Sweet potatoes originated in Central America and are thought to have been introduced into Papua New Guinea about 1,200 years ago. The sweet potato is high in carbohydrates and vitamin A and its edible leaves also provide protein, vitamins and minerals. The potatoes grow on a vine that provides weed-controlling ground cover and their many varieties differ in colour, texture, taste, size, and tolerance to salt, water or drought. The plants grow easily from cuttings, can be planted any time of the year and may be harvested multiple times after three to twelve months. Their versatility makes them an important food crop and they provide about 65% of the calorie intake of rural people in Papua New Guinea.
In 2004 the Australian Centre for International Agricultural Research (ACIAR), World Vision Australia, Papua New Guinea’s National Agricultural Research Institute (NARI) and local farmers in the Madang Province of northern Papua New Guinea began a joint study of sweet potato varieties. The project aimed to identify varieties of sweet potato that would provide a bigger harvest than local crops to ensure food was available all year round.
Sixteen varieties were selected according to different characteristics based on yield, plant vigour and taste, and susceptibility to rat damage and disease. They included two Solomon Island varieties, one Philippines variety and eleven varieties from different parts of Papua New Guinea. Over three years the project tested the 16 varieties in almost 270 locations during both wet and dry seasons. Farmers evaluated the crops not only on the number and size of potatoes produced but also on smoothness of skin, skin colour, shape and taste. While they preferred crops that were sweet with soft, non-fibrous flesh and high in nutritional content, farmers chose to adopt almost all the trial varieties so they could have a choice for varying uses and climate situations.
Role of women
The active involvement of farmers, particularly women, was a key factor in the success of the project. Women’s knowledge of the types of sweet potato was greater than men’s as women were traditionally responsible for the planting of sweet potato and feeding the family. Also, unlike taro and yam, sweet potato is not regarded as a culturally significant crop, so women were not reliant on men to make decisions about planting.
Women were paid to prepare land, tend to the plants and harvest crops. With their saved money, one women’s group established a general store selling supplies such as rice, soap, salt and tinned fish. This has made a great difference to the community as previously these supplies were only available 300 kilometres away in Madang. Also, women were taught new recipes and ways of preparing sweet potato and some mothers began to sell these goods at school.
The role of women was further emphasised by the leadership of the project manager Sharryll Ivahupa. Sharryll, from Oro province, has worked as an agronomist investigating nutrient deficiency in tropical root crops. She studied for her masters degree in Agricultural Science in Australia on an AusAID scholarship. She loved working with the local farmers on this project and her enthusiasm inspired many of the women to share their knowledge and adopt new ways.
The project has contributed to the region’s food security by extending the range of sweet potato types available and their ability to provide food in a variety of situations. The communities involved have also benefited from collaboration with each other and the researchers, and women have been recognised for their knowledge and have learned new skills to earn an income.
Although the project did include pest and disease resistance as selection criteria, virus infection was found to be higher than expected and contributed to significant loss of production. This has been identified as an area for further study to protect plant species and food supply.