Biochemistry

Acts as an antagonist by binding to postsynaptic nicotinic receptors in the insect central nervous system.

Mode of action

Systemic insecticide with translaminar activity and with contact and stomach action. Readily taken up by the plant and further distributed acropetally, with good root-systemic action.

Uses

Control of sucking insects, including rice-, leaf- and planthoppers, aphids, thrips and whitefly. Also effective against soil insects, termites and some species of biting insects, such as rice water weevil and colorado beetle. Has no effect on nematodes and spider mites. Used as a seed dressing, as soil treatment and as foliar treatment in different crops, e.g. rice, cotton, cereals, maize, sugar beet, potatoes, vegetables, citrus fruit, pome fruit and stone fruit. Applied at 25-100 g/ha for foliar application, 50-175 g/100 kg seed for most seed treatments, and 350-700 g/100 kg cotton seed. Also used to control fleas on dogs and cats.

Biochemistry

Inhibits protein synthesis in fungi, by interference with the synthesis of ribosomal RNA. The (R)- (metalaxyl-M) and (S)- isomers have the same mode of action, but differ in biological activity.

Mode of action

Systemic fungicide with protective and curative action, taken up by leaves, stems and roots.

Uses

To control diseases caused by air- and soil-borne Peronosporales on a wide range of temperate, subtropical and tropical crops. Foliar sprays with mixtures of metalaxyl-M and protectant fungicides are recommended to control air-borne diseases caused by Pseudoperonospora humuli on hops, Phytophthora infestans on potatoes and tomatoes, Peronospora tabacina on tobacco, Plasmopara viticola on vines, downy mildews of vegetables, and Bremia lactucae on lettuce, at 100-140 g metalaxyl-M/ha. Soil applications of metalaxyl-M alone are used to control soil-borne pathogens causing root and lower stem rots on avocado and citrus, Phytophthora nicotianae on tobacco, Phytophthora spp. on peppers, and Pythium spp. on many different crops, including ornamentals, at 250-1000 g/ha. Seed treatments control systemic Peronosporaceae on maize, peas, sorghum and sunflowers, at 35-300 g/100 kg seed, as well as Damping-off (Pythium spp.) of various crops, at 8.25-17.5 g/100 kg seed.

Biochemistry

Sterol demethylation (ergosterol biosynthesis) inhibitor.

Mode of action

Systemic fungicide with protective, curative and eradicative action. Rapidly absorbed into the vegetative parts of the plant, with translocation principally acropetally.

Uses

As a seed dressing, tebuconazole is effective against various Smut and bunt diseases of cereals, such as Tilletia spp., Ustilago spp. and Urocystis spp., also against Septoria nodorum (seed-borne), at 1-3 g/dt seed; and Sphacelotheca reiliana in maize, at 7.5 g/dt seed. As a spray, tebuconazole controls numerous pathogens in various crops, including: rust species (Puccinia spp.) at 125-250 g/ha, powdery mildew (Erysiphe graminis) at 200-250 g/ha, scald (Rhynchosporium secalis) at 200-312 g/ha, Septoria spp. at 200-250 g/ha, Pyrenophora spp. at 200-312 g/ha, Cochliobolus sativus at 150-200 g/ha, and head scab (Fusarium spp.) at 188-250 g/ha, in cereals; Leaf spots (Mycosphaerella spp.) at 125-250 g/ha, leaf rust (Puccinia arachidis) at 125 g/ha, and Sclerotium rolfsii at 200-250 g/ha, in peanuts; black leaf streak (Mycosphaerella fijiensis) at 100 g/ha, in bananas; stem rot (Sclerotinia sclerotiorum) at 250-375 g/ha, Alternaria spp. at 150-250 g/ha, stem canker (Leptosphaeria maculans) at 250 g/ha, and Pyrenopeziza brassicae at 125-250 g/ha, in oilseed rape; blister blight (Exobasidium vexans) at 25 g/ha, in tea; Phakopsora pachyrhizi at 100-150 g/ha, in soya beans; Monilinia spp. at 12.5-18.8 g/100 l, powdery mildew (Podosphaera leucotricha) at 10.0-12.5 g/100 l, Sphaerotheca pannosa at 12.5-18.8 g/100 l, scab (Venturia spp.) at 7.5-10.0 g/100 l, and apple white rot (Botryosphaeria dothidea) at 25 g/100 l, in pome and stone fruit; powdery mildew (Uncinula necator) at 100 g/ha, in grapevines; rust (Hemileia vastatrix) at 125-250 g/ha, berry spot disease (Cercospora coffeicola) at 188-250 g/ha, and American leaf disease (Mycena citricolor) at 125-188 g/ha, in coffee; white rot (Sclerotium cepivorum) at 250-375 g/ha, and purple blotch (Alternaria porri) at 125-250 g/ha, in bulb vegetables; leaf spot (Phaeoisariopsis griseola) at 250 g/ha, in beans; early blight (Alternaria solani) at 150-200 g/ha, in tomatoes and potatoes.

Phytotoxicity

Good plant compatibility in most crops with any formulation, and achieved in more sensitive crops by appropriate formulations, e.g. WP, WG or SC.