Bindweed, herbicides

So far as the author is aware, the first statement of the herbicidal action of 2,4-dichlorophenoxyacetic acid, made in the United States, was in a publication by Hamner and Tukey (14) in 1944. They sprayed 2,4-dichlorophenoxyacetic acid and 2,4,5-trichlorophenoxyacetic acid on bindweed and obtained a complete kill down to the root tips. At about the same time Hamner and Tukey (13) and Marth and Mitchell (24) demonstrated the effect of 2,4-dichlorophenoxyacetic acid as a differential herbicide on lawns. All plants growing on the lawns (except the grasses) were destroyed with apparently no noticeable ill effect on the grasses. 

Except direct use of allelopathic crops as cover crops, smother crops, and intercrops, applications of allelopathy for weed control include the use of allelopathic residues as an herbicide agent, e.g., pellets flours, water extracts, etc. The most common example of crop residue utilization is application of straw on the soil surface (mulching), e.g., rice straw inhibited germination of field bindweed (Convolvulus arvensis L.), winter wild oat (Avena ludoviciana Durieu), and little-seed canarygrass (Phalaris minor Retz.) (Lee et al. 1991 Tamak et al. 1994 Young et al. 1989). 

The product is a broad-spectrum, non-selective herbicide particularly effective against perennial weeds such as nutsedge and bindweed. Since the effect of changes in structure on biological activity is similar in several series of compounds, this topic will be discussed later. 

Herbicides. The use of herbicides (qv) based on iodine compounds has its main market in Western Europe. In Canada and the United States these compounds are used only to a small extent. The only significant iodine-containing herbicide is ioxynil [1689-85 4] (4,-hydroxy-3,5,-diiodobenzoic acid). This compound, often used in combination with other herbicides, is formulated for controlling many annual broad-leaved weeds, especially black-bindweed, knotgrass, mayweeds, and com marigold post-emergence in wheat, barley, oats, rye, and triticale (142). Annual consumption of iodine in relation to ioxynils is considered to be about 300—500 t (66). 

In some orchards where repeated applications of triazine herbicides have been used, there are isolated instances of triazine-resistant weeds. These include common groundsel in the United Kingdom (Holliday and Putwain, 1977) and common lambsquarters and pigweeds in Czechoslovakia, Poland, and Bavaria. Some studies indicated an increased prevalence of some tolerant weeds in orchards when triazine herbicides were used in certain crop weed systems of common vetch (Heeney et al., 1981a), field bindweed (Meith and Connell, 1985), and quackgrass (Hertz and Wildung, 1978). 

Phenoxy herbicides which are routinely used in agriculture for the control of common weeds, are generally ineffective in suppressing the spread of bindweed. Consequently, a number of independent studies on its possible biological control have recently been initiated. One of these efforts led to the isolation and identification of the host-specific pathogen P. convolvulus, whose infection results in necrotic lesions and wilting of the leaf tissues of bindweed. Initially, it was also noted that the lesions formed on the infected leaves were often surrounded by yellow... 

Uses Selective preemergence or postemergence herbicide used to effectively control a wide variety of broad-leaved weeds (such as bindweed, jimsonweed, kochia, mustards, pigweeds, sesbania, smartweed and velvet-leaf) in tolerant erops (com, grain sorghum, maize, rice and soybeans). 

Uses Selective contact foliage-applied herbicide used to control many broad-leaved weeds such as bindweed, chickweed and Veronica spp. in cereals. 

Uses Selective, systemic preemergence and postemergence herbicide used to control both aimual and perennial broad-leaved weeds, chickweed, mayweed and bindweed in cereals and other related crops. 

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