Broad-scale patterns of body size in squamate reptiles of Europe and North America

Aim To document geographical interspecific patterns of body size of European and North American squamate reptile assemblages and explore the relationship between body size patterns and environmental gradients. Location North America and western Europe. Methods We processed distribution maps for native species of squamate reptiles to document interspecific spatial variation of body size at a grain size of 110 x 110 km. We also examined seven environmental variables linked to four hypotheses possibly influencing body size gradients. We used simple and multiple regression, evaluated using information theory, to identify the set of models best supported by the data. Results Europe is characterized by clear latitudinal trends in body size, whereas geographical variation in body size in North America is complex. There is a consistent association of mean body size with measures of ambient energy in both regions, although lizards increase in size northwards whereas snakes show the opposite pattern. Our best models accounted for almost 60% of the variation in body size of lizards and snakes within Europe, but the proportions of variance explained in North America were less than 20%. Main conclusions Although body size influences the energy balance of thermoregulating ectotherms, inconsistent biogeographical patterns and contrasting associations with energy in lizards and snakes suggest that no single mechanism can explain variation of reptile body size in the northern temperate zone

Technical equipment in soilless production systems

Technical innovations in fertilization and irrigation have resulted in adoption of fertigation technologies wherein completely soluble fertilizers are dissolved in irrigation water so as to deliver to plants the nutrients they need for optimal growth. This chapter focuses on the technical equipment associated with fertigation and irrigation in greenhouse production. In most such soilless production systems, fertilization is accomplished through injection of soluble fertilizer into irrigation water. It also demonstrates which system is best suited to which crop and where continued innovation is likely to result in future technical advances. In all modern production systems, fertilization and irrigation have been integrated into a system that the grower seeks to optimize. Traditionally growers applied dry fertilizer products to the top of the root zone, resulting in fertilizer nutrients being carried to the root surfaces with the applied irrigation water. Once it was realized, through repeated experiments, that all essential fertilizers could be supplied through completely soluble fertilizer salts, systems were developed where such salts are dissolved at relatively high concentrations in special stock solutions. By using one or more injectors, such concentrated solutions could be injected into the irrigation water (fertigation), a method which is prevalent today

Technical equipment in soilless production systems

Technical innovations in fertilization and irrigation have resulted in adoption of fertigation technologies wherein completely soluble fertilizers are dissolved in irrigation water so as to deliver to plants the nutrients they need for optimal growth. This chapter focuses on the technical equipment associated with fertigation and irrigation in greenhouse production. In most such soilless production systems, fertilization is accomplished through injection of soluble fertilizer into irrigation water. It also demonstrates which system is best suited to which crop and where continued innovation is likely to result in future technical advances. In all modern production systems, fertilization and irrigation have been integrated into a system that the grower seeks to optimize. Traditionally growers applied dry fertilizer products to the top of the root zone, resulting in fertilizer nutrients being carried to the root surfaces with the applied irrigation water. Once it was realized, through repeated experiments, that all essential fertilizers could be supplied through completely soluble fertilizer salts, systems were developed where such salts are dissolved at relatively high concentrations in special stock solutions. By using one or more injectors, such concentrated solutions could be injected into the irrigation water (fertigation), a method which is prevalent today

A functional-structural plant model for cut roses - new techniques for modelling manipulation of plant structure

Experience is the main guide for cut rose growers to make decisions on crop management and climate control. Because of continuous change in cultivar characteristics and technology there is a need for a general theory, capturing how the number of flower shoots produced and their quality depend on the main determinants: plant structure (as a product of the interaction of natural growth and development with manipulation by the grower), cultivar characteristics and greenhouse environment. ‘Virtual Rose’ is an interdisciplinary project working on the development of a 3D model that simulates and visualizes shoot production over time. 3D modelling, or rather functional-structural plant modelling, differs fundamentally from previously published rose crop models, the most striking aspect being the 3D simulation and visualization of plant structure. This paper introduces the basic modelling approach, i.e., the use of Relational Growth Grammars (RGG) and the modelling language eXtended L-Systems (XL). The final model needs to be able to use greenhouse climate data from practice as input, most importantly the light regime, consisting of light from the sun and additional assimilation lamps (SON-T). Furthermore, the model needs to be equipped with provisions that allow the model user to execute ‘virtual’ bending, harvesting, and pruning. In this paper, we will focus on new modelling techniques for simulating complex interventions in plant growt

Vernalização afeta o filocrono em lírio Vernalization affects the phyllochron in lily

O experimento foi desenvolvido com o objetivo de estudar o efeito da vernalização sobre o filocrono (intervalo de tempo entre o aparecimento de duas folhas sucessivas) em lírio (Lilium longiflorum Thunb.), cv. Snow Queen, no campo experimental do Departamento de Fitotecnia da Universidade Federal de Santa Maria (UFSM), Santa Maria (RS). Os tratamentos constituíram-se de bulbos submetidos a -0,5 ºC; 4 ºC e 10 ºC com períodos de vernalização dos bulbos de 2, 4, 6 e 8 semanas. O tratamento testemunha correspondeu a bulbos não vernalizados. Após o tratamento de vernalização, os bulbos foram plantados no interior de uma estufa plástica em 5 de dezembro de 2002 e observado o desenvolvimento das plantas. O filocrono foi estimado pelo inverso do coeficiente angular da regressão linear entre o número de folhas e o acúmulo térmico acima de 1 ºC, a partir da emergência das plantas. Os resultados evidenciaram que o estado de vernalização da planta afeta o filocrono em lírio, e plantas não vernalizadas ou com pouca vernalização têm um filocrono mais elevado do que plantas completamente vernalizadas. Quando o tratamento de vernalização é maior que 30 dias efetivos de vernalização, o valor do filocrono foi em torno de 25 ºC dia/folha, valor que pode ser utilizado como referência quando os bulbos são vernalizados e utilizados em plantios comerciais.<br>An experiment was carried out to verify the effect of vernalization period on the phyllochron (time interval between the appearance of two successive leaves) in lily (Lilium longiflorum Thunb), cv. 'Snow Queen'. The trial was conducted at Santa Maria, RS, Brazil. Treatments were bulbs stored at vernalizing temperatures of -0.5, 4, and 10ºC during periods of 2, 4, 6 and 8 weeks. Control treatment was unvernalized bulbs. Bulbs were planted inside a plastic greenhouse on December 05, 2002, and crop development was evaluated throughout the growing season. Phyllochron for each treatment was estimated as the inverse of the slope of the linear regression relating leaf number and accumulated thermal time above 1ºC after emergence. Results showed that the phyllochron is affected by vernalization. Unvernalized plants and plants with low vernalization treatments had greater phyllochron values compared to completely vernalized plants. Plants vernalized with 30 or higher effective vernalization days had a phyllochron value around 25 ºC days/leaf. This phyllochron can be used as a reference when vernalized bulbs are used in commercial croppings