to maintain successive cultivation. Ash or fungicide must be applied on cutting surface.  

Land Preparation
Loose soils with organic matter more suitable for the Dioscorea spp. Large size pits must be prepared with the rigid soil. Normal size of the pit is about 1X1X1 feets. Straw, coconut husk, paddy husk as well as grass debris can be used as organic matter. Pits is filled with these matter and tubers with active bud can be planted on it.

Dioscorea spp
The most popular Dioscorea spp in Sri Lanka is Dioscorea alata  or Maha vel ala. Apart of that Dioscorea esculenta (Lesser yam) and Dioscorea bulbifera also can be seen. Dioscorea rotandata or the African Dioscorea is the species which is introduced to Sri Lanka.

Recommended spacing
Maha vel ala (greater yam) - 1X1m
Kuda vel ala (lesser yam) - 1X0.5m

Recommended varieties

	RAJA ALA	KEKULU ALA	KADIRA
Anthocyanin pigment	Edges of the vine, leaf stalk as well as tuber	Pigments can be seen at the edges of the vine only with germination	No pigments
Shape of tuber	Globular, Occasionally divided tubers	Fan shape tubers	Cylindrical shape small tubers
Weight of tuber	1-2.5kg	3-5kg	100-200g
Flesh colour	Purple colour	White colour	White colour
Taste	Starchy	Medium  starch with mild sweetness	Starchy
Yield	Height yield 32-35t/ha	Height yield 35-38t/ha	30-32t/ha

DOA released varieties
DOA recommended three Dioscorea varieties for cultivation. Those are “Kadira” from Dioscorea esculenta and “raja ala” and “kekulu ala” from Dioscorea alata. Instead of that there are other popular Dioscorea varieties.

Trellising
6 feats and 2.5 inches diameter supporting stalks must be used for each plant. It causes to higher yield. Usage of rope or “V” shape trellising can be use with lack of stalks.
It is very important to train the vine towards trellising.  

Eat Local First by Pubudu: Sweet Potato

Eat Local First by Pubudu: Sweet Potato: SWEET POTATO The cultivation of sweet potato has traditionally been confined to varying growing systems such as open land highland, r...

Sweet Potato

SWEET POTATO

    The cultivation of sweet potato has traditionally been confined to varying growing systems such as open land highland, rice fallow system, under shade, owita and homestead conditions. Sweet potato has remarkable ability to convert solar and soil energies into carbohydrates giving impressive yields under marginal and stress situations having low input requirements and little attention, wide adaptability, flexibility in crop management and non-seasonality make sweet potato a viable crop in all agroecological zones excluding high elevations.

Recommended Varieties

1. CARI-9                2. CARI-273            3.CARI-126

4. Wariyapola red    5. Wariyapola white   6. Ranabima

Variety		Age (month)	Flesh colour
CARI-9		3 1/2 - 4	Light yellow
CARI-273		3 1/2 - 4	Light yellow
Wariyapola-red		3 1/2	White
Wariyapola-white		3 1/2	White
Ranabima		3 1/2 - 4	Light yellow
BW-8 (Shanthi)		3 1/2	White
BW-21 (Chitra)		3 1/2	White
Gannoruwa - Sudu		3 1/2 - 4	Light yellow

Variety Discription

CARI-9

Semi-vine plant type with entire to very slightly lobbed leaves. Root tubers have dark pinkish skin with highly variable tuber shapes which are fusiform.

CARI-273

Semi-vine plant type with entire leaves. The mature leaves are green in colour and the tender leaves are light green with purple at margin. Petioles are light green with purple at leaf end and petiole base. Root tubers are fusiform shape with purple coloured skin.

CARI-426

It is a polycross hybrid and maternal parent is a native variety Beli-batala. It has a bushy plant type with deeply cut leaf laminas. Vines and leaves are green in colour with purplish green tender leaves. Root tubers are highly uniform and fusiform in shape having pinkish orange skin.

Wariyapola red

It is a selection from the local sweet potato collection and planting material is available in all sweet potato growing areas. Semi-vine plant type with entire to very slightly lobbed leaves. Root tubers are highly uniform and fusiform in shape having purple skin.

Wariyapola white

Wariyapola white is a mutant, originated from the variety Wariyapola red. Semi-vine plant type with entire to very slightly lobbed leaves. Root tubers are highly uniform and fusiform in shape having white skin.

Ranabima

Semi-vine plant type, the leaves are entire to slightly lobbed, vines are yellowish green except tender vine apices are slightly pigmented. The root tubers are round elliptical shape with pink skin.

