Saturday 2 February 2013

IRRIGATION


Irrigation is the the controlled application of water for agricultural purposes through man made systems to supply water requirements not satisfied by rainfall. Crop irrigation is vital throughout the world in order to provide the world's ever-growing populations with enough food. Irrigation is the act of artificially applying water to soil to allow plant growth. This can also include applying water to a lawn or garden. The term usually refers to providing large amounts of water in arid or dry regions to grow crops. The world's rapid population growth has produced more of a need for irrigation. With it, a higher crop yield is possible on older lands.

Although irrigation is most commonly used in areas with up to 20 inches (500 mm) of rainfall annually, sometimes it also is practiced in areas where the annual rainfall is 20 to 40 inches (500 to 1,000 mm). Irrigation helps to protect against droughts where rainfall is plentiful but uncertain. And in many circumstances, irrigation is applied to grow crops on a set schedule of cultivation and harvest. This type of irrigation also is applied to crops as flood irrigation -- water pumps or is brought to the fields along the ground to flood the crops. It is not an efficient watering method [source: United States Geological Survey].

 Water Use


The amount of water that is to be used for irrigation depends on the type of crop that is being farmed as well as the amount of rainfall in the region. There are some countries where water is used for irrigating land more than it is used for other purposes. In the US, about one-third of the water that is utilized each year is used for irrigation. Worldwide, it is more than half.


Water Sources

Water that is brought to a farm from a source of surface water, such as a lake or reservoir, usually is done so through a series of canals. In some places, snowfall and rainfall are the main suppliers of irrigation water, but in other locales, groundwater is essential. Surface water used for irrigation is stored naturally in lakes and ponds and is conveyed by rivers and streams. Groundwater collects in basins of coarse gravel and in aquifers, which are water-bearing rocks. It reaches the surface through springs. The natural sources discharge mainly in the spring and dry up in summer. Because of that natural cycle, artificial surface reservoirs are increasingly being used to store irrigation water. The largest are dams. Water also can be obtained from wells, where water from storm-filled streams is directed and collected in the ground to fill underground basins.

Some irrigation methods

Many different irrigation methods are used worldwide, including:
  • Center-Pivot: Automated sprinkler irrigation achieved by automatically rotating the sprinkler pipe or boom, supplying water to the sprinkler heads or nozzles, as a radius from the center of the field to be irrigated. Water is delivered to the center or pivot point of the system. The pipe is supported above the crop by towers at fixed spacings and propelled by pneumatic, mechanical, hydraulic, or electric power on wheels or skids in fixed circular paths at uniform angular speeds. Water is applied at a uniform rate by progressive increase of nozzle size from the pivot to the end of the line. The depth of water applied is determined by the rate of travel of the system. Single units are ordinarily about 1,250 to 1,300 feet long and irrigate about a 130-acre circular area.
  • Drip: A planned irrigation system in which water is applied directly to the Root Zone of plants by means of applicators (orifices, emitters, porous tubing, perforated pipe, etc.) operated under low pressure with the applicators being placed either on or below the surface of the ground.
  • Flood: The application of irrigation water where the entire surface of the soil is covered by ponded water.
  • Furrow: A partial surface flooding method of irrigation normally used with clean-tilled crops where water is applied in furrows or rows of sufficient capacity to contain the designed irrigation system.
  • Gravity: Irrigation in which the water is not pumped but flows and is distributed by gravity.
  • Rotation: A system by which irrigators receive an allotted quantity of water, not a continuous rate, but at stated intervals.
  • Sprinkler: A planned irrigation system in which water is applied by means of perforated pipes or nozzles operated under pressure so as to form a spray pattern.
  • Subirrigation: Applying irrigation water below the ground surface either by raising the water table within or near the root zone or by using a buried perforated or porous pipe system that discharges directly into the root zone.
  • Traveling Gun: Sprinkler irrigation system consisting of a single large nozzle that rotates and is self-propelled. The name refers to the fact that the base is on wheels and can be moved by the irrigator or affixed to a guide wire.
  • Supplemental: Irrigation to ensure increased crop production in areas where rainfall normally supplies most of the moisture needed.
  • Surface: Irrigation where the soil surface is used as a conduit, as in furrow and border irrigation as opposed to sprinkler irrigation or subirrigation.

