# MedQ Agri Chemicals — Extended AI Reference Brief # MedQ Agri Chemicals > Specialist supplier and reference library for agricultural chemicals — herbicides (weed killers), insecticides, fungicides, fertilisers, adjuvants, public-health pest control, fumigation and application equipment — based in Johannesburg, South Africa, serving South Africa, Namibia and Botswana. MedQ Agri Chemicals is a trading division of MedQ Supplies. The site combines a transparently priced catalogue of 790+ products with an authority knowledge base on the chemistry, uses and safe handling of agrochemicals in southern Africa. ## Contact - Email (quotes & enquiries): hello@medq.africa - Tel: +27 65 392 8985 · WhatsApp: +27 78 703 5553 - Address: 25 West Road, Houghton, Johannesburg 2191, South Africa ## Key pages - [Product catalogue](https://www.vitalchain.co.za/shop): 790+ products with ZAR pricing, displayed ex VAT (15% VAT added on quotation) - [Knowledge Centre](https://www.vitalchain.co.za/knowledge): guides on herbicide types, bush-encroachment control, fungicide resistance, vector control, PPE and fumigation - [Active ingredients A–Z](https://www.vitalchain.co.za/actives): 38 monographs — mode of action, uses, targets, safety - [Tender insights 2023–2026](https://www.vitalchain.co.za/tenders): most-specified agrochemicals in SA/Namibia/Botswana public tenders, with pack-size requirements (5L/20L/25L) - [Glossary](https://www.vitalchain.co.za/glossary): agrochemical terminology - [Research & AI index](https://www.vitalchain.co.za/ai): machine-readable access and citation policy ## Machine-readable data - [Full product catalogue (JSON)](https://www.vitalchain.co.za/ai/products.json): SKU, name, active ingredient, pack size, category, price, use - [Knowledge base (JSON)](https://www.vitalchain.co.za/ai/knowledge.json): monographs, guides, glossary - [Extended brief](https://www.vitalchain.co.za/llms-full.txt) - [Sitemap](https://www.vitalchain.co.za/sitemap.xml) ## Pricing model our_price_ex_vat = supplier list price × 1.40; price_incl_vat = ex-VAT × 1.15 (South African VAT). The website and quotations display our_price_ex_vat, labelled "ex VAT" — VAT is added once, at the quotation total. price_basis is one of: price-list (taken from a supplier list), estimated (pack-size variant extrapolated per litre — confirm on quotation), POA (price on application). ## Categories - Herbicides & Weed Killers (111 products) - Bush Encroachment & Arboricides (60 products) - Insecticides (107 products) - Public Health & Pest Control (141 products) - Fungicides (71 products) - Fertilizers & Plant Nutrition (30 products) - Adjuvants, Surfactants & Spray Aids (71 products) - Rodenticides & Vertebrate Control (31 products) - Bio-Pesticides & Organic Inputs (20 products) - Plant Growth Regulators (10 products) - Fumigants (Restricted Use) (18 products) - Spraying Equipment, Traps & PPE (104 products) - Cleaning & Detergents (17 products) ## Active ingredient monographs ### Glyphosate (Herbicide) Group: Glycine (HRAC Group 9 — EPSPS inhibitor) Mode of action: Systemic, non-selective. Inhibits the EPSPS enzyme in the shikimic-acid pathway, blocking aromatic amino-acid synthesis. Absorbed through green tissue and translocated to roots and meristems; plants yellow and die over 7–21 days. Uses: Total weed control in minimum-till cropping, orchards, vineyards, fence lines, roadsides, industrial sites and aquatic margins (registered formulations). The single most-tendered herbicide in South African, Namibian and Botswanan municipal and roads contracts, typically specified as 360 g/l SL or 540 g/l SL in 20L packs. Crops/targets: Annual and perennial grasses and broadleaf weeds; no soil residual activity. Safety: Low acute mammalian toxicity but formulations with tallow-amine surfactants are more hazardous — use crop-safe formulations near water. Avoid drift onto desirable plants. Resistance documented in rigid ryegrass and hairy fleabane in SA — rotate modes of action. Notes: Hard water antagonises glyphosate; condition spray water with ammonium sulphate (Amsul-50, Hyperboost) for full efficacy. Rainfast within ~6 hours with quality formulations. ### 2,4-D (Herbicide) Group: Phenoxy-carboxylic acid (HRAC Group 4 — synthetic auxin) Mode of action: Selective systemic. Mimics indole-acetic acid, causing uncontrolled growth, stem twisting and death in susceptible broadleaf plants. Grasses are tolerant. Uses: Broadleaf weed control in lawns, sports turf, pastures, maize, wheat and sugarcane. A staple of municipal turf-care tenders, frequently specified with MCPA and dicamba in 5L packs. Crops/targets: Broadleaf weeds (dandelion, plantain, khaki weed, thistles) in grass crops and turf. Safety: Highly volatile ester formulations can drift and damage tomatoes, vines, citrus