urban agriculture & plant pathology by mian nasir

7/31/2019 Urban Agriculture & Plant Pathology by Mian Nasir

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Urban agriculture is not a relict of the past that will fade away (urban agriculture increases when

the city grows) nor brought to the city by rural immigrants that will loose their rural habits over time. It

is an integral part of the urban system.In each city a further specification of urban agriculture is possible

by looking at the following dimensions:

TYPES OF ACTORS INVOLVED IN URBAN AGRICULTURE

Large part of the people involved in urban agriculture is the urban poor. Contrary to general

belief they are often not recent immigrants from rural areas (since the urban farmer needs time to get

access to urban land, water and other productive resources). In many cities, one will often also find

Lower And Mid-Level government officials, school teachers and the like involved in agriculture, as

well as richer people who are seeking a good investment for their capital.

Women constitute an important part of urban farmers, since agriculture and related processing and

selling activities, among others, can often be more easily combined with their other tasks in the

household. It is however more difficult to combine it with urban jobs that require travelling to the town

centre, industrial areas or to the houses of the rich.

TYPES OF LOCATION IN URBAN AGRICULTURE

Urban agriculture may take place in locations inside the cities (intra-urban) or in the peri-

urban areas. The activities may take place on the homestead (on-plot) or on land away from theresidence (off-plot), on private land (owned, leased) or on public land (parks, conservation areas, along

roads, streams and railways), or semi-public land (schoolyards, grounds of schools and hospitals).

TYPES OF PRODUCTS GROWN IN URBAN AGRICULTURE

Urban agriculture includes food products, from different types of crops (grains, root crops,

vegetables, mushrooms, fruits) and animals (poultry, rabbits, goats, sheep, cattle, pigs, guinea pigs, fish,

etc.) as well as non-food products (like aromatic and medicinal herbs, ornamental plants, tree products,

etc.) or combinations of these. Often the more perishable and relatively high-valued vegetables and

animal products and by-products are favored.


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Production units in urban agriculture in general tend to be more specialized than rural enterprises, and

exchanges are taking place across production units.

TYPES OF ECONOMIC ACTIVITIES IN URBAN AGRICULTURE

Urban agriculture includes agricultural production activities as well as related processing and

marketing activities as well as inputs (e.g. compost) and services delivery (e.g. animal health

services) by specialized micro-enterprises or NGOs, etc. In urban agriculture, production and marketing

tend to be more closely interrelated in terms of time and space than for rural agriculture, thanks to

greater geographic proximity and quicker resource flow.

PRODUCT DESTINATION / DEGREE OF MARKET ORIENTATION

In most cities in developing countries, an important part of urban agricultural production is for self-

consumption, with surpluses being traded. However, the importance of the market-oriented urbanagriculture, both in volume and economic value, should not be. Products are sold at the farm gate, by

cart in the same or other neighborhoods, in local shops, on local (farmers) markets or to inter-med iaries

and supermarkets. Mainly fresh products are sold, but part of it is processed for own use, cooked and

sold on the streets, or processed and packaged for sale to one of the outlets mentioned above.

SCALES OF PRODUCTION AND TECHNOLOGY USED

In the city, we may encounter individual or family farms, group or cooperative farms and commercial

enterprises at various scales ranging from micro- and small farms (the majority) to medium-sized and

some large-scale enterprises. The technological level of the majority of urban agriculture enterprises in

developing countries is still rather low. However, the tendency is towards more technically advanced

and intensive agriculture and various examples of such can be found in all cities.

WHY IS URBAN AGRICULTURE IMPORTANT?

The rapid urbanization that is taking place goes together with a rapid increase in urban poverty

and urban food insecurity. By 2020 the developing countries of Africa, Asia, and Latin America will be

home to some 75% of all urban dwellers, and to eight of the anticipated nine mega-cities with


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populations in excess of 20 million. It is expected that by 2020, 85% of the poor in Latin America, and

about 40-45% of the poor in Africa and Asia will be concentrated in towns and cities.