This information is courtesy of the Nevada Division of Water Planning, wisegeek, United States Geological survey

Thursday 31 January 2013

MEDICINAL PLANT-ASOKAM/ ASOKA/ OSAKA




Common name: asoka, Asok, Ashok, Asogam, Wu You Hua, Osaka

Scientific name: Saraca asoca (ROXB.) DE WILDE

Part Used : Bark, Leaves, Flowers, Seeds.

Commercial importance:

The bark contains tannins and some chemicals and is prescribed as a tonic. Crushed flowers and leaves are rubbed on the skin to get relief from skin diseases. When selecting trees for avenues or large gardens, it will be an excellent idea to choose Saraca asoka instead of the usual rusty shield bearer or the ubiquitous gulmohur. The dried flowers are used in diabetes and haemorrhagic dysentery and seeds are used for curing bone fractires, strangury and vesical calculi. The flowers are considered to be a uterine tonic and is used in cases like burning sensation, dysentery, hyperdypsia, scabiesin children and inflammation. It is also used in fever, dipsia, colic, ulsers and pimples. The seeds are strengthening and the ash of plant is good for external application in rheum-arthritis. It is considered as best female tonic.

How to cultivate


Soil and climate: The plant requires slightly acidic to neutral soils for good growth with
medium to deep well drained fertile soils. It grows well in tropical to sub-tropical
situations under irrigation.

Nursery raising and planting: The crop can be propagated by seeds and stem grafting. The seeds has to be collected from the matured tress in august- September. As the seeds have less life span, it will be betterto plant the seeds as early as possible. Prior to seeding, soak the seeds in water for one day and then sow them in either  nursery beds or in polythene covers filled with soil. Transfer the plants in nursery bed to polythene cover after two weeks of germination. After two years these plantlings can be used for planting in main field. The seedlings are planted in the well manured field during the rainy season with a spacing of 3* 3 meter.

Thinning and weeding: Weeding and thinning of the plants may be done as and when
required usually after 15-30 days for better growth.

Manures, fertilizers and pesticides: The medicinal plants have to be grown without
chemical fertilizers and use of pesticides. Organic manures like, Farm Yard Manure
(FYM), Vermi-Compost, Green Manure etc. may be used as per requirement of the
species. To prevent diseases, bio-pesticides could be prepared (either single or mixture)
from Neem (kernel, seeds & leaves), Chitrakmool, Dhatura, Cow's urine etc.

Irrigation: Normally grown as rainfed crop but for better yield irrigation may be done as
per requirement (weekly/fortnightly).

Harvesting/ post harvesting operation: Bark is removed from about ten years or older
tree and then it has to be sun dried. By thus time tree will also produce flowers.


Wednesday 30 January 2013

MEDICINAL PLANT- ARAYAL/ Bodhi Tree, Peepal Tree, Sacred Tree

Common Name : Bodhi Tree, Peepal Tree, Sacred Tree
Scientific name :Ficus religosa

Part Used : Bark, Leaves, Tender Shoots, Latex, Seeds, Fruits.
 Commercial importance: The bark is cooling and astringent and is useful in inflammations and glandular swellings of neck. Root bark is good for stomatitis, clean ulcers and it is astringent in leucorrhoea and promotes granulations. According to Unani system of medicine, root, bark is aphrodisiac and also good for lumbago. Roots are said to be good for gout. The roots are chewed to prevent gum disease. The fruit is laxative, promotes digestion, aphrodisiac and checks vomiting. Ripe fruits are alexipharmic (an antidote or defensive remedy against poison, venom or infection), are good for foul taste, thirst and heart disease. The powdered fruit is taken for asthma. The seeds are cooling, laxative and refrigerant. Seeds are useful in urinary troubles. The leaves alone are used to treat constipation. The leaves and young shoots together are purgative (strong laxative). An infusion or decoction of the bark is used with some honey for the treatment of gonorrhoea, ulcers, skin diseases and scabies. Its power bark has been used to heal the wounds for years. 

