Pampering potatoes
RESEARCHERs at the International Potato Centre's regional division in Delhi have designed an on-farm facility for storing potatoes throughout the summer months. Dubbed the "rustic, evaporative cooled store", this indigenous refrigerator is made of easily available materials - bricks, sand, mud, straw and bamboo or sticks.
The new storage facility - a large room with a thatched roof - has several drains 22.5 cm deep, half-filled with sand. Water let into the drains is absorbed by the sand. As water evaporates slowly, it reduces the temperature to as low as 18'c. The potatoes rest on a bamboo mesh placed above the drains. The store is designed to allow a constant flow of air through openings at the base.
This design is based on traditional techniques used by farmers in Tripura. Tripura is not a seed potato- producing state. The state government spends Rs 20 lakhs every crop season as subsidy to transport seed potatoes from outside, meeting 25 per cent of the state's total requirements. The variety mainly supplied to the farmers is the high-yield Kufri Jyoti, nicknamed "block aloo".
Tried and tested systems However, desi (indigenous) potatoes are said to respond better to traditional storage systems, despit'e low yields; farmers prefer to grow varieties like the Desi White or Bulaganji, and the Desi Red or Saleti potatoes. Says Bharendra Chandra Debnath, a 60-yearold veteran farmer of Deocchara village in south Tripura, sagely, "There is nothing to beat the local varieties in taste."
There are about 15,000 potato farmers in Tripura producing 4,000 tonnes of potato a year, half its requirement. The estimated seed potato requirement of Tripura is 5,000 tonnes.
Every farmer storing seed potatoes using indigenous reduce the rat menace.
Lalmohan Sarkar, a potato farmer in East Aralia, near Agartala, the state capital, who earlier used to store his seed potatoes under the cot, says, "When you store on the ground, one side of the potatoes will be cooler and the other side warmer, which is bad for the potatoes." For the past 12 years, Sarkar has been using manchas (bamboo racks) for storage.
Manchas are built in a dark corner of the house. The potatoes are spread out on the racks in a single layer, or stored in baskets placed on the racks. Says Sarkar, "On the manchas, there is proper aeration and the potatoes remain evenly cool." Kulachand Debnath, a 45-year-old farmer from Uptakali vil- lage in *south Tripura, has been using racks for the past 8 years; he came to know of this technique during an exchange of ideas in a farmers' training programme. "The rats can't get to the potatoes now," he smiles.
Unfortunately for Ramanand Nath of Bishnupur, the rats are still at it. Nath used manchas for storing, but had to resort to storing seeds under the bed once he replaced the thatch roof of his hut with galvanised iron (GI) sheets. "With the GI sheets, the room gets warmer, and so the potatoes start sprouting,"he explains. He is unhappy with the switch. 11 Earlier, I used to store potatoes for my personal consumption under the bed. Now, there is no place since all the space is occupied by the seed potatoes. And the losses were less with manchas. But I have no choice because of the GI sheets."
The GI sheets also rule out the adoption of another method extremely popular among the Tripura farmers - a false ceiling. Ratan Name, a dynamic young farmer in Laugang in south Tripura, has been storing seedpotatoes on a false bamboo ceiling for a long 14 years. He was used to storing the potatoes in baskets and keeping them under a cot. But he noticed that a large number of them started sprouting. "I realised that a dark place with good air circulation is needed. That's how I thought of a false ceiling."
Name stores the tubers in a corner of the false ceiling and uses the rest of the space to keep his agricultural implements. "The losses are less. It's space saving. It gives the whole house a new and better look. Even my neighbours are following my example now," he says happily. In some houses, the false ceiling extends only over the verandah of the house, although in most, it covers the entire house.
Nityanand Das from east Aralia also uses a false ceiling to store his seed potatoes. But a year ago, he decided to experiment with another method @Ping sand. "I got the idea by looking at the potatoes that come to the market from Shillong in Meghalaya," he reveals. "They are usually covered with a layer of red soil."
Das has kept the potato4s on a single layer of a 5-cm-thick layer of red coloured sand, jovered with an equally thick layer of the same stuff. He screenid the potatoes thrice for any signs of decay or disease. According to him, the losses were negligible. He plans to experimpnt with more potatoes. This method is fairly widespread in the KAimarghat area of western Tripura, where farmers mix a small amount of pesticide like DDT in the sand to keep pests at bay.
Bhanu Das of Satdubari village in west Tripura practises an interesting method of seed potato storage. "I remember my grandfather storing tubers this way," he says. "When my father came here from Bangladesh, he used the same method. I've been doing it for the past 25 years." Das first spreads the potatoes to be stored on the floor below a cot for one month. He then sorts them out, disposing off those that seem likely to rot. The remaining potatoes are placed in earthen pots, each pot carrying 5 kg. Twenty such pots are balanced one over the other in a corner of the house. Support is provided by bamboo poles that keep the pots stable. This method prevents damage by rats and postpones the rot. Das stores up to 300 kg of seed potatoes, both for home consumption and selling in the market. For some reason, this method has not caught on much with the other farmers in the village, despite its apparently superior technique.
---The authors are researchers at the International Potato Centre's regional division in New Delhi.