New approaches are needed for another Green Revolution.

Twenty-first century agriculture needs low-input advances like the System of Rice Intensification, says Norman Uphoff.
According to the principle of diminishing returns, continuing to producesomething in the same way, with the same inputs and technology, usually becomes less productive over time. This appears to apply to agriculture‘s ‘Green Revolution, as yield improvement has slowed in recent decades, no longer lowering the real price of basic foods as it did in its first three decades. Diminishing returns may not be a universal principle — but agronomists should take it seriously.

Although there is talk of another Green Revolution, the approaches beingproposed are essentially more of the same. This technological strategy for raising production is running into major economic and environmentalconstraints, however. The costs of fossil fuel-derived inputs keep rising, while impaired soil health and degraded water quality are growing concerns. 

Paradigm shift
Fortunately, there are agroecological options available, such as conservation agriculture and the System of Rice Intensification (SRI), which differ fromhigh-tech and input-dependent production systems. 

Agroecological management systems capitalise on the potential for more productive and robust crops from existing plant genomes and on their intricate, symbiotic associations with other organisms, particularly microorganisms — in what is now becoming better understood as the plant-soil microbiome. [1]

A paradigm shift  from regarding non-crop organisms as mostly pests or pathogens and treating plants as carbon-based machines, to understanding networks and webs of symbiotic relationships  can help us ‘rebiologise‘ agriculture and adopt alternative methods that are better suited to current and foreseeable challenges.

More for less
By changing how plants, soil, water and nutrients are managed, SRI practices grow larger, betterfunctioning root systems that interact with a bigger and more diverse soil biota, also promoted by these same practices. 

Compared with standard crop management methods, SRI practices raise yields usually by 50100 per cent and sometimes more. These gains are achieved with less water, greatly reduced seed rates, less or no inorganic fertilisers, and often even with less labour once the methods have been mastered. [2,3,4,5]

Other benefits include greater resistance to drought and water stress, storm damage, and to pests and diseases  pressures on crop production that willcertainly increase with climate change. 

Record yields
In 2011, a farmer in the Bihar state of India who had adopted SRI reportedlysurpassed the world-record paddy yield previously set in China. This stirred controversy — but having analysed how this yield of 22.4 tonnes per hectarewas achieved and measured, with data from the Indian government’s Directorate of Rice Development, I am satisfied that the farmer achieved this yield. [6

Agriculture in the twenty-first century will need to change considerably from the technologies and paradigms that evolved in the preceding century.

Norman Uphoff, Cornell University

This record yield is less significant, however, than two other statistics. First, the rice area under SRI methods in Bihar has risen from 30 hectares in 2007 to more than 300,000 in 2012, a 10,000-fold increase in five years. Second, even without all of the farmers following SRI recommendations fully, their average SRI yield in 2012 was calculated by government technicians as 8.08tonnes per hectare — three times the usual yield in Bihar. 

These figures and differences are so large that SRI can no longer be ignored by sceptics and critics. They come from farmers’ fields and from officialreports, not from experimental stations and partisan sources.

Winning the argument
Published criticisms of SRI have ebbed since 2006, with the benefits from SRInow demonstrated in more than 50 countries. But initial opinions die hard,even as governments in Cambodia, China, India, Indonesia and Vietnam, where two-thirds of the world’s rice is produced, have begun supporting the spread of SRI, based on farmers’ experiences and scientific evidence.

It is time to put the ‘controversy’ over SRI behind us. And it is time to begin learning more about how these new ideas and methods can help get more from less. 

For instance, we have begun to learn how microorganisms that livemutualistically within plant organs and tissues, and even cells, bring benefitssuch as increasing the chlorophyll levels in leaves and protecting against pathogens in roots. [7,8]

Learning from farmers
Importantly, experience with SRI in countries such as Burundi, Cuba, India,Madagascar, Nepal and Rwanda is helping us to better understand how to learn from and with farmers. Some very informative and impressive videos are now available where farmers themselves explain their good experienceswith these new methods. [9]

Farmers have been adapting and improving the methods to which they were introduced, and they have been disseminating their knowledge and experience to other farmers — changing the usual linear ‘from lab to land’model of developing and transmitting innovations.

