جستجوی مقالات مرتبط با کلیدواژه "صفات رویشی" در نشریات گروه "اکولوژی"

Sweet Basil (Ocimum basilicum L.) an herbaceous annual fragrant herb belongs to the Lamiaceae family is a cosmopolitan herb and aromatic plant with abundant applications in pharmaceutical, food and fragrance Industries. The effects of salinity (0 and 50 mM NaCl) and applications of humic acid 18% (0, 500,1000 and 2000 mg.l-1) on some growth characteristics such as chlorophyll index, height, leaf number, total plant fresh, dry weight, essential oil content and yield were investigated under hydroponic production. This study was conducted by factorial experiment in randomized complete block design with two factors. The result showed that the growth characteristics of plants under 25 mM NaCl salinity with application of 500 mg/l humic acid had no significant differences with control. The highest essential oil content was recorded in 50mM NaCl salinity and the lowest was obtained in control. In general, the result of this experiment showed that salinity stress decreased on all growth characteristics but application of humic acid improved the negative effects of salinity stress.

Prediction of the leaf area is essential in crop simulation models. The objective of this study was to find relationships between leaf area index (LAI) and numbers of leaves (NL), leaf dry weight (LDW), leaf fresh weight (LFW), number of nodes (NN) and plant height (PH), in Pumpkin (Cucurbita pepo L.). For this purpose, an experiment was conducted using three planting dates (20 April, 21 May, 21 June) at the research field of Aburaihan Campus, the University of Tehran, Pakdasht, Tehran, Iran, in 2009-2010 cropping season. The experimental design was randomized complete block with four replications. Sampling was performed during the whole growing season. In each sampling LA, NL, LDW, LFW, NN and PH, were measured. Various equations were used to describe relationships between LAI and aforementioned characteristics. The best result was obtained a simple ln-transformed linear equation {ln(y)= a+b×ln(x)}. Results showed that significant relationships were found between LAI and LA (R2 = 90), LAI and NL (R2 = 90), LAI and NN (R2 = 90), LAI and LDW (R2 = 98) and LAI and LFW (R2 = 98). These equations LAI can be used for estimation in simulation models of Pumpkin as well as for the fast and easy estimation of LAI, especially where there is no LAI-meter available.