Handleiding Paprika model “Cultivista” - Project Topmodel4all / 2010-2011

Abstract NL Deze handleiding is bedoeld voor telers die aan de slag willen met het paprika model “Cultivista”. Er wordt uitgelegd hoe met het interactieve paprika model “Cultivista” kan worden gewerkt. De installatie van het model en de verschillende in te voeren gegevens (inputs) van het model worden besproken. Vervolgens worden de werking van het model en de onderdelen van de interface besproken. Tevens worden de voorwaarden voor mogelijke automatisering van de inputs en het oplossen van de meest voorkomende problemen besproken. Abstract UK This manual is meant for growers who would like to work with the sweet pepper growth model “Cultivista”. This manual explains how the model works, how to install the model and which inputs are used. Furthermore, the different parts of the interface are explained. Finally, the conditions for automation of the inputs and troubleshooting of the most common problems are discussed

Het Nieuwe Telen voor groente-opkweek

Het Nieuwe Telen (HNT) is als systeem ontwikkeld voor de primaire productie bedrijven. Voor de opkweekbedrijven, die in korte teelten het basis uitgangsmateriaal maken is dit systeem niet één op één toepasbaar. Om de in Kas als Energiebron opgedane kennis te laten landen bij plantenkwekerijen moet een analyse en een vertaalslag gemaakt worden. In het project ‘Het Nieuwe Telen voor groente-opkweek’ is door middel van gesprekken met 10 opkweekbedrijven, een workshop en literatuurstudie in kaart gebracht waar de kansen en knelpunten liggen

Safety conscious or living dangerously: what is the ‘right’ level of plant photoprotection for fitness and productivity?

Due to their sessile nature, plants could be perceived to be relatively slow and rather un-reactive. However, a plant scientist will tell you that the inability to run away (tropism notwithstanding) actually demands a highly sophisticated physiological response to the environment. Light presents an extreme case: cloud cover and wind-induced motion can lead to irradiance changes of several orders of magnitude over timescales of seconds and minutes. Being autotrophic organisms and having evolved to harvest light, plants need to dynamically regulate their biochemistry so that it operates efficiently during these fluxes, maintaining plant fitness but minimising the risk of damage. Photosynthesis is driven at a rate that depends on the amount of available light, as shown by the schematic photosynthesis-light response curves of C3 species (Fig. 1). In nature, CO2 assimilation can go from being light-limited to being light-saturated within a very short period of time. To maximise CO2 uptake, photosynthesis should ‘track’ light levels accurately inducing and removing photoprotective processes accurately. Being able to measure photoprotection precisely in naturally fluctuating settings is difficult; however, a paper in this volume of Plant, Cell and Environment proposes a significant advance (Tietz et al. 2017)

Improving photosynthesis and crop productivity by accelerating recovery from photoprotection

Crop leaves in full sunlight dissipate damaging excess absorbed light energy as heat. When sunlit leaves are shaded by clouds or other leaves, this protective dissipation continues for many minutes and reduces photosynthesis. Calculations have shown that this could cost field crops up to 20% of their potential yield. Here, we describe the bioengineering of an accelerated response to natural shading events in Nicotiana (tobacco), resulting in increased leaf carbon dioxide uptake and plant dry matter productivity by about 15% in fluctuating light. Because the photoprotective mechanism that has been altered is common to all flowering plants and crops, the findings provide proof of concept for a route to obtaining a sustainable increase in productivity for food crops and a much-needed yield jump

Relaxing non-photochemical quenching (NPQ) to improve photosynthesis in crops

Sunlight intercepted by crop plants drives photosynthesis and growth. However, the light-harvesting antenna complexes that capture light energy for photosynthesis can also absorb too much light, which enhances the formation for reactive oxygen species and can result in damage to photosynthetic reaction centres. In order to prevent excessive damage, light-harvesting efficiency is reduced under high light, via upregulation of non-photochemical quenching (NPQ) processes involved in thermal dissipation of excitation energy in the photosystem II antennae. Relaxation of NPQ following high light exposure is not instantaneous and the response time increases with severity and longevity of the high light exposure. Due to slow NPQ relaxation, photosynthetic light use efficiency can be decreased for prolonged periods after high light exposure. In this chapter we review mechanistic understanding of light harvesting and NPQ, how NPQ can be measured and results from recent attempts to accelerate NPQ responses to light

Food chain inefficiency (FCI) : accounting conversion efficiencies across entire food supply chains to re-define food loss and waste

Achieving global food security requires a new approach that integrates not only all aspects of the growing, harvesting and processing of food (necessary to ensure sufficient affordable and sustainable production to alleviate hunger) but also the complexities associated with food consumption including deterring unhealthy overconsumption. Inefficiencies occur at various points along the agri-food supply chain but at present they are inadequately conceptualized via separate accounts of food loss, food waste, supply chain management, and public health. Here we re-define food loss and waste through the concept of conversion efficiency applied to the entire system, an approach up to now only applied to the primary processes of crop productivity. Nine conversion efficiencies are defined: sunlight capture efficiency; photosynthesis use efficiency; biomass allocation efficiency; harvesting efficiency; storage and distribution efficiency; processing efficiency; retailing efficiency; consumption efficiency; and dietary efficiency. Using the production and consumption of bread in the UK as an example, we demonstrate how efficiencies may be estimated and thus where the main inefficiencies lie, so indicating where the most significant improvements could be made. We suggest that our approach, which introduces the term Food Chain Inefficiency (FCI) to re-define food loss and waste, provides a rational and effective way to devise the practical interventions and policies needed to deliver a sustainable agri-food system

Deriving C4 photosynthetic parameters from combined gas exchange and chlorophyll fluorescence using an Excel tool: theory and practice

The higher photosynthetic potential of C4 plants has led to extensive research over the past 50 years, including C4-dominated natural biomes, crops such as maize, or for evaluating the transfer of C4 traits into C3 lineages. Photosynthetic gas exchange can be measured in air or in a 2% Oxygen mixture using readily available commercial gas exchange and modulated PSII fluorescence systems. Interpretation of these data, however, requires an understanding (or the development) of various modelling approaches, which limit the use by non-specialists. In this paper we present an accessible summary of the theory behind the analysis and derivation of C4 photosynthetic parameters, and provide a freely available Excel Fitting Tool (EFT), making rigorous C4 data analysis accessible to a broader audience. Outputs include those defining C4 photochemical and biochemical efficiency, the rate of photorespiration, bundle sheath conductance to CO2 diffusion and the in vivo biochemical constants for PEP carboxylase. The EFT compares several methodological variants proposed by different investigators, allowing users to choose the level of complexity required to interpret data. We provide a complete analysis of gas exchange data on maize (as a model C4 organism and key global crop) to illustrate the approaches, their analysis and interpretation

The Chlamydomonas CO2-concentrating mechanism and its potential for engineering photosynthesis in plants

To meet the food demands of a rising global population, innovative strategies are required to increase crop yields. Improvements in plant photosynthesis by genetic engineering show considerable potential towards this goal. One prospective approach is to introduce a CO2-concentrating mechanism into crop plants to increase carbon fixation by supplying the central carbon-fixing enzyme, Rubisco, with a higher concentration of its substrate, CO2. A promising donor organism for the molecular machinery of this mechanism is the eukaryotic alga Chlamydomonas reinhardtii. This review summarizes the recent advances in our understanding of carbon concentration in Chlamydomonas, outlines the most pressing gaps in our knowledge and discusses strategies to transfer a CO2-concentrating mechanism into higher plants to increase photosynthetic performance