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\"Plants have roots, stems, leaves, and sometimes flowers. Each part of a plant does a special job. But do you know what a stem does? Or how different seeds travel away from their parent plants? Let's experiment to find out! Simple step-by-step instructions help readers explore science concepts and analyze information.\"--Provided by publisher.

Several plant-soil biota (PSB) studies were recently published in high profile journals that used the suspect “mixed soil sampling” methodology. To explore the extent to which mixing field samples (i.e. employing mixed soil sample designs) can generate erroneous conclusions, we used real data to parameterize a system for simulating results for experiments based independent vs. mixed soil samples per greenhouse container. We quantified the probability of type I statistical errors for each soil handling technique. We found that correct methods had predicted levels of type I statistical errors (ca. 5%). Incorrect methodology (mixed soil samples) had unacceptably high levels of type I statistical errors (ca. 50%). Our simulation highlights how robust PSB experiments require proper soil handling technique.

\"A plant's environment helps it grow. Weather, soil, and animals are important to a plant's survival. But do you know what happens to a plant when the seasons change? Or how earthworms help a plant's roots? Let's experiment to find out! Simple step-by-step instructions help readers explore science concepts and analyze information.\"--Provided by publisher.

The resistance of Echinochloa crus-galli (barnyardgrass) to cyhalofop-p-butyl has already been confirmed in rice fields in Santa Catarina, Brazil. However, it is not known if this resistance affects other ACCase inhibitors. This study evaluated the occurrence of cross-resistance in Echinochloa crus-galli biotypes from the main rice-growing regions of Santa Catarina to ACCase inhibitors. The research was conducted in a greenhouse, using a completely randomized design with a factorial scheme that included three ACCase-inhibiting herbicides (cyhalofop-p-butyl, quizalofop-p-ethyl, and profoxydim) belonging to two chemical groups (aryl-oxifenoxi-propionates and cyclohexanediones), eight herbicide doses, and four biotypes evaluated in the F1 generation and two biotypes evaluated in the F2 generation. These biotypes were selected based on the results of a preliminary trial with 21 populations. The herbicides were applied when the plants presented two true leaves. After control evaluations, the lethal dose required to control 50% and 80% of the population (LD50 and LD80) and the resistance factor (RF) were determined by nonlinear regression. The results showed that only one biotype from Tubarão, Santa Catarina met all statistical and agronomic criteria and had cross-resistance to ACCase inhibitors confirmed. In both generations, the RF was greater than 1.0, and the dose required to achieve 80% control exceeded the maximum recommended dose on the label. Resistance levels were higher for herbicides belonging to the aryl-oxifenoxi-propionate chemical group, with RF greater than 7.0. For the cyclohexanedione chemical group, the RF was less than 5.0. RESUMO: A resistência de capim-arroz (Echinochloa crus-galli) ao cyhalofop-p-butyl já foi confirmada em áreas de produção de arroz de Santa Catarina, entretanto não se sabe se essa resistência compromete outros inibidores da ACCase. O objetivo desse trabalho foi avaliar a ocorrência de resistência cruzada em biótipos de capim-arroz das principais regiões orizícolas do Estado de Santa Catarina a inibidores de ACCase. A pesquisa foi desenvolvida em casa de vegetação, em delineamento inteiramente casualizado com esquema fatorial, sendo: três herbicidas inibidores de ACCase (cyhalofop-p-butyl; quizalofop-p-ethyl e profoxydim) pertencentes a dois grupos químicos (ariloxifenoxipropionatos e ciclohexanodionas); oito doses dos herbicidas e quatro biótipos foram avaliados na geração F1 e dois biótipos na geração F2. Estes biótipos foram selecionados a partir dos resultados de um ensaio preliminar com 21 populações. A aplicação foi realizada quando as plantas apresentaram duas folhas verdadeiras. Após as avaliações de controle determinou-se, por regressão não-linear, a dose letal necessária para controlar 50% e 80% da população (DL50 e DL80) e o fator de resistência (FR). Os resultados demonstraram que apenas um biótipo de Tubarão-SC atendeu todos os critérios estatísticos e agronômicos e teve a resistência cruzada a inibidores da ACCase confirmada. Nas duas gerações observou-se que o FR foi superior a 1,0 e que a dose necessária para atingir o controle de 80% excedeu a dose máxima recomendada em bula. O nível de resistência foi superior para os herbicidas do grupo químico ariloxifenoxipropionatos, com FR maior que 7,0. Para o grupo químico ciclohexanodionas o FR foi menor que 5,0.

