The plants are important in fulfilling the basic requirements of human beings like food, cloth and shelter. Need of food is to survive the human and other organisms worldwide. They supply primary nutrients like protein, carbohydrate, lipids, vitamins, etc.
and complete energy demand by human beings.
Worldwide large numbers of plant species and varieties are present. According to Karthikeyan S. (2009), Indian Angiosperm flora comprises 17,527 species,296 sub species, 2215 varieties, 33 subvarieties and 70 forma, total 20141 taxa of angiosperm under 2991 genera and 251 families. Every plant has its own economic value, some are explored while others are remaining suspended in specific locality or tribe of the human population, and again some are yet to be unknown.
Plants are classified on the basis of their use, like plants used for construction of houses are timbers, plants use for medicine are medicinal plant, plants used as feed for cattle are fodder, likewise plants used along with starchy staple food to make meal perfect and supplemented with other basic vital nutrients are vegetable.
Vegetables are generally including all vegetative parts sometimes flower and seeds also. No one can put boundaries between vegetables and other plant. Vegetables are consuming alone or along with some others by peoples to overcome their food requirements.
Vegetables are classified by different workers according to their ease. Some classified them as green vegetable (leafy) and others. While some classified them on the basis of edible part like root vegetable, tuber vegetable, leafy vegetable, Stem vegetable, Flower bud or mature flower, fruit vegetable, seed vegetables, etc. Some classify them on the basis of botany or use or both together:
Leafy Vegetable, Salad Vegetable, Root vegetable, Bulb vegetable, Pulses, Cucurbit vegetables, Solanaceous vegetables, etc.
Classical botanical classification divides vegetables into six groups. It based on use of botanical terminology like Family, genus, species, Variety, Group, cultivars, line strain, lot, type etc.
The most convenient classification is as follows-
- Earth vegetable- like carrots, sweet potatoes, etc.
- Modifies stem-like potatoes etc.
- Modified bud – tubers like onion, garlic, etc.
- Herbaceous vegetables like leaves cabbage, amaranth, spinach, etc.
- Herbaceous flower buds like Cauliflower etc.
- Fruit vegetables like legumes, peas, vine fruits, cucumbers berries, tomatoes, etc.
Along with civilization, the human tried to cultivate and develop vegetables for nutrients or taste. Recent days much effort has been focused on developing new varieties of vegetables for their nutritive quality and quantity by using the breeding program or genetically manipulations. These programs are also involved to develop pathogen-resistant crops, such variety are helpful to control deterioration and degradation of specific nutrient or many nutrients.
Pathogens are of different kinds; some are visible while others require microscopic investigations. Vegetables are rich in nutrients and that’s why they are more vulnerable to pathogen attack. Broadly pathogens are classified as a viral pathogen, a bacterial pathogen, a fungal pathogen, insect pathogen or some other tiny or large living organism.
When pathogen attacks on host plant it is for specific nutrient. And when pathogen feeds on host its lead to adverse impact on that host. This change from the normal is sometimes defined as the disease.
The disease is not always come in existence with living organism only, but they are sometimes due to surrounding conditions or imbalance of specific organic or inorganic component. Such diseases are known as abiotic diseases, like salt stress disease, chilling injuries, drought-related diseases, mineral imbalance diseases, etc.
Plants specifically vegetables are more prone to viruses, bacteria, fungi and few other microorganisms. Bacterial diseases rank first while fungi occupy second position.
Fungi are non-photosynthetic heterotrophic organisms. Feed on living or dead material. They are saprophytic mostly, but some are facultative or obligate parasite also. Fungi never always attacking vegetable crops in their field conditions, but mostly during faulty transportation and storage. On the basis of occurrence of pathogen and development of disease, vegetable diseases are categorized into two types: Preharvest disease and Post-harvest disease.
Fungal diseases like blight, wart, anthracnose, rot, wilt, leaf hole, mildew is more common in occurrence. Some pathogens are occurring in Preharvest as well as post-harvest condition like Alternaria, Stemphyllium, Colletotrichum, Cercospora, etc.
Environmental factors play vital role in establishment of pathogen and pathogenicity. Fungi mostly spread through physical contact and improper handling processes. Other biotic and abiotic vectors also play important role in their dispersion.
Agriculture and its related activities accounted for 12.4 % of the GSDP at current prices in 2011-12, but the role of agriculture is more in employment, according to census 2001 it accounts for 55%. (Highlights of economic survey 2011-12)
According to Indian horticulture database 2013, NHB, MoA, GoI, India, west Bengal produce total 16 % of vegetable in India and rank 1st, Utter Pradesh, Bihar, Madhya Pradesh, Andhra Pradesh, Gujrat Odisha, and then Maharashtra respectively. Maharashtra produce only 5% of total Indian vegetable. (Indian horticulture database, 2013 NHB, MoA, GoI, India.)