 How to cultivate

Peepal tree is easily propagated through the seeds or through the cuttings. propagating the sacred fig (ficus religiosa) with seeds isn’t difficult. you can use a good regular potting mix. give the seeds just on the soil. to increase humidity put a glas or a freezing bag over the pot. don’t forget to air daily. place the pot on a bright location without direct sun. temperature should be +20 °c/68 °c. keep the soil moist but not wet. the sacred fig needs approx. 7 to 21 days to germinate (at 25 °c/77 °f). if the seedlings are approx. 5 cm/1.97 tall you can start slowly adapting them to your room climate with extending the airing time day by day. when they are 10 cm/3.94 inches tall they can be divided an re-potted. It can grow in any type of soil. Young peepal needs proper nourishment. It requires full sunlight and proper watering. Commonly cultivated areas Peepal tree is grown throughout India. It is mainly grown in State of Haryana, Bihar, Kerala and Madhya Pradesh. It is also found in the Ranthambore National Park in India.

Thursday 1 December 2011

MEDICINAL PLANT- ANALIVEGAM/DEVIL TREE

Common name: Sinnappalai, Devil Tree
Scientific name:  Alstonia venenata R.BR.
 Parts used: roots and fruits
Commercial importance:  it can used for treating pitta, cobra bite, skin diseases, other venomous bites, epilepsy, fever and otalgia. Fruits are useful in insanity and epilepsy. The latex is used in treating coughs, throat sores and fever. It is a remedy for impure blood. the seeds of Alstonia venenata as an aphrodisiac and stimulant in their tantric sex rituals.
 
How to cultivate
 Plant seeds just under the surface (0.5cm) in a well drained mixture, (potting mix:perlite:washed sand) in full sun. Keep moist until germination. They are drought tolerant and hardy species once established.

MEDICINAL PLANT- TINOSPORA / AMRUTHU

Common name: Gulancha tinospora, Tinospora
 
Scientific name: Tinospora cordifolia (WILLD.) HOOK.F. & THOMS.
 
Parts used: stem
 
Commercial importance: amruthu acts as a diuretic and found to be effective against Renal obstruction like calculi and other urinary disorders. It acts as a memory booster, develops inteligence, promotes mental clarity. It is described as one of the Medhya Rasayana (mental rejuvenative) in the Charak Samhita (The oldest and most potent book of Ayurvedic Medicine). It is regarded as a liver protector. It is considered helpful in eye disorders as a tissue builder and promotes mental clarity. The stem is used in general debility, dyspepsia and urinary diseases. It is anti-pyretic and act as a tonic after fever, also has action against alternative fever like Malaria. Tinospora or Guduchi acts as a diuretic and found to be effective against Renal obstruction like calculi and other urinary disorders
How to cultivate
Medium black soil or red soil is the best for the cultivation of Tinospora Cordifolia. A well drained, rich in organic matter soil is very good for the growth of this plant. The plant is very hardy and it can be grown in almost all climates but prefers warm climate.
 
Tinospora can be propagated by seeds and also vegetative cuttings. The best way is vegetative way. The cuttings of the small finger thickness with 6 to 8 inch length long stem having two nodes are used. The cuttings are dipped by quick dip method in 2500 ppm of IBA and get greater success of rooting. This may be planted in poly bags of 4 inch ×6 inch size. The poly bags filled with mud, sand and dry cow dung in the ratio 1:1:1. The rooting of the cuttings takes almost 4 to 5 weeks. The cuttings of Tinospora Cordifolia will be ready for planting into the main field by this time.
Tinospora is a climber and hence needs some source of support to get higher yields. Proper training structures like the wires are required. The first harvest can be made by plucking the leaves without damaging the vines. These leaves are then spread on clean dry floor for drying.
 
Irrigation: Tinospora Cordifolia should be watered everyday in the early stages and later at weekly intervals depending upon soil and climate conditions.