SRI is one of the few innovations where scientists have had difficulty replicating farmers’ results in their on-station trials  usually the situation is reversed. Farmers may be getting higher yields than the researchers dobecause, more often than not, farmers’ soils have less impairment fromfertiliser and agrochemical applications than on experiment plots. 

Changing times need changing practices
Agriculture in the twenty-first century will need to change considerably from the technologies and paradigms that evolved in the preceding century.Conditions are becoming increasingly different from the past. The need to change should not be taken as derogation of past research and practices. 
Both scientists and farmers need to evaluate alternative methods that could be more suited to our new realities. Proponents of agroecological alternatives welcome systematic evaluation that is conducted rigorously, with open minds and with farmers’ participation. 

Norman Uphoff is professor of government and international agriculture at Cornell University, United States, and senior advisor to the SRI-Rice Centerthere. For 15 years he has been trying to get SRI principles and practices better known, evaluated and taken up where beneficial for farmers, consumers and the environment. You can contact him at

This article is part of the Spotlight on Producing food sustainably.



[1] Nature  doi: 10.1038/501S18a (2013)
[2SRI International Network and Resources Center (SRI-Rice) website
[3] Sato, S. and Uphoff, N. Raising factor productivity in irrigated rice production: Opportunities with the System of Rice Intensification. CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources (Commonwealth Agricultural Bureau International, UK2007)
[4] Experimental Agriculture doi10.1017/S0014479707005340 (2007)
[5] Agriculture and Food Security doi: 10.1186/2048-7010-1-18 (2012)
[6] Diwakar, M.C. et al. Report on the world record SRI yield in kharif season 2011 in Nalanda district, Bihar state, India (Agriculture Today, New Delhi,July 2012)
[7] Applied and Environmental Microbiology doi: 10.1128/AEM.71.11.7271-7278.2005 (2005)
[8] Proteomics doi: 10.1002/pmic.200900694 (2010)
[9] Farmers from Burundi, Cuba, India, Madagascar, Nepal and Rwanda speak for themselves in videos about their experiences with SRI: Flooded Cellar Productions,

Fukushima has ‘new leak of radioactive water which may have entered the Pacific Ocean’

  • At least 430 litres spilled when workers overfilled a storage tank 

Japan’s crippled Fukushima nuclear plant has a new leak of radioactive water which may have entered the Pacific Ocean. 

The operator of the meltdown-plagued plant says at least 430 litres spilled when workers overfilled a storage tank that lacked a gauge that could have warned them of the danger.

The amount is tiny compared to the untold thousands of tons of radioactive water that have leaked, much of it into the Pacific Ocean, since a massive earthquake and tsunami wrecked the plant in 2011. 

Concerning: Japan's crippled Fukushima nuclear plant has a new leak of radioactive water which may have entered the Pacific Ocean

Concerning: Japan’s crippled Fukushima nuclear plant has a new leak of radioactive water which may have entered the Pacific Ocean

Danger: The operator of the meltdown-plagued plant says at least 430 litres spilled when workers overfilled a storage tank that lacked a gauge that could have warned them of the danger

But the error is one of many the operator has committed as it struggles to manage a seemingly endless, tainted flow.

Plant operator Tokyo Electric Power Co. said this morning that workers detected the water spilling from the top of one large tank when they were patrolling the site the night before. 

The tank is one of about 1,000 erected on the grounds around the plant to hold water used to cool the melted nuclear fuel in the broken reactors. 

Wrecked: This aerial view shows the Fukushima Daiichi Nuclear Power Station 2011

Wrecked: This aerial view shows the Fukushima Daiichi Nuclear Power Station in 2011.

TEPCO said the water spilled out of a concrete barrier surrounding the tank and believed that most of it reached the sea via a ditch next to the river. 

The new leak is sure to add to public concern and criticism of TEPCO and the government for their handling of the nuclear crisis. 