BW - 8 (Shanthi)

It is a natural selection from Kalutara district. BW - 8 is a semi-vine type plant with light green stems. Leaf type is moderately lobbed with purple colouration at the base of the leaf on the lower side. Tuber shape is egg shaped with tapering ends and skin colour is white.

BW - 21 (Chitra)

It is a natural selection from Galle district. Viny plant type with moderately lobbed leaves. Mature leaves are green while the young leaves are reddish brown in colour. It has conical shape root tubers with white skin.

Gannoruwa Sudu

It is a polycrose hybrid and material parent is recommended variety CARI-426. Semi-vine plant type with numerous major branches. Entire vines are green in colour except the very tender vine apices which are slightly pigmented with moderately lobbed leaves. The root tubers are round to elliptical shape, highly uniformed with white skin.

Field Establishment
Climate 

Sweet potato is grown in the tropical, sub tropical and warm temperate regions of the world. Sweet potato is a sun loving crop. It requires considerable amount of rain during the growth period and a dry period during root formation. Warm sunnydays and cool nights are very much favourable for storage root formation in sweet potato. Tuber yields are reduced considerably if drought occurs within first six weeks after planting.

Soil 

Sweet potato can be successfully grown in a variety of soils, however well drained sandy loam soils are best suited. On heavy clay soils shoots grow well, but yield of tubers will be poor with deformed tubers.

Land preparation 

Till to a depth of 25cm. Soils must be well drained and well aerated for a successful tuber growth. Ridge and furrow method, mound method, narrow bed and broad bed method are practiced in sweet potato cultivation in different areas. Ridge and furrow method and narrow bed method are better than other methods.

Planting material requirement 

Vine cuttings are suitable for planting. The vine tip cuttings are found to be best to get higher tuber yield from sweet potato. In some varieties recurrent use of vines as planting material for more than 5,6 seasons showed marked decrease in yield. For these varieties root tubers can be sprouted and get cuttings. About 55,000 - 60,000 cuttings are required to plant one hectare.

Time of planting 

Under rainfed conditions, plant with the Yala and Maha rains. In the wet zone in both Yala and Maha and in the dry zone in Maha season only.

Under irrigated conditions, planting can be done at any time of the year.

Nursery preparation 

To produce enough planting material a nursery can be prepared.

Planting and spacing 

No of cuttings and method of planting depend on the method of bed preparation. Spacing between 2 plants is 20cm. In ridge and furrow method cuttings are planted at a spacing of 90cm x 20cm. Vines of 20-25cm length with at least 5 leaves are found to be ideal as planting material.

Nutritional value of INNALA

INNALA

Nutritional value
Innala is the most profitable tuber crop that is grown in Sri Lanka. It is grown basically for the local market and where cultivation is done in large extents marketing is not a problem. A net profit of over Rs 100,000 / acre is earned by certain farmers in the traditional areas. It also has a nutritive value that is similar to potato and is considered a 'safe' vegetable as it is grown basically without any pesticides.

Nutritional value: (% d.w.)
Moisture	72.9-77.6
Carbohydrates	19.7-23.4
Protein	1.3- 1.46
Fat	0.3-0.6
Fibre	0.4-0.87
Minerals	0.9-1.07

Per 100g dry weight
Ca-17.0mg; Fe- 6.0mg;
Thiamin 0.05 mg; riboflavin 0.02 mg; niacin 1.0 mg; ascorbic acid 1.0 mg
Principal amino acids are: argenine; aspartic and glutamic acids

Some physical properties
Starch granules- shape: round; size: 70% between 8-16? (smaller than other root crops hence, high digestibility)
Total amylose content: 33%
Gelatinisation temperature: 65-85 0C
Cooling to room temperature: 56 seconds

Unique record in yam preservation

By preserving 64 varieties of local yams, the Aranayaka Community Development Centre (ACDC) has established a unique record islandwide as well as abroad, according to reports.

ACDC Manager, Damayanthi Godakumbura told the Daily News that the centre initially had preserved 36 local varieties of yams with the participation of 100 farmers belonging to 10 villages in 2001.

Preservation had been done for 50 varieties of yams with the participation of 200 farmers and in 2011, ACDC was able to preserve 64 varieties of yams with the help of 500 farmers.

Godakumbura added that the majority of activists in yam cultivation was women.

In 2007, the ACDC had won the 'Soba Jana Prasadinie' award. The ACDC had also won the first place at the Bio-Diversity Preservation Contest 2008 in Barcelona, Spain beating the best 25 projects out of 6,000 different projects.

