CUCUMBER: THERMAL SCREEN AND GROWING MEDIA INVESTIGATIONS

Information is presented on the effects on cropping on January planted cucumbers by the use of a thermal screen. The data refers to the complete crop in 1979 and until mid-June for the 1980 crop.

Four different growing substrates were used with and without screens in both years and trimming treatments were also compared.

The effect of the thermal screen in both years was to produce a more vegetative plant in the early part of the season and a reduction in fruit yield. As the crop progressed the percentage reduction between the screened and unscreened compartments decreased but in 1979 the screened crop never equalled the yield and monetary return of the unscreened. The use of a "Peritherm" screen saved an estimated 9.3 l per m² of heating oil under average weather conditions but the value of the crop loss was £1.6/m². Revenue lost was therefore greater than the saving in fuel and the annual charges on the installation of a screen have not been taken into consideration.

In 1979 the peat troughs gave the highest early yield and return but later declined to give the lowest yield and return by the final harvest. This was likely to be due to problems in maintaining adequate nutrient status in the peat with liquid feeding.

The thinning of the fruit to one cucumber per node on the main stem gave a slightly higher yield, return and percentage Class I throughout the crop compared with leaving all fruit on the plant.