Prospects of Hydroponic Production of Vegetable Crops

Muhammad Umar

M.Sc Scholar Institute of Horticultural Sciences, University of Agriculture Faisalabad

Email: umar_1879@yahoo.com

Cell: 00923466520724

Hydroponics is a method of growing plants using mineral nutrient solutions, in water, without soil (Anonymous, 2011a). Terrestrial plants can be grown with their roots in the mineral nutrient solution only or in an inert medium, such as perlite, gravel, mineral wool, or coconut husk. The hydroponic systems may be classified under eight headings like surface watering technique, sub-irrigation, wick system, grow bag technique, soak and drain, rockwool technique, drip feed technique and nutrient film technique. Generally seven types of cultures are commonly used in hydroponics including water culture, sand culture, gravel culture, vermiculaponics, horticultural rockwool culture, hydroculture and aeroponics (Anonymous, 2011b).

There are several advantages of hydroponics production like less labour input, light manual operations than soil cultivation, lack of crop rotation, competition for nutrients, minimum wastage of water, no weeds, all seasons production and very less or no usage of pesticides. But along with advantages there are several disadvantages or limitations of hydroponics including high initial capital investment, high degree of management skills, difficult to manage at large scale, nonstop energy requirements to maintain system and very much dependent on nutrient solution temperature (Daha. 2006).

A variety of crops can be grown using hydroponics/soil-less culture. In vegetables lettuce, kang kong, tomato, egg plant, green bean, capsicum, bell pepper and cucumbers, in fodder crops sorghum, alphalfa, barley, in cereals rice, maize, in fruit crops strawberry, in ornamentals anthurium, merrygold, coleus, roses, carnations, orchids, chrysanthemums and in medicinal crops alovera can be grown by using hydroponics (Douglas.1975)

One must keep some precautions in his/her mind while dealing with hydroponics. First precaution is high temperature during mid afternoons in green/ net houses and under protective covers. Adoption of closed system of hydroponics where the solution is recycled to reduce such rise in temperature to some extent. Second precautions is less penetration of sunlight to inner rows of hanging bag and grow bag techniques resulting poor growth and low yield. Third precaution is pollination. As protected structures effectively prevent insects reaching crops, pollination by insects does not take place in the protected structures (Daha. 2006).

As experienced in normal crop husbandry, pests diseases also affect hydroponics plants and they also show physiological as well as nutritional disorders under unfavorable conditions. First and most observed physiological disorder in hydroponics is blossom end rot of tomato. It appears at the bottom end fruits, brown, sunken leathery spots appear. Second most important physiological disorder is concentric fruit cracking of tomato. Concentric cracks appear around the fruit stalk or cracks extending from fruit stalk appear. High day temperatures, large differences between day and night temperature and sudden change in growing media moisture content are the causes of this condition. Shrink cracks of bell pepper is also an alarming physiological threat in hydroponics. Fruit crooking of cucumber is a serious physiological disorder in cucumber. The curvature of known as fruit crooking begins at early stages of fruit development and may be caused by adverse temperature, excessive moisture in growing medium, poor nutrition, excessive fruit load or insect damage (Jones. 1977)

Increasing the temperature of water supplied to spinach during winter improved growth and yield of the crop. It has been reported that in hydroponics, root temperature can be controlled by warming the nutrient solution and thus providing the heat energy requirements for optimum plant growth and development (Calatayud et al., 2008)

Flooded I. aquatic plants produced plenty adventitious roots at the stem bases that promote oxygen diffusion to the roots and facilitate nutrients uptake (Yamamoto et al, 1995).

Use of plant uptake and plant-mediated conversions also has great potential for the removal of nutrients from nutrient enriched waters. Recently, there is an increased interest in integrating treatment systems and production systems based on the common-sense approach of conversion of wastes into products. By integrating these techniques, it is possible to reduce wastes and associated environmental impacts, and at the same time generate an additional crop (Naegel, 1977; Quillere et al., 1995; Rakocy et al., 2006).

