Previous research has shown that a considerable number of primates can remember the location and fruiting state of individual trees in their home range. This enables them to relocate fruit or predict whether previously encountered fruit has ripened. Recent studies, however, suggest that the ability of primates to cognitively map fruit-bearing trees is limited. In this study, we investigated an alternative and arguably simpler, more efficient strategy, the use of synchrony, a botanical characteristic of a large number of fruit species. Synchronous fruiting would allow the prediction of the fruiting state of a large number of trees without having to first check the trees. We studied whether rainforest primates, grey-cheeked mangabeys in the Kibale National Park, Uganda, used synchrony in fruit emergence to find fruit. We analysed the movements of adult males towards Uvariopsis congensis food trees, a strongly synchronous fruiting species with different local patterns of synchrony. Monkeys approached within crown distance, entered and inspected significantly more Uvariopsis trees when the percentage of trees with ripe fruit was high compared to when it was low. Since the effect was also found for empty trees, the monkeys likely followed a synchrony-based inspection strategy. We found no indication that the monkeys generalised this strategy to all Uvariopsis trees within their home range. Instead, they attended to fruiting peaks in local areas within the home range and adjusted their inspective behaviour accordingly revealing that non-human primates use botanical knowledge in a flexible way.

As a starting point for future international cooperation in research on Organic Greenhouse Horticulture, an inventory was done to map the state of art of organic greenhouse horticulture worldwide. This inventory resulted in overview of national area sizes, characterisation of practised organic growing systems, regulations, and topics on the national research agenda for each country. The overview is presented and discussed in this paper. The emphasis in this overview is on the EU countries because that information was best available.

The EU Water Framework Directive demands a sound ecological and chemical basis for ground and surface waters. This has motivated the Dutch greenhouse industry to seek more sustainable water management procedures which will enable a zero-emission of nutrients and plant protection products (PPP) in the year 2027. Although closed soilless growing systems are widely applied in The Netherlands, it appears that discharge of nutrients varies between 5 and 40%. Discharge based on salinity is only a minor part, up to 15%. In rose cultivation, growth inhibition is the major reason for discharge of the nutrient solution. Former research could not find a proper reason for growth inhibition, but it is most likely of organic origin. The water treatment method of advanced oxidation, at which first hydrogen peroxide is added, directly followed by an exposure to UV-C light (

Predatory bugs (essentially Miridae and Anthocoridae) are used since years as biocontrol agents in greenhouses. These bugs occur naturally in the Mediterranean area. They are found colonizing vegetable crops, if they are not disturbed by chemical treatments. They are omnivorous predators which can feed on various arthropod preys as well as plant sap and/or pollen. The broad range of prey of these generalist predators is very interesting in vegetable production, where the diversity of cultivated species points to a high diversity of pests. Their biological traits (indigenous, generalist predators, phytophagy that allows them to survive during periods of prey scarcity) make them good candidates for an effective pest control. However, their establishment is slow, whereas their presence is eliminated at the end of the crop cycle and new releases have to be applied. These shortcomings can be substantially improved by habitat management (Perdikis et al., 2011), especially through companion plant useful to attract and maintain natural enemies. Their insertion inside or outside greenhouses (e.g., flower strips) provides food and shelter for Miridae and Anthocoridae throughout the year. This is especially important in winter because winter crops are often very poor host plants for beneficials. Applying this method, the beneficials remain in the greenhouse moving between the crop and the companion plants and may offer pest control for a long period at a very low cost.

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