In August, the utility reported a 300-ton leak from another storage tank, one of a string of leaks in recent months. 

That came after the utility acknowledged that contaminated groundwater was seeping into ocean at a rate of 300 tons a day. 

TEPCO spokesman Masayuki Ono told an urgent news conference Thursday that the overflow occurred at a tank without a water gauge and standing on an unlevel ground, slightly tilting toward the sea. 

The tank was already nearly full, but workers pumped in more contaminated water into it to maximize capacity as the plant was facing storage crunch. 

Dangerous: Workers spray water to cool down the spent nuclear fuel in the fourth reactor building at Fukushima in 2011

Dangerous: Workers spray water to cool down the spent nuclear fuel in the fourth reactor building at Fukushima in 2011.

Experts have faulted TEPCO for sloppiness in its handling of the water management, including insufficient tank inspection records, lack of water gauges, as well as connecting hoses lying directly on the grass-covered ground. 

Until recently, only one worker was assigned to 500 tanks in a two-hour patrol. 

In recent meetings, regulators criticized TEPCO for even lacking basic skills to properly measure radioactivity in contaminated areas, and taking too long to find causes in case of problems.

They also have criticized the one-foot (30-centimetre) high protective barriers around the tanks as being too low. 

The government has said it will spend $470 billion to build an underground ‘ice wall’ around the reactor and turbine buildings to block groundwater inflows and prevent potential leaks from spreading. 

It is also funding more advanced water treatment equipment to make the contaminated water clean enough to be eventually released into the sea. 

People wear face masks as they visit the cemetery at the tsunami destroyed coastal area of the evacuated town of Namie

People wear face masks as they visit the cemetery at the tsunami destroyed coastal area of the evacuated town of Namie.

The level of radiation is seen near the abandoned civic centre at the tsunami destroyed coastal area of the evacuated town of Namie

The level of radiation is seen near the abandoned civic centre at the tsunami destroyed coastal area of the evacuated town of Namie

The TomTato: Plant which produces both potatoes and tomatoes launched in UK.

Plant can grow sweet cherry tomatoes while producing white potatoes.

A plant which produces both potatoes and tomatoes, described as a “veg plot in a pot”, has been launched in the UK.

The TomTato can grow more than 500 sweet cherry tomatoes while producing white potatoes.

Horticultural mail order company Thompson & Morgan, which is selling the plants for £14.99 each, said the hybrid plants were individually hand-crafted and not a product of genetic engineering.

Grafted potato-tomato plants have already been produced in the UK, but Thompson & Morgan says this is the first time they have been successfully produced commercially.

The company says the tomatoes are far sweeter than those available in supermarkets.

Paul Hansord, horticultural director at the company, said he first had the idea for the plant 15 years ago in the US, when he visited a garden where someone had planted a potato under a tomato as a joke.

He said: “The TomTato has been trialled for several years and the end result is far superior than anything I could have hoped for, trusses full of tomatoes which have a flavour that makes shop tomatoes inedible, as well as, a good hearty crop of potatoes for late in the season.

“It has been very difficult to achieve the TomTato because the tomato stem and the potato stem have to be the same thickness for the graft to work, it is a very highly skilled operation.

“We have seen similar products, however on closer inspection the potato is planted in a pot with a tomato planted in the same pot – our plant is one plant and produces no potato foliage.”

The plants can be grown either outside or inside, as long as they are in a large pot or bag.

A similar product, dubbed the “Potato Tom”, was launched in garden centres in New Zealand this week.

Chamomile Benefits: Growing Your Own Medicine.

Chamomile marks many people’s first venture into herbalism, and it’s usually because they have problems sleeping. The value of the plant as a mild relaxant has made it a popular choice in prepared teas found in nearly every grocery store. But chamomile benefits don’t stop there—this flowering jewel is able to provide an array of health perks. What’s more, growing chamomile at home is quite an easy task.

There are several varieties of chamomile, all members of the Asteraceae family. Most popular in herb gardens and commercially prepared teas, however, is German chamomile (Matricaria recutita), also sometimes called Hungarian chamomile, wild chamomile, or scented mayweed.

