The weediness of wild plants: molecular analysis of genes influencing dispersal and persistence of johnsongrass, Sorghum halepense (L.) Pers.

Many major weeds rely upon vegetative dispersal by rhizomes and seed dispersal by "shattering" of the mature inflorescence. We report molecular analysis of these traits in a cross between cultivated and wild species of Sorghum that are the probable progenitors of the major weed "johnsongrass." By restriction fragment length polymorphism mapping, variation in the number of rhizomes producing above-ground shoots was associated with three quantitative trait loci (QTLs). Variation in regrowth (ratooning) after overwintering was associated with QTLs accounting for additional rhizomatous growth and with QTLs influencing tillering. Vegetative buds that become rhizomes are similar to those that become tillers--one QTL appears to influence the number of such vegetative buds available, and additional independent genes determine whether individual buds differentiate into tillers or rhizomes. DNA markers described herein facilitate cloning of genes associated with weediness, comparative study of rhizomatousness in other Poaceae, and assessment of gene flow between cultivated and weedy sorghums--a risk that constrains improvement of sorghum through biotechnology. Cloning of "weediness" genes may create opportunities for plant growth regulation, in suppressing propagation of weeds and enhancing productivity of major forage, turf, and "ratoon" crops.

Noxious Weed Management: A Review of Herbicide Use at Colorado State Parks

Weed control in recreation areas is a complex public land management issue. Colorado State Parks are managed for both recreation and conservation, which often conflict. Noxious weeds affect both recreation and conservation efforts, and Parks often use herbicides to control these weeds. While herbicides are effective, they can be harmful to the environment and human health. Herbicide use at State Parks was reviewed to determine if chemical control is effective, safe, and efficient. The results revealed that many Parks are not using effective herbicides to treat noxious weeds and that some weed management plans lack pertinent information on chemical control. The results and recommendations provided can be used to improve the success of noxious weed control and create healthier Parks.

[Admittatur of Samuel Weed (Harvard AB 1800)], 1796 August 17

Published copy of the 1790 College Laws, bound in modern board binding, with the admittatur of undergraduate Samuel Weed signed by President Joseph Willard on August 17, 1796.

Pike, pickerel and muskalonge / by Alfred C. Weed, Assistant Curator of Fishes.

no.9(1927)

Helena National Forest (N.F.), noxious weed treatment project : environmental impact statement.

Mode of access: Internet.

Weed management guide for commercial vegetable growers, 1984 /

Cover title.

Improving Klamath weed ranges /

Mode of access: Internet.

University of Illinois weed control research report.

Issued 1987- in parts; part II has title: Illinois weed science research report.

WEED, a wonderful equation elimination device.

Thesis--University of Illinois.

General-contact weed killers : water soluble chemicals, oils & fortified oils, emulsions /

Mode of access: Internet.

Weed management guide 1988 for commercial vegetable growers /

"September 1987."

Report of results of national noxious weed questionnaire.

Caption title.

Outline of a proposed national program of weed research and control.

Mode of access: Internet.

Chemical weed-control equipment /

Mode of access: Internet.

Weed control by soil sterilization /

Mode of access: Internet.