Rate of growth of S. oleracea L. and biomass increased with increased water temperature, an indication for possible increase in yield when grown at higher temperatures during winter in controlled settings (Nxawe. 2009). Kankung and mukunuwenna in hydroponics, specially in NFT and Grow bag cultures, exhibit faster growth and greater marketable yield, giving a satisfactory turnover for the grower. (Weerakkody. 2002). I. aquatica and L. sativa are promising species to be included in integrated hydroponic and aquaculture facilities. Brassica varieties did not grow well at water-saturated conditions and therefore has less potential. (Trang et al., 2010)

Hydroponics or soil-less culture is relatively a new system of growing plants which helps reduce dependency on labour, threat of insect pest & diseases and efficient use of water. But due to certain limitations like high initial cost, some nutritional as well as physiological disorders and difficulties to maintain long term commercial hydroponic system, it is not well adopted to our country.

References:

Anonymous, 2011a. Hydroponics. http://en.wikipedia.org/wiki/Hydroponics. Retrieved on 23 October 2011
Anonymous, 2011b.http://www.techno-preneur.net/information-desk/sciencetech-magazine/2007/jan07/Hydroponics.pdf . Retrieved on 2 November 2011
Calatayud, A., E. Gorbe, D. Roca, P. F. Martínez. 2008. Effect of two nutrient solution temperatures on nitrate uptake, nitrate reductase activity, NH4 + concentration and chlorophyll a fluorescence in rose plants. Environ. Exper. Bot. 64:65-74.
Daha, M. 2006. Growing Edge: 9(2): 37-38
Douglas, S.J. 1975. Hydroponics: Bombay: Oxford UP. (5) pp:1-3
Harris, D. 1992 . Hydroponics (Key to sustain agriculture in water): New Holland Publishers
Jones, L. 1977. Home Hydroponics & How To Do It: Crown Publishers, Inc. New York, N.Y.
Naegel, L.C.A. 1977. Combined production of fish and plants in recirculating water. Aquaculture.10:17-24.
Nxawe, S., C. P. Laubscher and P. A. Ndakidemi. 2009. Effect of regulated irrigation water temperature on hydroponics production of spinach. Afr. J. Agric. Res. 4(12):1442-1446
Rakocy, J.E., M.P. Masser and T.M. Losordo. 2006. Recirculating aquaculture tank production systems: aquaponics-integrating fish and plant culture. SRAC Publication No. 454. Southern Regional.
Trang, N. T. D., H. H. Schierup and H. Brix. 2010. Leaf vegetables for use in integrated hydroponics and aquaculture systems: Effects of root flooding on growth, mineral composition and nutrient uptake. Afr. J. Agric. Res. 9(27):4186-4196.
Weerakkody, W.A.P., N.A.K.G.E. Kumari, W.M.S.M. Bandara, R. Drisa and O. I. Oladele. 2002. Appropriate hydroponic systems for growing leafy vegetables in greenhouse. Nig. J. Hort. Sci. 7(1):707-712
Yamamoto, F., Sakata and T. Terazawa. 1995. Physiological, morphological and anatomical responses of Fraxinus mandshurica seedlings to flooding. Tree Physiol. 15: 713-719.Aquaculture Center. Texas A & M University, Texas, USA.

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Knowledge and Agriculture

Education, the cornerstone of a knowledge economy, is given a low priority in developing countries. This is because of the vested interests of powerful but corrupt parliamentarians who find it in their interests to keep the masses subjugated and enslaved. Education brings understanding and awareness, and frees the minds to question those in power. Distorted forms of democracy in which there is no accountability of the rulers have been set up in many developing countries. Such democracies only serve a few corrupt leaders who loot and plunder at will.
The attempt in 2010 to destroy the Higher Education Commission (HEC) was the brainchild of some politicians with forged degrees who felt threatened by a high quality, merit-based organisation operating like an oasis in a sea of corruption. It was saved by the intervention of the Supreme Court of Pakistan on an appeal (filed by the Atta-ur-Rahman, Ms Marvi Memon and Azam Swati) that gave a judgment that the attempt to shred the HEC was unconstitutional. Now, however, some evil minds are plotting the death of the HEC again.
With their eyes on the Rs44 billion annual grant of higher education, some “honourable” parliamentarians have recently moved a bill in parliament that will take away the control of the funds from the HEC and give it to a federal ministry. At present the funds are controlled by a 17-member commission that includes the provincial secretaries of education, eminent educationists and respected citizens. India, by contrast, has decided to close down its University Grants Commission and establish an organisation similar to the HEC. The Indian cabinet approved the establishment of the National Commission on Higher Education and Research (NCHR) in December 2011.

