The resolved isomer of metolachlor, S-metolachlor, was registered in 1997. New formulations based primarily on the S-metolachlor isomer are more active on a gram for gram metolachlor basis than formulations based on a racemic mixture of metolachlor containing a 50:50 ratio of the R and S isomers. The labelled use rates of S-metolachlor-based products were reduced by 35% to give equivalent weed ...

Allelopathic substances can be used to develop weed control alternatives based on natural products. The objective of this study was to compare the phytotoxic activity of aqueous leaf extracts of Rapanea umbellata with the toxicity of a synthetic herbicide on the germination and growth of weed species. The weeds species barnyard grass (Echinochloa crus-galli), wild poinsettia (Euphorbia heteroph...

Hyptis suaveolens (Lamiaceae) is an exotic invasive plant in many countries. Earlier studies reported that the aqueous, methanol, and aqueous methanol extract of H. suaveolens and its residues have phytotoxic properties. However, to date, the phytotoxic substances of this plant have not been reported. Therefore, the objectives of this study were isolation and identification of phytotoxic substa...

Sagitaria trifolia, Alisma plantago-aquatica and Echinochloa spp. are among the most important damaging weeds in paddy fields. In this research, Alternaria pellucida was isolated from the weeds and then its pathogenicity effects was examined on these weeds and five other rice cultivars, including two bred (Sepidroud and Khazar) and three landraces (Ali Kazemi, Hashemi and Binam), in a completel...

In organic solvents, 1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-hydroxypyrazole (DTP) converted chlorophyll a and b extracted from rice seedlings (Oryza sativa L. ;Kinmaze') into pheophytin a and b, respectively. On comparing the chlorophyll-converting activity of DTP to those of acetic, glycolic, 2,4-dichlorobenzoic, monochloroacetic, 2,6-dichlorobenzoic, pyruvic, and dichloroacetic acids, it was ...

in recent years, machine vision and optical sensors, which can be used in an autonomous weed killing equipment, are being used extensively to detect weeds from crops. in this study, seven types of weeds that grow in most of the sugar beet fields in iran, especially in fars province, were considered in real outdoor conditions. several color feature extraction algorithms have also been investigat...

The n-hexane extract of S. salignus plants inhibited ATP synthesis and two sesquiterpenes, the β-caryophyllene (1) and caryophyllene oxide (2) were isolated from this nonpolar fraction. Compound 1 inhibited by 42% the root elongation of Physalis ixocarpa seedlings at 50 µg/mL and by 53% at 150 µg/mL, whereas at 150 µg/mL this compound only inhibited root elongation of Echinochloa crus-galli by ...

Responses of barnyardgrass (Echinochloa crus-galli var. crux-galli) to water drained, saturated, or flooded soils were assessed in relation to the aerenchyma formation in crown roots. Plant height, fresh weight of shoots, the number of crown roots, and the fresh weight of roots of 4-week-old barnyardgrass increased in the following order: saturated>drained>flooded. By contrast, aerenchyma was r...

Studies were initiated to evaluate absorption, translocation, and distribution of C-quinclorac in propaniland quinclorac-resistant (R-BYG) and -susceptible (S-BYG) barnyardgrass. No differential absorption of C-quinclorac was observed between R-BYG and S-BYG, but more C remained in the treated leaf of S-BYG (57% of total absorbed) compared with the R-BYG leaf (34% of total absorbed) at 72 h aft...

This paper describes a dynamic simulation model that allows for comprehensive assessment of integrated weed management programmes for the control of annual barnyardgrass (Echinochloa crus-galli complex) in Philippine rice farming systems. The main outputs of the model include weed seed and plant densities and seasonal and annualised profit over the simulated planning horizon. Results broadly in...