Effect of Plant Density, Spacing and Trellising System on Productivity of Yellow Passion Fruit (Passiflora edulis f. flavicarpa O. Deg)

Horana Gold, the widely cultivated yellow passion fruit (Passiflora edulis f. flavicarpa O. Deg.) variety in Sri Lanka, has a high yield potential (50 t ha^-1), but its low average productivity (30 t ha^-1) creates supply and price issues. Plant density is considered as one of the major factors influencing the yield gap and high density planting is recognized as a successful strategy to increase crop productivity. Yield and fruit quality of Horana Gold passion fruit in presently recommended trellising system (vertical), spacing (2 m × 4.5 m) and plant density (1,111 plants/ha) were compared with a vertical system with 2,222 plant density and 2 m × 2.25 m spacing, T- trellis system with two plant densities (1,777 and 888 plants /ha) in 2.5 m × 2.25 m and 2.5 m × 4.5 m spacing respectively at Fruit Research and Development Institute Horana and Mahaweli farm at Kattakaduwa. The highest productivity of 44.1 t ha-1 was obtained with the high density (1,777) in T- trellis which was 51.5% and 52.6% higher than the productivity of 888 plants/ha in T- trellis system and 1,111 plants in vertical trellis system, respectively. High density planting in vertical trellis system did not increase the productivity and gave comparable productivity with lower density in both trellis systems. Significant differences were not observed in fruit weight, Juice content, soluble solids, titratable acidity and the soluble solids/ titratable acidity ratio in the fruits cultivated at the different spacing in both years at two locations. As the yield increases by more than 50% without affecting fruit quality, the spacing 2.5 m × 2.25 m of 1777 plant density in T- trellis system can be practiced in productivity improvement of yellow passion fruit.