Greenhouses shelter the crop from unfavourable environmental conditions and the covering largely contributes to creating beneficial growing conditions inside. There is no perfect greenhouse cover for all combinations of crop and climatic regions. Usually a greenhouse cover has permanent optical properties determining the amount of solar radiation entering the greenhouse. Consequently during crop growth, the amount and quality (spectrum, direct/diffuse ratio) of the solar radiation is not ideal for the crop. Growers try to compensate for this by using different additional techniques such as temporary coatings, screens (mobile or fixed, etc.) and heating or cooling. New materials are currently being developed, whose optical properties can be (almost) instantaneously changed (materials with switchable properties). This will allow growers to gain real-time control on the quantity and quality of the light entering the greenhouse to match crop requirement. The present study uses advanced simulation models to predict the potential of covers with switchable properties to improve tomato yield and use of resources in different climatic regions (mild winter and tropical) and with different greenhouse types (artisan and industrial type). Results indicate that covers with switchable properties have advantages over permanent properties for most combinations of filter type/location. Only in very extreme tropical climates will covering materials with permanent filter properties have advantages. Furthermore, simulations models can play a major role in optimising the switchable filter design.

中文翻译：

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具有可切换辐射特性的材料：它们能否成为完美的温室覆盖物？

温室使作物免受不利环境条件的影响，覆盖物在很大程度上有助于在内部创造有利的生长条件。对于作物和气候区域的所有组合，没有完美的温室覆盖。通常温室覆盖物具有决定进入温室的太阳辐射量的永久性光学特性。因此，在作物生长期间，太阳辐射的数量和质量（光谱、直接/漫射比）对于作物来说并不理想。种植者试图通过使用不同的附加技术来弥补这一点，例如临时涂层、屏幕（移动或固定等）以及加热或冷却。目前正在开发新材料，其光学特性可以（几乎）瞬间改变（具有可切换特性的材料）。这将使种植者能够实时控制进入温室的光的数量和质量，以满足作物需求。本研究使用先进的模拟模型来预测具有可切换特性的覆盖物在不同气候区域（温和的冬季和热带）和不同温室类型（工匠和工业类型）中提高番茄产量和资源利用的潜力。结果表明，对于过滤器类型/位置的大多数组合，具有可切换特性的覆盖物比永久特性更具优势。只有在非常极端的热带气候下，具有永久过滤特性的覆盖材料才有优势。此外，仿真模型可以在优化可切换滤波器设计方面发挥重要作用。