Zinc: Importance and Current situation

Zaghum Sattar & Abdul Saboor Butt

Institute of soil & Environmental Sciences, University of Agriculture, Faisalabad

Zinc (Zn) is among those minerals that were first considered as essential for plants, animals and human. Zn is a basic essential trace mineral element for normal healthy growth in plants, animals and humans that uptake as a divalent cation (Zn²⁺) by plants. Zn is playing principal metabolically role in plants and required in the carbonic enzyme present in all photosynthetic tissues, and also required for chlorophyll biosynthesis. Zinc is one of the essential micronutrient for the normal healthy growth and reproduction of crop plants. Zn plays an important role in plant metabolism by influencing the activities of enzymes, hydrogenase and carbonic anhydrase, stabilization of ribosomal fractions and also synthesis of cytochrome.  Zn also activate plant enzymes involved in carbohydrate metabolism, integrity maintenance of cellular membranes, synthesis of nucleic acids and specific proteins, regulate auxin synthesis and pollen formation. The regulation of the gene expression required for the tolerance of environmental stresses in plants also depend on the Zn.Zinc deficiency involves in the abnormalities development in plants as deficiency symptoms such as stunted growth, chlorosis and smaller leaves, spikelet sterility. Zn deficiency can also adversely affect the quality of harvested products; plants susceptibility to injury by high sunlight or temperature intensity and to infection by fungal diseases can also increase. A zinc deficiency affects the capacity for water uptake and transport in plants. Zn involves in the synthesis of tryptophan which is a precursor of IAA, and in the production of growth hormoneauxin. Zinc deficiency is common in humans, animals and plants. More than 30% world’s population suffers from Zn deficiency. Zinc deficiency is found to be more common in developing countries due to low Zn in their diet. Zinc plays a part.in the basic roles of. Cellular functions in all living organisms and also involved in the human immune system. The optimum dietary intake for human adults is 12-15 mg Zn per day. Zinc acts as a catalytic or structural component in various body enzymes.Unsatisfactory intake and improper absorption of Zinc in the body may cause deficiency of Zn.  Zn malnutrition in humans can result in many fatal and other diseases like hair and memory loss, skin problems and weakness in eye side and body muscles. Insufficient intake of Zn during pregnancy in women also causes stunted brain development of the fetus. Infertility has also been observed in Zn deficient men. Zinc deficiency may cause congenital diseases like Acrodermatitis enteropathica. According to FAO/WHO recommendations an average male need 11 mg of Zn daily while an average female needs 9 mg of Zn. During pregnancy and lactation, the female needs 13 mg to 14 mg of Zn daily. Infants from 7 months to 3 years need 3 mg, 4 to 8 years need 5 mg and children from 9 to 13 years need 8 mg of Zn daily. In Pakistan, Zn deficiency is common in children and in women.Trace elements such as Zn are contained in all soils in measurable amounts. However, these concentrations can vary considerably. The overall mean total Zn concentration in soil is around 55 mg Zn kg^-1. A typical range of Zn in soils is from 10 to 300 mg Zn kg^-1. These values do not include contaminated soils, which may have much higher zinc concentrations.However, plant available Zn is very low as compared to its total amount. For a better Zn nutrition of human beings, cereal grain should contain around 40-60 mg Zn kg^-1 where current situation is 10-30 mg Zn kg^-1. Soils with low zinc availability for plant uptake represent nearly half of the cereal-growing areas of the world. The countries most affected by zinc deficient soils are Pakistan, India, Iran, China and Turkey with 50-70% of arable land classified as zinc deficient.

Soil management Practices

Besides storing more carbon and making more efficient use of nitrogen, good soil management will provide economic benefits through increased productivity, more efficient use of nutrients, and improved air and water quality.

Agricultural soils act as efficient repositories for carbon, but under certain conditions soils also release carbon dioxide back into the atmosphere. Plants fix atmospheric carbon into foliage and roots, which eventually becomes soil organic matter. Soil organic matter is fundamental to healthy soil.

While much of the stored carbon is released back into the atmosphere when plants decay, some of it remains trapped in the soil as organic matter. Soil conditions and management will determine how much carbon is stored at any one time.