Most cities in developing countries have great difficulties to cope with this development and are unable

to create sufficient formal employment opportunities for the poor. They also have increasing problems

with the disposal of urban wastes and waste water and maintaining air and river water quality.

Urban agriculture provides a complementary strategy to reduce urban poverty and food

insecurity and enhance urban environmental management. Urban agriculture plays an important role in

enhancing urban food security since the costs of supplying and distributing food to urban areas based on

rural production and imports continue to increase, and do not satisfy the demand, especially of the

poorer sectors of the population. Next to food security, urban agriculture contributes to local economic

development, poverty alleviation and social inclusion of the urban poor and women in particular, as well

as to the greening of the city and the productive reuse of urban wastes (see below for further

explanations and examples).

The importance of urban agriculture is increasingly being recognized by international organizations like

UNCED (Agenda 21), UNCHS (Habitat), FAO (World Food and Agriculture Organization), and CGIAR

(international agricultural research centers).

1. FOOD SECURITY AND NUTRITION

The contribution of urban agriculture to food security and healthy nutrition is probably its most

important asset. Food production in the city is in many cases a response of the urban poor to inadequate,

unreliable and irregular access to food, and the lack of purchasing power.

Most cities in developing countries are not able to generate sufficient (formal or informal) income

opportunities for the rapidly growing population. The World Bank (2000) estimates that approximately

50% of the poor live in urban areas (25% in 1988). In urban settings, lack of income translates more

directly into lack of food than in a rural setting (cash is needed). The costs of supplying and distributing

food from rural areas to the urban areas or to import food for the cities are rising continuously, and it is


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expected that urban food insecurity will increase.

Food prices in Harare, for example, rose 534 percent between 1991 and 1992 due to the removal of

subsidies and price controls, spurring poor urban consumers to get access to food outside of market

channels through home production or bartering .Urban agriculture may improve both food intake

(improved access to a cheap source of proteins) and the quality of the food may improve (poor urban

families involved in farming eat more fresh vegetables than other families in the same income category).

In addition to production for their own consumption needs, large amounts of food are produced for

other categories of the population. It is estimated (UNDP 1996; FAO 1999) that 200 million urban

residents provide food for the market and 800 million urban dwellers are actively engaged in urban

agriculture in one way or another. These urban farmers produce substantial amounts of food for urban

consumers. A global estimate (data 1993) is that 15-20% of the worlds food is produced in urban areas.

Over 26000 popular gardens cover 2438,7 hectares in Havana and produce 25000 tons of food each

year; a total of 299 square kilometers of urban agriculture produces 113525 tons/year.

Urban agriculture to a large extent complements rural agriculture and increases the efficiency of

the national food system in that it (IDRC 1998) provides products that rural agriculture cannot supply

easily (e.g. perishable products, products that require rapid delivery upon harvest), that can substitute for

food imports and can release rural lands for export production of commodities.

2. ECONOMIC IMPACTS

Growing your own food saves household expenditures on food; poor people in poor countries

generally spend a substantial part of their income (50 70%) on food. Growing the relatively expensive

vegetables therefore saves money as well as on bartering of produce. Selling produce (fresh or

processed) brings in cash.

Besides the economic benefits for the urban agricultural producers, urban agriculture stimulates

the development of related micro-enterprises: the production of necessary agricultural inputs and the

processing, packaging and marketing of outputs. The activities or services rendered by these enterprises


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may owe their existence in part or wholly to urban agriculture. Other services may also be rendered by

independent families and groups (e.g. animal health services, bookkeeping, transportation).Input

production and delivery may include activities like the collection and composting of urban wastes,

production of organic pesticides, fabrication of tools, delivery of water, buying and bringing of chemical

fertilizers, etc.)