Maharashtra produces total 80.08 lakh Metric ton of vegetable per year in the country, among them onion 46.60 lakh Metric ton i.e. 58% of total vegetable in the country, from 260-thousand-hectare area. Tomato rank second by 10.50 lakh Metric ton (13%), Brinjal rank Third 5.78 Lakh Metric ton (7%), Cabbage 4.21lakh Metric ton (5%), Okra 3.28 Lakh Metric ton (4%), potato 3.21 Lakh Metric ton (4%), cauliflower 2.38 lakh Metric ton (3%), peas 0.51 Lakh Metric ton (1%) and other vegetables 3. 61 Lakh Metric tons (5%). (Indian Horticulture Database, 2013, NHB, MoA, GoI, India.)
Many vegetables are exported to other country from Maharashtra or other state within country. Export of any substance helps to build the economical backbone of farmer and that area. As the pathogen like fungi attack crops in its field or during transportation or improper storage, the degradation occurs. This leads to loss in quantity of specific character or nutrient or many in combinations.
Ultimately the demand for such vegetable collapse and lead to more economical harm to producer. Person who purchase it from market may also affected due to its altered nature from normal one, and may be not fulfil the qualitative requirement of consumer.
Reasons for undertaking the research topic:
Agriculture scenario of India (2017, NHB)
- Total area used for vegetable production: -24.9 million hectares (2017)
- Total horticulture crop production: – 295.2 million tonnes
- Vegetable production :175 million tonnes
- Leading vegetable production states (Horticulture statistic at glance 2017, National Horticulture Board.)
- Uttar Pradesh 15%
- West Bengal 15%
- Madhya Pradesh 10%
- Bihar 8%
- Gujarat 8%
- Maharashtra 6%
- Odisha 5%
- Karnataka 5%
- Haryana 4%
- Chhattisgarh 4%
- Others 22%
Diseases on vegetables studied by various plant pathologist. In comparison to the voluminous work carried out in the field of fungal plant pathology by a galaxy of eminent plant pathologist Theophrastus(286BC), Antonio Micheli (Nova Plantarum Genera 1729), Needham(1743), Lazarro Spallanzani (1775), C.H.Persoon ( Synopsis Methodica Fungorum 1793), E.M.Fries ( Systema Mycologicum 1821-1832), Tillet (Smut of Wheat 1775), Felice Fontana ( Rust 1767), Benedict Prevost (Life cycle of bunt fungus 1807), Prevost ( Microorganisms are causal agent of disease and control of smut using copper sulphate)M.J.Berkeley (Supporting Parasitic theory1846), Montague ( Describe Botrytis infestans as causal agent of disease 1845) and Anton de Bary (Fungus the real causal agent 1861).
In Indian history the milestones of Plant pathology are D.D. Cunninggham and A. Barclay (Identifying fungi in India1850-1875), K.R. Kirtikar (first Indian Scientist Who collect and identify Indian Fungi), E.J.Butler (Father of Indian Plant Pathology , Wrote Monograph ‘Pythiaceous and Allied Fungi’ and Text book ‘Fungi and Diseases in Plants’ 1918), J.F. Dastur ( First Indian who studied detail of plant Diseases 1886-1971), g.S.Kulkarni (Downy mildew and smut of sugarcane), B.B. Mundkur (Indian Phytopathological Society and Journal Indian Phytopathology 1948, Authored Textbook ‘Fungi and Plant Diseases’), Dr. K.C. Mehta (Life cycle of Cereal rusts in India), Luthra and Sattar (Solar heat treatment to control Loose smut of Wheat 1953), S.N. Dasgupta (Black tip of Mango), T.S. Sadasivan (Mechanism of Wilting of cotton due to Fusarium oxysporum f.sp. vasinfectum), M.J. Thirumalachar (Control of Rust and smut), B.L. Chona (Sugarcane diseases), Agnihothrudu (Tea diseases), R.K. Agrawala (Apple Diseases), G.S. Saharan (Oil seed diseases) and many others.
Very little attention has been paid to the study of the impact of the fungal pathogen on nutritional alteration study of vegetables from India.
Taking into account the nutritional value of vegetables, the impact of the fungal pathogen on changes in quantity of nutrient were determine.
Lack of knowledge and scanty work done from this part, hence studies on the impact of the fungal pathogen on nutrient status of vegetables from Maharashtra have been undertaken.
Vegetables are the main sources of various primary metabolites, which are along with other food material most of time cereals make food balance. The overall aim of this research work was to study comparative differentiate between primary nutrients of healthy pathogen free vegetables with that of infected or diseased vegetables, within the Maharashtra state.
The following are the objectives of the present study.
- Collecting diseased and healthy vegetable from the vegetable farm or market places.
- Identification and description of collected isolates with a classical mycological method.
- To test the pathogenicity of fungal pathogen isolated or sometimes collected directly from diseased vegetables.
- To study the quantitative analysis of various nutrients like Total Carbohydrates, Reducing Sugars, Dietary fibers, Proteins, Amino acids, Vitamins, Moisture content, Chlorophyll content etc.
- To compare the qualitative alteration of nutrients analyzed from diseased vegetable and control or healthy one.
- To decide the severity of pathogen in nutrient alteration.
Quantity and quality of nutrient may vary at different stages of infection and severity as well as the variety of vegetable crop.