Saturday 12 November 2011

GREENHOUSES/ POLYHOUSES AND ITS IMPORTANCE

The Greenhouses/polyhouses are constructed with the help of ultraviolet plastic sheets, so that they may last for more than 5 years. The structure is covered with 1501 m thick plastic sheet. The structure is prepared with the bamboos or iron pipes. Iron pipe structure is costly but more durable than bamboo.
Generally the length of the polyhouse is 25-30 feet and width 4-5 feet. The direction of polyhouse is always East to West, so that the maximum sunshine is available. The house should not be constructed in shade. The size of polyhouse may differ depending on the necessity. The polyhouses are kept cold or hot depending upon the season.
Use of Greenhouses:
From the point of view of earning more profit only such off-season crops should be grown, which are being sold at higher prices in the market. Big hotels in cities are mostly in the need of off-season vegetables and so is the case with some prosperous people in big cities. In such areas and also in the hill and remote regions where fresh vegetables are required regularly for meeting out the requirements of security forces, the construction of polyhouses is more lucrative and is a must.
The crops grown under the polyhouse are safe from unfavourable environment and hailstorm, heavy rains or scorching sunshine, etc. Crops of the polyhouse can be saved from birds and other wild animals. The humidity of polyhouse is not adversely affected by evaporation resulting in less requirement of water. In limited area of polyhouse, insects and pests control is also easy and less expensive.
By adopting the modern technology of polyhouse, the difference in the demand and supply of off-season vegetables and fruits etc. can be minimised. This facilitates in maintaining the quality of the product also.
Greenhouse can be used for:

·        Producing half hardy perennials or bedding annually grown from seed both during sowing and pricking out.
·        Protect tender plants and bulbs during the winter months.
·        Grow hobby plants such as chrysanthemums, fuschia's or exotic orchids.
·        Cultivate indoor pot plants.
·        Cultivate alpine species.
·        Use it for commercial purposes.

  1. Natural Roof and side wall ventilation system.
  2. UV stabilized covering materials of Polyethylene / Polycarbonate / Acrylic.
  3. Cellulose Cooling Pad and Exhaust Fan System.
  4. Heating system in cold climate.
  5. CO2 Generator.
  6. Shading / Thermal Net
  7. Trellising system for vegetable
  8. Trestles system for flowers.
  9. Green House G.I. structure.
  10. Covering material-UV stabilized Polyethylene / Polycarbonate / Acrylic.
  11. Root Ventilation & Side wall roll up curtains.
  12. Cooling pad and Fan System.
  13. Shading / Thermal net Manually / motorized.
  14. Micro Irrigation System.
  15. Fertigation System
  16. Misting System.
  17. Heating System.
  18. CO2 Generator.
  19. Control System - Manual / Semi Automatic / Automatic. Fully Computerized / Weather Station.
  20. Planting material, soil media.

Fully Computerized Control System

Most of the time, the owners prefer Mutually Controlled System or Semi Automatic Controlled System for green house, because of low investment. But in such type of Control Systems it requires a lot of attention and care. Also it is very difficult and cumbersome to maintain uniform environment inside the Green House. Ultimately this affects crop production, non uniform growth and low quality of the crop.
Computerized Control System is the solution to come over this problem and to maximize returns. Computer provides a faster and precise operation in the Green House. Also it stores, displays and prints the Green House information as needed. Computer can do the following operations as per the pre-scheduled programme:

1.      Starting and closing of Micro Irrigation System.
2.      Application of Liquid Fertilizer or Water Soluble Fertilizer (N:P:K) and other Nutrients to the plant.
3.      Operation of Misting System as required.
4.      Opening and closing of ventilators and side wall roll up curtains as needed.
5.      Operation of shading net / Thermal screen.
6.      Operation of cooling pad and fan.
7.      Operation of heating system.
8.      Operation of CO2 Generator, Climate Control, Temperature, Humidity, Heat Radiation, Control of EC, PH, PPM level in irrigation water etc. as required to the plant.
benefits of instrumentation in green house

1. Optimised Humidity control

2. Irrigation and water saving

3. Nutrients supply

4. Quality

5. Energy conservation

6. Development of a modern Management and control package.



1. Optimised Humidity control

 