HIt is time for the political parties in Pakistan to unite, rise up once again and kill the vile attempt by the corrupt to take control of the Rs44 billion annually made available to the HEC for the operational and development needs of the universities in Pakistan.
By the year 2000 the gap between rich and poor countries had reached 500:1 (World Bank) and it continues to increase with every passing day. While some countries such as Japan, South Korea, Singapore, Taiwan and, more recently, China have managed to narrow this gap between the rich and the poor, most other developing countries, including Pakistan, are lagging far behind. Knowledge and technological innovations are identified as two essential capabilities for bridging this gap. Since no country has all the resources to achieve technological competence in all fields, most countries have concentrated on finding one or two areas of specialisation for comparative advantage. For Pakistan, this advantage at present, according to our study, lies in the agriculture sector.
The agriculture sector in Pakistan supports two-thirds of the rural population and remains the largest income and employment generating sector of the economy but accounts for only 22 percent of the total gross domestic product. Pakistan has not been able to exploit its immense agriculture potential due to under- investment in human resource development and agriculture research. According to the Consultative Group on International Agricultural Research (CGIR), public expenditure for agriculture research in Pakistan as a percentage of agricultural GDP is only 0.29 percent, whereas India and Bangladesh spend 0.36 percent and Mexico and Kenya spend 1.21 percent and 1.30 percent, respectively.
The 15-year agriculture reform and development vision for Pakistan was prepared under the supervision of one of us (Dr Atta-ur-Rahman). It involved research scientists, industrialists, farmers association and economists and identified critical skills, technology, management and public policy gaps in all fields of agriculture including major grain crops, horticulture, fisheries, animal husbandry, rangelands and forestry. Research areas, technological inputs and better operational practices needed in soil, seed, fertilisers, pesticides and water management as well as the transport, grain storage and cold chain infrastructure required for prevention of 40-45 percent of post harvest losses have been identified.
It was observed that 75 percent of Pakistan’s agriculture potential remains untapped. Crop yields on average are lower by 31-75 percent of the productivity level achieved at local research stations and lower by 50 percent to 83 percent in developed countries. These productivity gaps can be addressed through increased inputs in human resource development, research, technology and extension services and through improved management of resources and inputs. Improved access to institutional credit and access to local and international markets are essential prerequisites. Pakistan has all the basic ingredients to excel and eventually lead in agricultural innovation at regional level.
Most of the agriculture research organisations. however, are poorly managed and remain ill-equipped with modern machinery, library and information infrastructure and qualified staff. There are no incentives for scientists to innovate and there are weak linkages between stakeholders (i.e., researcher, farmers, entrepreneurs and policymakers) due to a weak extension services system. In order to carry out reforms of the system and to increase agriculture productivity an investment of Rs1078 billion will be required over a period of 15 years. This investment is expected to generate Rs2,368 billion as net benefits with an internal rate of return close to 108 percent (PIDE 2003).
At their initial stages of development most developed countries invested in agriculture innovations to eliminate rural poverty and to bridge the income inequality gap between rural and urban populations in their societies. China’s agriculture reform programme has not only lifted millions out of poverty but generated enough income for investment in industrial innovations. The successful programme, which began in the early 1980s, is premised on providing flexible, demand-driven packages of services, not just technology but also information, technical assistance, marketing and developing supply networks and supply chains.
In 1986, the Chinese ministry of science and technology initiated the nationwide “Spark” Programme (derived from the Chinese proverb “A single spark can start a prairie fire,” meaning that the spark of science and technology will spread over vast rural areas of China). Its overall objectives were to help transfer managerial and technological knowledge from more advanced sectors to rural enterprises and to help increase productivity and employment.
We need to learn how countries such as China, Egypt and India have modernised agriculture and are using it to tackle poverty and transition to a knowledge economy. Simultaneously we must resist continuing attempts by crooked minds to destroy the HEC.
Acknowledgement: We are grateful to Bilal Mirza, PhD Fellow, United Nations University-MERIT, the Netherlands, for his valuable input
Prof. Atta-ur-Rahman is former federal minister for science an technology and former chairman of the Higher Education Commission
Dr S T K Naim is an expert on STI policy and a consultant at COMSTECH, Islamabad.Courtesy: The NEWS

