OPTIMIZATION OF COVERING TIME WITH PERFORATED PLASTIC ON EARLY CARROTS (DAUCUS CAROTA L.)

In Belgium’s maritime climatic environment (51° N Lat; 4° 30′ E Long) carrots of the cultivar Amsterdamse Zoete Bak (Nunhem) were sown on 1st February 1980 and covered immediately with P.E. sheets, 50 micron thick with 250 and 500 holes of 1 cm in diameter per square meter.

Optimum carrot development was obtained by leaving direct cover on the crops until after the first ten days of May 1980 for the plastic sheeting with 250 holes and until after the second ten days of May for the plastic sheeting with 500 holes per square meter.
The best yields were obtained under direct plastic sheeting with 250 holes per square meter.

The optimum point of time until which the direct sheeting should be left on the crops is when the minimum soil temperature exceeds 8° C.

A longer period of cover than the said optimum restrains root development.
This restraining effect is caused by maximum soil and air temperatures of 26° C, in the sense that such temperatures stimulate the development of the leaves at the expense of root growth.

Symposium on Timing of Field Production of Vegetables

N. Ceustermans, F. Benoit, A. Calus

https://doi.org/10.17660/ActaHortic.1981.122.6