Changing the row structure has no consequences for production and energy demand of a tomato crop. This is shown in research by Wageningen UR Greenhouse Horticulture. During a full growing season scientists compared the traditional conventional interplanting method with so-called intercropping ‘per gutter’ or ‘per path’. The study was financed by the Product Board for Horticulture and the Ministry of LNV upon commission by the programme ‘Greenhouse as Energy Source’.
The experiment, with grafted tomato plants, was carried out at the Improvement Centre in Bleiswijk and lasted from early October 2006 until the end of October 2007. The experiment comprised three consecutive cultivations. The first cultivation served as start-up of the system and three intercropping variants were applied in both subsequent crops, resulting in different row structures. Leaf angle, light interception, photosynthesis, stomatal conductivity and evapotransporation were recorded. In addition, two substrate types (coconut fibre or rockwool) were compared.
Same yield, different labour requirement
The results of this experiment do not allow a clear conclusion whether one of the three row structures is better than the other two. Through to week 42 production was the same in all three systems and substrate type was neither found to have an effect. Labour demand, on the other hand, in the treatments differed. Traditional interplanting demands more labour during interplanting and subsequent plant handling, because this must be done between the old plants. This is much simpler for both alternative methods and less labour is required during this period because a full path or a full gutter is removed at the same time. Interplanting per gutter requires more labour than interplanting per path because more backward and forward driving in the path is required.
The scientists conclude that a different method of interplanting will not contribute to energy saving in tomato cultivation.