The measurement of fitness is critical to biological research. Although the determination of fitness for some organisms may be relatively straightforward under controlled conditions, it is often a difficult or nearly impossible task in nature. Plants are no exception. The potential for long-distance pollen dispersal, likelihood of multiple reproductive events per inflorescence, varying degrees ...

Biomass processing plants have a trade-off between two competing cost factors: as size increases, the economy of scale reduces per unit processing cost, while a longer biomass transportation distance increases the delivered cost of biomass. The competition between these cost factors leads to an optimum size at which the cost of energy produced from biomass is minimized. Four processing options ...

【Objective】 In order to quantify the yield formation of protected tomato, 【Method】 the field experiments on varieties and fertilizer were conducted in 2009 and 2010, and cultivars: (B1) American mole 1 (early maturing), (B2) Chaoshijifanqiedawang (late maturing), and (B3) American 903 (medium maturing) were adopted; The models of dry matter production and yield formation for protected tomato we...

20 hulless barley lines were assessed by grain yield and other agronomic traits in 2006 and 2007 in the research station of the university of tabriz, iran. the experiments in each year were carried out as randomized complete block design with four replications. the genotypes were significantly different for most of the studied traits. this indicated the existence of large genetic variation in t...

BACKGROUND AND AIMS The resurgence of malaria, particularly in the developing world, is considerable and exacerbated by the development of single-gene multi-drug resistances to chemicals such as chloroquinone. Drug therapies, as recommended by the World Health Organization, now include the use of antimalarial compounds derived from Artemisia annua--in particular, the use of artemisinin-based in...

Tomato plants were inoculated with Meloidogyne incognita at initial populations (Pi) of 0, 1, 10, 50, 100, and 200 (x 1,000) eggs per plant and maintained in a growth chamber for 40 days. Total fresh biomass (roots + shoots) at harvest was unchanged by nematode inoculation with Pi of 1 x 10 eggs or less. Reductions in fresh shoot weight with increasing Pi coincided with increases in root weight...

extra use of chemical fertilizers in recent decades had resulted in pollution of water, soil and other environmental recourses. to investigate the effects of humic acid as an organic fertilizer on some yield components of three tomato (lycopersicon esculentum l.) varieties, an experiment was conducted during 2010 growing season at khorasan-e-razavi, ahmadabad suburb of mashhad. experiment was a...

We extend the resource concentration hypothesis (herbivorous insects are more likely to find and stay in more dense and less diverse patches of their host plants) to plant communities. Specifically, whenever superior plant competitors spread to form dense stands, they will be found and attacked by their specialist insect enemies. This will decrease host plant abundance, causing a reduction in s...

Cover and yield are two of the most commonly monitored plant attributes in rangeland vegetation surveys. These variables are usually highly correlated and many previous authors have suggested point-intercept estimates of plant cover could be used as a surrogate for more expensive and destructive methods of estimating plant biomass. When measurement variables are highly correlated, double sampli...

In some medicinal plants a specific plant-fungus association, known as arbuscular mycorrhizal (AM) symbiosis, increases the levels of secondary plant metabolites and/or plant growth. In this study, the effects of three different AM treatments on biomass and sesquiterpenic acid concentrations in two IN VITRO propagated genotypes of valerian ( VALERIANA OFFICINALIS L., Valerianaceae) were investi...