Optimum Replanting Stage for Two Varieties of Pit-Pit (Setaria palmifolia) in the Highlands of Papua New Guinea.

Abstract

Two varieties of edible pit-pit were grown near Tari in the Southern Highlands Province. The crop was progressively harvested over 512 days with a total of five harvests. Yields over the whole trial were 5.0 and 3.9 tonnes of edible portion per hectare for the two varieties, Mbu and Banguma respectively. A quadratic regression of cumulative edible portion per day on days after planting demonstrated that rate of growth declined approximately 350 days after planting for Mbu and 325 days for Banguma. The decline in both varieties was due to a lower individual stem weight and a higher percentage of waste (non-edible portion of total harvested) the longer the crop was in the ground. It is estimated that an increase of 2.0 and 1.8 tonnes per hectare for Mbu and Banguma respectively could be attained by harvesting every 100 days and practicing 325 day replanting rather than leaving the crop in situ for over 600 days.