Fusarium ear blight (FEB), is a fungal disease of cereals, including wheat, barley, oats, rye and triticale. FEB is caused by a range of Fusarium fungi, which infects the heads of the crop, reducing grain yield. The disease is often associated with contamination by mycotoxins produced by the fungi already when the crop is growing in the field. The disease can cause severe economic losses as mycotoxin-contaminated grain cannot be sold for food or feed.
Phytophthora infestans is an oomycete or water mold, a fungus-like microorganism that causes the serious potato and tomato disease known as late blight or potato blight. Early blight, caused by Alternaria solani, is also often called "potato blight". Late blight was a major culprit in the 1840s European, the 1845–1852 Irish, and the 1846 Highland potato famines. The organism can also infect some other members of the Solanaceae. The pathogen is favored by moist, cool environments: sporulation is optimal at 12–18 °C (54–64 °F) in water-saturated or nearly saturated environments, and zoospore production is favored at temperatures below 15 °C (59 °F). Lesion growth rates are typically optimal at a slightly warmer temperature range of 20 to 24 °C.
Fungicides are pesticides used to kill parasitic fungi or their spores. They are most commonly chemical compounds, but may include biocontrols and fungistatics. Fungi can cause serious damage in agriculture, resulting in critical losses of yield, quality, and profit. Fungicides are used both in agriculture and to fight fungal infections in animals. Fungicides are also used to control oomycetes, which are not taxonomically/genetically fungi, although sharing similar methods of infecting plants. Fungicides can either be contact, translaminar or systemic. Contact fungicides are not taken up into the plant tissue and protect only the plant where the spray is deposited. Translaminar fungicides redistribute the fungicide from the upper, sprayed leaf surface to the lower, unsprayed surface. Systemic fungicides are taken up and redistributed through the xylem vessels. Few fungicides move to all parts of a plant. Some are locally systemic, and some move upward.
Carbendazim is a widely used, systemic, broad-spectrum benzimidazole fungicide and a metabolite of benomyl. It is also employed as a casting worm control agent in amenity turf situations such as golf greens, tennis courts etc. and in some countries is licensed for that use only.
Captan is a general use pesticide (GUP) that belongs to the phthalimide class of fungicides. It is a white solid, although commercial samples appear yellow or brownish.
Pythium is a genus of parasitic oomycetes. They were formerly classified as fungi. Most species are plant parasites, but Pythium insidiosum is an important pathogen of animals, causing pythiosis. The feet of the fungus gnat are frequently a vector for their transmission.
Glufosinate is a naturally occurring broad-spectrum herbicide produced by several species of Streptomyces soil bacteria. Glufosinate is a non-selective, contact herbicide, with some systemic action. Plants may also metabolize bialaphos and phosalacine, other naturally occurring herbicides, directly into glufosinate. The compound irreversibly inhibits glutamine synthetase, an enzyme necessary for the production of glutamine and for ammonia detoxification, giving it antibacterial, antifungal and herbicidal properties. Application of glufosinate to plants leads to reduced glutamine and elevated ammonia levels in tissues, halting photosynthesis and resulting in plant death.
Phytophthora sojae is an oomycete and a soil-borne plant pathogen that causes stem and root rot of soybean. This is a prevalent disease in most soybean growing regions, and a major cause of crop loss. In wet conditions the pathogen produces zoospores that move in water and are attracted to soybean roots. Zoospores can attach to roots, germinate, and infect the plant tissues. Diseased roots develop lesions that may spread up the stem and eventually kill the entire plant. Phytophthora sojae also produces oospores that can remain dormant in the soil over the winter, or longer, and germinate when conditions are favourable. Oospores may also be spread by animals or machinery.
Acibenzolar-S-methyl is the ISO common name for an organic compound that is used as a fungicide. Unusually, it is not directly toxic to fungi but works by inducing systemic acquired resistance, the natural defence system of plants.
Phytophthora citrophthora, also known as brown rot of citrus, is a soil borne oomycete that infects several economically important citrus crops. A diagnostic symptom of P. citrophthora is gummosis, wherein lesions around the base of the tree exude sap. Other common symptoms include dark longitudinal lesions forming at the soil line, a sour smell, and eventual cracking of the bark. Advanced symptoms include yellowing and necrosis of the tree canopy. Girdling action caused by the pathogen around the trunk can often cause the collapse of the tree. Resistant lemon varieties have been developed and their implementation has been effective at controlling the spread of the disease. Fruits that have been infected with P. citrophthora exhibit symptoms of brown rot characterized by a distinct odor. This disease is most active in the moderate temperatures of spring, fall, and winter months, opposite of most other Phytophthora species.