and cotton — use amine or low-volatile formulations near sensitive crops. Notes: Do not use the same spray equipment for hormone-type herbicides and sensitive broadleaf crops without rigorous decontamination (Flushall). ### MCPA (Herbicide) Group: Phenoxy-carboxylic acid (HRAC Group 4 — synthetic auxin) Mode of action: Synthetic auxin, similar to 2,4-D but gentler on cereals and turf; systemic and selective. Uses: Broadleaf weed control in wheat, oats, barley, pastures and fine turf. Common in tender turf-mix specifications (MCPA + dicamba + 2,4-D). Crops/targets: Broadleaf weeds in cereals and turf; safe on most grasses. Safety: Moderate persistence in soil; observe grazing withholding periods on treated pastures. Notes: Often sold as 400 g/l dimethylamine salt; mixes well with dicamba for woody broadleaf weeds. ### Dicamba (Herbicide) Group: Benzoic acid (HRAC Group 4 — synthetic auxin) Mode of action: Systemic auxin mimic with strong activity on woody and deep-rooted broadleaf weeds. Uses: Turf, maize and pasture broadleaf control; brush suppression in mixtures. Tender turf mixes frequently pair dicamba with MCPA and 2,4-D. Crops/targets: Hard-to-kill broadleaf weeds, bramble and woody regrowth. Safety: Volatile and drift-prone; buffer zones near sensitive broadleaf crops are essential. Notes: Garden Route / George municipal tender specifications repeatedly list an MCPA+dicamba+2,4-D combination in 5L for turf. ### Simazine (Herbicide) Group: Triazine (HRAC Group 5 — photosystem II inhibitor) Mode of action: Root-absorbed, residual. Blocks electron transport in photosystem II, starving emerged and germinating weeds. Uses: Long-residual bareground control on roadsides, railways, substations and industrial yards; also registered in maize, orchards and vineyards. 500 SC in 20L is a recurring roads-department tender item. Crops/targets: Germinating annual grasses and broadleaf weeds; residual 6–12 months on soil. Safety: Leaches in sandy soils — keep away from boreholes and watercourses; rotational crop restrictions apply. Notes: Combine with glyphosate for knockdown-plus-residual vegetation contracts. ### Imazapyr (Herbicide) Group: Imidazolinone (HRAC Group 2 — ALS inhibitor) Mode of action: Systemic ALS-inhibitor absorbed by roots and foliage; residual in soil for many months. Uses: Total vegetation control on non-crop land, firebreaks, powerline servitudes; cut-stump and soil treatment of invasive bush (prosopis, acacia) — a key Namibian bush-encroachment tender active. Crops/targets: Woody species, grasses and broadleaf weeds on non-crop areas. Safety: Long soil residual — never use where desirable vegetation roots may extend; groundwater caution on sandy soils. Notes: Typically supplied as 250 g/l SL (Outpace Super and equivalents) in 5L/20L/25L. ### Glufosinate (Herbicide) Group: Phosphinic acid (HRAC Group 10 — glutamine synthetase inhibitor) Mode of action: Contact, partially systemic. Causes ammonia accumulation and rapid photosynthetic disruption. Uses: Non-selective weed control in orchards, vineyards and fallow; the leading glyphosate rotation partner for resistance management. Tendered as 200/280 g/l SL. Crops/targets: Annual weeds; weaker on perennials than glyphosate. Safety: Higher acute toxicity than glyphosate — full PPE (gloves, respirator) required when mixing. Notes: Works best in warm, humid conditions with good coverage; add a wetter (Wetcit Duo, Charge). ### Triclopyr (Herbicide) Group: Pyridine-carboxylic acid (HRAC Group 4 — synthetic auxin) Mode of action: Systemic auxin mimic particularly effective on woody plants; translocates to roots. Uses: Brush and invasive tree control (black wattle, prosopis, lantana) by foliar spray, cut-stump or basal-bark application with mineral oil carrier (Actipron Super). Gel formulations (triclopyr+picloram, Kaput-type) are standard for targeted cut-stump work. Crops/targets: Woody weeds, bramble, invasive acacia and eucalyptus regrowth. Safety: Butoxyethyl ester is for non-crop use; amine salt has wider crop registration. Avoid drift to broadleaf crops. Notes: 480 g/l EC in 1L/5L/20L; ester form is rainfast within hours. ### Picloram (Herbicide) Group: Pyridine-carboxylic acid (HRAC Group 4 — synthetic auxin) Mode of action: Potent, residual auxin mimic — among the most persistent pyridine herbicides. Uses: Deep-rooted woody weed and bush control, often co-formulated with fluroxypyr (ME) or triclopyr (gel). Namibian and Botswanan bush-encroachment programmes specify picloram mixtures for prosopis and dichrostachys. Crops/targets: Woody invasive species; do not use near desirable trees or gardens. Safety: Soil residual can exceed 12 months; manure from animals grazing treated forage can damage sensitive crops. Notes: Kaput-type gel (triclopyr 120 + picloram 