Through denitrification and other processes soils also release excess nitrogen into the atmosphere as nitrous oxide and nitrogen gas.

The following farming practices can reduce the amount of greenhouse gas emissions from soils.

"Low till" (Conservation tillage)

In conservation tillage, crops are directly planted into the previous year’s stubble, with minimum or no tillage. This practice not only reduces fossil fuel consumption, but also increases soil organic matter (compared to conventional tillage*) that otherwise would be emitted as carbon dioxide. Conservation tillage, along with reduced use of summerfallow, can store from 0.3 to 0.5 tonnes of carbon per hectare per year in the soil, depending on weather and moisture conditions.

As well, research from the University of Saskatchewan has shown there’s more available organic nitrogen in long-term zero tillage fields than in fields tilled using conventional methods.

Choosing to seed with narrow, low disturbance openers (knives or discs) has the further advantage of minimal seedbed disturbance. Crops seeded with low disturbance disc and knife openers have shown improved production and fewer weeds over crops seeded with higher disturbance openers, such as spoons or sweeps.

Additional benefits of conservation tillage include enhanced water infiltration, moisture conservation, reduced labour requirements, and less runoff and soil erosion due to wind and water.

Crop rotations

The best crop rotations should not only effectively manage nutrients and reduce pest problems, but also improve soil quality. While the environmental benefits of certain crop rotations are clear, market constraints may limit which crops are included. Some suggestions:

• The addition of legume crops in crop rotations will fix nitrogen. Perennial legumes, such as alfalfa, increase soil organic matter, while the residues contain nitrogen, which can easily be broken down to be used by subsequent crops.
• Crops with high nitrogen requirements, such as corn or cereals, used as a follow-up to legumes will capitalize on the fixed nitrogen in the soil.
• Planting a winter cereal or another cover crop after harvest (if timing permits) will help remove surplus nitrogen. Cover crops also store nutrients for the crops that follow them, as well as reduce weeds, host beneficial insects, and improve soil quality.
• Forage production is a further way to reduce emissions. Increasing forage production not only increases soil organic carbon, but it also uses surplus soil nutrients, reducing the risk of nitrogen losses, including denitrification.
• Crop mixtures, such as alfalfa-bromegrass, use soil nitrogen more efficiently and reduce the potential for nitrogen losses to the environment.

Marginal land

Marginal lands require the same inputs as productive land, but produce lower yields and profit. By planting these marginal or fragile lands to perennial cover, farmers can improve profit margins, create a carbon sink and provide natural habitat.

The best solution for flood-prone areas or lands with excess moisture may be restoring them back to wetlands. Wetlands can remove carbon dioxide from the atmosphere, reduce downstream flooding, help to clean water and provide wildlife habitat.

Stubble burning

On average, more than 90 percent of all carbon in crop residues is lost (mostly as carbon dioxide) when it is burned. Alternate uses for cereal straw include chopping and spreading back onto the fields, baling, grazing, and using for bio-energy feedstock and bio-fibre.

Soil drainage

Since saturated soils during the growing season are more prone to denitrification and producing nitrous oxide emissions, improving drainage encourages efficient crop growth and uptake of nitrogen fertilizer.

Drainage improvements may include enhanced surface drainage, installation of tile drains, or the use of trees, shrubs and other perennial crops to remove excess water. In some cases, it may be more appropriate to store water and refrain from annual crop production and fertilizer applications.

Soil cover

Crop residues left on the surface help prevent soil erosion.  Manitoba Agriculture recommends that 60 percent of the soil surface should be covered with crop residue in the fall to prevent erosion.

Summerfallow

Summerfallow is already a dying practice in Manitoba. But it is worth noting that besides leaving fields susceptible to wind and soil erosion, soils that were frequently summerfallowed usually had reduced soil organic matter compared to continuously cropped soils.

Source:http://www.climatechangeconnection.org

What Does Organic Matter Do In Soil?

By Eddie Funderburg

Of all the components of soil, organic matter is probably the most important and most misunderstood. Organic matter serves as a reservoir of nutrients and water in the soil, aids in reducing compaction and surface crusting, and increases water infiltration into the soil. Yet it's often ignored and neglected. Let's examine the contributions of soil organic matter and talk about how to maintain or increase it.