This plant is an annual (dies off in the cold season) and grows in small bushes to be about 20 to 30 inches high. It has smooth stems with long, narrow leaves, and little white flowers that used in herbal preparations. These small flowers resemble small daisies, with yellow centers and a strong, pleasant scent.

Brief History of Chamomile

The first recorded use of chamomile occurred in Ancient Egypt. The plant was held in high reverence for its ability to cure ‘Ague’, what is very much like an acute fever. Because an acute fever can be relatively common, extremely uncomfortable, and usually just goes away with time, a cure for the illness probably made chamomile quite popular.

The word chamomile comes from the Greek Chamomaela, which translates to “ground apple”. In Spain, it is still called the “Little Apple”. These titles likely come from its scent.

Over the years, the herb has been used for flavorings, incense, beverages, and for treating a variety of health ailments.

Chamomile Benefits: Healing Uses of Chamomile

Perhaps the most widely known use of chamomile is in its benefits as a mild relaxant or sedative. It has been used in this manner for centuries and can be found in grocery store aisles under names like “Sleepy Time Tea” for precisely this reason. Taken 30 to 45 minutes before bed, chamomile can help you relax and prepare for a restful slumber.

But despite its popularity as a soothing relaxant, chamomile benefits don’t end there.

Much of Chamomile’s ability to heal is due to phenolics within the plant. Phenolics represent a large family of compounds including flavonoids, quinones, phenolic acids, and other antioxidant compounds; they provide a range of health benefits, including protection against stress and healing cells. But what else is Chamomile good for?

Researchers with the American Chemical Society found that chamomile’s phenolics have antibacterial activity, suggesting it could be useful in boosting the immune system and fighting illnesses like the common cold. In addition, study subjects who drank the tea on a regular basis had elevated levels of glycine, a protein known for relieving muscle spasms, which could explain it’s relaxing qualities.

Chamomile has also been shown to have antimicrobial, antioxidant, antiplatelet, anti-inflammatory, antispasmodic and antimutagenic properties, according to researchers with the USDA Human Nutrition Research Center.

While science is slowly unlocking all of Chamomile’s benefits in the lab, there is no question that individuals throughout history have experienced the benefits even without the science to back it up.

Through tradition and folk healing over the years, chamomile has also been used to treat:

·         Anxiety

·         Insomnia

·         Digestive problems like nausea and bloating

·         Menstrual cramps

·         Migraines

·         Burns and scrapes

·         Rashes like eczema

·         Mouth sores and gum disease

Even better news? You can easily grow your own chamomile to experience chamomile benefits.

Growing and Harvesting Your Own Chamomile

Like growing oregano or growing parsley, growing chamomile is fairly easy with some basic tips. Because there are several varieties of the herb we know as chamomile, these tips are specifically geared towards growing the variety known as German chamomile.

The plant is best grown from seed, rather than potted as an already partially grown plant. Seeds can be started indoors and moved outside after fear of the last frost has passed. Otherwise you can direct sow in the soil in late spring.

Chamomile seeds need sunlight to germinate. This means you don’t want to completely bury them in the dirt or plant them in a heavily shaded area. Instead, scatter the seeds and lightly mix with the top soil. As for water, the plant doesn’t need to be overwatered, but it shouldn’t be completely dry between soakings either.

When the flowers on your chamomile plant begin opening up, harvest them. The more you harvest, the more that will grow. You should be harvesting every few days. Cut the stem just above a lead node, or where a leaf joins the stem, then remove the flower and place in a basket or on a drying rack.

Move the flowers around from time to time to ensure they are drying completely. Once they are thoroughly dried, you can store the flowers in a glass jar in your cabinet. They will keep for several months as long as they are kept dry and out of the sun.

Using Medicinal Chamomile

There are many applications for dried chamomile including tinctures and essential oils though the easiest and most often used is an infusion or tea. For stomach ailments, muscle spasms, and help in falling asleep, use about one tablespoon of dried herb per cup of water. Pour boiling water over the herbs and allow to steep for about 5 minutes. Strain and enjoy.