120) applied to freshly cut stumps gives near-100% kill with minimal environmental loading. ### Tebuthiuron (Herbicide / Arboricide) Group: Substituted urea (HRAC Group 5 — photosystem II inhibitor) Mode of action: Soil-applied, root-absorbed PSII inhibitor; slow, thorough kill of woody plants over 6–24 months. Uses: The backbone of Namibian bush-encroachment tenders: granular (200 g/kg GG) applied to soil around target shrubs (acacia mellifera, terminalia, dichrostachys) to restore grassland. Also used on fence lines and firebreaks. Crops/targets: Encroaching bush species; grass cover recovers after shrub death. Safety: Very persistent and mobile — keep well away from desirable trees, watercourses and boreholes. Non-crop use only. Notes: Limpopo 200 GG (25 kg) is the reference product; application rates vary by species and soil — follow label tables. ### Bromacil (Herbicide) Group: Uracil (HRAC Group 5 — photosystem II inhibitor) Mode of action: Root-absorbed residual PSII inhibitor for total soil sterilisation. Uses: Railways, road shoulders, substations, tank farms — anywhere total bareground is specified. Frequent tender item as 250 SC or 80 WP. Crops/targets: All vegetation on non-crop land; residual 12+ months. Safety: Leaches readily; do not apply over shallow water tables or near desirable plants' root zones. Notes: Often rotated or mixed with diuron and imazapyr to manage resistance and cost. ### Imidacloprid (Insecticide) Group: Neonicotinoid (IRAC Group 4A — nAChR agonist) Mode of action: Systemic. Binds nicotinic acetylcholine receptors, causing paralysis and death; moves acropetally in the plant. Uses: Sucking pests (aphids, whitefly, scale, psylla) in crops; lawn grub and mole-cricket control; termite barriers; tree injection for polyphagous shot hole borer programmes. 350 SC (Kohinor, Starbug class) in 5L is a recurring municipal and turf tender item. Crops/targets: Aphids, leafhoppers, whiteflies, soil grubs, termites. Safety: Highly toxic to bees — never spray flowering crops; observe pollinator label restrictions strictly. Notes: Soil drench gives 4–8 weeks protection; resistance common in whitefly — rotate with Group 4D/28. ### Cypermethrin (Insecticide) Group: Pyrethroid (IRAC Group 3A — sodium channel modulator) Mode of action: Contact and stomach action; disrupts sodium-channel gating causing rapid knockdown. Uses: Broad crop-pest control (bollworm, cutworm, leaf-eating caterpillars) and vector/structural pest control; 200 EC is a standard crop and municipal formulation. Crops/targets: Chewing and sucking insects on most crops; flies and mosquitoes in public health. Safety: Highly toxic to fish, bees and aquatic invertebrates — strict buffer zones around water. Notes: Synthetic pyrethroid resistance is widespread in some pests — use in rotation, not as sole chemistry. ### Deltamethrin (Insecticide) Group: Pyrethroid (IRAC Group 3A) Mode of action: Potent pyrethroid with fast knockdown and long residual on surfaces. Uses: Indoor residual spraying (IRS) for malaria vector control, stored-grain protection, crop pests. Decis/K-Othrine class; WP formulations specified in health-department tenders. Crops/targets: Mosquitoes, flies, stored-product beetles, crop caterpillars. Safety: Aquatic toxicity very high; cold-blooded animals (fish, reptiles) extremely sensitive. Notes: Among the most potent pyrethroids per gram — follow dilution tables exactly. ### Lambda-cyhalothrin (Insecticide) Group: Pyrethroid (IRAC Group 3A) Mode of action: Fast-acting sodium-channel modulator; capsule-suspension (CS) forms extend residual. Uses: Crop insects, turf pests, public-health residual sprays (Impact CS class). Crops/targets: Caterpillars, aphids, beetles, cockroaches, ants. Safety: Skin paresthesia common on exposure — wear coveralls and gloves. Notes: CS micro-encapsulation reduces odour and staining for structural use. ### Fipronil (Insecticide) Group: Phenylpyrazole (IRAC Group 2B — GABA antagonist) Mode of action: Blocks GABA-gated chloride channels; contact and ingestion, with colony transfer in social insects. Uses: Termite barriers and baiting, ant and cockroach gels, locust control, seed treatment. Regent/Terminator class. Crops/targets: Termites, ants, cockroaches, locusts, soil insects. Safety: Toxic to bees and aquatic life; restricted in some jurisdictions — confirm current registration. Notes: Gel baits (Domino class) exploit trophallaxis for colony elimination at very low doses. ### Chlorpyrifos (Insecticide) Group: Organophosphate (IRAC Group 1B — acetylcholinesterase inhibitor) Mode of action: Irreversible AChE inhibition causing synaptic overstimulation. Uses: Soil pests, termites (structural), certain crop pests. Registrations have narrowed sharply — many uses now restricted. Crops/targets: Termites, cutworms, soil larvae where still registered. Safety: Significant mammalian neurotoxicity; cholinesterase monitoring advised for regular handlers. Check current label before supply. Notes: 480 EC (Inhibitor 48 SC class) remains specified in older termite tenders; verify legal status per country. ### Dimethoate (Insecticide) Group: Organophosphate (IRAC Group 1B) Mode of action: Systemic AChE inhibitor absorbed by roots and foliage. Uses: Aphids, fruit fly, leaf miners in citrus, vegetables and field crops (400 EC). Crops/targets: Sucking and mining insects. Safety: Moderate-to-high acute toxicity; strict re-entry intervals. Notes: Being phased down in some markets — recommend alternatives (Group 4A, 28) where available. ### Mercaptothion (Malathion) (Insecticide) Group: Organophosphate (IRAC Group 1B) Mode of action: Contact AChE inhibitor with relatively low mammalian toxicity. Uses: Vector control (mosquito larviciding/adulticiding), grain protectant, garden insect control; 500 EC/ULV in health tenders. Crops/targets: Mosquitoes, flies, stored-grain insects, garden pests. Safety: Among the safer OPs but still an AChE inhibitor — standard OP precautions apply. Notes: ULV formulations for space spraying at very low volume. ### Propiconazole (Fungicide) Group: Triazole (FRAC Group 3 — DMI) Mode of action: Systemic; inhibits C14-demethylation in ergosterol biosynthesis, disrupting fungal membranes. Uses: Rusts, leaf spots and powdery mildew in cereals, turf and ornamentals (250 EC). Curative and protectant. Crops/targets: Rust, powdery mildew, leaf spot, dollar spot in turf. Safety: Growth-regulating side-effect on some ornamentals at high rates — follow label. Notes: Rotate with FRAC 11 (azoxystrobin) to delay resistance. ### Azoxystrobin (Fungicide) Group: Strobilurin (FRAC Group 11 — QoI) Mode of action: Blocks mitochondrial respiration at the Qo site; broad-spectrum, translaminar. Uses: Cereals, maize, vegetables, turf; excellent preventative activity (250 SC). Crops/targets: Rusts, mildews, anthracnose, turf diseases. Safety: Very phytotoxic to certain apple varieties — never use on or drift onto apples. Notes: High resistance risk when used solo — always mix or alternate with multi-site (mancozeb/chlorothalonil). ### Chlorothalonil (Fungicide) Group: Chloronitrile (FRAC Group M05 — multi-site) Mode of action: Multi-site protectant disrupting multiple enzymes; negligible resistance risk. Uses: Protectant backbone for vegetables, potatoes, turf (720 SC / 75 WP). Crops/targets: Early/late blight, leaf spots, downy mildew (in mixes). Safety: Protectant only — must precede infection; eye irritant. Notes: Ideal resistance-management partner for single-site fungicides. ### Mancozeb (Fungicide) Group: Dithiocarbamate (FRAC Group M03 — multi-site) Mode of action: Multi-site protectant interfering with sulphydryl enzymes. Uses: Potatoes, tomatoes, citrus, ornamentals (800 WP); cornerstone of blight programmes. Crops/targets: Early blight, late blight, downy mildew (with cymoxanil), black spot. Safety: Re-entry intervals apply; avoid in hot, wet conditions on sensitive crops. Notes: Cheap, effective, resistance-proof — the workhorse protectant. ### Copper oxychloride (Fungicide / Bactericide) Group: Inorganic copper (FRAC Group M01 — multi-site) Mode of action: Copper ions denature enzymes on contact; protectant only. Uses: Citrus, vines, tomatoes, potatoes; bacterial disease suppression (850 WP / 500 SC). Crops/targets: Blight, leaf spot, bacterial canker, citrus scab. Safety: Accumulates in soil with decades of use; phytotoxic in slow-drying conditions. Notes: Apply before rain/infection; compatible with most protectants. ### Sulphur (Fungicide / Miticide) Group: Inorganic (FRAC Group M02 — multi-site) Mode of action: Vapour-phase multi-site action against powdery mildew and mites. Uses: Powdery mildew in vines, cucurbits, roses; mite suppression (800 WP / dusts). Crops/targets: Powdery mildew, eriophyid and spider mites. Safety: Phytotoxic above ~30 °C and on sulphur-shy cucurbits; do not combine with oils within 14 days. Notes: Acceptable in organic production — a dual-use conventional/organic tool. ### Metaldehyde (Molluscicide) Group: Molluscicide Mode of action: Neurotoxic to molluscs; causes excessive mucus production and dehydration. Uses: Snail and slug control in gardens, crops and export orchards (pellets, 40 SC). Crops/targets: Snails, slugs. Safety: Attractive and toxic to dogs and wildlife — use pet-safer formulations and bait stations. Notes: Carbaryl-based baits are alternatives where metaldehyde is restricted. ### Paraquat (Herbicide) Group: Bipyridylium (HRAC Group 22 — photosystem I diverters) Mode of action: Contact; generates reactive oxygen species destroying green tissue within hours. Uses: Fast