What is Organic Matter?
Many times we think of organic matter as the plant and animal residues we incorporate into the soil. We see a pile of leaves, manure, or plant parts and think, "Wow! I'm adding a lot of organic matter to the soil." This stuff is actually organic material, not organic matter.

What's the difference between organic material and organic matter? Organic material is anything that was alive and is now in or on the soil. For it to become organic matter, it must be decomposed into humus. Humus is organic material that has been converted by microorganisms to a resistant state of decomposition. Organic material is unstable in the soil, changing form and mass readily as it decomposes. As much as 90 percent of it disappears quickly because of decomposition.

Organic matter is stable in the soil. It has been decomposed until it is resistant to further decomposition. Usually, only about 5 percent of it mineralizes yearly. That rate increases if temperature, oxygen, and moisture conditions become favorable for decomposition, which often occurs with excessive tillage. It is the stable organic matter that is analyzed in the soil test.

How Much Organic Matter Is in the Soil?
An acre of soil measured to a depth of 6 inches weighs approximately 2,000,000 pounds, which means that 1 percent organic matter in the soil would weigh about 20,000 pounds per acre. Remember that it takes at least 10 pounds of organic material to decompose to 1 pound of organic matter, so it takes at least 200,000 pounds (100 tons) of organic material applied or returned to the soil to add 1 percent stable organic matter under favorable conditions.

In soils that formed under prairie vegetation, organic-matter levels are generally comparatively high because organic material was supplied from both the top growth and the roots. We don't usually think of roots as supplying organic material, but a study in the Upper Great Plains showed that a mixed prairie had an above-ground (shoot) yield of 1.4 tons of organic material per acre, while the root yield was about 4 tons per acre. The plants were producing roots that were more than twice the weight of the shoots.

Soils that have developed under forest vegetation usually have comparably low organic-matter levels. There are at least two reasons for these levels:

1. trees produce a much smaller root mass per acre than grass plants, and
2. trees do not die back and decompose every year. Instead, much of the organic material in a forest is tied up in the tree instead of being returned to the soil.

Soils that formed under prairie vegetation usually have native organic matter levels at least twice as high as those formed under forest vegetation.

What Are the Benefits of Organic Matter?

• Nutrient Supply
  Organic matter is a reservoir of nutrients that can be released to the soil. Each percent of organic matter in the soil releases 20 to 30 pounds of nitrogen, 4.5 to 6.6 pounds of P₂O₅, and 2 to 3 pounds of sulfur per year. The nutrient release occurs predominantly in the spring and summer, so summer crops benefit more from organic-matter mineralization than winter crops.
• Water-Holding Capacity
  Organic matter behaves somewhat like a sponge, with the ability to absorb and hold up to 90 percent of its weight in water. A great advantage of the water-holding capacity of organic matter is that the matter will release most of the water that it absorbs to plants. In contrast, clay holds great quantities of water, but much of it is unavailable to plants.
• Soil Structure Aggregation
  Organic matter causes soil to clump and form soil aggregates, which improves soil structure. With better soil structure, permeability (infiltration of water through the soil) improves, in turn improving the soil's ability to take up and hold water.
• Erosion Prevention
  This property of organic matter is not widely known. Data used in the universal soil loss equation indicate that increasing soil organic matter from 1 to 3 percent can reduce erosion 20 to 33 percent because of increased water infiltration and stable soil aggregate formation caused by organic matter.

How Can I Maintain or Improve Soil Organic Matter Levels?
Building soil organic matter is a long-term process but can be beneficial. Here are a few ways to do it.

• Reduce or Eliminate Tillage
  Tillage improves the aeration of the soil and causes a flush of microbial action that speeds up the decomposition of organic matter. Tillage also often increases erosion. No-till practices can help build organic matter.
• Reduce Erosion
  Most soil organic matter is in the topsoil. When soil erodes, organic matter goes with it. Saving soil and soil organic matter go hand in hand.
• Soil-Test and Fertilize Properly
  You may not have considered this one. Proper fertilization encourages growth of plants, which increases root growth. Increased root growth can help build or maintain soil organic matter, even if you are removing much of the top growth.
• Cover Crops
  Growing cover crops can help build or maintain soil organic matter. However, best results are achieved if growing cover crops is combined with tillage reduction and erosion control measures.