If you want to use chamomile topically– on rashes, cuts and other skin ailments, for instance—you can create a compress by simply making a more concentrated “tea”. Once the tea has cooled, dip a cloth in it, wring it out and apply to the affected area. You can similarly use this tea as a facial or hair rinse.

From your skin to your stomach or even a stressed mind, chamomile is a master-soother, and one you can easily add to your healing herb garden. Experience chamomile benefits today, and share your thoughts with others!


Scientists Discover That Plants Communicate via Symbiotic Root Fungi.

Human arrogance has always assumed we are evolutionarily superior to plants, but it appears that modern science may be the antidote to this egocentric view.

Researchers in the UK have discovered an extensive underground network connecting plants by their roots, serving as a complex interplant communication system… a “plant Internet,” if you will.

One organism is responsible for this amazing biochemical highway: a type of fungus called mycorrhizae. Researchers from the University of Aberdeen devised a clever experiment to isolate the effects of these extensive underground networks. They grew sets of broad bean plants, allowing some to develop mycorrhizal nets, but preventing them in others.

They also eliminated the plants’ normal through-the-air communication by covering the plants with bags. Then they infested some of the plants with aphids. The results were remarkable.1

Most people have no idea how important mycorrhizal fungi are for plant growth. They really are one of the keys to successful growth of plants. In my own garden, I just purchased a 15 gallon vortex compost brewer in which I grow these fungi in large quantities for my ornamental and edible landscape.

Underground Communications Network Thwarts Infestation

The aphid-infested plants were able to signal the other plants, connected through mycorrhizae, of an imminent attack—giving them a “heads up” and affording them time to mount their own chemical defenses in order to prevent infestation.

In this case, the alerted bean plants deployed aphid-repelling chemicals and other chemicals that attract wasps, which are aphids’ natural predators. The bean plants that were not connected received no such warning and became easy prey for the pesky insects.

This study is not the first to discover plant communication along mycorrhizal networks. A 2012 article in the Journal of Chemical Ecology describes mycorrhizae-induced resistance as part of plants’ systemic “immune response,” protecting them from pathogens, herbivores, and parasitic plants.2

And in 2010, Song et al published a report about the interplant communication of tomato plants, in which they wrote:3

CMNs [common mycorrhizal networks] may function as a plant-plant underground communication conduit whereby disease resistance and induced defense signals can be transferred between the healthy and pathogen-infected neighboring plants, suggesting that plants can ‘eavesdrop’ on defense signals from the pathogen-challenged neighbors through CMNs to activate defenses before being attacked themselves.”

Miles of Mycorrhizae in One Thimbleful of Soil

The name mycorrhiza literally means fungus-root.4 These fungi form a symbiotic relationship with the plant, colonizing the roots and sending extremely fine filaments far out into the soil that act as root extensions. Not only do these networks sound the alarm about invaders, but the filaments are more effective in nutrient and water absorption than the plant roots themselves—mycorrhizae increase the nutrient absorption of the plant 100 to 1,000 times.5

In one thimbleful of healthy soil, you can find several MILES of fungal filaments, all releasing powerful enzymes that help dissolve tightly bound soil nutrients, such as organic nitrogen, phosphorus, and iron. The networks can be enormous—one was found weaving its way through an entire Canadian forest, with each tree connected to dozens of others over distances of 30 meters.

These fungi have been fundamental to plant growth for 460 million years. Even more interesting, mycorrhizae can even connect plants of different species, perhaps allowing interspecies communication.6

More than 90 percent of plant species have these naturally-occurring symbiotic relationships with mycorrhizae, but in order for these CMNs to exist, the soil must be undisturbed. Erosion, tillage, cultivation, compaction, and other human activities destroy these beneficial fungi, and they are slow to colonize once disrupted. Therefore, intensively farmed plants don’t develop mycorrhizae and are typically less healthy, as a result.

