BACKGROUND: Nitrogen is a crucial component of plant nutrition, and its deficiency limits productivity of crops more than any other element. To manage the sorghum crop for achievement of maximum forage production, the farmer should be concerned about nitrogen requirement and plant height. OBJECTIVES: This research was carried out to evaluate response of m...

The National Longitudinal Study of Adolescent Health data were used to test predictions from life history theory. We hypothesized that (1) in young adulthood an emerging life history strategy would exist as a common factor underlying many life history traits (e.g., health, relationship stability, economic success), (2) both environmental harshness and unpredictability would account for unique v...

the oak genus (quercus l.) is one of the most important genera of beach family (fagaceae) that has ecological and economical importance. chestnutleaf oak (quercus castaneifolia c.a. mey.) is native to iran and distributed in hyrcanian forests. pure and mixed stands of this taxon have covered about 6.5 % of hyrcanian forests. this study was undertaken to evaluate the effects of ecological factor...

at the research farm of vali-e-asr university of rafsanjan in 2013. the experiment was arranged in a randomized complete block design with four replications and four irrigation intervals. irrigation was done after 40 (control), 60, 80 and 100 mm evaporation from pan class a, from seedling establishment till physiological maturity. results showed that irrigation level did not significantly chang...

The large variation in the relationships between environmental factors and plant traits observed in natural communities exemplifies the alternative solutions that plants have developed in response to the same environmental limitations. Qualitative attributes, such as growth form, woodiness, and leaf habit can be used to approximate these alternative solutions. Here, we quantified the extent to ...