Transformation of foodstuffs may include the making of yoghurt from milk, or the frying of

plantains or yams, chicken or eggs, etc. This might be done at the household level, to sell at the farm

gate or in a local shop or market, and larger units to sell in supermarkets or even for export. Special

attention is needed for the strengthening of the linkages between the various types of enterprises in

clusters or chains. The municipality and sectoral organisations can play a crucial role in stimulating

micro-enterprise development related to urban agriculture.

3. SOCIAL IMPACTS

Urban agriculture may function as an important strategy for poverty alleviation and social

integration. We mentioned earlier the positive stimulus it may give to women.

Several examples exist of municipalities or NGOs that have initiated urban agriculture projects that

involve disadvantaged groups such as orphans, disabled people, women, recent immigrants without jobs,

or elderly people, with the aim to integrate them more strongly into the urban network and to provide

them with a decent livelihood. The participants in the project may feel enriched by the possibility of

working constructively, building their community, working together and in addition producing food and

other products for consumption and for sale.

In more developed cities, urban agriculture may be undertaken for the physical and/or

psychological relaxation it provides, rather than for food production per se. Also, urban and peri-urban

farms may take on an important role in providing recreational opportunities for citizens (recreational

routes, food buying and meals on the farm, visiting facilities) or having educational functions (bringing

youth in contact with animals, teaching about ecology, etc.).


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4. CONTRIBUTIONS TO URBAN ECOLOGY

Urban agriculture is part of the urban ecological system and can play an important role in the urban

environmental management system. Firstly, a growing city will produce more and more wastewater and

organic wastes. For most cities the disposal of wastes has become a serious problem. Urban agriculture

can help to solve such problems by turning urban wastes into a productive resource.

In many cities, local or municipal initiatives exist to collect household waste and organic refuse from

vegetable markets and agro-industries in order to produce compost or animal feed, but one can also find

urban farmers who use fresh organic waste (which may cause environmental and health problems).

Quality compost is an important input that can fetch a good price, as the example from Tanzania

shows. Compost allows an urban farmer to use less chemical fertilisers and by doing so preventing

problems related to the contamination of groundwater. In addition, compost-making initiatives create

employment and provide income for the urban poor.

Farmers may use wastewater for irrigating their farms when they lack access to other sources of

water or because of its high price. The use of fresh (untreated) wastewater has the additional advantage

for poor urban farmers that it contains a lot of nutrients (although often not in the proportions required

by their soils and crops). However, without proper guidance, the use of wastewater may lead to health

and environmental problems. Farmers need to be trained in self- protection during handling of the

wastewater, proper crop selection and adequate irrigation methods, among other things.

Technologies such as hydroponics or organoponics, drip irrigation, zero tillage etc. substantially

reduce water needs and health risks and are very interesting for the urban environment and can indeed be

found in many cities.

The treatment and reuse of more urban wastewater in agriculture also needs to be ensured. This

necessitates special decentralised treatment facilities and low cost (preferably bio-) technologies. In

many cases, partial treatment will be optimal for agricultural reuse. More and more experience is being

gained in public-private initiatives involving private enterprises and/or civic organizations in the


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development and management of municipal wastewater treatment plants.

Secondly, urban agriculture may also positively impact upon the greening and cleaning of the city by

turning derelict open spaces into green zones and maintaining buffer and reserve zones free of housing,

with positive impacts on the micro-climate (shade, temperature, sequestration of CO2).

Degraded open spaces and vacant land are often used as informal waste dumpsites and are a source of

crime and health problems. When such zones are turned into productive green spaces, not only an

unhealthy situation is cleared, but also the neighbours will passively or actively enjoy the green area.

Such activities may also enhance community self-esteem in the neighbourhood and stimulate other

actions for improving the community's livelihood.

