Management strategies for tubers, livestock

Nari, Normal

The National, Tuesday October 6th, 2015

 Strategies for sustaining food supply

Diets of Papua New Guineans mainly consist of root crop staples like sweet potato, yam, taro and cassava. These, unlike grain crops, generally have poor storage qualities. Storage qualities depend on a range of things (including respiration, senescence (a period when plants “sleep”), attack by fungi and other microbiological agents) that vary from one root crop to another, as well as biochemical and chemical processes that affect the concentrations of nutrients in the different species.


Sweet potato tuber storage

The common practice in PNG of continuous planting and sequential harvesting (harvesting only a few mature tubers from under the growing plant and leaving other tubers to mature) decreases the need for long-term storage. But in 1997/98, sequential harvesting became impossible because the soil became very dry, and weevils destroyed tubers stored in the soil.

Traditional storage of tubers on platforms in the sun can extend storage for up to a month. Otherwise, not much is known on methods used for storage. Weevil control is very important.


Storage of taro

True taro, and Singapore taro

Less is known about the storage of taro and Singapore taro compared to sweet potato, yam and cassava. Both taros can be harvested after maturity at 6 months and field stored for many months, which is the general practice in the country.

It is also known that taro can be stored in pits lined with coconut fibre or banana leaves, then covered with the same material and then sealed with a layer of soil. This enables unpeeled tubers to be stored for 2 – 3 months and peeled tubers for a month.


Giant taro & giant swamp taro

These crops are mainly grown at sea level, especially among atoll communities. These are planted independently of season and harvested from about 9 months to 4 years or more, hence corms are not usually stored. However, giant taro may be stored in special houses with yams.

Submerging tubers in water or covering them with wet sand may help store giant swamp taro. Storage using methods similar to that of taro in lined pits covered with soil or stones is reported to allow storage of giant swamp taro for 2-3 months.


Storage of yams

Unlike the other root crops mentioned yam becomes senescent (dormant or asleep), and is storable for several months. Yams in many parts of PNG are traditionally harvested in May to July and may be stored till October/ November before replanting. For yams to be stored for a longer period, physical damage that occurs during harvesting and handling must be minimised. Traditional storage in yam houses or any dry shelter should be applied for successful storage. Shoots can be removed a number of times to extend the dormancy.


Storage of cassava

Cassava’s swollen roots unlike the other tuber crops roots that bud, act simply as carbohydrate stores that may be used by the plant, enabling it to survive during periods of drought. Deterioration is extremely rapid once roots are detached from the plant. Cassava can be left attached to the plant in the ground for longer periods after it is ready for harvest.

Sugar content increases during storage. Cassava tubers stored in the ground during a drought may become more fibrous but remain edible.


Livestock management

We must manage our livestock properly during droughts. If we do not, animals will roam food gardens and water holes, causing destruction and contamination. Those that are left to fend for themselves can die of starvation.

There are various benefits of rearing livestock at home. First and by far the most important benefit is the protein that they provide, then money from sales, as forms of payment, and droppings as valuable organic manure for gardens. In some areas where dogs are eaten, they also provide security. Pigs form an integral part of livestock rearing in most parts of PNG. Although they are seen as wealth, they can be a pest in times of droughts. Under dry conditions, pigs will be more difficult to keep than other livestock like chickens.

In most villages, chickens and ducks are a normal sight. Sheep and goat rearing had picked up pace, particularly in high mountain areas. Rabbits are also being reared in small numbers. These minor livestock usually demand less attention and food.

Steps should be taken to ensure that animals do not put a strain on the food supply and destroy gardens, natural bushlands and water. 

  • Sell most and use money to buy and store livestock feed. Some of this money should be used to buy and store food like oil, flour and rice;
  • use most of the pigs to settle debts; 
  • kill, distribute & eat animals as feed supply starts getting scarce; 
  • most minor livestock would feed on grass and leaves of vegetables that are not normally eaten by humans, thus animals like goats and rabbits should not be affected immediately;
  • chicken and duck populations should be reduced to a manageable size. Both could live on plants and insects but not for long;
  • pigs should be given less priority when kaukau becomes scarce;
  • give to relatives for safekeeping, in areas near rivers or places where drought will harm the animals less;
  • fence in vital gardens and water sources if there are possibilities of pigs accessing those sites;
  • all livestock should be kept in fenced areas. In cases where goats are reared, ropes should be tied around the neck at appropriate lengths to minimise destruction to gardens; and,
  • There should always be at least a healthy reproducing male and female kept for breeding purposes after a drought.


Animal manure

When animals are fenced in, waste can easily be collected and applied in backyard gardens, which are much easier to maintain. Waste can also be used in fishponds to feed fish.