laboratory experiments were performed to determine the effect of various scarification treatments at four temperature regimes on germination of licorice seeds . a randomized complete block design with four replications was used. germination counts were made every day for 2 weeks. at 50c, none of the chemically and mechanically scarified and non scarified seeds germinated. at 15, 25, and 350...

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Sp...

Dormancy is a form of developmental arrest and is an adaptive trait that promotes the survival of many organisms. In flowering plants, dormancy occurs in seeds and vegetative propagules (Lang 1996). Seed dormancy increases the distribution of germination over time, thus enhancing the survival of plants in an ever-changing environment. Seed dormancy is of intrinsic interest to weed scientists be...

Urena lobata is becoming a noxious and invasive weed in rangelands, pastures, and undisturbed areas in the Philippines. This study determined the effects of seed scarification, light, salt and water stress, amount of rice residue, and seed burial depth on seed germination and emergence of U. lobata; and evaluated the weed's response to post-emergence herbicides. Germination was stimulated by bo...

ABSTRACT- This experiment was carried out during the growing seasons of 2010 and 2011 at the Agricultural Research Farm of Bu-Ali Sina University, to study the effect of weed competition on subsequent germination and seed vigour of chickpea. 12 weed interference durations were evaluated in a randomized complete block design with three replications. Experiments consisted of two sets of treatment...

Kent J. Bradford Department of Vegetable Crops, One Shields Avenue, University of California, Davis, CA 956168631, U.S.A. E-mail: [email protected] Knowledge and prediction of seasonal weed seedling emergence patterns is useful in weed management programs. Seed dormancy is a major factor influencing the timing of seedling emergence, and once dormancy is broken, environmental conditions det...

An investigation was made to see the salt tolerance of 10 weed species of rice. Properly dried and treated seeds of weed species were placed on 9 cm diameter petridishes lined with Whatman No. 1 filter paper under 6 salinity regimes, viz. 0 (control), 4, 8, 16, 24 and 32 dS m(-1). The petri dishes were then kept in germinator at 25 +/- 1.0 degrees C and 12 hr light. The number of germinated see...

Echinochloaoryzicola(syn.E. phyllopogon) is an exotic weed of California rice paddies that has evolved resistance to multiple herbicides. Elimination of seedlingsthroughcertain weed control methods can limit the spread of this weed, but is contingent on accurate predictions of germination and emergence timing, which are influenced by seed dormancy levels.In summer annuals, dormancy can often be...

To screen allelochemical-resistant species of the alien invasive weed Mikania micrantha, we studied the allelopathic inhibition effects of the leaf aqueous extract (LAE) of Mikania on seed germination and seedling growth of the 26 species native or naturalized in the invaded region in South China. Seed germination was more strongly negatively affected by LAE than seedling growth. Responses of s...