Water relations in passionfruit: Effect of moisture stress on growth, flowering and nutrient uptake

Abstract

The response of passionfruit hybrids (Passiflora edulis f. edulis × P. edulis f. flavicarpa cultivar E-23 on P. edulis f. flavicarpa seedling rootstocks) to soil moisture was evaluated in a heated glasshouse by irrigating when soil water pressure potential fell to −0.0025, −0.01, −0.14 and −1.5 MPa. Leaf, stem and root dry weight, leaf area, vine extension and node, flower bud and open flower number were reduced by soil moisture stress. Changes were also noted in a range of morphological characteristics. Reductions in growth and flowering were associated with reduced nutrient uptake and leaf water potential, but not leaf conductance. It was concluded that moisture stress may be one of the major environmental factors responsible for seasonal fluctuations in passionfruit yields.