burndown pre-plant, inter-row and directed sprays (200 SL). Restricted/prohibited in some countries — confirm legality before supply. Crops/targets: All green tissue contacted; no soil activity. Safety: Extremely toxic if swallowed — no antidote. Handle with full PPE; keep secure. Notes: Still appears in some regional tenders; glufosinate or glyphosate are alternatives where paraquat is banned. ### Diquat (Herbicide) Group: Bipyridylium (HRAC Group 22) Mode of action: Contact desiccant, similar to paraquat but registered for aquatic and potato-haulm uses in some markets. Uses: Aquatic weed control, haulm desiccation, pre-harvest drying (200 SL). Crops/targets: Aquatic weeds, potato haulms, annual weeds. Safety: Corrosive to eyes and skin; strict PPE. Notes: Check aquatic-use registration per country. ### Metsulfuron-methyl (Herbicide) Group: Sulfonylurea (HRAC Group 2 — ALS inhibitor) Mode of action: ALS inhibition at very low use rates; systemic with soil residual. Uses: Broadleaf control in cereals, turf and non-crop areas (600 WG); brush mixes. Crops/targets: Broadleaf weeds incl. khaki burr, cosmos. Safety: Very low rates — measure precisely; sprayer contamination damages broadleaf crops. Notes: Tank-clean with Flushall after use. ### Clethodim (Herbicide) Group: Cyclohexanedione (HRAC Group 1 — ACCase inhibitor) Mode of action: Selective ACCase inhibitor killing grasses in broadleaf crops. Uses: Grass weeds in soya, sunflower, vegetables and orchards (120 EC). Crops/targets: Annual and perennial grasses. Safety: Low broadleaf phytotoxicity; add crop oil for full efficacy. Notes: Rotate with glyphosate/glufosinate to manage ryegrass resistance. ### Pendimethalin (Herbicide) Group: Dinitroaniline (HRAC Group 3 — microtubule inhibitor) Mode of action: Pre-emergence root/shoot growth inhibition in germinating weeds. Uses: Pre-emergence control in maize, onions, vegetables, turf (330/455 EC). Crops/targets: Annual grasses and small-seeded broadleaf weeds. Safety: Orange staining of surfaces; incorporate lightly for activation. Notes: Needs soil moisture to activate. ### Acetochlor (Herbicide) Group: Chloroacetamide (HRAC Group 15 — VLCFA inhibitor) Mode of action: Shoot-absorbed pre-emergence inhibitor of very-long-chain fatty acid synthesis. Uses: Pre-emergence grass and sedge control in maize (900 EC). Crops/targets: Annual grasses, yellow nutsedge. Safety: Apply pre-emergence; limited post-emergence activity. Notes: Often pre-mixed with atrazine for broad-spectrum maize programmes. ### S-metolachlor (Herbicide) Group: Chloroacetamide (HRAC Group 15) Mode of action: Pre-emergence VLCFA inhibitor with improved selectivity over metolachlor. Uses: Maize, soya, sunflower pre-emergence grass control (960 EC). Crops/targets: Annual grasses and some sedges. Safety: Needs incorporation or rainfall within days of application. Notes: Dual Gold class; standard in conservation-tillage programmes. ### Diuron (Herbicide) Group: Substituted urea (HRAC Group 5) Mode of action: Residual PSII inhibitor, root-absorbed. Uses: Industrial bareground, orchards, sugarcane (800 SC/WP). Crops/targets: Germinating weeds; residual months. Safety: Watercourse contamination risk — buffer zones mandatory. Notes: Mixes with bromacil/hexazinone for extended residual. ### Hexazinone (Herbicide) Group: Triazinone (HRAC Group 5) Mode of action: Root- and foliar-absorbed PSII inhibitor active on woody plants. Uses: Industrial weed control, forestry site preparation, bush control (250 SL). Crops/targets: Woody weeds, grasses on non-crop land. Safety: Mobile in soil — groundwater caution. Notes: Velpar class; effective by spot-gun soil application. ### Brodifacoum (Rodenticide) Group: Second-generation anticoagulant (AVK) Mode of action: Vitamin-K antagonist causing fatal internal haemorrhage after a single feed. Uses: Rat and mouse control in bait stations around food premises, warehouses, farms (blocks, pellets, wax). Crops/targets: Rattus norvegicus, R. rattus, Mus musculus. Safety: Severe secondary-poisoning risk to owls and pets — always use secured bait stations and recover carcasses. Notes: Rotate with coumatetralyl to manage anticoagulant resistance. ### Coumatetralyl (Rodenticide) Group: First-generation anticoagulant Mode of action: Anticoagulant requiring multiple feeds; lower secondary-poisoning profile. Uses: Rodent control where non-target risk is high (Racumin class). Crops/targets: Rats and mice. Safety: Still hazardous to pets — bait stations required. Notes: Preferred near raptor conservation areas. ### Zinc phosphide (Rodenticide) Group: Acute rodenticide Mode of action: Releases phosphine gas in the stomach — acute, single-feed kill. Uses: Field rodent outbreaks (gerbils, multimammate rats) and mole control. Crops/targets: Field rodents. Safety: No antidote; extremely dangerous to all mammals — trained applicators only. Notes: Use pulses between anticoagulant programmes. ### Aluminium phosphide (Fumigant) Group: Fumigant (phosphine generator) Mode of action: Releases phosphine (PH₃) on contact with moisture; disrupts cellular respiration. Uses: Stored-grain, silo and commodity fumigation (tablets/pellets, Phostoxin class). Restricted — certified fumigators only. Crops/targets: All stored-product insects and rodents in sealed structures. Safety: Lethal gas; requires Fumiscope monitoring, SCBA standby and clearance certification. Notes: Tendered by grain boards and ports; sale restricted to licensed operators. ### Mineral oil (spray oils) (Adjuvant / Insecticide) Group: Adjuvant / physical insecticide Mode of action: Physical — smothers scale, mite eggs and soft-bodied insects; as adjuvant, improves spreading and cuticle penetration. Uses: Dormant and summer oil sprays for citrus and deciduous fruit; standard oil carrier for cut-stump arboricide mixes (Actipron Super, H&R Crop Oil 822 EC). Crops/targets: Scale, mealybug, red spider mite eggs. Safety: Phytotoxic above 30 °C or with sulphur within 14 days. Notes: George Municipality tender item 6 specifies mineral oil 822 g/l in 20L — covered by H&R Crop Oil and Performer 363 EW. ### Ammonium sulphate (AMS adjuvants) (Adjuvant) Group: Water conditioner Mode of action: Sequesters hard-water cations (Ca²⁺, Mg²⁺) that antagonise glyphosate and other weak-acid herbicides; lowers spray pH. Uses: Add to every glyphosate tank on borehole water (Amsul-50, Hyperboost, Booster AS, Balancer). Crops/targets: Improves efficacy of glyphosate, 2,4-D, glufosinate. Safety: Low hazard; corrosive to mild-steel equipment over time. Notes: Typically 1–2% v/v; add first, before herbicide. ## Guides ### Herbicides Explained: Selective, Non-Selective and Residual How weed killers are classified, how to match chemistry to the job, and why pack size and water conditioning decide real-world results. Herbicides are grouped first by selectivity. Non-selective products such as glyphosate, glufosinate and paraquat kill almost any green plant they contact and are the tools for total vegetation control on roadsides, fence lines, fallow land and industrial yards. Selective products — the phenoxy group (2,4-D, MCPA, dicamba), sulfonylureas (metsulfuron) and ACCase inhibitors (clethodim) — remove target weeds while leaving the crop or turf unharmed. The second axis is residual activity. Contact/systemic herbicides (glyphosate, 2,4-D) have no soil life and must hit green leaf. Residual herbicides — simazine, bromacil, diuron, imazapyr, tebuthiuron — bind to soil and keep killing germinating weeds for months, which is why roads departments, railways and municipalities specify them for bareground contracts, and why they must never be used where desirable plants root. Mode of action matters because weeds adapt. Southern Africa has confirmed glyphosate-resistant rigid ryegrass and hairy fleabane. The defence is rotation and mixture: alternate HRAC groups (9 → 10 → 22), add residual partners, and never run the same chemistry season after season. Practical field notes: glyphosate is crippled by hard borehole water — always condition with ammonium sulphate first. Ester formulations of 2,4-D and triclopyr drift onto vines, tomatoes and citrus; use amine salts near sensitive crops. And buy pack sizes to match the contract: municipal tenders overwhelmingly specify 5L for turf selective mixes and 20L/25L for glyphosate, simazine and imazapyr programmes. ### Bush Encroachment Control in Namibia, Botswana and the Northern Cape Why prosopis, acacia and dichrostachys are taking over rangeland, and the arboricide toolkit — tebuthiuron, picloram, triclopyr — that tender specifications call for. Bush encroachment — the thickening of woody species at the expense of grass — affects an estimated 26–45 million hectares of Namibian rangeland alone, with Botswana and the South African interior facing the same trajectory. Carrying capacity collapses as thornbush crowds out grass, and government restoration tenders have become a major, recurring market for arboricides. Three active-ingredient families dominate tender specifications. Tebuthiuron granules (200 g/kg, e.g. Limpopo 200 GG in 25 kg) are scattered on soil around target shrubs and kill through root uptake over 6–24 months — slow but thorough, with grass recovery following shrub death. Picloram mixtures (with fluroxypyr as ME, or with triclopyr as gel) give faster foliar and cut-stump control. Triclopyr 480 EC in a mineral-oil carrier is the workhorse for foliar and basal-bark application on species like black wattle and prosopis. Cut-stump gels such as the triclopyr 120 + picloram 120 combination (Kaput