Phytophthora erythroseptica—also known as pink rot along with several other species of Phytophthora—is a plant pathogen. It infects potatoes causing their tubers to turn pink and damages leaves. It also infects tulips (Tulipa) damaging their leaves and shoots.
Phytophthora capsici is an oomycete plant pathogen that causes blight and fruit rot of peppers and other important commercial crops. It was first described by L. Leonian at the New Mexico State University Agricultural Experiment Station in Las Cruces in 1922 on a crop of chili peppers. In 1967, a study by M. M. Satour and E. E. Butler found 45 species of cultivated plants and weeds susceptible to P. capsici In Greek, Phytophthora capsici means "plant destroyer of capsicums". P. capsici has a wide range of hosts including members of the families Solanaceae and Cucurbitaceae as well as Fabaceae.
Azoxystrobin is a broad spectrum systemic fungicide widely used in agriculture to protect crops from fungal diseases. It was first marketed in 1996 using the brand name Amistar and by 1999 it had been registered in 48 countries on more than 50 crops. In the year 2000 it was announced that it had been granted UK Millennium product status.
This article summarizes different crops, what common fungal problems they have, and how fungicide should be used in order to mitigate damage and crop loss. This page also covers how specific fungal infections affect crops present in the United States.
Mancozeb is a dithiocarbamate non-systemic agricultural fungicide with multi-site, protective action on contact. It is a combination of two other dithiocarbamates: maneb and zineb. The mixture controls many fungal diseases in a wide range of field crops, fruits, nuts, vegetables, and ornamentals. It is marketed as Penncozeb, Trimanoc, Vondozeb, Dithane, Manzeb, Nemispot, and Manzane. In Canada, a mixture of zoxamide and mancozeb was registered for control of the mildew named Gavel as early as 2008.
Fluazinam is a broad-spectrum fungicide used in agriculture. It is classed as a diarylamine and more specifically an arylaminopyridine. Its chemical name is 3-chloro-N-(3-chloro-2,6-dinitro-4-trifluoromethylphenyl)-5-trifluoromethyl-2-pyridinamine. The mode of action involves the compound being an extremely potent uncoupler of oxidative phosphorylation in mitochondria and also having high reactivity with thiols. It is unique amongst uncouplers in displaying broad-spectrum activity against fungi and also very low toxicity to mammals due to it being rapidly metabolised to a compound without uncoupling activity. It was first described in 1992 and was developed by researchers at the Japanese company Ishihara Sangyo Kaisha.
Buckeye rot of tomato is caused by three species of pathogens in the genus Phytophthora: P. nicotianae var. parasitica, P. capsici, and P. drechsleri. It is an oomycete that thrives in warm, wet conditions and lives in the soil. It is characterized by a bull’s eye pattern of dark brown rotting on the tomato fruit, and affects fruit that is close to, or lying on the soil. The easiest management is to keep the plant out of contact with the soil, although other chemical methods can be very effective. This disease commonly occurs in the southeast and south central areas of the United States. The disease has affected a large portion of crop yield in the United States as well as India. The relatively small genome size of Phytophthora parasitica compared to Phytophthora infestans gives researchers the unique ability to further examine its ability to cause disease.
Fludioxonil is a synthetic phenylpyrrole chemical introduced by Ciba-Geigy in 1993 for use as a non-systemic fungicide. It is a structural analog of the natural fungicide pyrrolnitrin.
Pyraclostrobin is a quinone outside inhibitor (QoI)-type fungicide used in agriculture. Among the QoIs, it lies within the strobilurin chemical class.
Strawberries in the United States are almost entirely grown in California – 86% of fresh and 98% of frozen in 2017 – with Florida a distant second. Of that 30.0% was from Monterey, 28.6% from Ventura, 20.0% from Santa Barbara, 10.0% from San Luis Obispo, and 9.2% from Santa Cruz. The Watsonville/Salinas strawberry zone in Santa Cruz/Monterey, and the Oxnard zone in Ventura, contribute heavily to those concentrations.
