Azoxystrobin

Description

Azoxystrobin is a second broad-spectrum strobilurin fungicide (28,29). It forms white solids with a mp = 116 ?C; vp = 1.1 × 10?7 mPa at 25 ?C; logP = 2.5 at 20?C; water solubility = 6 mg/L; and a half-life of 11 to 17 days for aqueous photolysis.

Chemical properties

White to beige crystalline solid or powder.

The Uses of Azoxystrobin

Azoxystrobin has a very broad spectrum of activity and is active against fungal pathogens from all four taxonomic groups, the Oomycetes, Ascomycetes, Deuteromycetes and Basidiomycetes. It controls diseases on cereals, rice, vines, apples, peaches, bananas, citrus, curcurbits, potatoes, tomatoes, peanuts, coffee and turf.

The Uses of Azoxystrobin

Strobilurin fungicide; inhibits mitochondrial respiration by blocking electron transfer between cytochromes b and c1. Agricultural fungicide.

The Uses of Azoxystrobin

Agricultural fungicide.

What are the applications of Application

Azoxystrobin is Azoxystrobin is a potent and commonly used fungicide.

Definition

ChEBI: An aryloxypyrimidine having a 4,6-diphenoxypyrimidine skeleton in which one of the phenyl rings is cyano-substituted at C-2 and the other carries a 2-methoxy-1-(methoxycarbonyl)vinyl substituent, also at C-2. An inhibitor of mitochondrial respiration by b ocking electron transfer between cytochromes b and c1, it is used widely as a fungicide in agriculture.

Hazard

Moderately toxic by inhalation.

Agricultural Uses

Fungicide: Azoxystrobin has been processed as a Reduced Risk pesticide for Turf uses. Azoxystrobin is a systemic, broad-spectrum fungicide that was first introduced in 1998. It inhibits spore germination and is used on grape vines, cereals, potatoes, apples, bananas, citrus, tomatoes and other crops. Largest crop uses in California are on almonds, rice, pistachios, wine grapes, raisins and garlic. Among the diseases it controls are rusts, downey and powdery mildew, rice blast and apple scab. A U.S. EPA restricted Use Pesticide (RUP)

Trade name

ABOUND®; AMISTAR®; AMISTAR OPTI; AMISTAR PRO; BANKIT®; HERITAGE®; ICIA5504 80WG®; OLYMPUS®; ORTIVA®; PROTEGE®; PROTEGE-ALLEGIANCE WP®;PROTEGE-FL SEED APPLIED FUNGICIDE®; QUADRIS OPTI®; QUILT®; SOYGARD WITH PROTEGE®

Safety Profile

Moderately toxic by inhalation.When heated to decomposition it emits toxic vapors ofNOx.

Potential Exposure

A β-methyoxyacrylate, Strobilurin is an agricultural fungicide.

Metabolic pathway

Azoxystrobin is a recently developed fungicide with a novel mode of action (see Overview for relevant references). It was first registered in 1996. It has been and is being subjected to the full range of studies to meet current regulatory requirements for toxicology, metabolism and environmental fate. Information on its metabolism and environmental fate was presented as a lecture at the 9th International Congress of Pesticide Chemistry (IUPAC) in 1998 and this will be published in the Proceedings. The information presented below is derived from this source (Joseph, 1998).
Azoxystrobin is a carboxylic acid methyl ester and one of its pathways of metabolism is via hydrolysis to its carboxylic acid. The latter is not biologically active (see Overview) and the favourable selective toxicity of the fungicide is due to this and other metabolic reactions in non-target species. Azoxystrobin is readily degraded in soil and ultimately mineralised and it is metabolised in plants and animals. Metabolism is complex because the molecule possesses several functional groups. Five different pathways have been identified in plants and animals. Biotransformations occurring on the parent molecule include hydrolysis, aromatic hydroxylation, cleavage of both phenoxy linkages, nitrile to amide hydrolysis and fragmentation of the acrylate double bond. Some photo-induced changes also occur, including conversion to the (Z)-isomer.

Metabolism

Metabolites are also rapidly degraded in soil. Photolysis studies show a DT₅₀ of 11 days. Due to the rapid degradation and low soil mobility, no leaching is found in field studies.

Shipping

UN2811 Toxic solids, organic, n.o.s., Hazard Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name Required. UN3082 Environmentally hazardous substances, liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required.

Degradation

Azoxystrobin is degraded under conditions of aqueous photolysis with a DT₅₀ of 11-17 days (PM).
Soil surface photolysis of azoxystrobin (¹⁴C-labelled separately in each of the three rings) was studied on a sandy loam for a period of 30 days. The fungicide was degraded with a DT₅₀ measured as a mean of the three radiolabels, of 11 days in natural summer sunlight. The degradation was complex, affording many initial products, all at 40% of the applied radiocarbon. These products were themselves readily photolysed and no product accumulated during the course of the experiment. The yield of ¹⁴CO2 in 30 days was between 17% (phenylacrylate label) and 29% (cyanophenyl label). Thus soil surface photodegradation is likely to be an important mechanism for the removal of azoxystrobin from the environment.

Toxicity evaluation

Azoxystrobin has an acute oral LD₅₀ > 5,000 and an acute dermal LD₅₀ > 2,000 mg/kg in rats. Azoxystrobin gives only slight skin and eye irritation and is nonmutagenic and nonteratogenic. Its NOEL is 18 mg/kg bw/day. It has no toxicity to birds in acute studies (LD₅₀ > 2,000 mg/kg). It is harmless to other nontarget organisms (honey bees, earthworms, beneficial arthropods) due to low toxicity and rapid degradation in the environment, which minimizes exposure.

Incompatibilities

Combustible; dust may form explosive with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides.

Waste Disposal

Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Dispose of contents and container to an approved waste disposal plant. Use a licensed professional waste disposal service to dispose of this material. Ultimate disposal of the chemical, product, and waste containers must consider: the material’s impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with public health, local, state, and federal health and environmental regulations. Never reuse or recycle used product containers unless the recycling program specifically accepts pesticide containers and you follow the program’s instructions for preparing the empty containers for collection