A good supply of soil organic matter is beneficial in crop or forage production. Consider the benefits of this valuable resource and how you can manage your operation to build, or at least maintain, the organic matter in your soil.

References
Barber, S. A. Soil Nutrient Bioavailability: A Mechanistic Approach. New York: Wiley, 1984.
Brady, N. C. The Nature and Properties of Soils. New York: Macmillan Publishing Co., 1974.
Plaster, E. J. Soil Science and Management. 3rd ed. Albany: Delmar Publishers, 1996.
Tisdale, S. L. and W. L. Nelson. Soil Fertility and Fertilizers. 3rd ed. New York: Macmillan, 1975.
Source: Noble Foundation

Soil Testing: Give Your Ground a Surprise Pop Quiz

Written by  Annie Spiegelman

Having your yard landscaped can be expensive; so, before you or someone else starts digging, be sure to take the soil test so your money doesn’t go to waste…

If you’re thinking about here are some questions to first ask yourself (and anyone else who looks remotely interested) about your backyard soil:

• Is the soil worked easily?
• Is the soil full of living organisms?
• Are earthworms abundant in the soil?
• Is water and air available for plant growth?
• Does my garden make me look good?

“I’m really, really mystified by homeowners who will plop down $30,000 to a landscape designer who will come up with a plant palette without ever thinking to take a spoonful of soil to test it first,” says Professor Stephen Andrews, soil scientist at UC Berkeley. “One of the criteria for selecting a landscape architect is to give them a soil quiz! Ask them what kind of soil test they will be providing. Be an informed consumer.”

So, after you’re done hating your compacted soil and admiring yourself in front of the mirror in your new garden hat, it’s time to get scientific. Why? Because we compost- spinning tree huggers believe all home gardeners caring for a plot of land, large or small, can be become superb stewards of their gift from Mother Nature by learning a little soil science.

“If you’re going to do any type of landscaping project, make sure to test your soil first to understand what kind of a baseline you have,” says Andrews. “If you’re changing a large backyard area, doing drainage work or you’ve just purchased a new home, go get a ‘commercial’ soil test done. It may cost you a few hundred dollars, but you’ll have a thorough analysis and interpretation of your land. The soil scientists at the testing company will give you specific advice on how to proceed.”  

For the rest of us, who don’t have the green to spend on the brown, it’s perfectly fine to take the mom-and-pop route. Head down to your local plant nursery and purchase a home garden test kit. A good soil test will run about $20. Andrews recommends Mosser Lee’s Soil Master kit “because of the educational information included. It’s also a simple test. It’s color-coated and it’s idiot-proof, I promise. Do it with the kids or grandkids. Or, get the entire neighborhood and have a soil testing barbecue! One test kit will have enough tubes to do 10 soil tests. You may be the diva who does everything organic, but…you’re living next to Charlie Chevron who uses every petrochemical on the planet. Get together and literally talk dirt.”

With the home soil test, you’ll be testing your soil’s pH. The pH level will tell you if nutrients are actually available to your plants or if you’re just out fertilizing, polluting and wasting your hard-earned cash on garden products.

“The ideal pH of soil for many common plants is 6.5. The reason we want the soil to be slighty acidic is because the plant nutrients are carried in a solution. If it’s slightly acidic, the nutrients can dissolve and can be transported,” says Andrews. “If the pH is too alkaline, the nutrients will sit there like lead balls of pasta, not going anywhere. By having it slightly acidic you have the best pH for nutrient uptake. To lower the pH, use coffee grounds, tea bags, sulfur, aged animal manure or compost. To raise the pH, add limestone or oyster or egg shells.”

Home tests also check the availability of your soil’s macronutrients: nitrogen (N), phosphorus (P) and potassium (K). These are the main nutrients and minerals needed by your plants (which is why you’ll see the letters NPK on fertilizer containers). Once you know which nutrients are already hanging out in your soil, you won’t be wasting money on unnecessary products.