Figure 1: Schematic of the tomato plant growth where 5, 6 and 7 refer to truss number
In commercial greenhouses the relative humidity is constantly varying and the aim of humidity control is to avoid environments which would lead to a reduction in yield and/or quality.  A humidity event, when leaf transpiration rate is low resulting in symptoms of calcium deficiency occurring, influences the growth of leaves associated with several trusses (Hamer and Belay, 1997). An event on one day can result in the reduction of yield and quality of fruit harvested over about a four to five week period (Figure 1). A modification of the environment at one time of the year does not result in a return until later in the season. Crop values change throughout a season with the lowest values when supplies are at a peak, general in mid-season. The techniques for control must be cost-effective so that the benefits of a control strategy in terms of yield and quality are in excess of the costs of carrying out the dehumidification.
As there is a well-known need for humidity control at the lower end of the water-uptake range, a dynamic crop growth model (Hamer, 1997)was developed from measurements taken during the course of the Macqu project. Simulations using a model which predicted conditions inside the greenhouse enabled the cost benefit of de-humidification to be evaluated. A combination of ventilation and heating proved to be the only economically viable means of dehumidification in which the ventilation rates were constrained by restricting the angle of opening of the ventilators.
It was concluded that both visual and internal quality parameters can be modified through environmental manipulations. The techniques that have been developed , in course of Macqu project, can be implemented in a management system that reacts to on-line observations.
    

2. Irrigation and water saving


Protected crops have a high water requirement. Irrigation control is important to ensure that the plants needs can be met without overwatering. Overwatering has the potential to cause environmental damage particularly if the excess irrigation water containing fertilisers enters the ground water system.
The control of the water supply can be used as a management tools to control crop growth and to improve the quality of produce. A minor water requirement of the crop is for plant growth which is typically less than 4%. However, over short periods when transpiration rates are low the proportion of water used for storage compared to transpiration can be high.
To define an effective control strategy it is necessary to predict how the uptake of water by the plant depends on the climatic conditions, this can be achieved using a model. (Hamer, P.J.C., 1997). To ensure that the crop receives adequate irrigation throughout a season under all the environmental conditions experienced, the model must be robust, which implies simplicity, and that any input values needed by the model must be easily and reliably measurable. An irrigation model for greenhouse tomatoes (Hamer, 1997) was developed and validated, in course of Macqu project.

3. Nutrients supply


·      Feedfack control of the water and nutrient supply

Keeping the rate of water and nutrient drainage constant in a direct feedback control system, thus ensuring the compensation of both water and nutrient uptake by the plants, was shown, during Macqu project, to be viable in closed growing systems with a drain flow sensor and also in open growing systems when using a starting gully and drain flow sensor.  A tipping-bucket sensor was used to monitor the output of the controlled system and provide the feedback signal to the controller (Th. H. Gieling, A.J.W. van Antwerpen, J. Bontsema, M.HM.H Bastings, 1996).  The results showed very close control of the drainage flow, keeping it constant for long periods of time.
The value of the drain water flow can be chosen freely. It can be lowered in such a way, that only a minimal amount is supplied, but still all the plants in the greenhouse are receiving water. In this way, the amount of return water is minimized, giving rise to a reduction in the amount of water that has to be cleaned before being re-used, hence to a cost reduction. A constant drain return will also allow for an optimal usage of  connected equipment, which close the loop, like: drain  water cleaning and re-fertilizer equipment. No harm to the plants is risked, since the controlled supply system will act almost instantaneously and will immediately compensate any change in drain water return.
By closely matching the supply of irrigation water to the crop requirements, the discharge of fertilisers into the soil environment and the consumption of water can be reduced substantially. Model based control and constant drain return feedback control proved to be a reliable approach. It has been proved that improvements to growing system can reduce leaching of irrigation water.

·      “Tichelmann” lay-out

An irrigation review was undertaken, during Macqu project, which included methods for nutrient transport to the roots and the uptake of nutrients by the roots (Gieling, Th. H, J. Bontsema, A.W.J. van Antwerpen & L.J.S. Lukasse, 1995).  In order to improve the dynamic properties (dead time and delay times) of water supply systems, the so-called "Tichelmann" lay-out was proposed.  The properties of this lay-out have been described in a model based on "First Principles". It was tested by simulation and installed in a greenhouse growing system.  The results have been disseminated at two Horticultural Engineering Shows (NTV 1995 and 1996, The Netherlands) and  subsequently the system has been widely accepted by industry.
It was shown that improvements to the water supply lay-out considerably reduced the time delays and dead times in the supply system.