Challenges to Biotechnology in Pakistan

By  Sayyar Khan Kazi

We are living in an age, where almost all aspects of human life have been revolutionized by the highly sophisticated and advanced technologies.  In recent years, we have witnessed on print and electronic media, several scientific endeavors to target innovations and discoveries beyond the boundaries of our planet Earth. Technologically advanced countries such as the USA, European Union, Japan and emerging powers like China and India are beating one another to have speedy access to the mysteries of other planets.

In the quest of unraveling scientific mysteries, several missions from these countries have been launched to Moon, Mars and other planets in order to lead and dictate the terms upon which the human future will rely. Overall, there has been unpreced- ented progress towards industrialization that revolutionized every aspect of human life including medical and health care, aviation, urbanization, infrastructure and agriculture. 

This off course presents a bright picture of the evolution of human civilizations as a result of thousands years of transformation from living in an age of stone to highly civilized societies equipped with social and scientific tools to govern this planet Earth.

Like other scientific disciplines, Agriculture science has received much importance due to the growing needs of expanding populations for more food, feed, fiber and alternative energy resources. In this connection, the advent of modern biotechnology and genetic engineering tools has enabled scientists to manipulate the genetic material of organisms in order to exploit its hidden enormous potential.

In the past two decades, biotechnological tools have brought a paradigm shift in the orthodox and traditional ways and means of improving our various industries, health sciences, environment and agriculture.

For example, in agriculture, since 1995, there has been a sudden boom in the production of transgenic varieties of agricultural crops with enhanced protection from insect pests and diseases. Farmers around the world have gained maximum economic gains from the adoption of these improved crop varieties.

The wide adoption of these improved crop varieties by farmers around the world has resulted a huge economic benefit and positive effects on the environment by less pesticide application.

After the successful production and adoption of disease resistant crop plants, agriculture biotechnology is entering into a new phase of developing second generation transgenic crops that will be able to grow on marginal lands with high water and soil salinity and drought stresses.

It is anticipated that the development of these crop varieties will help to feed the growing populations, particularly in regions of Sub-Saharan Africa and Asia, where majority people are facing hunger, poor quality and malnourished food.

Keeping in view the promising role of biotechnology for securing the future of our coming generations, increasing number of countries, public, private sectors and multinational companies have joined the race and invested billions of dollars for research and development activities.

In some areas, scientists have excelled and accomplished significant targets like crop disease resistance as mentioned above and development of accurate laboratory tools for genetic dissection, diagnosis and research on human genetic diseases.

Pakistan, a developing country is facing multi-faceted challenges including energy crisis, food security, rapid urbanization and declining fresh water resources in the wake of increasing population and the more global phenomenon of climate change.

Like other countries, Pakistan also took a bold step towards adoption of modern biotechnology and started to establish biotechnology centers across the country. In all key national science and technology policies, the role of biotechnology as a potential tool for the growth and socio-economic development has been well acknowledged.
In National science and technology policies launched in 1997 and later in 2009, biotechnology was emphasized one of the priority areas. Pakistan also contributed and pioneered the establishment of an International Center for Genetic Engineering and Biotechnology (ICGEB), initially proposed to be built in Pakistan but later on jointly built in India and Italy.
Despite the initial recognition and quick response, biotechnology did not take roots as an emerging source of socio-economic development in the country. For example, we started research on insect resistant transgenic cotton varieties back in 1995 and developed some transgenic lines but it took almost 15 years to launch legal commercial cultivation of these varieties in 2010.

The other leading cotton producing countries namely USA, China and India adopted and commercialized transgenic cotton varieties in 1996, 1997 and 2002 respectively and farmers in these countries earned huge economic gains.

