HEATED HYDROPONIC SOLUTIONS AS AN ENERGY SAVING TECHNIQUE

Two tomato cultivars, Pipo Improved and Sleaford Superabundance, were grown in nutrient solution culture on a high-density cropping system.
Using a common positive day/ventilation temperature regime of 20°/26.7°C the following treatments were applied:

1. a night temperature of 17.8°C with a solution temperature at ambient;

2. a night temperature of 17.8°C with a solution temperature of 25.5°C; and

3. a night temperature of 12.2°C with a solution temperature of 25.5°C.

Excessive vegetative growth was a problem during the poor light conditions of early Spring and some abortion occurred.
Mean early yield was increased 24.7% in the warmer environment with the heated solution and there was no yield reduction at a night temperature of 12.2°C. Total yield was slightly reduced in the warmer environment with the heated solution, but there was a yield increase of 17.5% at 12.2°C. There were cultivar interactions in relation to yield and quality at both stages of cropping.
The satisfactory performance at the reduced night temperature is of some significance as this regime would result in up to a 30% saving in the heating requirement.

Symposium on More Profitable Use of Energy in Protected Cultivation

J.V. Morgan, R. O’Haire

https://doi.org/10.17660/ActaHortic.1978.76.24