Tunnel farming

What is Tunnel Farming

–        Growing crops in protected environment under plastic cover

Tunnels

A tunnel refers to an arched structure figured by inserting both ends of the rod into the ground. It is the simplest structure to support the covering materials

MAIN OBJECTIVES OF POLYTUNNEL FARMING

Alleviation of poverty by enhancing farmers’ net income through:-

Ø  Diversification to high value crop

Ø   Human Resource Development

Ø   Capacity building – Private/Public

Ø    Promotion of off–Season vegetable growing under       tunnels  /protected Horticulture

Status of Protected Horticulture in Pakistan

Ø  Number of large entities showing initial interest but reluctant to invest capital

Ø  Number of growers moving into “Low Tech” plastic tunnels

Ø  No knowledge of the latest developments in the market

Prospects for Development

•          Development needs

–        Good Climate

–        Efficient Water Use

–        Good radiation levels

•          Areas for Potential

–        Khyber Pakhtunkhwa

–        Desert/Dry Region

–        Punjab

–        Balochistan

•          What is a high tunnel?

•          A high tunnel is a solar heated, manually vented, plastic-covered cold frame that is used to lengthen the traditional growing season for many horticulture crops.

•          It can significantly increase the average daily temperature and protect the crop from wind, rain, snow, hail, insects and diseases.

•          High tunnels are not greenhouses, and thus require no electrical connections for ventilation and supplemental heat.

•          The crop is grown directly in the soil using raised beds or mulch depending on the type of vegetable

Advantage

Ø          The primary advantage to high tunnel production is profitability

Ø   High tunnels increase net returns per acre by    protecting quality, increasing yields, and               providing the                 opportunity to obtain off season price   premiums

Ø           This allows a farmer to profit significantly without    turning  into an oversized operation

         High tunnel growers may also find it easier to meet        the         market demands of restaurants and other         direct markets   that favor purchasing from          growers               who can provide produce over a longer period of time

Disadvantages

The disadvantages of high tunnel production are      increased fixed costs associated with the             construction, and labor requirements associated with the management of the facility.

Soil Selection  & Preparation

A permanent high tunnel should be placed on fertile, non-shaded, well-drained soils

The soil should be tilled to a depth of approximately 6-8 inches, and nutrients applied based on a recent soil test.

Tomatoes should be established on a raised bed.

Raised beds will significantly enhance soil warming, drainage and volume of soil for rooting.

Raised beds can be made with power tillers or compact bed shapers. After the raised beds are formed, fertilizer, drip tape and plastic mulch can be applied

Growing vegetables in tunnel farming:

Seeds are planted in plant blocks/seed-trays, and one seed is sown into each compartment of the tray, lightly covered and kept wet. Seedlings remain in the seed tray until they have grown to about 10cm. Seedlings are then planted in the planting bags and kept wet. Climbers are trained up to overhead wires by pieces of string. The bottom part of the string is placed in the planting hole. The plant is placed on top of the string and firmed down into the growth medium to remove air from the roots. Then the other end of the string is fastened to the overhead wire. Tomatoes, cucumbers, green peppers, beans and sweet melons can all be trained up in this way to the wires that are strung above the rows and are fastened to the roof of the tunnel. The string is, in constantly wound around the main stem of the plant. This applies to all the plants except green peppers which case three or four stems can be used

Optimum temperature

The optimum temperatures for pollination are 68-75°F (night) and 60-90°F (day).

At prolonged temperatures <55°F or >95°F, flowers can drop from the plant.

Growth of tomato plants will stall when the soil temperature is 56°F or less, but begin to grow when the soil temperature hits 58°F.

Fruit set does not occur at low night temperatures (consistently below 50°F); fruits will not develop properly when temperatures exceed 95°F.

At temperatures between 50 and 60°F, ‘rough’, irregular fruit growth may occur.

Temperatures above 95°F can damage tomato blossoms causing flowers to drop or to develop irregular shaped fruit.

Relative humidity

Relative humidity is an important consideration with regard to high tunnel production.

Relative humidity describes the amount of water vapor in the air at any time.

The closed conditions of a high tunnel create an environment with higher relative humidity and little air movement until ventilated. These conditions can promote diseases that flourish in high humidity, creating a need to ventilate even when outside conditions are cooler than desired.