Tichelmann lay-out description (figure 2): The outlet of the system situates on the opposite side of the inlet . Thus, the route of the water through the system is equal for all supply lines and the length of the routes in the system is equal for all supply lines, the distribution of the water is nearly uniform.
 

·      Hydroponic system

During Macqu an innovative dosing device for hydroponic systems has been designed and tested. The device was filed with Greek Industrial Intellectual Property Rights for a patent. It provides a cost effective, reliable and of high accuracy method for mixing corrosive chemicals. The overall system combined with a feedback loop in Macqu software accurately controls nutrients concentrations (EC) and pH. Its main innovative feature is that it can accept as many solution tanks as desired with very limited additional hardware. Proportions of the different tanks are set in a simple dialog with Macqu while total concentration (EC) and pH is control by feedback to high accuracy. The control loop was tuned to quickly respond to system disturbances and can maintain high accuracy in both “mixing tank systems” and “on line mixing systems”.
 

4. Quality

 Given sufficient knowledge about crop response, a management system could make an appropriate use of available tools for manipulating indoor climate and nutrition, in order to maximize yield value. In particular, one could choose to accept a decrease in yield, if there was a sufficient increment in quality of the product (C. Stanghellini, W. van Meurs, F. Corver E. van Dullemen and L. Simonse, 1997). Such a cost-benefit weighting obviously requires some knowledge about the crop response to both nutrition and selected factors of the climate within the house.
Research in course of Macqu project showed that:

·      Quality vs nutrition

High salinity reduces yield by reducing the influx of water to fruit. The observed reduction in fruit weight was 2.7 % for each dS m-1 by which the salinity (EC) in the root environment exceeded 2 dS m-1. High salinity is associated (in conditions of large water uptake) with blossom-end rot (BER), which reduces the number of marketable fruits by 3.2% for each dS m-1 that the EC exceeds 2 ds m-1.

·      Quality vs climate

Depressing water uptake by imposing a high greenhouse humidity significantly reduces the incidence of BER (C. Stanghellini, W. T.M. van Meurs, F.G.M. Corver, E. van Dullemen and L.Simonse, 1996).  However, high humidity reduces transpiration which can produce calcium deficiency symptoms on leaves, and this can lead to yield and quality losses in tomato fruit. Water uptake can be increased by reducing the greenhouse humidity.

5. Energy conservation

The use of alternative energy sources and energy saving methods can reduce the emissions of contaminants into the environment and also increase energy efficiency thus improving the competitiveness of greenhouse production.
A number of techniques have been tested to investigate energy use and cost saving methods and useful tools have been developed under the MACQU project.

·      Energy saving

Greenhouse energy use models are practical ways to predict the behaviour of the greenhouse and to improve energy management, and three such models were developed in this project.
A dynamic greenhouse model was developed and validated to predict the response of the greenhouse environment to the external weather, the internal environment conditioning devices and the control actions (Navas L.M., De la Plaza S., Garcia J.L., Luna L. and Benavente R.M., 1996).
A second model, of the step-wise steady state type, was developed to estimate greenhouse energy needs with different energy saving measures and to calculate the energy needs covered by conventional or alternative energy sources (Garcia J.L., De la Plaza S., Navas L.M., Benavente R.M. and Luna L., 1996). This model has been included in a computer program and the logic code produced was integrated in the MACQU program.
Other models were developed for energy and investment cost analysis with different energy sources (heat pump, solar energy and cogeneration) and to check the experimental results, this showed that heat pumps could be feasible under certain conditions.

·      Energy management

An approach to solving the problem of remotely operating a complex greenhouse, designed for best use of equipment and resources, involves the design of an end-to-end system that includes the human operator as a critical component.
Therefore the growers' intuition and experience is allowed to intervene at different stages, and user goals can be expressed at different levels of management, from rules about quality and yield, down to set-point manipulation (figure 3). The remote controller unit (RCU) handles all of the closed loop controls for the greenhouse operation, such as heating or ventilator degree setting, mist operation, valve setting for irrigation and nutrient supply, etc. All RCU functions are parametric and can autonomously do scheduling of operations, take energy saving measures etc, in the framework of short to medium term planning. Higher level decisions, made at the central station, are concerned with long and medium term strategies and operator's goals, and are passed down to the RCU as parameters of reference generating functions for real time set-point derivation.
                      
