Leaf spot diseases

Higgins VJ. 1972. Role of the phytoalexin medicarpin in three leaf spot diseases of alfalfa. Physiol Plant Pathol 2 289-300. 

Uses as fungicide to control early and late blights of potatoes and tomatoes anthracnose in cucurbits leaf spot diseases in many crops glume blotch of wheat also used on vegetables, ornaments, berry fruits, melons, coffee and tobacco, etc. 

Uses fungicide for control of downy/powdery mildews, leaf spot diseases, etc. 

The leaves harvested in summer gave the highest oil recovery (1.84%) and eugenol content (83%), whereas in the rainy season, the concentration of esters, namely, eugenyl acetate and benzyl benzoate, were comparatively higher (Kaul et al., 1996). Cinnamon leaves affected by leaf spot disease yielded less oil (1.2%), but the eugenol content was unaffected (Kaul et al., 1998). Rao et al. (2006) reported that the essential oil content (1.9-2.2%) and the chemical composition of C. verum leaves were not affected by storage up to a period of 15 months. 

Kaul, P.N., Bhattacharjee, A.K. and Rao, B.R.R. (1998) Chemical composition of the essential oils of cinnamon (Cinnamomum zeylanicum Blume) leaves affected by leaf spot disease. Indian Perfumer 42(1), 33-35. 

AM-Toxin. The pathogen Alternarla mall causes leaf spot disease of apple and produces necrotic spots on fruits, leaves, and shoots of susceptible cultivars. AM-toxIn [18], a host-specific toxin, and several related toxins are responsible for these symptoms and their structures have been elucidated and confirmed by total synthesis 1101-1031. 

Fortunately, the same controls are effective against many leaf spot diseases. Remove and discard infected leaves. Thin plants and avoid crowding future plantings. Wash your tools and hands after handling infected plants.. Avoid overhead watering. Inspect bedding plants on purchase. Clean up plant debris to remove overwinterins sites. 

Leaves with dark or water-soaked spots. Cause Various bacterial or fungal leaf spot diseases. Destroy badly spotted plants or leaves. Thin plants to increase air movement, and a oid wetting leaves when watering. Prevent rroblems by keeping plants well-fed. 

An extreme example of diverse structures which can arise by extensive and varied modifications of a single polyketide-derived metabolite is provided by the phytotoxic spiciferones (28)-(30), spiciferinone (31) and spiciferin (32) produced by the fungus Cochlioholus spicifer responsible for leaf spot disease in... 

Alternaria species are associated with several leaf-spot diseases of plants. Alternaric acid (8.10), produced by A. solani, which is the cause of early blight on potatoes and tomatoes, has a marked phytotoxic activity and may be responsible for many of the symptoms of the plant disease caused by the fungus. It also shows a specific anti-fungal activity. The branched chain structure is biosynthesized from nine acetate units and three Ci units derived from formate. The solanopyrones are another group of phytotoxic metabolites of A. solani. Solanopyrone A (8.11) induced necrotic lesions on the leaves of potatoes typical of this fungal infection. The structures of the solanopyrones were established by... 

Cercospora species are responsible for various leaf-spot diseases. C. rosicola produces small brown lesions surrounded by a red-violet ring on rose leaves. The common black spot is caused by a different fungus, Diplocarpon rosae. A severe Cercospora infection can cause loss of the leaf. The phytotoxic fungus... 

Mancozeb is a fungicide used to control many fungal diseases such as blight, leaf spot, rust, downy mildew, and scab in field crops, fruits, nuts, vegetables, ornamentals, etc. In particular, it is used to control the following early and late blights of potatoes and tomatoes leaf spot diseases on celery, cucurbits, beets. 

Although all the major companies pursued this lead intensively, only Ube Industries was successful in developing a commercial compound. No broad spectrum fungicide with the complex I mode of action has been found to date, despite the discovery of many compounds with a broad spectrum of activity (e.g., powdery mildew, brown rust and leaf spot diseases) and reasonable application rates in the greenhouse. 

The first triazole introduced into the market, in 1976, was triadimefon, which became rapidly known under its trade name Bayleton . This first representative of the triazole group was considered as real progress at that time because of excellent activity against powdery mildew and rust combined with significant activity against several leaf spot diseases. 

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