Readers won t believe the amazing results of these fantastic experiments! This book introduces the science behind plants and other living things through fun hands-on activities. Simple language explains complex concepts, and step-by-step instructions with accompanying photographs make experiments accessible. Nifty tips help readers safely reach the best results.

Tidal marsh plant species commonly zonate along environmental gradients such as elevation, but it is not always clear to what extent plant distribution is driven by abiotic factors vs. biotic interactions. Yet, the distinction has importance for how plant communities will respond to future change such as higher sea level, particularly given the distinct flooding tolerances and contributions to elevation gain of different species. We used observations from a 33-year experiment to determine co-occurrence patterns for the sedge, Schoenoplectus americanus, and two C4 grasses, Spartina patens and Distichlis spicata, to infer functional group interactions. Then, we conducted a functional group removal experiment to directly assess the interaction between sedge and grasses throughout the range in which they cooccur. The observational record suggested negative interactions between sedge and grasses across sedge- and grass-dominated plots, though the relationship weakened in years with greater flooding stress. The removal experiment revealed mutual release effects, indicating competition was the predominant interaction, and here, too, competition tended to weaken, though nonsignificantly, in more flooded, lower elevation zones. Whereas zonation patterns in undisturbed portions of marsh suggest that the sedge will dominate this marsh as flooding stress increases with sea level rise, we propose that grasses may exhibit a competition release effect and contribute to biomass and elevation gain even in sedge-dominated communities as sea level continues to rise. Even as abiotic stresses drive changes in the relative contributions of sedges and grasses, competition among them moderates fluctuations in total plant biomass production through time.

Over the last decade new technologies are emerging even more for wastewater treatment. Among the new technologies, a recent possible solution regards Moving Bed Biofilm Reactors (MBBRs) that represent an effective alternative to conventional processes. More specifically such systems consist in the introduction of plastic elements inside the aerobic reactor as carrier material for the growth of attached biomass. Recently, one of the mostly used alternatives is to couple the Moving Bed Biofilm Reactor (MBBR) process with the conventional activated sludge process, and the resulting process is usually called HMBBR (Hybrid MBBR). In the MBBR process the biofilm grows attached on small plastic elements that are kept in constant motion throughout the entire volume of the reactor. Indeed, in such a system, a competition between the two biomasses, suspended and attached, can arise for the availability of the substrates, leading, as a consequence, to a modification in the biokinetic parameters of the two biomasses, compared to that of a pure suspended or attached biomass process. This paper presents the first results of a study aimed at estimating the kinetic heterotrophic constants in a HMBBR pilot plant using respirometric techniques. The pilot plant was built at the Acqua dei Corsari (Palermo) wastewater treatment plant and consisted of two parallel lines realized in a pre-anoxic scheme, in one of which the carrier material was added to the aerobic reactor with a filling ratio of 30%.

Presents several experiments with plants and discusses biology.

The growing increment of the urbanization and, on the other hand, the even more strict effluent limits imposed by the Water Framework Directive for the receiving water body quality state have led to the need for upgrading several existing WWTP. With this respect HMBBR systems are an innovative solution since they allow to upgrade existing high loaded WWTP without building new tanks. However, some uncertainties in their design, maintenance as well as performance have to be addressed due to their recent acquisition compared with well consolidated technologies such as activated sludge systems. In this light, a data gathering campaign on a HMBBR pilot plant has been performed. The aim was to detect the performance of such new technology as well as to survey the influencing effect of the carrier media filling ratio. Indeed, there may be problem of competitiveness between attached and suspended biomass that jointly operate in the same system for carbon and nitrogen removal. Such competitiveness may lead to a worsening of the system efficiency. The results are interesting and the gathered data in the experimental period show a slight difference in terms of performance behaviour, between the two systems (35 and 66%). Such result leads to address the filling ratio choice towards the 35%.