Making Farming More Eco-friendly

The discovery that fungi may be providing plants with an early warning system has profound implications for how we grow our food. We may be able to arrange for “sacrificial plants” specifically designed for pest infestation so that the network can warn, and thereby arm, the rest of the crop.7 In order to feed the world’s increasing population, farmers must return to working WITH nature, instead of against it.

Raising food is really about building soil, and modern agricultural practices are degrading million year-old topsoils, without any attention to rebuilding them. Spreading toxic chemicals, monoculture, using genetically engineered seed, generating toxic runoff and destroying biodiversity are all examples of working against nature. Mycorrhizae not only assist the plants in staying vital and healthy, but they enrich the soil and improve its productivity, add organic matter, protect crops from drought, and increase the overall balance and resilience of the ecosystem.

Many fungi are as beneficial to people as they are to plants. Mushrooms are powerhouses when it comes to nutrition, with high-quality protein, enzymes, antioxidants, and B vitamins.

About 100 species of mushrooms are being studied for their health-promoting benefits, and about a half dozen really stand out for their ability to deliver a tremendous boost to your immune system. Studies have shown that mushrooms can combat infectious disease (including smallpox), inflammation, cancer and even help regenerate nerves. A compound from the Coriolus versicolor mushroom was recently found to significantly slow hemangiosarcoma in dogs, a deadly cancer.

Mushrooms are also nature’s recycling system, according to mycologist Paul Stamets. Various mushrooms can break down the toxins in nerve gas and clean up petroleum waste.

Mushrooms and their parent mycelium break down rocks and organic matter, turning them into soil. The mycelia, just like the mycorrhizal network, occupy landscapes in a web-like mat that, in some cases, stretches across thousands of acres. Stamets describes this intricate, branching network as “the Earth’s Internet” because it functions as a complex communication highway. There is also evidence mycelia are “sentient” beings that demonstrate the ability to learn. Speaking of cool and calculating…

Now that the secret’s out, companies are beginning to offer mycorrhizae to home gardeners and commercial farmers alike. If you have an organic garden, adding a sprinkle of mycorrhizae, along with good organic fertilizer, is a great way to ensure your garden will be the envy of your neighborhood.

For tips on how to use this in your garden at home, I recommend watching the “smiling gardener” video above. It’s important to remember that mycorrhizae must be applied to the roots of your plants. If you just sprinkle the granules onto the soil and they don’t make contact with the roots within about 48 hours, they’ll die and your efforts will be wasted. So, you can make a “tea” out of it and apply it as a spray, or you can rub a small amount directly onto the roots of your transplant. But it has to come into direct contact with some part of the root.

The only vegetable garden occupants that will not benefit from mycorrhizae are your brassicas (members of the mustard family, such as cabbage, broccoli, cauliflower, turnips, radishes, etc.), because they don’t allow this colonization.8 But all your other veggies will love you for it. The benefits will be even greater in a year or two, after the mycorrhizae really have a chance to grow and spread.

Also, remember to refrain from tilling and manipulating the soil. This isn’t necessary and is actually counterproductive, as it disrupts helpful organisms and crushes their tunnels.9 Just topdress your garden with a blend of good compost and topsoil each year, and leave the bed alone, which will allow those beneficial organisms to grow and flourish, undisturbed.

When you practice ecofriendly gardening, you greatly lessen your need for fertilizers and herbicides, reduce your need for watering, and reduce runoff and erosion, while giving your garden plants the best nutrition and resistance to disease. And best of all, a healthy veggie garden means more nutrients passed along to you!


Staining Science: Capillary Action of Dyed Water in Plants.

A wondrous, watery activity from Science Buddies

Have you ever heard someone say, “That plant is thirsty,” or “Give that plant a drink of water.”? We know that all plants need water to survive, even bouquets of cut flowers and plants living in deserts. But have you ever thought about how water moves within the plant? In this activity, you’ll put carnations in dyed water to figure out where the water goes. Where do you think the dyed water will travel, and what will this tell you about how the water moves in the cut flowers?