MOST FREQUENT DISEASES OF URBAN PLANTS

INTRODUCTION

Parasitic Diseases

FUNGI NEMATODES

Phymatotrichopsis Root RotRoot-knot Nematodes

Phytophthora Disease PARASITIC HIGHER PLANTS

Pythium Disease Mistletoes

Rhizoctonia Disease NONPARASITIC DISEASES

Verticillium and Fusarium Wilts Aleppo Pine Blight

Powdery Mildew Scorch

Rust Diseases Arizona Ash Decline

Cytospora Canker Mulberry Tree Decline

Oleander Decline

Sooty Canker SALT PROBLEMS

Wood Rots and Decays MISCELLANEOUS PROBLEMS
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Ganoderma Root Rot

Bacteria

Crown Gall

Oleander Gall

Fire Blight

Bacterial Necrosis Of Saguaro

Wedgwood or Slime Flux

URBAN PLANT PATHOLOGY

It deals with the management of diseases in the urban agriculture system and to make strategies

according to urban agriculture for control of diseases and to halt their further spread.

Urban plant pathology has its deep interrelationship with the phytosanitary which can be

explained well in terms of an overall control and management of diseases. An urban agriculture that is

established and then further maintained over the strong foundation of phytosanitary practices, can lead to

a superb output. it is only the cleanliness or sanitary that lies behind the secrets of fighting against pests

diseases and other sort of contamination or disorders. Phytosanitary regulation is an official rule to

prevent spread of quarantine pests by regulating the production movement are existence of commodities

or other articles. Thereby establishing schemes for phytosanitary certification. Therefore, all countries

have to maintain measures to ensure that food is safe for the consumers and dissemination or spread of

diseases or pathogens is prevented among the growing plants.

PRESENT AND FUTURE DIRECTIONS OF URBAN PLANT PATHOLOGY:-

Studies have revealed that urbanization has great impact on plant pathology. It has been

confirmed that more diseases are prevalent in cities than in rural areas. In a study, it was revealed that

urbanization alters the functional composition, but not the taxonomic diversity of the pathogens. For

example, soil borne pathogens such as fungi, nematodes and some bacteria which can be introduced

through foreign soils, infected material or water, survive for long periods and under favorable conditions
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multiply and result in the build up of inoculum potential in a locality. Viral diseases are mainly

introduced by insect vectors or infected seeds or vegetative material but once introduced in an area are

difficult to eradicate. Therefore, the discipline of plant pathology is likely to be strengthened in its

concept and application in urban agriculture.

FOOD SAFETY AND QUALITY

In recent years, food safety has been threatened by a number of events and developments that

allow food borne microorganisms or pathogenic to reach humans, e.g. the bacteria salmonella, listeria,

Escherichia coli, some protozoa and the hepatitis a virus. These contaminate the food in a variety of

ways; therefore, food produced must be free from contaminants, preservatives and pesticide residues and

their metabolites, as people are now much more conscious of these problems. Phytosanitry measures and

occasional inspections can eliminate these problems.

PLANT PATHOLOGY AS A PROFESSION IN URBAN AGRICULTURE:

In many parts of the world where urban agriculture was introduced and developed on highly

scientific lines, considerable efforts have been made to broaden both plant ;health and plant protection.

The American Psychopathological Society realizing the need for such a broader concept has launched a

new electronic journal called Plant Health Progress: which published articles on all facts of plant

health. The society is also emphasizing on the production of professional graduates in urban plant

pathology and doctors of plant medicine program.

PLANT DISEASE CLINICS:-

The functions and practices of plant pathology, e.g. collection of diseased specimens, their

examination, proper identifications of pathogens, communication and recommendations, are performed

by the highly specialized professors and researchers who have advanced knowledge in their respective

fields. They come from the universities, Research and Extension departments. However, these activities

are carried out occasionally at much lower scientific ad professional levels and unorganized basis with

no inventory records. With the onset of urban agriculture, time has come now that plant disease clinics


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are also initiated in big cities as medicines and veterinary clinics. Plant disease clinics can actively

involve in site visits, collection of diseased samples, their timely examination and proper

recommendations. Growers and country agents, home growers can also send disease plants, soil with

disease plants and some time insects to plant disease clinic for identification, control measures all free or

nominal charges. Plant disease clinic can be equipped primarily with surface sterilants, dissecting

microscopes, culture dishes and test tubes, nutrient media for culturing fungi and bacteria. At the same

time, nematode isolation from roots or soil can be made. Diagnosis of vial diseases (bases on

symptomatology and host range) can become integral function of the plant disease clinics.