When collecting your home soil sample, choose a few different sections of your yard. For instance, your edible garden in raised beds would be one test area while your front lawn, a slope or a woody spot would each be a separate area to test. “For each chosen area, do a representative sampling. Pick ten to fifteen different spots in that area and dig down 6-8 in.,” recommends Andrews. “Remove critters, rocks, roots and plant material. You just want soil parts. Take all samples from that area and mix them into a plastic baggie. Label the bag and the area accordingly. For a lawn, dig down only 2-3 in..”

If you’ve decided to do the commercial test, you’ll want to decide just how comprehensive a test you need. Andrews suggests testing for pH nutrient availability, particle size analysis, bulk density, moisture content, organic matter content, macro- and micronutrients and soluble salts. If you live in an urban area and are growing edibles, or in an older home where lead contamination from paint is prevalent, heavy metals testing should be done as well.

As mentioned above, commercial soil testing should be done when you first move into a home. It should also be done every ten years or so, depending on your budget and your gardening success or utter failure. The home soil test, on the other hand, would be useful to do any time a considerable amount of plants in your yard look beaten down, chewed up or super sluggish. (Gardeners don’t have patience for lollygagging plants. Testing your soil twice a year—once in the spring and again in the fall—is especially helpful if you’re growing fruits and vegetables year round.

“Cold season crops have different needs than warm season crops. Like us, our underground soil friends slow down when it’s colder outside,” says Andrews. “The bacteria slow down; but, once the soil warms up, the disco lights come on and they’re ready to party!”

Source: maximum yield

Hydroponics Vs Soil

With hydroponics currently at new heights in the gardening world, the question facing gardeners today is Hydroponics or Soil? This question is also becoming an age old debate of battling sides fighting to prove the other wrong. I won’t be taking a stance on the issue. Instead I’ll explain the key differences among hydroponic and soil gardening as well as advantages and disadvantages for both techniques.

The fundamental difference between hydroponic and soil gardening is the growing medium. In a soil-based garden, that medium is the soil itself. In hydroponics, the medium is a nutrient-enriched liquid solution. Each method has advantages and disadvantages. For either to produce healthy plants, the basic nutrients must be made available to the plant roots.

Hydroponics commercially efficient and time-saving, is not practical for the amateur. There are too many risky factors involved- most importantly, it is easy to have an unbalanced nutrient solution, which will stunt the growth of the plants. Our nutrient solution lacked enough of the important nutrients nitrogen and potassium, as we could tell by the appearance of our plants. The nitrogen deficiency caused the plants to have abnormally light-colored leaves and stunted growth. The fact that our hydroponics plants did not grow very much is explained here. 

The potassium deficiency caused our plants to have stunted growth and slightly withered leaves. Although the hydroponics clearly fared worse than the soil plants, the soil plants still were not productive in this experiment. This was probably caused by the fact that the fluorescent gro-light was not as close to the plants as to simulate sunlight, and therefore the plants did not grow as fast as we had hoped. However, the soil plants did grow steadily if slowly, and were more healthy than the hydroponics plants in the end.

Advantage of Hydroponics

An advantage hydroponics gardening compared to soil gardening is the control the gardener has over the quantity and content of the nutrients. The solutions may be tailored to specific plant needs and plants needn't compete with other plants or weeds for nutrients as happens in soil gardening. The risk of damage or disease from soil-borne pests is greatly reduced, due to the lessened exposure to these pests.

Advantage of Soil

Soil has the advantage of the organic factor. Although all nutrients need to be in an inert form for roots to access and process, the nutrients may be in organic form when added to soil. In hydroponics, the nutrients must already be inert and immediately soluble, and so are synthetic. The organic nature of soil gardening encourages the development of ecosystems that include bacteria, fungi, worms, insects and birds, all of which contribute to the natural renewal of nutrients in soil. The soil gardener need only assist in nutrient renewal, rather than control it. No such sustaining ecosystem exists within hydroponic gardening methods.