If possible, use wider plant spacing to increase air circulation. Older leaves are more susceptible to fungal infections.

Provide ventilation as early and as late in the day as possible. All of the foliar fungal diseases are favored by high relative humidity (> 85%) in the tomato canopy. The length of time above 90% relative humidity should be limited.

High humidity (>80%) can also adversely affect pollination

Remove suckers and the oldest leaves to increase air circulation. Provide adequate drainage around the base of the structure to make sure no water flows or seeps into the high tunnel

Pruning

Increases fruit size

Promotes earlier harvest

Reduces disease incidence

Reduces grey wall

Better air flow

TUNNEL DIMENSION

•          High Tunnels                                            30ҳ180ҳ12  feet

•          Walk-In Tunnel                                        12ҳ180ҳ6   feet

•          Low Tunnel Row Cover)                         3ҳ180ҳ3     feet

ECONOMICS

High Tunnel

1. Steel Permanent Structure(10-15 Years)                        (30ҳ180ҳ12 feet)          

 Cost       Rs. 350,000-450,000

2. Bamboo Structure(2-3 Years)                                         (30ҳ180ҳ12 feet)

                        Cost    Rs. 30,000-35,000                              

All  these are Fixed costs

Low tunnel, which are less expensive compared to high tunnels but crop yield is low. Soil preparation, spraying and picking is difficult in this tunnel. Cucumber, melons, watermelons, bitter gourds, squashes, and snake gourds etc can be grown in these tunnels

LOW TUNNELS VEGETABLE 

Ø  MARROW

Ø  BOTTLE GOURD

Ø  SPONGE GOURD

Ø  BITTER GOURD

Ø  MELONS

Walk-in Tunnel

Walk-in tunnel, which are lower in height compared to high tunnels. Walk-in-tunnels provide higher yields than low tunnels because of better sun light and ventilation. The tunnel is suitable for growing tomatoes, cucumbers, sweet pepper and hot pepper

WALK IN TUNNELS VEGETABLE

      SWEET PEPPER

      TOMATO

      HOT PEPPER

      CUCUMBER

High Tunnel

High Tunnel: High tunnels give maximum yield of crops and make easy soil preparation, picking, spraying due to its width and height. The tunnel is suitable for growing tomatoes, cucumbers and Bottle Gourd

HIGH TUNNELS VEGETABLE

      CUCUMBER

      TOMATO

      BITTER GOURD

      BOTTLE GOURD

WHY USE THESE STRUCTURES?

•          To control environment

•          Early crop

•          Meet market demand

•          Enhance life span

•          Quality production

•          Maximizing production

•          Control (Insect, pest, disease)

•          Increase income per unit area

Tunnel Farming

–        Environmental conditions can not be completely controlled

–        Due high humidity incidence of pest and diseases will be high

–        It can be used in winter only as in summer additional shade or cooling is required

–        High initial cost and intensive care

Factors affecting yield and profits

–        Soil and climate

–        Crop variety

–        Irrigation

–        Fertilizer application

–        Control of pest and Diseases

–        Harvesting and marketing

FUTURE PROSPECTS OF VEGETABLE FORCING

Ø  Good potential to promote this technology all over the country

Ø  Development of low cost material for installation of poly houses and other protected structures to promote the vegetable forcing

Ø  Raising of nurseries have many fold benefits and a  source of income generation for the growers

Ø  Local hybrid vegetable seed production for protected structures is also a good activity of increasing the income

Ø  The activity is very much useful for small land holders and conservation of water and land

Ø  Bright chances of employment and good for poverty alleviation

Recommendations/suggestions

•          The awareness among the farming community about the potential and usefulness of off-season vegetable cultivation through seminars, by extension/research services Agriculture Universities, NGO’s and media

•          Introduction of Micro-credit schemes for the installation of poly farming structures at government level for the small farmers

•           Establishment of demonstration/training blocks for the capacity building of local farmers

•          Development and adoption of cheaper protective material/accessories locally

•          Availability of quality vegetable seeds and other inputs be ensured

•          Initiation of targeted research for the development of indigenous hybrid varieties

•           Development of improved and cheaper packing materials

•          Development of centers for the provision of updated information/knowledge of better marketing of produce.

•          Encouragement to adopt co-operative farming for the better utilization of available resources