Improving yield and economic viability of peanut production in Papua New Guinea and Australia using integrated management and modelling approaches

• Trukai Industries, Papua New Guinea
• National Agricultural Research Institute, Papua New Guinea
• International Crops Research Institute for the Semi Arid Tropics, India
• Ramu Sugar Ltd, Papua New Guinea

Peanut production used to be an important industry in Papua New Guinea (PNG). Production for commercial processing and for export has declined since the late 1980s with the lack of high-yielding varieties, seed supply and cost-effective practices suited to local farming systems all factors. Aflatoxin, a potential health problem, is another as consumption of raw peanuts is common. There is little information on the incidence and extent of contamination of peanuts with aflatoxin in PNG, but studies from similar environments in Indonesia suggest that aflatoxin is likely to be a major problem.

Australia also has some common issues such as drought and aflatoxin contamination - although the peanut industry is more developed than PNG. Australian peanut growers have expressed a need for an economic support package that could help them to make critical decisions about farm management and financial planning. The modelling systems available focus on crop production risks and do not currently incorporate whole farm economic risks. In India, the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) has a peanut breeding program to produce high-yielding varieties with desirable characteristics, such as large kernel size and tolerance to foliar diseases, for use in developing countries.

The project is developing sustainable practices to improve the yield, quality and economic viability of peanut production in PNG and Australia. This will be achieved by gathering information on peanut production, storage, use, marketing and aflatoxin contamination in PNG, and by developing economics management software for the Australian peanut industry. ICRISAT will participate in the project's activities in PNG.

Researchers will first use surveys to assess the status of the peanut industry in PNG and aflatoxin contamination in peanuts at the three major market outlets. The team will combine an existing crop model with weather and soil data from PNG to characterise different peanut growing regions, with the aim of determining what varieties and management strategies are needed and the potential aflatoxin risk. Using elite varieties imported from ICRISAT and the Queensland Department of Primary Industries (QDPI), researchers will validate the results from the model in field trials at three strategic locations representing the major peanut areas of PNG. Trials will include some optimisation of plant populations and planting dates. Scientists from QDPI, ICRISAT, NARI and TI will collectively monitor field experiments. Researchers will then evaluate promising genotypes and appropriate management practices on farms, and will multiply seed from two or three top performing varieties for potential release to peanut growers.
A coordination and methodology workshop at the beginning of the project will allow the researchers to standardise procedures. The project team will also meet annually to review the project and plan for future work.

A peanut farmer survey conducted in four major peanut-growing regions, i.e. Eastern Highlands Province (Highlands), Markham Valley (Dry Lowlands), National Capital District (NCD-Dry Lowlands and Peri-Urban) and East New Britain Province (Wet Lowlands), assessed the status of peanut production, postharvest storage, utilisation, marketing systems and the extent of aflatoxin contamination. It revealed that peanuts play a significant role in increasing individual household incomes, thus contributing to living standards of the farming communities.

Peanut ranked amongst the top five income-generating crops across all the survey regions. It is estimated that about 60 percent of PNG farming families or households in the surveyed areas grew peanuts over an estimated land area of 14,000 hectares. The production estimate of 12,600 tonnes earned a gross income of around 30 million kina.

As part of the survey, a total of 274 peanut samples were collected from four major road side markets in the surveyed regions and analysed for aflatoxin content. Aflatoxin contamination was found in all the four markets with the percentage of positive samples being 22% in the Morobe Province, 35% in the East New Britain Province, 16% in NCD and 12% in the Eastern Highlands Province. Although >80% of samples recorded less than 20 ppb, 5% of the samples contained unacceptable levels of aflatoxin (up to 1000 ppb). Higher levels of contamination were often present in the roasted and dry pod samples. Combining results of the aflatoxin survey with the APSIM modelling work conducted in the project enabled the project team to draw some conclusions and make recommendations for future work related to aflatoxin minimisation in PNG.

A total of 47 improved lines of peanuts, consisting of short- and medium-duration varieties with foliar disease resistance and large kernel characteristics, were introduced from ICRISAT, India in 2002. The field trials resulted in identification of promising varieties with significant yield advantage over local checks. However, a large genotype x environment interaction observed in the trials meant that the varietal releases may have to be specific to each region. The selected varieties are being further evaluated on farmers fields to asses their local adaptation before releasing for general cultivation.
The APSIM peanut model was validated using the yield data from field trials and daily climate records of Aiyura, Bubia and Ramu Sugar sites. The model predicted pod yield satisfactorily for Bubia and Ramu Sugar sites but poorly for Aiyura site, due to unknown site-specific constraints. The analysis also suggested peanut crops sown between April and June at Ramu Sugar are more likely to experience dry weather, consequently, low yields and increased risk of pre-harvest aflatoxin contamination.

The project developed a 'beta' version of the economic modelling software package 'SmartPeanut', which is a suite of software tools that combines an economic framework and crop simulation models to analyse farming systems as an investment. Applications of 'SmartPeanut' include comparing economic risks and opportunities of various crop rotations, investments on new farm machinery, options to improve economic viability of the enterprise in relation to resources such as farm size, leasing versus owning land/machinery etc. SmartPeanut' will also be useful for researchers and consultants in studying the impact of climate and agronomic practices on farm sustainability and profits.