International Agrophysics 

About: International Agrophysics is an academic journal published by De Gruyter Open. The journal publishes majorly in the area(s): Soil water & Water content. It has an ISSN identifier of 0236-8722. It is also open access. Over the lifetime, 1574 publications have been published receiving 22047 citations.

Effect of drought and heat stresses on plant growth and yield: a review

Abstract: Abstract Drought and heat stresses are important threat limitations to plant growth and sustainable agriculture worldwide. Our objective is to provide a review of plant responses and adaptations to drought and elevated temperature including roots, shoots, and final yield and management approaches for alleviating adverse effects of the stresses based mostly on recent literature. The sections of the paper deal with plant responses including root growth, transpiration, photosynthesis, water use efficiency, phenotypic flexibility, accumulation of compounds of low molecular mass (eg proline and gibberellins), and expression of some genes and proteins for increasing the tolerance to the abiotic stresses. Soil and crop management practices to alleviate negative effects of drought and heat stresses are also discussed. Investigations involving determination of plant assimilate partitioning, phenotypic plasticity, and identification of most stress-tolerant plant genotypes are essential for understanding the complexity of the responses and for future plant breeding. The adverse effects of drought and heat stress can be mitigated by soil management practices, crop establishment, and foliar application of growth regulators by maintaining an appropriate level of water in the leaves due to osmotic adjustment and stomatal performance.

The tandem scanning reflected light microscope

Abstract: Reflected-light microscopy of semitransparent material, such as unstained nervous tissue, is usually unsatisfactory because of low contrast and light scattering. In a new microscope both the object plane and the image plane were scanned in tandem so that only light reflected from the object plane was included in the image. The object was illuminated with nearly incoherent light passing through holes in one side of a rotating scanning disk (Nipkow wheel) which was imaged by the objective into the object plane. Reflected-light images of these spots were conducted to the opposite side of the same disk. Light could pass from the source to the object plane, and from the object to the image plane, only through optically congruent holes on opposite side of the rotating disk. The image obtained had better contrast and sharpness for some semitransparent material than possible in usual reflected-light microscopy.

Prediction of cetane number of biodiesel fuel from the fatty acid methyl ester (fame) composition

Abstract: Cetane number is an important parameter in evaluating the quality of biodiesel fuel Its determination is usually arduous and expensive, and the results obtained are not always accurate due to experimental error This work is aimed at deve- loping a relationship between the fatty acid methyl ester (FAME) composition and the cetane number (CN) Data were collected from the literature on the cetane number of various biodiesel fuels and their FAME composition A regres- sion analysis was performed on pure FAME to establish a rela- tionship between the cetane number and FAME composition An equation was developed relating the cetane number with the % composition by weight of FAME of biodiesel fuel The pre- dicted cetane number values compare well with the average measured cetane number values This work establishes the general dependence of cetane number on FAME composition of biodiesels

Review of optimum temperature, humidity, and vapour pressure deficit for microclimate evaluation and control in greenhouse cultivation of tomato: a review

Abstract: Greenhouse technology is a flexible solution for sustainable year-round cultivation of Tomato (Lycopersicon esculentum Mill), particularly in regions with adverse climate conditions or limited land and resources. Accurate knowledge about plant requirements at different growth stages, and under various light conditions, can contribute to the design of adaptive control strategies for a more cost-effective and competitive production. In this context, different scientific publications have recommended different values of microclimate parameters at different tomato growth stages. This paper provides a detailed summary of optimal, marginal and failure air and root-zone temperatures, relative humidity and vapour pressure deficit for successful greenhouse cultivation of tomato. Graphical representations of the membership function model to define the optimality degrees of these three parameters are included with a view to determining how close the greenhouse microclimate is to the optimal condition. Several production constraints have also been discussed to highlight the short and long-term effects of adverse microclimate conditions on the quality and yield of tomato, which are associated with interactions between suboptimal parameters, greenhouse environment and growth responses.

Influence of water stress on growth, essential oil, and chemical composition of herbs (Ocimum sp.)

Abstract: This work investigates the influence of water stress on vegetative growth, essential oil, proline, total carbo- hydrates, N, P, K, and protein contents of two species of an herb plant ie Ocimum basilicum L. (sweet basil) and Ocimum ameri- canum L. (american basil). Experiments were carried out during two successive seasons, 2004 and 2005, with experimental pots containing Typic Torrifluvents soil (a clay loam) in a growth chamber at the Experimental Farm, National Research Center (NRC), Giza, Egypt. Seedlings were treated with different levels of water-stress, determined as a percentage of field water capacity (FWC) by weight (50, 75, 100, and 125%). Fresh and dry weights of the herbs were significantly influenced by water stress. For both species under water stress, essential oil percentage, the main constituents of essential oil, proline, and total carbohydrate content increased, and N, P, K, and protein content decreased. Seventy five percent field water capacity resulted in the highest yield of herb and essential oil for both species.