Effect of diffuse glass on the growth and winter production of cucumber

Research in The Netherlands has shown that it was possible to increase the yield of cucumbers in greenhouses covered with diffuse glass by 6 to 9%, despite the fact that light transmission was sometimes even reduced by diffuse glass. However, these experiments were performed in spring and summer, and never started before the middle of February. The proportion of direct to diffuse light during the winter months is relatively low in the north of Europe. For cucumber growers it is important to know if a yield increase due to the use of diffuse glass will also occur in an early cucumber crop, with a planting in December. Thus an experiment was designed to examine the effects of diffuse glass on cucumber compared to those of standard glass in the winter season. The diffuse glass had a haze factor of 71% and was covered with an anti-reflexion coating in order to realize the same light transmission as standard glass. The cucumbers, cv. Venice were planted in December 2011 and were grown in an umbrella system to the end of April 2012. The growing conditions in each treatment were optimized. The effect of diffuse light on e.g. light interception, light spectrum, photosynthesis, crop morphology, growth, energy consumption, yield and quality were measured and analysed. Results on the growth and development of cucumber are discussed in relation to the light quality and quantity in these treatments.