APPLICATION OF NEW TECHNOLOGY:-

A ) MOLECULAR PLANT PATHOLOGY:-

The molecular phase of plant pathology is expected to develop a great deal more and to make

contributions in ways that we can hardly imagine at present. One area in which molecular plant

pathology is expected to greatly contribute and to provide tremendous benefits is the area of detection,

identification, isolation, modification, transfer and expression of genes for disease resistance from one

plant to another. Several such resistance genes have already been identified, isolated, transferred into

susceptible plants, and when expressed made the plants resistant. The possibility that molecular plant

pathology can modify and combine resistance genes makes likely the future utilization of resistance

genes from unrelated plants or from other organisms and perhaps even the synthesis of artificial genes

for resistance for incorporation into crop plants. The practical implication of such developments cannot

be overestimated, as they are likely to revolutionize the control of plant disease by providing us with

cultivars that can resist disease in the presence of the pathogen, without the need to use any pesticides.

Urban agriculture is the best to test and utilize these innovations.

B) PLANT BIOTECHNOLOGY


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It is the use of tissue culture and genetic engineering techniques to produce genetically modified

transgenic plants that exhibit new or improved desirable characteristics. A large number of crops,

ornamental, and forest plants have been modified and released by various organizations around the

world. Practical examples of successfully engineered and disease resistant plants include melon, squash,

tomato, tobacco ad papaya that are protected from a variety of viral diseases. Classical Cross Protection

and Engineered Protection are highly promising and fit very well for application I urban agriculture.

Several viral diseases are now controlled; the best example is control of papaya crop from Papaya Ring

Spot Poty virus (PRSV)

SPECIFIC STRATEGIES FOR THE MANAGEMENT OF DISEASES IN URBAN

AGRICULTURE

To conduct research on urban agriculture and the diseases related to urban agriculture, build

collaboration between government and farmers to control diseases to ensure food security.

To conduct research on ecological, socioeconomic, nutritional, policy related and environmental

dimensions of urban agriculture and alternative food systems.

To set up, within a working urban farm, experimental plots where various alternative technologies of

crop management (e.g. biological pest control, organic soil management, intercropping designs, raised

beds, bio dynamics farming techniques and permaculture, etc) are researched for optimal yields,

sustainability, economic viability and land / labour productivity.

EDUCATION:-

To establish programs to teach graduates and undergraduates students the theory and practices of

urban agriculture and alternative urban food system to control disease and ensure food security.

To establish a clearing house/resource centre to meet the particular need of public school teachers and

administrators. Such a resource centre would offer information about curricula and activities which help


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integrate gardening into the current curriculum and meet the state mandated subject frameworks, offer

funding information and ideas for developing a sustainable gardening program, offer information about

coordinating a school garden with the school custodial, lunch program, local business and the larger

school community.

To train community members in environmentally sound methods of controlling diseases and ensure food

security and food production through hand on learning and field practices in organic horticultural

methods, fields days, workshops, seminars, plant clinic etc.

EXTENSIONS:

In order to control diseases in urban agriculture, a policy is needed among scientists/extension

workers and farmers/nursery holders on the implementation of programs and organizes training courses.

REFERENCES

http://www.ruaf.org/node/513

http://ag.arizona.edu/pubs/diseases/az1124/#phyd

http://www.cityfarmer.org/uajustification.html

http://en.wikipedia.org/wiki/Urban_agriculture

Notes Given By Dr.S.M.Mughal

http://www.urbanfarming.org/
http://www.ruaf.org/node/513http://ag.arizona.edu/pubs/diseases/az1124/#phydhttp://www.ruaf.org/node/513http://ag.arizona.edu/pubs/diseases/az1124/#phyd

urban agriculture & plant pathology by mian nasir

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