Classification of Fungicides

FUNGICIDES
Definitions –

1.Fungicide - is a chemical, which is capable of killing fungi.

2. Antibiotic- is a chemical produced by a microorganism, which is inhibitory to other organisms. Fungicides can be classified as protectants, eradicants & systemic fungicides.

a. Protectant- Fungicide which is effective only if applied prior to fungal infection is called Protectant. Example – Mancozeb, Zineb.

b. Eradicant – is the one, which removes fungi from an infection court. An Eradicant can penetrate the host tissues to a limited extent & eliminate an established infection. Example – Lime Sulpher.

c. Systemic Fungicides- Systemic fungicides are the compounds, which are transported over a considerable distance in plant system after-penetration. They kill fungi, which are found remote from the point of application.

I) SULPHER FUNGICIDES

a) Inorganic Sulpher fungicides - includes elemental Sulpher, wettable Sulpher & lime Sulpher. Sulpher fungicides effectively control powdery mildew of different crops such as chilli, okra, grape, rubber, mango, citrus, black gram & green gram. Sulpher controls tikka leaf spot of groundnut & Diplocapron black spot of rose. Sulpher dust is used as seed treatment also.

b) Organic Sulpher fungicides- Dithiocarba mates are the organic Sulpher fungicides. They are divided into-

(i) Dialkyldithiocarbamtes- Thiram, Ziram & ferban & Ziram is used as Protectant & sprayed before the outbreak of the disease. It controls early blight of potato & tomato and anthracnose disease of cucurbits & beans. Thiram is commonly used for seed treatment. Thiram seed treatment controls seed-borne pathogens as well as soil born pathogens. It controls seed borne infection of colletotrichum capsici of chilli, root rot of groundnut, sorghum grain smut & Helminthosporium leaf spot of rice. As seed treatment it controls soil-borne infection of Phthium spp. of tomato, tobacco & brinjal (Damping off) Rhizoctonia solani of cotton & Sheath blight of rice. Ferban control diseases of apple. It controls leaf spot of banana, leaf mould of tomato & leaf spot of coffee.

(ii) Monoalkyldithio carbamates- maneb, Zineb, Mancozeb, vapam & nabam. Zineb controls anthracnose disease of bean, chilli, & cucurbits, rust disease of wheat, sorghum & bajra, downy mildew of grapevine, cucurbits, Onion & cabbage, cercospora leaf spot of groundnut, cabbage, cauliflower, Alternaria leaf spot of potato, tomato singer. Mancozeb is widely used for the control of late blight of potato, cercospora leaf spot of groundnut, cucurbits & sugar beet. Helminthosporium leaf spot of rice, ragi, maize & sorghum, downy mildew of grapevine & tobacco, rust disease of wheat groundnut, bajra & sorghum, Alternaria leaf spot of ginger, potato, tomato & wheat anthracnose of chilli, grapevine, sorghum, bean & cucurbits.
Vapam controls cotton wilt & damping off of papaya, tobacco & tomato. It controls nematodes also.

(II) Copper Fungicides

(a) Copper Sulphate Preparations – It include Bordeaux mixture, Bordeaux Paste, Burgundy mixture, & chestnut compound. Bordeaux mixture is highly effective against late blight of potato, downy mildew of grapevine, coffee rust, betel vine wilt, pepper wilt, tomato early & late blights & coconut will & bud rot.
(b) Copper Carbonate Preparations- It controls many fungal diseases of apple, pear, peach, plums & apricot.

c) Copper Oxychloride Preparations – Some formulations available in the market are Fytolan, Blue copper, Blitox etc. They are generally effective against all diseases against which Bordeaux mixture has been found effective.
Mercury Fungicides-
Various mercury fungicides sold in the market are ceresan, aretan, agallol, wet ceresan, Dry ceresan etc. They are effective as seed treatment.

IV Heterocylic nitrogen compounds-
a) Captan- It is commercially marketed as Captan, orthocide, vancide etc. It is Protectant fungicide. It controls maize helminthosporiose, chilli fruit rot & apple scab. It is mostly used as seed treatment.

b) Folpet – It is commercially marketed as Phaltan. It controls rose black spot & apple scab.

(c) Captofol – It is marketed as Difolotan, Foltaf etc.
It effectively controls sheath rot of rice & mango anthracnose.

V) Quinone Fungicides-

a) Chloranil – It is commercially marketed as spergon. It is good seed dressing fungicide. It controls grain smut of sorghum & damping off of beans & cotton.

b) Dichlone- The commercial name of the fungicide is phygon. It controls peach leaf curl, apple scab & bean anthracnose.
Miscellaneous Fungicides-
a) Quintozene - Commercial names of the fungicide are Brassicol, Terraclor, PCNB & Tritisan. It is used to control soil borne pathogens. It is effective against Rhizoctonia Solani, Macrophomina Phaseolina & Sclerotiana Sclerotiorum.
b) Dinocap - It is marketed in the name of karthane, Arathane, Mildex etc. Dinocap is effective in controlling powdery mildews.
c) Fenaminsosulph- it is commercially known as Dexon. It is highly effective against phycomycetes like pythium phytophthora & Aphanomyces.
d) Dicloran_ Its trade name is Botran. It controls Botrytis infection in several crops.
e) Chlorothalonil- It is marketed as Daconil & Kavach. It controls both tikka leaf spot & rust disease of groundnut & betelvine wilt.

SYSTEMIC FUNGICIDES-
Some of the systemic fungicides are-
a) Carbendazim – It is marketed as Bavistin, Derosal, B-Sten etc. It controls Powdery Mildews, smut diseases & bunts.
b) Benomyl- Benomyl is effective against Fusarium , Rhizoctonia, Macrophomina, Cercospora, Colletotrichum, Puricularia, Verticillium, Phomopsis, Septoria, Erysiphe, Plasmodiophora, Botrytis, Ustilago, Urocystis & Tilletia Spp.
c) Thiabendazole – It is commercially available as Tecto & Mertect. It controls wheat bunt.
d) Carboxin- it is commercially available as vitavax. It is the most effective fungicide to control internally seed borne loose smuts of cereals.
e) Oxycarboxin- it is commercially marketed as Plantvax. It is specifically effective against rust pathogens.
f) Pyracarbolid- it is commercially available as sicarol. It is effective against rust & smut & Rhizoctonia Spp.
g) Metalaxyl- it is marketed as Ridomil & Apron. Metalaxyl is highly effective against phycomyces fungi like Phytophthrora, Pythium, Scierospora, Pseudopernospora, Plasmopara, Sclerophthora & Albugo.
h) Tride morph- its trade name is calixin. It is mainly used against powdery mildews as foliar sprays
i) Pyroquilon- it is commercially available as Fongorene. It effectively controls rice blast.
j) Kitazin- it is commercially marketed as Kitazin. It is highly effective against rice blast.
k) Tricyclazole – it is commercially marketed as Beam. It is highly specific for the control of rice blast.
l) Probenazole- its commercial name is oryzemate. It is also specific against rice blast.
m) Triadimefon- it is commercially market as Bayleton. It is highly effective against powdery mildews. It also controls rust diseases.
n) Biloxazole- it is marketed as Baycor. It is effective against cercospora diseases & rusts.
o) Triademenol- The commercial name of the fungicide is Bayton. As seed treatment it controls smut & powdery mildews.