In addition, we are also lagging behind other countries in development of second generation transgenic crops with improved tolerance to environmental stresses and crops for bio-energy production. The dependency on fossil fuels as energy sources is on the decline because of the enormous potential of bio-feed stocks (crops, trees and grasses) to produce bio-energy products such as ethanol, biodiesel, butanol and petroleum on industrial scale.Source: The Frontier Post

Chlorophyll - Health Benefits and Natural Food Sources

Chlorophyll is the  green pigment that gives plants  and algae their green color.   Chlorophyll is an antioxidant  nutrient and also an essential  component in photosynthesis,  the process which allows plants  to obtain energy from the sun.  Plants use chlorophyll to trap  light that's needed for  photosynthesis.  Although the natural chlorophyll found in green plants and algae is fat-soluble, most chlorophyll found in health food stores is water-soluble.  In order for chlorophyll to be water-soluble, the natural fat-soluble chlorophyll must be altered chemically. Natural chlorophyll from green plants and algae is the most nutritious source of chlorophyll.  It offers some advantages over the chemically altered water-soluble chlorophyll.  One of the most important advantages of natural chlorophyll is that it can stimulate hemoglobin and red blood cell production , while water-soluble chlorophyll cannot.  The chlorophyll molecule is very similar to the heme portion of the hemoglobin molecule of red blood cells.  Chlorophyll is a natural blood purifier and is often called "the blood of plant life".  It provides management of bacterial growth, it removes unwanted residues, and it activate enzymes.  Chlorophyll is nutrient dense and it's an anti-inflammatory.  Due to it's alkalizing qualities, chlorophyll also helps the body to be pH balanced.  Maintaining pH balance increases the body's resistance to disease.  Since water-soluble chlorophyll is not absorbed by the digestive system, its use is limited to soothing the gastrointestinal tract and reducing fecal odor. 

Natural Food Sources of ChlorophyllCereal Grasses (wheat grass juice and barley grass juice) - Cereal grasses are a nutrient dense, high chlorophyll food.  Although wheatgrass and barley grass have similar nutritional qualities, barley grass is milder and more bitter than the slightly sweet wheatgrass.  People who are allergic to wheat or gluten are usually not allergic to wheat in it's grass stage.  Barley grass is a great alternative for individuals who can't tolerate wheatgrass.  Cereal grasses are an excellent source of many nutrients and enzymes.  Wheatgrass juice is especially known for the following health benefits:  it cleanses the lymph system, it restores balance in the body, it removes toxic metals from the cells, and it restores vitality.   Barley grass juice is well known for the following health benefits: it improves stamina and increases energy, it provides clarity of thought, and it improves the texture of the skin.    
Microalgae (Spirulina, Chlorella, and Wild Blue-Green Algae) - These three types of microalgae contain more chlorophyll than any other food on the planet.  In addition to chlorophyll they're also a great source of complete protein, beta carotene, and nucleic acids (RNA and DNA).  Of the three types of microalgae, spirulina is an especially rich source of protein, beta-caroteine, and the beneficial fatty acid GLA (gamma-linolenic acid).  Unlike the other two microalgae, spirulina also contains a pigment called phycocyanin.  Phycocyanin has antioxidant and anti-inflammatory properties.  The cell wall of spirulina contains mucopolysaccharides (MPs), which are composed of amino acids, sugars, and protein.  The nutrients in MPs are completely digestible unlike the nutrients within the cell walls of other microalgae.  
Although chlorella has a similar nutrient composition to spirulina, chlorella contains a little less protein, much less beta-carotene, and much more chlorophyll and nucleic acids than spirulina.  Chlorella has more chlorophyll than any other food, and it contains a higher amount of fatty acids when compared to other microalgae.  Another health benefits of chlorella is that it has a tough outer cell wall that binds with heavy metals, pesticides, and other carcinogens.  It then carries the toxins safely out of the body.  
Wild blue-green algae offers similar nutritional benefits as spirulina and chlorella.   Although wild blue-green algae is highly nutritious, during the growing period it can transform into a very toxic plant.  For this reason, it's crucial that any purchases made for wild blue-green microalgae are from well known, reputable sources.     
Green Leafy Vegetables - Aside from cereal grasses, green leafy vegetables are the most nutrient dense of all vegetables.  Not only are they a rich source of chlorophyll, they're also an excellent source of many other nutrients including vitamins A and C, calcium, potassium, and fiber.   The amount of each nutrient varies with each green leafy vegetable.  There are several varieties of green leafy vegetables available in most grocery stores and farmer's market stands including collard greens, mustard greens, kale, spinach, bok choy, kolrabi, and swiss chard.   They all contain their own unique  composition of nutrients.

