Sensible use of primary energy in organic greenhouse production.

This document addresses the direct and indirect use of energy in European organic greenhouse horticulture (OGH) with the aim of reviewing available means for making it more environmental friendly and identifying knowledge gaps that should be addressed to attain this aim. The first observation is that there is no common regulation for energy use in OGH, which is not unexpected, since the need for climatisation is not uniformly distributed in the EU (and outside). Accordingly, the EU directive on organic agriculture does not set limitations on the use of energy, but rather promotes the responsible use of energy and of natural resources. The restrictions and rules of most private standards are slightly more stringent. Some standards have specific restrictions on the amount and sources of energy and/or on the seasonal use of energy for heating. Some standards also address processes that may affect (in)direct energy use, such as cultivation methods, mulching, lighting and growing media or substrates. However, most private standards have no or little restrictions or regulations on energy use. Accordingly, it should not surprise that very little quantitative information is available about energy use in OGH. In the present document we have filled the gaps with data with estimates drawn on energy use in conventional greenhouses. With respect to ongoing research, whereas many of the present research results about energy use and saving in conventional greenhouses are relevant (and also applied) in OGH, little research is devoted to address the energy use that is peculiar to OGH, particularly energy use for humidity control. In short, there are still a lot of knowledge gaps to improve quality and to lower energy use in organic greenhouses. The purpose of this document is a summary of present relevant knowledge about energy use and energy saving and of the perspective for improvement. In particular, the goal is to make an overview on the methods and technologies which can be used to reduce the energy use in OGH. We start from the assumption that methods and technologies that are used for reducing direct and indirect energy in conventional greenhouses can also be applied in organic greenhouses. Research on reducing energy use in conventional greenhouses is also more widely available because the area of conventional greenhouse horticulture is much larger than the area of OGH. When implementing these methods and techniques we should take into account the specific characteristics of organic agriculture like soil-based cultivation, use of organic fertilizers and the limited use of crop protection products. This document is organised as follows: first we report the results of a survey about energy use and relevant standards in the countries participating to the COST action (chapter 1); then we review the energy use for climatisation: heating (chapter 2) and humidity (chapter 3). In chapter 4 we review the available design and management means that would either reduce energy use and/or increase energy use efficiency by increasing productivity of OGH. In chapter 5 we present a short summary of existing information on indirect energy use, that is the energy required to manufacture production means (greenhouse structure and cover, fertilisers, equipment etc.) and for crop protection, particularly steaming, and briefly discuss possible savings. Finally (chapter 6) we review briefly the potential for application of renewable energy sources in OGH.

Modulation of gregarious settlement of the stalked barnacle, Pollicipes pollicipes: a laboratory study

Although recruitment patterns of Pollicipes pollicipes (Crustacea: Scalpelliformes) in the wild have been inves- tigated, no studies have yet focused on the factors that affect settlement. In the present paper, settlement of P. pollicipes on conspecifics (gregarious settlement) was investigated in the laboratory as a function of environmental conditions (hydrody- namics, temperature, light and salinity), larval age and batch. This study aimed to understand how these factors modulate set- tlement in the laboratory and elucidate how they might impact recruitment patterns in nature. Maximum attachment on adults was 30-35%, with a one-week metamorphosis rate of 70-80%. Batch differences affected both attachment and metamorpho- sis. Attachment rate was higher at natural salinity (30-40 psu), with lower salinity (20 psu) decreasing metamorphosis rate. Cyprid attachment was stimulated by light conditions and circulating water. This might relate to a preference for positioning high in the water column in nature, but also to increased cyprid-surface contact in conditions of circulating water. Older cyprids (3 or 6 days) showed higher attachment than un-aged larvae, though fewer 6-day-old larvae metamorphosed. Tem- perature did not affect attachment rate, but the metamorphosis rate decreased at 14°C (compared with 17 or 20°C), implying that differences in temperature during the breeding season can affect how quickly cyprids metamorphose to the juvenile. Cyprids survived for prolonged periods ( 20 days; 40% survival), likely due to efficient energy saving by intercalating long periods of inactivity with fast bursts of activity upon stimulation.