Reference: http://www.ehow.com/
                 http://hubpages.com/

10 gardening tips for beginners

Anyone new to gardening could be excused for thinking the process is rather daunting, especially if they read some of the books on the market. Often these books are so loaded with technical jargon that the average person can't understand it. One exception is Yates Garden Guide which should have a place in every home. Gardening expert Colin Campbell has put together this list of 10 basic gardening rules which will help to make gardening a satisfying leisure activity.

1. Know your soil type

Get to know your soil type. When you know this, you will know how to manage it and get the best out of it. There are three basic types - sand, silt and clay - and if you are not sure about what you have, ask your neighbours if there isn't a nursery or garden centre nearby.

2. Use organic fertiliser

Use plenty of organic matter, regardless of the soil type. Organic fertilisers, compost and mulching materials enhance the nutrient level and encourage life-giving soil microbes and worms. The more you can use, the better.

3. Follow fertiliser directions

Fertilisers should always be used in accordance with manufacturers' directions

4. Keep soil mulched

Keep the soil well-mulched all year. Mulching helps to minimise weed growth and this is important because weeds compete with plants for moisture and nutrients. Mulching also modifies soil temperature - in warm weather it helps to keep it cool and in cold weather it keeps the soil warm. A thick layer will also reduce moisture loss through evaporation. It doesn't really matter what type of mulch is used - it comes down to personal choice. I prefer sugarcane mulch, but others opt for lucerne mulch, straw, tea-tree or bark mulch.

5. Plant similar species together

Plant appropriate species together, such as those that require the same soil, light and nutrients.

6. Pests and diseases

Learn to identify pests and diseases so that appropriate action can be taken, ensuring that you use the “softest'' option available. Spraying with chemicals may be necessary as a last resort.

7. Pruning

Prune shrubs early rather than leaving them until they get too large to trim back.
Australian native species, in particular, should be pruned back by about one-third from their first year in your garden.

8. Flowering plants

Remove spent flowers from flowering plants every few days as this will prolong the flowering season. This is especially important in the case of flowering annuals but it also applies to many flowering shrubs.

9. Watering

For plants that require a regular supply of water, water deeply every few days rather than a shallow watering every day. A long, deep watering will encourage the plant roots to go deeper in response to the deeper moisture level.

10. Composting

Make your own compost. Every day there are kitchen scraps, so instead of throwing them away in the garbage bin, start a compost heap.  The same applies to prunings - cut these into small pieces and place in the compost heap or bin.

Source of Article: www.couriermail.com.au

Growing the GERBERA (Gerbera jamesonii)

The meanings of gerbera flowers stem from those attributed to the general daisy family. These meanings include innocence and purity. Daisies are also a classic symbol of beauty however, the gerbera variety holds an added meaning of cheerfulness, which stems from the assortment of colors available.

Some Interesting Facts About Gerberas

• Having a long vase life, Gerbera flowers are widely used in the Cut Flower Industry. Gerberas are great flowers for adding color to any room or garden.
• Gerberas are also referred to as Gerbera Daisies, daisy being a general name for all species in the family Asteraceae, to which Gerberas belong.
• Gerbera flowers often measure 7 inches (17.8 cm) across.
• Gerberas come in a wide range of colors - from light to dark yellow, orange, pink, brilliant scarlet, deep red, and many more.
• Gerberas can be used in landscapes as bedding plants for borders and flower beds or as Cut Flowers for table arrangements.
• Gerberas are native to Transvaal, South Africa.
• Hybrid Gerbera varieties cloned through tissue culture are uniform, and have long-lasting flowers with thick peduncles that are not light sensitive; hence, flowers remain open in the dark, lending themselves to indoor use in flower arrangements.

Some species of Gerberas, such as Gerbera anandria, Gerbera aurantiaca and Gerbera jamesonii bear the suffix Daisy - Ghostly Daisy, Hilton Daisy, Barberton Daisy, Gerbera Daisy and Transvaal Daisy

About Gerbera Flower

Gerberas are perennial flowering plants featuring a large capitulum with striking, 2-lipped ray florets. The capitulum on the Gerberas has the appearance of a single flower, but is actually a cluster of hundreds of individual flowers. The morphology of the flowers varies depending on their position in the capitulum of the Gerberas.

