Vol. 73 No: 1

Title:
Low Temperatures Decrease CO₂ Assimilation and Growth in the Tropical Rambutan

Authors:
Y. DICZBALIS and C.M. MENZEL

pp: 65-72

Abstract:
In glasshouse experiments, high temperatures increased vegetative growth in the tropical rambutan (Nephelium lappaceum L. seedlings of cv. Rapiah). In absolute terms, there was generally a greater response to night temperature (day/night temperatures of 32°/14°C vs. 32°/28°C) than to day temperature (22°/14°C vs. 32°/14°C), and better growth at 32°/28°C than at 32°/22°C. The effects of temperature on nutrient concentrations were small, whereas average leaf water potential (ψ_L during the day was –1.5 MPa at 32°/28°C, 0.1 to 0.4 MPa higher with nights of 14° or 22°C, and 0.7 MPa higher at 22°/14°C. Average net CO₂ assimilation rate (A) was 5.3 µmol m^-2 s^-1 at 32°/22° and 32°/28°C, 50% lower at 32°/14°C and 80% lower at 22°/14°C. When seedlings of cv. Rapiah were grown in water baths, the two critical root temperatures at which 90% of maximum plant weight occurred were similar for leaves and stems (about 24° to 30°C), but lower for roots (19° to 25°C). There was only a small effect of temperature on the concentration of most nutrients, and on average day time ψ_L, whereas average A was 4.5 µmol m^-2 s^-1 at 28°C, 30% lower at 20°C, and 80% lower at 15° and 38°C. These experiments show that rambutan growth was strongly reduced when night or root temperatures fell to 14° or 15°C. The main effect was through lower CO₂ assimilation, whereas the changes in water and nutrient status were relatively small. Areas where night or root temperatures remain at or below 14°C for prolonged periods should be avoided for rambutan production.

Full text: JHSB Subscribers     ISHS members & other users
(PDF 561275 bytes)

Translate:

Go back to previous page