User:Ghambari

Agroecological aspects of Glycyrrizia glabra L. by: Ghanbari, A. Rahimian Mashhadi, H. Nasiri Mehallati, M. and M. Kafei Abstract Glycyrrizia is an industrial/medicinal plant however, in Iran is known as a weedy species in drylands and orchards. Therefore, to study its agroecophysiological characteristics as an attempt for domestication as well as control of this species in wheat fields, series of experiments were conducted in Tehran, Mashhad and Kermanshah. Germination of Glycyrrizia seeds collected from Kermanshah and Fars (Zarghan) were studies in PEG-induced drought treatments (0, -3, -6, -9, -15, and –18 bars) in a range of temperatures (0, 3, 10, 15, 20, 25, 30, 35 and 40 C). The highest germination percentage for both Kermanshah and Fars populations were obtained at 20 and 25 C while maximum germination percentage of Fars seeds was higher than Kermanshah. At 40 C maximum germination of 27 and 43% was observed for Kermanshah and Fars seeds, respectively. Germination was also affected by drought treatments. Maximum germination of 77 and 88%, respectively for Fras and Kermanshah seeds was achieved in 0 bar while the lowest germination of 10 and 17% was obtained in –15 bars with no germination at –18 bars. Negative effect of drought on germination was increased at lower temperatures resulting in lack of germination at –9 bars or lower in 0 and 3C. It seems that germination of Glycyrrizia is more tolerant to drought in temperatures between 15-25 C. The same trend was observed for germination rate. Time period for 10, 50 and 90% germination was lowest between 20-30 C for both seed populations but such germination percentages were never achieved in drought levels below –15 bars. Base, optimum and ceiling temperatures were obtained respectively, 2.2, 29.1, and 45.3 C for Kermanshah and 2.4, 29,2 and 44 C for Fars populations. Optimum temperature for germination was not affected by drought and varied between 28-29.5 and 28-29.6 C for Kermanshah and Fars populations, respectively. However, base and ceiling temperatures were increased with increasing drought severity. Comparison of development stages in plants produced from seed or rhizomes showed that in both cases growth of above ground organs started before roots. Induction of roots in rhizomes was observed at 5-7 leaf stage (60-75 days after planting in Mashhad conditions). Plants generated from roots showed higher vigor and larger leaflets with dark green color. However, at germination plants propagated by rhizome had stronger stems that seed-borne plants. Herbicides translocation was studied at 4 growth stages in seed-born plants using 14C-labeled 2,4-D and Glyphosate with activities of 0.06 and 0.1018 μKori (per 10 μl of solution), respectively. Results showed that at 6-leaf stage and after 72 hours herbicides translocation was directed towards roots with a higher rate of absorption and translocation for 2,4-D. Application of 2,4-D + MCPA (4 kg a.i. ha-1), Pickloram (Tordon 28% a.i. at 22 kg ha-1) and combination of two herbicides (3 and 14 kg a.i. ha-1) were studied in a field experiment in Kermanshah. Herbicides were applied in mid-May, early-June and late-July coinciding with growth stages of 20-25 cm height, blossoming and seed filling period, respectively. The best application time was at blossoming and the 2,4-D + MCAP was the most effective herbicide. Introduction of rapeseed in crop rotation in Kermanshah showed that density and shoot number of Glycyrrizia was affected by rotation, soil manipulation method and application of herbicides. Population density of Glycyrrizia was decreased significantly in rapeseed-wheat rotation with deep summer plough after harvesting of rapeseed and application of 2,4-D in the second year before planting of wheat. However, Glycyrrizia population was increased in chickpea-wheat rotation under no tillage management.