class) deserve special mention: applied to a freshly cut stump, they deliver near-complete kill with a fraction of the chemical load of foliar spraying — increasingly preferred in environmentally scored tenders. All of these actives are persistent by design. Application must respect buffer zones around watercourses, boreholes and desirable vegetation, and operators need the mineral-oil adjuvants (Actipron Super class) that carry stem applications into the bark. MedQ stocks the full toolkit in the pack sizes the tenders specify. ### Fungicide Resistance Management: Protectants, Systemics and Rotation Single-site fungicides fail fast when used alone. How to build programmes with mancozeb, chlorothalonil, copper, triazoles and strobilurins. Fungicides divide into multi-site protectants and single-site systemics. Protectants — mancozeb (FRAC M03), chlorothalonil (M05), copper (M01) and sulphur (M02) — attack many enzymes at once, so pathogens almost never evolve resistance; but they only protect tissue they cover and must be applied before infection. Systemics — triazoles like propiconazole (FRAC 3) and strobilurins like azoxystrobin (FRAC 11) — move inside the plant and can cure early infections, but each blocks a single biochemical step, so resistance develops quickly when they are used solo. QoI (strobilurin) resistance in powdery mildew can appear within a few seasons of exclusive use. The standard defence: open with a protectant, bring in a systemic only at high-risk growth stages, never exceed label limits on consecutive single-site applications, and alternate FRAC groups. Azoxystrobin is also highly phytotoxic to apples — never let it drift onto apple orchards. Sulphur and copper remain dual conventional/organic tools and stay effective precisely because they are multi-site. For post-harvest fruit, thiabendazole-class treatments (Tenderfrut) extend shelf life under export cold-chain requirements. ### Public Health & Vector Control: IRS, Space Sprays and Baiting The insecticide toolkit behind malaria IRS programmes, municipal fly control and structural pest management — pyrethroids, OPs and fipronil baits. Public-health pest control splits into residual surface treatment, space treatment and baiting. Indoor residual spraying (IRS) against malaria mosquitoes relies on long-residual pyrethroids such as deltamethrin WP and lambda-cyhalothrin CS, applied to interior walls where mosquitoes rest; provincial health departments tender these by the kilogram and litre each season. Space treatment — ULV cold fogging and thermal fogging — knocks down flying adults with fine droplets of pyrethrin/pyrethroid or malathion formulations (Deltacide, mercaptothion ULV). Machines such as the Hornet ULV apply these at very low volume per hectare. Baiting exploits social behaviour: imidacloprid and fipronil gels (Domino class) for cockroaches, fipronil granules (Optima class) for ants, and fly baits combining imidacloprid with attractants (Snap Fly Bait, Fly-Tac). Baiting achieves colony-level control at very low chemical loading — the preferred approach in food premises. Safety discipline is non-negotiable: pyrethroids are devastating to aquatic life, OPs require cholinesterase-awareness for handlers, and all structural work needs the PPE range — nitrile gloves, respirators with A2B2 filters, coveralls — that MedQ stocks alongside the chemistry. ### Safe Handling, PPE and Storage of Agricultural Chemicals The practical rules that keep operators safe and businesses compliant: reading labels, matching PPE to hazard class, and storing chemicals correctly. Every registered agrochemical label carries a hazard band (colour stripe) and the legally required PPE for mixing and application. The label is the law: rates, withholding periods, buffer zones and PPE listed there override any general guidance. Match PPE to the task. Mixing and loading concentrates is the highest-exposure step — chemical-resistant nitrile gloves, splash goggles or face shield, and a respirator with the correct filter (organic vapours need A2 cartridges; A2B2P3 combined filters cover mixed gas and particulate hazards). Application PPE includes coveralls and, for fumigation, self-contained breathing apparatus standby with gas monitoring (Fumiscope class instruments). Storage rules: locked, ventilated, bunded store; flammables separated; fumigants (aluminium phosphide) in sealed containers with restricted access; never store chemicals near food, seed or animal feed. Keep an inventory and safety data sheets on file — auditors and insurers ask for both. Disposal: triple-rinse empty containers, puncture them, and return through recognised recycling schemes; never reuse chemical containers for any purpose. Spill kits and eyewash must be on hand wherever concentrates are