biology of amaranth stem-boring weevil, hypolixus pica (fabricius) on red root pigweed, amaranthus retroflexus l. was investigated under natural conditions in a citrus orchard in dezful. each red root pigweed was covered by a wooden cage of 50×50×100cm dimentions screened by muslin. three to four adult females and males were introduced into each cage. after 3-4 days past the weevils were remove...

Prickly lettuce (Lactuca serriola L.) is a problematic weed of Pacific Northwest and recently developed resistance to the auxinic herbicide 2,4-D. There are no publically available simple sequence repeat (SSR) markers to tag 2,4-D resistance genes in L. serriola. Therefore, a study was conducted to develop SSR markers from expressed sequence tags (ESTs) of 5 Lactuca species. A total of 15,970 S...

Weeds are a major problem in seeding rangeland and cropland to native grasses. However, many immature weedy forbs and grasses are palatable to cattle. Research was conducted using yearling cattle for weed control in big bluestem (Andropogon gerardii var. gerardii Vitman) seedings (1987, 1988) at Mead, Nebraska on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudoll) soil....

Mieslerová B., Lebeda A., Petrželová I., Korbelová P. (2013): Incidence of lettuce downy mildew (Bremia lactucae) and powdery mildew (Golovinomyces cichoracearum) in natural populations of prickly lettuce (Lactuca serriola). Plant Protect. Sci., 39 (Special Issue): S24–S32. The study was focused on the wild pathosystem Lactuca serriola–lettuce downy mildew (Bremia lactucae) and lettuce powdery ...

the objective of this work was to study the responses of two baby lettuce (lactuca sativa l.) cultivars, namely, green paris island and red sanguine, to different nacl concentrations (0, 5, 10, and 20 mm). the study was conducted in a floating system and plants were harvested at the stage of 5-6 leaves, outside leaf 6-10 cm in length (25 and 31 days after sowing for green and red lettuce, respe...

Ethylene increased the germination of freshly imbibed lettuce (Lactuca sativa L. var. Grand Rapids) seeds. Seeds receiving either red or far-red light or darkness all showed a positive response to the gas. However, ethylene was apparently without effect on dormant seeds, those which failed to germinate after an initial red or far-red treatment. Carbon dioxide, which often acts as a competitive ...

The phenomenon that wild grasses did not grow beneath the tree of Quercus mongolica Fisch var. grosseserrata Rehd. Wils. while they grew vigorously beneath other species of trees around Q. mongolica was observed in many places in the Hokkaido district. The allelochemicals in the soil beneath Q. mongolica were studied. This soil inhibited the growth of lettuce (Lactuca scariola L. var. sativa Bi...

Renewed interest in the identification of alternative sources of natural rubber to Hevea brasiliensis has focused on the Compositae family. In our search for Compositae models for rubber synthesis, we extracted latex from stems of two lettuce species: Lactuca serriola, prickly lettuce, and Lactuca sativa cv. Salinas, crisphead lettuce. Both species contained cis-1,4-polyisoprene rubber in the d...

plant tissue culture technique could provide sterile and controllable condition in order to assay direct effect of different compounds on plant growth accurately. in this study, the effects of aqueous extracts prepared from roots and shoots of goosefoot (chenopodium album l.), redroot pigweed (amaranthus retroflexus l.), fennel (foeniculum vulgare), and wormwood (artemisia absinthium l.) were e...

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...