Transient shading effect on tomato yield in plastic greenhouse

Abstract

This paper studies the effects of temporally heterogenous shading on phenology, fruit set and yield of tomatoes. 3 double-ranks of tomatoes were cultivated in a northwest-southeast non-heated plastic tunnel greenhouse. The central double-rank was covered by a shading net, providing morning shading to the western rank, midday shading to the central rank and afternoon shading to the eastern rank. Midday shading decreased the tomato fresh mass production by 21 %, but increased the marketable rate of fruits, resulting in an only 4% marketable production reduction. Fresh production for morning and afternoon shading was in-between, but afternoon shading achieved an even 5% better marketable production than control. The fresh production loss was related to a lower number of fruits, which can be due to a slower production of trusses by the plants of the shaded treatments. Shading did not influence fruit loss after flowering. Anticipating the relation between panel-induced shading and microclimate, and tomato yield is useful to choose panel-stirring policies for dynamic agrivoltaism, as well as for deciding the plant spatial organization in tomato greenhouses.