EFFECT OF THE REMOVAL OF THE TWO DIRECT COVER SHEETINGS (DC) ON THE DEVELOPMENT OF CARROTS (DAUCUS CAROTA L.)

From the comparison of the results obtained in the colder and relatively dark 1987 spring with those of the warmer and bright 1988 spring, it appears that the initial plant development is mainly promoted by temperature up to the second 10 days in April.

The hypothesis was proposed that from an average minimum air temperature of 8.7°C an optimal root-leaf ratio develops in carrots, and that from that moment on the plant also becomes more light-dependent.

Both in 1987 and 1988 these conditions were obtained in the second 10 days of April.
So that the upper perforated sheet of the double direct covering had therefore to be removed at that time, so as to allow a better light transmission.

Removal of the lower PP sheet took place during the first 10 days of May and was not influenced by the upper perforated sheet being applied or not.

Better results were consistently obtained with the more thermophile and translucent PE-EVA-IR-AC sheeting than with PE.

VI Symposium on the Timing of Field Production of Vegetables

F. Benoit, N. Ceustermans

https://doi.org/10.17660/ActaHortic.1990.267.5