Various Forms of Gerbera Flowers

Gerberas come in various forms. Broadly, they can be put into four groups-

• Single Flowers - These Gerberas have a row of non-overlapping petals (ray florets) with a green center (disc florets). These are the most common gerberas available in the market.
• Double or duplex - These Gerberas have a double row of overlapping petals with a green, black, or dark red eye.
• Crested doubles - These doubles contain two rows of overlapping petals with one or more inner rows of shorter petals with a green, black, or dark red eye.
• Full crested doubles - These have solid overlapping rows of petals with an inner row diminishing in size, covering the eye entirely.

Varieties                                                                                                                 
Sun Set, Nevada, Sangna, Lynx, Macho, YCD-1, YCD-2, Vino, Venturi. etc. are the popular varieties of gerbera.

                 

Soil and Climate                                                                                                   
Sandy loam with good drainage capacity having a pH of 5.5 – 6.0 is more suitable. Temperature should be within the range of 25° C - 27°C to avoid bud abortion/scorching.  It is better to raise the crop under poly/green house.

Media preparation

Season                                                                                                                   
The crop can be cultivated throughout the year.

GROWING CONDITIONS

Gerbera plants grown in locations with insufficient light will not bloom well. If you intend to grow a Gerbera indoors, give the plant as much direct sunlight as you can. Six hours of direct sunlight usually suffice in this case and can be achieved by placing it on a sunny windowsill. Do not try to grow it under office lights, since fluorescent lighting, even if placed within close proximity, don't seem to give encouraging results.

The Gerbera loves to suntan but it must still be protected from the afternoon sun. The afternoon sun here will very likely fry your plants, hence Gerbera is rarely grown outdoors. They grow pretty fine as potted plants under semi-shaded conditions, like under a shaded verandah or patio, if placed outdoors. Slowly acclimatise your newly bought plants before exposing them to full sun outside.

Gerbera thrive well in well-drained soil. The peaty substrate in which a newly bought Gerbera is grown is not suitable for growing the plant on the long term under local conditions. After the first flowers have wilted, grab the opportunity to change the substrate to one which river sand is added to improve its drainage. Never over water the plant and let the soil dry out a little before watering it again. This is especially important if the plant is grown indoors.

Feed your plants regularly to encourage flowering. You can use a water-soluble fertilizer for flowering plants - those with a high phosphorous (P) and potassium (K) ratio.

Remove spent blooms to encourage further flowering. Remove flower stalks of wilted blooms at the base of the crown, and at the same time remove yellowing leaves, if any, to reduce the possibility of fungus infection.

Above: These are the common colours and forms that are commonly available on sale in local nurseries.

PEST & DISEASES

The Gerbera is extremely prone to red spider mites and one of the most obvious symptoms is distorted young leaves with a puckered appearance. In serious infestations, you can literally see spider webs on the plants and you can also rub off some "red dust" from the undersides of the leaves. It is highly recommended to discard the plant once an infestation sets in. Red spider mites can spread really fast before you can take any action. Miticides are often extremely toxic and are not recommended for use in an environment where there is human traffic. Besides, a bottle of miticide will cost more than a new pot of Gerbera! Prevention is better than cure - mist your plants regularly to increase the humidity which may deter red spider mites.

Other pests include aphids which like to cluster around young growth and whiteflies which are tiny fly-like insects that hide on the underside of leaves. Minor infestations can be treated with thorough washing using a water spray. Alternatively, you can also eradicate these pests by using pyrethrum-based insecticides or soaps. These insects suck sap from the plant, weakening it and are capable of spreading viral diseases from an infected plant to a nearby healthy plant.

Crown and root rots are common due to over-watering and burying the crown in the growing medium.

Above: Remember to check the undersides of both young and mature leaves to ensure they are pest-free before buying! Do the same for routine checks at home.

PROPAGATION

Plants can be grown from seeds but it will be an exceedingly tedious process. Germination can be tricky since the seeds do not remain viable for long. Give up if you notice no seedlings emerging for more than a fortnight.

A faster and easier method of propagating Gerbera is via division of the crown. The Gerbera will produce numerous suckers, which can be split into many individual plants. In the process of dividing the plant, try to give each sucker some roots and be as careful as you can so as to minimize any damage to the plant. You may find it necessary to cover the divided plants with a clear plastic bag to reduce moisture loss.