In 2010, the ACDC had represented village women at the United Nations Bio-Diversity Summit held in Nagoya in Japan, where 192 countries participated.

Courtesy: DailyNews 

How to cook lotus root

How to cook lotus root 

(From the archives - since all of a sudden, a lot of people are asking about lotus root! Originally published in April 2008.)

Lotus root (renkon in Japanese) is actually the rhizome of the lotus plant. It’s a popular vegetable throughout southern and eastern Asia, but it’s still not that well known in the west. Lotus root is full of fiber and various vitamins and other nutrients. In Asia it’s believed to have various medicinal qualities, but in macro-nutrient terms it’s best to think of it as a starchy vegetable, like potato. Visually of course, it’s very appealing with all those little holes. Here I’ll explain how it’s prepared and eaten in Japan.

How to prepare lotus root

First off, this is how a raw lotus root looks like. You can buy them at an Asian (South or Eastern) grocery store. More often than not they will be vacuum packed. A nice fresh one is a light orangey-brown. The older the root the browner and darker it is.

Mature lotus root has a sort of slightly bitter or tannic quality, so should not be eaten raw. (Apparently young lotus roots can be eaten raw, but I’ve never encountered them unfortunately.) The bitter/tannic substance is most concentrated in the skin, so you should peel it. Inside, it’s a light flesh color.

(Another way to deal with a raw lotus root is to steam it whole, but peeling and slicing is easier for beginners.)

Raw lotus root will start to darken almost right away, rather like raw potato. To prevent this, put the peeled lotus root in water with a little vinegar in it. If I slice it up, I put the slices in the vinegar water.

If using the slices for a salad, or for any dish that has no further or very little more cooking, they should be boiled for a couple of minutes in vinegared water. This retains the crunchy texture but gets rid of that tannic-ness.

You can also buy lotus root in cans, which can be used straight away. However, many canned lotus roots have been bleached to make then whiter, so I prefer to use raw lotus root if I can find it. (The natural color of lotus root is a very light flesh-orange.)

Changing textures

Depending on how long it’s cooked, the texture of lotus root varies from crunchy to very starchy and a little sticky. I like it either way. Here are two ways of using lotus root in its crunchy stage.

Recipe: Lotus root, cucumber and Serrano ham salad

• 1/2 lotus root, sliced very thinly and the slices cut into halves
• 1/2 English or seedless cucumber, de-seeded and sliced thin
• 1-2 slices of Serrano or other dried ham, cut into thin slivers
• 1/2 Tbs. rice vinegar plus additional for cooking
• Dash salt
• 1 tsp. sugar
• 1 Tbs. mayonnaise

Put the sliced lotus root into vinegar water as you slice it, as described above. Bring a pot of water to a boil, and add a little vinegar. Boil the lotus root for a couple of minutes. Drain and cool under running water; drain well.

Mix the vegetables and seasonings except the mayonnaise together well with your hands, scrunching them a bit to let the flavors penetrate. Add the mayonnaise and ham and mix well. Serve immediately, or cool in the refrigerator until dinner time.

Recipe: Stir-fried lotus root with sesame and green onions

• 1/2 lotus root, sliced very thinly
• 1 piece of fresh ginger about 1 inch / 2 cm or so long, peeled and chopped
• 2 garlic cloved, peeled and chopped
• 1 1/2 cups of roughly chopped green onions
• 2 Tbs. hot red chili pepper, finely chopped
• Oil
• Vinegar for the lotus root water
• 1 Tbs. sesame seeds
• Pepper
• 1 1/2 Tbs. soy sauce
• 1 tsp. sesame oil

Put the sliced lotus root into vinegar water as you slice it, as described above. Drain well just before cooking.

Heat up a large frying pan with the oil. Add ginger and garlic, and stir fry until the oil is very fragrant. Add the drained lotus root slices in a single layer. Cook until the lotus root slices start to change color - they turn a bit translucent looking. Turn over and cook a couple more minutes.

Add the chili pepper and green onions, and stir-fry. Add the sesame seeds, pepper, soy sauce and sesame oil. The lotus roots should get a bit caramelized from the soy sauce. Serve hot or cold. This is very nice for bento.

Other ways to eat lotus root

• Lotus root mini-cakes with sweet chili sauce. This uses the starchy, sticky quality of grated cooked lotus root.
• Lotus root slices poached in dashi and vinegar - a very traditional Japanese dish
• Cut up and put into soups or stews - the longer it’s cooked, the more starchy it gets
• Deep-fried or baked as chips (these baked ones on jugalbandi look great)
• With a batter as tempura
• Sandwich some meaty filling inside and pan-fry (hasami-age)