A. Elings

Bladplukken tomaat : experiment 2015-2016 ‘Tomatenproductie sturen van blad naar vrucht’

Various leaf removal treatments were applied during winter and summer to tomato variety Brioso. The standardwinter treatment knew 33% removal of small leaves in the top of the canopy while in total 11-12 leaves per stemwere maintained. The two other winter treatments each knew 55% leaf removal and maintaining 8-9 and 10-11leaves, respectively. The standard summer treatment was the same as in winter. One summer treatment had noleaf removal and therefore a high leaf area, and one summer treatment had 66% leaf removal at the 4th to 5thtruss with approximately the same leaf number as the standard. It was concluded that 55% leaf removal in winterunder the ambient weather conditions has weakened the crop towards the end of winter. This is therefore a riskystrategy. Production was in the first place related to fruit weight and in the second place to the number of fruits.Leaf removal in winter results in a better dry matter partitioning to the fruits, while leaf removal mid-way canopydepth in summer results in a poorer dry matter partitioning to the fruits. An important question is how the excessof assimilates that is accumulated during summer by a small-fruited tomato can be utilized for production.

Plantmonitoring op basis van fotosynthese sensoren : Praktijktesten in de teelt van tomaat en gerbera

Wageningen University & Research, Business Unit Glastuinbouw has investigated two methods of monitoring crop photosynthesis that might be used in greenhouse horticulture: the crop photosynthesis monitor and the CropObserver. This project was funded by ‘Kas als Energiebron’ and executed together with PhenoVation and PlantDynamics. The data of the crop photosynthesis monitor were compared to those of the photosynthesis module of the crop growth model INTKAM. Furthermore, the pattern of stomatal opening during the day was calculated with the Stomata sensor. Measurements showed that the crop photosynthesis monitor was too sensitive to changes in window opening and in CO2 supply to determine the crop photosynthesis accurately. The CropObserver was useful in determining the relative light use efficiency of the crop. The best methods to accurately and reliably determine crop photosynthesis might be the following: 1. By a photosynthesis model (as in INTKAM) to calculate the crop photosynthesis, coupled to a sensor that monitors the crop status to register when the performance of the crop deviates from what might be expected, or 2. Via the CropObserver to which a module is added that determines the stomatal conductance and a measurement of the CO2 concentration which is necessary to translate the signal of the CropObserver to CO2 uptake by the crop

Workshops on Climate Smart Agriculture in Algeria

This study was carried out by the Wageningen Research Foundation (WR) business units Agrosystems Research and Greenhouse Horticulture and was commissioned and financed by Rijksdienst voor Ondernemend Nederland in the context of Policy Support. Project title: Workshops Climate Smart Agriculture (Mak17ALG01). WR is part of Wageningen University & Research, the collaboration of Wageningen University and Wageningen Research Foundation. Wageningen, November 2017

Integrated pest management component of the Ethio-Dutch Program for Horticulture Development : contribution of Wageningen University and Research - final report

The Ethiopian Horticulture Producer Exporters Association (EHPEA) is responsible for the Ethio-Dutch Program for Horticulture Development (EDPHD). One of the components of this program is the Integrated Pest Management (IPM) which has been executed by Wageningen University and Research, Business Unit Greenhouse Horticulture in collaboration with Ethiopian research organizations and EHPEA. This final report of the WUR team reports on the following project activities: 1) Technical advice on formulation of the best microbial bca’s obtained from the conducted research, 2) Survey, collection and commercialization of indigenous natural enemies for the management of major horticultural pests, 3) Support and advice on the study of the biology of identified potential indigenous natural enemies, 4) Support and advice on small-scale mass production for evaluation trials and methods to establish persistent populations in crops, 5) Technical advice on the efficacy trials under laboratory and field conditions on the identified predators and parasitoids, 6) Review of IPM course delivered at Jimma University, 7) Sharing information with growers and companies, 8) Train the trainer, and 9) All collection and other missions

Het winterlicht gewas : proof off principle met komkommer

In winter, for almost all crops light is the limiting factor for production. In the search for the maximum use of the limited light in the winter months, it is important to convert the light into crop production as optimal as possible. In order to improve, the knowledge gained in the project “verbetering lichtinval winterlicht”, where natural light entrance of the greenhouse roof for the winter period was optimized, in this project the scope was on the crop itself. The work in this project has been funded by the research program Kas Als Energiebron. This research program is a cooperation between the Ministry of Agriculture, Nature and Food quality and LTO-Glaskracht Nederland. To maximize light interception by the crop, an east-west oriented crop direction is the first step. The characteristics of the chosen cucumber variety, due to the variation in leaf size during cultivation from large to small leaves, require adaptation of crop management to the change in plant shape. A narrow trough distance showed a lot of damage of the crop. The best results were shown by the biggest gutter distance.