Propagation and Planting 

                                                                                
It can be propagated through suckers and tissue culture plantlets. Raised beds with 4 ft. width and 40 cm height are formed at an interval of 60 cm and planting is done at a spacing of 30 x 30 cm.

   Greenhouse cultivation of gerbera
              

Before starting gerbera cultivation, disinfection of the soil is absolutely necessary to minimize the infestation of soil borne pathogens like Phytophthora, Fusarium and Pythium which could otherwise destroy the crop completely. The beds should be drenched / fumigated with 2% formaldehyde (100 ml formalin in 5 litres of water / m2 area) or methyl bromide (70 g / m2) and then covered with a plastic sheet for a minimum period of 2 to 3 days.  The beds should be subsequently watered thoroughly to drain the chemicals before planting. Well developed tissue culture plants having 4 -6 leaves can be planted firmly without burying the crown.

Irrigation
Drip irrigation is done once in 2 – 3 days @ 3.75 litre/drip/plant for 15 – 20 minutes. Average water requirement is about 500 – 700 ml/day/plant.

Drip irrigation for gerbera

 Manuring Basal                                                                                                                       
Neem cake 2.5 ton/ha
P  - 400 g/100 sq.ft.
MgSo4 - 0.5 kg/100 sq.ft.

Top dressing
Calcium Ammonium Nitrate and Muriate of Potash at the ratio of 5:3 is mixed and applied at 2.5 g/plant/month.

Aftercultivation
1. Hand weeding is done whenever necessary.
2. Remove the flower buds up to 2 months and then allow for flowering
3. Rake the soil once in 15 days to facilitate easy absorption of water, fertilizer and to provide air to the roots.
4. Remove older leaves to facilitate new leaf growth and good sanitation.

Plant Protection
1. To control Nematode - Carbofuran 7-8 kg/ha is applied at the time of planting.
2. Leaf spot - Carbendazim 2 g/lit or Mancozeb 2 g/lit is sprayed alternatively.
3. Leaf miner - Chlorpyriphos 20 EC 2 ml/lit.
4. Glasshouse whitefly   - Monocrotophos 36 WSC 2 ml/lit or Neem oil 3 ml/lit.

Season of flowering and Harvesting                                                              
When flowers completely open, harvesting is done. Flower stalk is soaked in Sodium hypochloride solution (5-7 ml/lit of water) for 4-5 hours to improve vase life.    

Gerbera ready for harvest

Post harvest handling
Harvesting is done when outer 2-3 rows of disc florets are perpendicular to the stalk. The heel for the stalk should be cut about 2-3 cm above the base and kept in fresh chlorinated water. Flowers should be graded and sorted out in uniform batches. Flowers packed individually in poly puches and then put in to carton boxes in two layers.

Bushiness
An abnormality characterized by numerous leaves, short petioles and small laminae, which gives some cultivars of gerbera a bushy appearance known as bushiness. Nodes are not clearly distinguished and no internode elongation is seen.

Stem break
It is a common post harvest disorder in cut gerberas. This is mainly caused by water imbalances. It could be ethylene controlled and associated with early senescence caused by water stress.

Yellowing and purple margin
Nitrogen deficiency causes yellowing and early senescence of leaves. Phosphorus deficiency causes pale yellow colour with purple margin. Increase in levels of nitrogen and phosphorus were found to promote development of suckers and improve flowering in gerbera.

Grading                                                                                                                  
Based on stem length and diameter, flowers are graded in A, B, C and D.

Yield                                                                                                                        
The crop yields 2 stems / plant / month.  Harvest starts from 3rd month of planting and continued up to two years. Under open condition, 130 -160 flowers / m2 / year and under greenhouse condition, 175 - 200 flowers /m2 / year can be obtained.

Source
1. http://www.starfiber.com/image.php?id=182&type=Gerbera%20Substrate
2. http://image59.webshots.com/759/5/14/95/2838514950026222415OIwUdq_fs.jpg

3. http://agritech.tnau.ac.in/

4. http://www.theflowerexpert.com/

5. http://www.greenculturesg.com/