Plants use water to keep their roots, stems, leaves and flowers healthy as well as prevent them from drying and wilting. The water is also used to carry dissolved nutrients throughout the plant.

Most of the time, plants get their water from the ground. This means it has to transport the water from its roots up and throughout the rest of the plant. How does it do this? Water moves through the plant by means of capillary action. Capillary action occurs when the forces binding a liquid together (cohesion and surface tension) and the forces attracting that bound liquid to another surface (adhesion) are greater than the force of gravity. Through these binding and surface forces, the plant’s stem basically sucks up water—almost like drinking through a straw!

A simple way of observing capillary action is to take a teaspoon of water and gently pour it in a pool on a countertop. You’ll notice that the water stays together in the pool, rather than flattening out across the countertop. (This happens because of cohesion and surface tension.) Now gently dip the corner of a paper towel in the pool of water. The water adheres to the paper and “climbs” up the paper towel. This is called capillary action.

•     Water
•     Measuring cup
•     Glass cup or vase
•     Blue or red food color
•     Several white carnations (at least three). Tip: Fresher flowers work better than older ones
•     Knife
•     Camera (optional)

•     Measure a half cup of water and pour it into the glass or vase.
•     Add 20 drops of food color to the water in the glass.
•     With the help of an adult, use a knife to cut the bottom stem tips of several (at least three) white carnations at a 45-degree angle. Tip: Be sure not to use scissors, they will crush the stems, reducing their ability to absorb water. Also, shorter stems work better than longer ones.
•     Place the carnations in the dyed water. As you do this, use the stems of the carnations to stir the water until the dye has fully dissolved.

•     Observe the flowers immediately after you put them in the water. If you have a camera, take a picture of the flowers.
•     Observe the flowers two, four, 24, 48 and 72 hours after you put them in the dyed water. Be sure to also observe their stems, especially the bumps where the leaves branch from the stem and it is lighter green (it may be easier to see the dye here). If you have a camera, take pictures of the flowers and stems at these time points.
•     How did the flowers look after two hours? What about after four, 24, 48 and 72 hours? How did their appearance change over this time period?
•     What does the flowers’ change in appearance tell you about how water moves through them?
•     Extra: In this activity, you used carnations, but do you think you’d see the same results with other flowers and plants? Try this activity with another white flower— a daisy, for instance—or a plant that is mostly stem, such as a stalk of celery.
•     Extra: Try doing this activity again but use higher or lower concentrations of food color, such as one half, twice, four times or 10 times as much; be sure to mix each dye amount with the same amount of water. What happens if you increase or decrease the concentration of food color in the water?
•     Extra: How would you make a multicolor carnation? Tip: You could try (1) leaving the flower for a day in one color of water and then putting it in another color of water for a second day or (2) splitting the end of the stem in two and immersing each half in a different color of water.

Observations and results
When you put the flowers in the dyed water, did you see some of the flowers start to show spots of dye after two hours? Did you also see some dye in the stems? After 24 hours did the flowers overall have a colored hue to them? Did this hue become more pronounced, or darker, after 48 and 72 hours?

Water moves through the plant by means of capillary action. Specifically, the water is pulled through the stem and then makes its way up to the flower. After two hours of being in the dyed water, some flowers should have clearly showed dyed spots near the edges of their petals. The water that has been pulled up undergoes a process called transpiration, which is when the water from leaves and flower petals evaporates. However, the dye it brought along doesn’t evaporate, and stays around to color the flower. The loss of water generates low water pressure in the leaves and petals, causing more colored water to be pulled through the stem. By 24 hours the flowers should have gained an overall dyed hue, which darkened a little over time. The stems should have also become slightly dyed in places, particularly where the leaves branch off.

More to explore
Plant Parts: What Do Different Plant Parts Do? from Missouri Botanical Garden
Capillary action from The U.S. Geological Survey, Water Science School
The Water Cycle: Transpiration from The USGS Water Science School
Transpiration in Plants from
Suck It Up: Capillary Action of Water in Plants from Science Buddies.

Source: Scientific American