Asian Journal of Plant and Soil Sciences

The winged bean is a native plant of Papua New Guinea (PNG), is highly nutritious and the entire plant can be eaten. Despite these, it is an orphan (underutilized) crop grown on a small scale. Since climate change is anticipated to cause food insecurity due to a decline in the yield and quality of staples, there is a need to promote underutilized crops. This research aimed to study the agronomic potentials of PNG’s winged bean and make it a staple crop to address malnutrition and food security under climate change by promoting wider publicity and production. To attain this aim, three-winged bean cultivars collected from the highlands (Hgn and K92) and the lowland (Rab) were grown under greenhouse conditions at the School of Agriculture, PNG University of Technology, Papua New Guinea. The three cultivars were grown in 30 cm polythene pots containing nearly 1,300 g of topsoil and replicated five times, set up in a completely randomized design (CRD) manner. In each pot, a total of ten seeds of each cultivar were sown, except in the control treatment, and allowed to run for five months. Within the first month, the plants were thinned to five per pot and managed until harvest. Assessment of plant growth parameters began around this time and continued for three months. During harvesting, soil samples were taken from within the 30 cm root zone of each plant and composited by mixing with samples from all the replicates. A 500 g subsample was taken from the composite samples, packed into sealable paper bags and transported to the laboratory. The samples were air-dried for three days and then processed for instrumental analysis of soil nutrients and measurement of soil parameters. The average data from the five replicates of each treatment, plant, and soil were pooled, averages calculated, and statistically analysed. The results showed winged bean cultivar-specific induced changes in soil chemistry, and growth was dependent on the origin of the agroclimatic zones. The lowland cultivar was fast-growing, taller, leafier, and more productive than the two highland cultivars. This is the first study to evaluate the soil requirements of winged bean collected from different agroecological zones in PNG. The results have broader implications for future research and medium-to-large-scale production, making the winged bean a popular and alternative staple crop under climate change.