                      Figure 3: Different levels of operators input and rules manipulating adaptive set-point derivation.
 An energy management rule-base is being prepared which will do off-line energy utilization planning regarding energy availability, cost and projected energy needs, as well as on-line energy saving, based on a diurnal reference trajectory adjustment (figure 3).

·      Heating technologies

Experiments were conducted with alternative energy sources and localised heating as an energy saving method (De la Plaza S., Garcia, J.L., Navas, L.M., Benavente R.M. and Luna L., 1996). The results showed that localised substrate heating could be economically feasible in ornamentals crops (geranium, gerbera) when supplied with hot water from an oil or gas fuelled boiler; but the feasibility of electricity was strongly dependent on the price of the product; it was not feasible for tomato production.  A heated concrete floor, another localised heating method, showed an energy saving up to 20%.  The feasibility of this system was proved with crops having low canopies and a high temperature requirement.
Energy use analyses were carried out for seven European locations to determine the economical applicability of the systems related to investment costs, and fuel and electricity prices.  The use of localised heating, industrial thermal effluents and co-generation were the best techniques to obtain a higher energy efficiency and a reduction of environmental pollution.

6. Development of a modern Management and control package.

 
A system was designed, to be  “OPEN” and with the innovative features of Virtual Variables and MACQU-native KBS, it is possible to incorporate any new functionality without programming. The system was successfully installed at the evaluation site (MAICH) and tested for the period of March through June 97.
The development of a modern Control and Management system for greenhouses (N. Sigrimis, A. Anastasiou, V.Vogli, 1997)  used recent advances in software design and development tools to provide a “no programming needed OPEN system”. The system provides a vehicle through which all research achievements can be immediately implemented in the field. The main innovative features implemented to provide such a flexible system are:
1.      Functional objects: Object oriented design not only on the programming style but also on the “user_functionality”. A complete set of “prime functions”, needed at the different signal processing stages (input-processing-output), were identified and designed as independent objects. These objects can be specified and chained to provide a “custom” higher level function, i.e. management of supplementary lights.
2.      Virtual variables (VV): The system starts with no variables, other than hardware related, defined. At any time the “user” can institute, in the field, new variables as functions of other variables. Such a nesting has no limit (except physical memory). A rich set of function templates (library) has been designed-in, from which the user can select his signal processing building blocks. Polynomials, adjustable Time-Integrated-Variables, multi-in-one-out, thresholds-decisions, timers and multi-point day_clocks, , hard and soft events, are some of such VVs which can be defined and used as input to other functions.
3.      Virtual control loops: Almost any control philosophy can be implemented using a well defined chain of building blocks and smart virtual variables. Non-linear PIDs, configurable output functions and functional enable/disable switches are the tools to build control loops, which may also be nested or cascaded. Virtual variables can implement models used for adaptive set-point control (optimize greenhouse performance) or for a feed-forward action (optimize loop performance).
4.      KBS-Tasks/subtasks: Higher level management can be implemented using a Fuzzy Logic, rule based, expert system, native of Macqu. This system provides input, output and rule editor on line. The outputs can directly affect the greenhouse equipment or may influence control loops, previously defined in the greenhouse computer. The rules may refer to (consequent) tasks which are open objects including one or more subtasks. Subtasks are the “modes” of operation of equipment drivers, programmed in the greenhouse computer. In this way a Fuzzy Logic Controller, native of Macqu, can interact with or overtake the control functions of the greenhouse computer. Such a high degree of functionality needs “careful set-up” /the present status/, or a well designed “supervisor”/macqu evolution/.
  