handled. ### Stored-Product Fumigation: Phosphine, Sulfuryl Fluoride and Compliance How grain and commodity fumigation works, why it is restricted to certified operators, and the equipment chain a compliant job requires. Fumigation is the only reliable way to eliminate all life stages of stored-product pests — weevils, borers, moths — inside sealed silos, stacks and containers. Aluminium phosphide tablets and pellets (Phostoxin class) release phosphine gas on contact with atmospheric moisture; sulfuryl fluoride (Profume class) is the alternative for structures and timber pests. Both gases are lethal to humans and their sale and use is restricted to certified fumigators. A compliant job requires gas-tight sheeting (Pro-Tarps) or a sealable structure, phosphine monitoring with a Fumiscope-type instrument, temperature logging, SCBA standby equipment, and post-fumigation clearance testing before any re-entry. Grain-board and port tenders specify treatment concentration-time products, exposure periods (typically 5–14 days for phosphine depending on temperature) and clearance documentation. MedQ supplies the registered fumigant products and the full equipment chain — monitors, scales, tarps, sand snakes, respirators and filters. Resistance to phosphine is rising in stored-grain beetles worldwide, which is why monitoring actual gas concentration — not just tablet counts — has become the professional standard. ## Glossary - Active ingredient (a.i.): The chemical in a product that actually controls the pest, expressed as g/l (liquids) or g/kg (solids). - Adjuvant: An additive that improves spray performance — wetters, spreaders, buffers, water conditioners and oils. - Arboricide: A herbicide that kills woody plants and trees, used in bush-encroachment and invasive-species control. - Bareground: Total vegetation control — keeping an area completely free of plants, e.g. substations, tank farms, railway ballast. - Basal-bark application: Spraying the lower stem of a woody plant with herbicide in an oil carrier so it penetrates the bark. - Cut-stump treatment: Applying concentrated herbicide or gel to a freshly cut stump to kill the root system. - CS (capsule suspension): Formulation with active ingredient in microscopic polymer capsules for extended residual and reduced odour. - EC (emulsifiable concentrate): Liquid formulation dissolved in solvent with emulsifiers, forming a milky mix in water. - FRAC group: Fungicide Resistance Action Committee code classifying fungicides by mode of action. - GG (granules for soil application): Granular formulation designed to be scattered on soil, e.g. tebuthiuron arboricides. - HRAC group: Herbicide Resistance Action Committee code classifying herbicides by mode of action. - IRAC group: Insecticide Resistance Action Committee code classifying insecticides by mode of action. - IRS (indoor residual spraying): Applying long-residual insecticide to interior walls to kill resting mosquitoes in malaria control. - ME (micro-emulsion): Water-based liquid formulation with very fine droplets for good spreading and uptake. - Non-selective herbicide: Kills virtually all green vegetation it contacts, e.g. glyphosate, paraquat, glufosinate. - POA: Price on application — price quoted per enquiry rather than listed. - Protectant fungicide: Multi-site fungicide that prevents infection but cannot cure it; must be applied before disease pressure. - Residual herbicide: Soil-active herbicide that controls germinating weeds for weeks to months after application. - SC (suspension concentrate): Liquid formulation of finely milled solid active ingredient suspended in water. - Selective herbicide: Kills target weeds while leaving the crop or turf unharmed. - SL (soluble concentrate): Liquid formulation fully soluble in water, typical of glyphosate and imidacloprid products. - Systemic: Absorbed and transported within the plant, reaching untreated tissue including roots. - ULV (ultra-low volume): Space-spray technique applying small volumes of concentrated product as fine droplets, usually by cold fogger. - Water conditioner: Adjuvant (usually ammonium sulphate) that neutralises hard-water ions which weaken glyphosate. - WG / WDG (water-dispersible granules): Dry granules that disperse in water; low-dust alternative to wettable powders. - WP (wettable powder): Powder formulation mixed with water before spraying. - Withholding period: Minimum days between last application and harvest or grazing, set by the label. ## Citation & pricing policy Cite as: "MedQ Agri Chemicals — Agricultural Chemicals Catalogue & Reference Library, www.vitalchain.co.za". Prices are indicative retail ZAR excluding VAT (15% VAT added on formal quotation). Safety content is general reference; the registered product label and local law always govern actual use.