A new instrument for the recording of leaf movement rhythm is described. Coleus blumei x C. frederici, a short day plant, exhibits a circadian rhythm of leaf movement. The period length of the free running rhythm is shortest in continuous darkness and is increased with an increase in the light intensity. The amplitude of the rhythm tends to damp in continuous bright light.

in order to study of some effective phenologic and physiologic characteristics on 18 sunflower hybrids yield under optimum conditions, an experiment was conducted as randomized complete block design with three replications at the research field of seed and plant improvement institute-karaj in 2006-2007. the result indicated that the hybrids showed significant difference in phonologic characteri...

background and objectives. integrated weed management approaches can help to decline costs weed control and improve its condition. critical period of weed control (cpwc) is defined as the best time for weeding. if cpwc is recognized we can accurately use herbicides and prevent environmental pollutions. beginning and duration of cpwc despond on some agents such as crop and weed traits, environme...

Leaf area index (LAI) is an important variable in the study of forest ecosystem processes, but very few studies are designed to monitor LAI and the seasonal variability in a mixed forest using non-destructive sampling. In this study, first, true LAI from May 1(st) and November 15(th) was estimated by making several calibrations to LAI as measured from the WinSCANOPY 2006 Plant Canopy Analyzer. ...

Zinnia is an annual plant with the long flowering period from late spring to mid-autumn. It is a popular plant for landscape. In the present study, the effect of two types of growth promoting bacteria and Azolla compost on some ornamental characteristics of Zinnia were evaluated in pot cultivation and greenhouse conditions. The factorial experiment was conducted in three replications based on a...

Anthropogenic activities have caused important increases in soil Cu levels not only in urban areas but also in croplands. This study was designed to find out the effect of different concentration of copper on physiological and biochemical changes in Eucalyptus camaldulensis seedlings. Seeds of Eucalyptus camaldulensis were grown in marble chips and irrigated with nutrient solution mixed with co...

salinity is one of the most limitation factors for crop production in agricultural systems due to the toxic effects and preventing water and nutrients absorption, in this research the efficiency of four strains of fluorescent pseudomonads on concentration of nutrient elements in rice was determined, under saline conditions. a pot experiment was carried out based on the factorial completely rand...

The effect of various day temperatures on NADH-nitrate reductase, NADH- and NADPH-glutamate dehydrogenases, nitrate, protein and leaf area, measured at intervals during the ontogeny of the first trifoliolate soybean leaf, was determined. At 32.5 C and 25 C, nitrate concentration, nitrate reductase, and NADPH-glutamate dehydrogenase activities increased concurrently with leaf development and the...