THE  EXPECTED  BENEFITS  ARE:
  Technical:
The determination of the most cost effective method for limiting greenhouse humidity. The development of a new and effective way of controlling plant irrigation, which could have application on open field cultivation as well. Tuning heating system efficiency with the phase of the protected crop. Standardisation of conventional sensors and development of new sensing techniques to enable "quality control" in prime production. Advanced concepts of Information technologies to provide a vehicle for speeding up the transfer of research results to practice.
Scientific:
The development of a method of predicting plant water and nutrient requirement based on easily measured weather variables. A significant advance in the simulation techniques used to predict the environment in cropped enclosures. Innovative sensing of plant physiological responses, including early nonvisible symptoms of disease onset. The development of on-line techniques for the real time optimisation, cost vs quality-grade, of controlled conditions.
Economic:
Reduction of precious water and nutrient chemicals consumption, by an amount of up to 40% in greenhouse production and ensure quality by water availability and balanced nutrient supply. This will be of particular importance in regions of scarce water. Reduction of labour cost and pesticides with the "soilless closed irrigation" systems. Optimal control of greenhouse humidity and of energy utilisation will enable grower income be maximised. An integrated product will satisfy constraints for both; the private competitiveness and the public benefit.
Environment:
A reduction in pollution caused by the fertilisers contained in excess irrigation water drained to the soil. Reduction of crop protection chemicals (reaching the consumer directly through the product and indirectly through the environment) by: controlling humidity, early detection of diseases, and finely controlled closed irrigation systems.

Thursday 10 November 2011

MEDICINAL PLANT- INDIAN GINSENG/ WITHANIA SOMNIFERA

Common name: Winter cherry, Indian Ginseng
Scientific name: Withania somnifera (Linn.) Dunal.
Parts used: Roots and Leaves

Commercial importance: The root of Asvagandha is used in the form of powder to treat consumption, excessive emaciation, bronchial asthma, rheumatic ailments, insomnia, cardiac diseases, wound due to accident, suppression of urine, and for conception in sterility. Also used for inflammatory conditions , ulcers , and scabies in the form of external application . Leaves are used as a febrifuge and applied to lesions, painful swellings and sore eyes . Also used in rejuvenating preparations . Ashwagandha, if given in proper dose, can restore the neurotransmitters and hence can be useful in various mental disorders. Ashwagandha can be used by both men and women and it acts to calm the mind and promote sound, restful sleep. Ashwagandha works as an adaptogen, promoting the body's ability to maintain homeostasis and resist stress. It prevents or minimizes imbalances that may lead to disease, whether from poor diet, lack of sleep, mental or physical strain, or chemical toxins in the environment. It is especially beneficial in stress related disorders such as arthritis, hypertension, diabetes, general debility, etc. It has also shown impressive results when used as a stimulant for the immune system. Ashwagandha is a unique herb with anti-stress adaptogenic action that leads to better physical fitness and helps to cope with life's daily stress.

How to cultivate


Withania somnifera is cultivated in sandy loam or light red soils having a PH of 7.5 to 8.0 with good drainage. It is a late rainy season crop. It requires relatively dry seasons, and the roots are fully developed when 1-2 late winter rains are received. The areas receiving 65-75 cm rainfall are best suited for its cultivation.
Withania somnifera is mainly grown on residual fertility and hence no manure or fertilizers are recommended.
Direct sowing: Seeds can be sown directly in the field by broadcasting since it is largely grown as a rainfed crop, sowing is determined by the monsoon. After receiving pre monsoon rainfall, soil is brought to fine tilth and the crop is sown during the second week of July. A seed rate of 10-12 kg per hectare is sufficient when the crop is raised by this method.
Transplanting: About 5 kg of seeds is required to provide seedlings for an area of one hectare. The seeds are sown in the nursery just before the onset of the rainy season. The seeds are lightly covered with soil and germinate in about 6-7 days after sowing. When the seedlings are about 6 weeks old they are transplanted in the field in 60 cms wide furrows 60 cm apart.
In the directly sown crop, the plants are thinned at 25-30 days after sowing to maintain a plant propulation of 20,000-25,000/ha. Hand weeding at 25-30 days interval helps to control the weeds effectively.
Harvesting starts from January and continues till March (150-170 days after sowing). The maturity of the crop is judged by the drying of leaves and red berries. The entire plant is uprooted for roots which are separated from the aerial parts by cutting the stem 1 - 2 cm above the crown.
The roots are cut into small pieces of 7 - 10 cm to facilitate drying. The berries plucked from dried plants are threshed to obtain the seeds for the next crop. An average yield of about 400 - 500 kg of roots and 50 kg of seeds are obtained from one hectare.