to study allelopathic effects of iranian walnut (juglans regia l.) on germination and initial growth of purslane (portulaca oleracea) and redroot pigweed (amaranthus retroflexus) an experiment was conducted in shahed university. the result showed that fresh leaf had negatively effected on radicle length. also, with increasing extract concentrations of persian walnut, the seed germination and se...

Weed plants characteristic for potato and hop fields have not been considered in the past as potential hosts that could transmit and lead to spreading of potato spindle tuber (PSTVd) and hop stunt (HSVd) viroids, respectively. To gain insight into this problem, we biolistically inoculated these weed plants with viroid populations either as RNA or as cDNA. New potential viroid host species, coll...

Coumarin is a natural compound well known for its phytotoxic potential. In the search for new herbicidal compounds to manage weeds, three synthetic derivatives bearing the coumarin scaffold (1-3), synthesized by a carbonylative organometallic approach, were in vitro assayed on germination and root growth of two noxious weeds, Amaranthus retroflexus and Echinochloa crus-galli. Moreover, the synt...

ABSTRACT-The critical period of weed control is a part of crop life cycle during which weeds must be kept weed-free to avoid yield losses due to competition. In order to evaluate the effect of deficit irrigation on critical period of redroot pigweed (Amaranthus retroflexus L.) in sunflower (Helianthus annuus L.), an experiment was carried out  as split plot ba...

during autumn and summer 2010 observed species from amaranthus genus were studied in segetal and ruderal environments of hamedan city. in this research, 100 plats randomly were selected and totally 6 species from amaranthus were identified as neophyte wild elements: a. retroflexus l. a. lividus l., a. chlorostachys willd, a. albus l., a. viridus l. and a. blitoides s. watson. dispersal of menti...

Different formae speciales of Fusarium oxysporum are the main causal agent of Fusarium wilts. In 2008 and 2009 we collected F. oxysporum samples from symptomless Abutilon theophrasti, xanthium strumarium, Chenopodium album, Matricaria perforata, Ambrosia artemisiifolia, Polygonum lapathifolium, Sonchus arvensis, Amaranthus blitoides, Amaranthus retroflexus, Datura stramonium, Sorghum halepense ...