Growth of cape gooseberry (<em>Physalis peruviana</em> L.) plants affected by salinity

Abstract

A greenhouse experiment was conducted to assess the effect of salt stress on the growth of the cape gooseberry. Sixty-seven-day-old cape gooseberry plants were surveyed in perlite pot cultures salinized with varying concentrations of NaCl, i.e. 0 (control), 30, 60, 90 and 120 mM for 75 days. The growth indices: leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), unit leaf rate (ULR = NAR), leaf area ratio (LAR), leaf weight ratio (LWR), and specific leaf area (SLA), were calculated. Increasing levels of NaCl (60 to 120 mM) in the growth medium caused a reduction in the leaf growth parameters: LAI, URL, LWR and SLA. The reduction of leaf area expansion per unit of plant biomass (LAR) was primarily caused by a decrease in the SLA, which played an important role in determining the RGR of salt stressed plants. Concentrations of 30 mM NaCl stimulated the growth parameters: CGR, RGR, ULR and LAI, suggesting that this response is associated with adaptative morphological and physiological mechanisms to salt stress, such as osmotic adjustments. The curves of CGR, URL, LAR and SLA at 55 days after transplanting showed a reflection point from which salt effect begins to act more severely. The cape gooseberry can be classified as a moderately salt-tolerant species.