The National, Tuesday July 30th, 2013
By JAMES LARAKI
POTATO is an important crop in the highland regions, particularly in high altitude areas.
These high altitude areas include Kandep and Sirunki in Enga, Tambul and Tomba in the Western Highlands, parts of Ialibu and upper Mendi in Southern Highlands, Gembogl in Simbu and parts of Magarima in Hela.
Due to the climate, the variety of food and cash crops that can be grown is limited.
This makes potato an important crop.
It is their favourite crop, both as a major cash earner and as an alternative staple food to sweet potato.
An outbreak of potato late blight (Phytophthora infestans)in 2003 completely wiped out this popular crop and left the growers in shock.
Reviving the industry was impossible as the common potato variety, Sequoia, was susceptible to the blight.
Because of its importance and the need to assist smallholder growers, NARI made urgent attempts to revive the crop.
The potato industry was worth about K10 million–K15 million at that time.
The challenge was enormous.
The climate in the region is ideal for the blight and devising control measures was challenging.
Chemical control measures were found to work, but spraying was needed every 3-5 days.
Most smallholder, moreover, could not afford the chemicals and equipment needed to fight off the blight.
Ensuring potatoes remained a viable crop for smallholders depended on finding new varieties that were resistant to the blight as well as effective and inexpensive control methods.
Small quantities of potato could still be found in local markets but these were from well-to-do growers who could afford seeds, chemicals, equipment and labour.
The challenge to assist the ordinary growers who represented the bulk of the population still remained.
NARI and its partners made a breakthrough in 2011 with the preliminary release of the two blight-resistant varieties.
This development was greeted with relief by smallholders.
NARI released another two varieties last month.
These were the result of a project supported by the Australian Centre for International Agricultural Research which was aimed at evaluating blight resistant potato varieties.
The objectives were to introduce, multiply, evaluate and deploy blight resistant materials to PNG and to develop safe and cost-effective integrated blight management strategies for existing and new cultivars.
Under the project, NARI sourced 59 International Potato Centre (CIP) clones in 2003 and evaluation work was undertaken at a number of sites to assess resistance and yield.
Of these, 12 clones where selected and evaluated against Sequoia at the institute station and farmers’ fields.
The varieties released to date have proven to be blight resistant, high-yielding and have other favourable characters such as good taste and processing quality.
These were observed through trials on farmers’ fields in all areas where the crop was grown.
The released varieties have been exposed to a wide range of farmers and the general public for their comments and views.
This was done both at growing and harvesting stages.
Many growers have shown their approval and have started growing them.
Potato late blight still remains a concern and work will continue to overcome the problem affecting PNG growers.
It is an extremely destructive disease particular to potato. It attacks both tubers and other growing parts. It is also capable of rapid development and spread.
It was responsible for the devastating Irish potato famine of the 1840s and remains a threat.
Since the Irish famine, blight has become the most-studied potato disease in the world.
Previously free of the disease, PNG was one of the world’s few remaining safe havens for growing potato until 2003 when the disease appeared.
The crop was wiped out in a matter of days after it was first discovered in the Sirunki area
The blight is believed to have come from the Indonesian province of West Papua.
Yield losses caused many smallholders, who relied on it as a cash and food crop, to withdraw from production.
This led to an increase in potato prices in the country.
Fungicides can control the disease but the extra input has been a burden for smallholders.
Identifying suitable varieties was the long lasting solution needed to revive the industry.
Hopefully, smallholder farmers will now be able grow their favourite crop once again with the released materials.
Growers are now being encouraged to try out the four varieties and adopt whichever depending on their own assessment and needs. – NARI