Sources:

Wikipedia The Free Encyclopedia

Murray , Michael N.D. The Encyclopedia Of Healing Foods. New York: Atria Books, 2005.

Bowden, Jonny, Ph.D., C.N.S. The 150 Healthiest Foods on Earth. Fairwinds Press, 2007

Linus Pauling Institue http://lpi.oregonstate.edu/infocenter/phytochemicals/chlorophylls/

Everynutrient http://www.everynutrient.com

Fruit Facial Mask

Cosmetic company are now using fruit acids (AHAI’s), vitamins (antioxidants) and enzymes in many beauty products but also include a large amount of synthetics which can actually be injurious to the skin. In organic beauty, only fresh ingredients are used and therefore a highly active and most effective cure can be given. You will be amazed at how something as simple as dabbing some fresh lemon juice on your face every morning can make an vast difference in how soft your skin feels.

Try any of the following fruit acids, but always take care to avoid your eyes.

→ Lemon juice
→ Strawberries
→ Grapes
→ Malic acid (apples, vinegar, applesauce, cider)
→ Lactic acid (buttermilk, yogurt, powdered skim milk, sour cream, blackberries, tomatoes)
→ Tartaric acid (grapes, grape juice, wine, cream of tartar)
→ Citric acid (citrus fruits such as lemons, limes, grapefruit, and orange)
→ Glycolic acid (sugar cane)

We all are aware of the fact that fresh fruits are good for health and the core vitamin and the mineral lies in the pulp and the skin of any fruit. And just as they are useful to the body, these nutrients can provide excellent rejuvenating factor for our skin too. If you know the properties of each fruit, you can pamper yourself with an all-natural fruit mask, without spending too much time or money. Here are few fruits that can keep your skin smooth and healthy.

Apple & Avacado facial mask

Apple Facial mask

Ingredients:

• 1 cored apple cut into quarters
• 2 tablespoons of honey
• ½ teaspoon of sage

Procedure:

Chop up the apple quarters in a food processor. Add the honey and sage and then refrigerate for about 10 minutes. Lightly pat the mixture onto the face until the honey feels tacky. Leave it on the skin for 30 minutes and then rinse the face mask off with cool water.

Avocado Facial mask

Ingredients:

• 2 tablespoons hot water
• 1 tablespoon honey

Procedure:

Mash the Avocado with a fork. Dissolve the honey into the water and mix well with fruits. Apply on your face smoothly. Let it sit on the skin for 10 minutes. Wash your face. It makes your skin soft and clean.

Source:Fruitsinfo

Five steps to get your garden started

It’s that time of year again, the time you start daydreaming of canning homemade salsas and tabling fresh salads made completely from ingredients pulled from your home garden. Only, er, maybe you haven’t gardened before and don’t know where to start. If so, here is a five-point plan to get your garden on this year.

1. Do your homework: If your thumb isn’t yet remotely green, start with some research. “So before you even break soil, pick up some books from the library or the Internet to get a plan in place of what you’d like,” said Michael Van Dongen of Van Dongen’s Landscaping and Nurseries Ltd. in Hornby, Ont. That way you can determine what kind of plot you have, and what sorts of vegetables and flowers might do well there. Stuck for research?

Van Dongen also suggests planning small at first. “That way you can let that small area expand from there, because if you try and do too much at once, it can be overwhelming,” he said. “And when you start small, you can decide whether you like it or not because not everyone’s got a green thumb and enjoys it.”

2. Plan your plot: After picking the sunniest spot in your yard or balcony, minimizing the changes of mold and mildew getting at your plants, you can pick from plants that are practically bulletproof. “Snapdragons are prolific flowers to grow. I sometimes let mine sit and they reseed themselves and they come up the following year,” Van Dongen said. “Geraniums and marigolds are also tougher, so if we get a cold snap, it won’t harm them too much.” As for a vegetable bounty, Van Dongen recommends root crops such as carrots, beets and onions, which are all tougher plants and can better sustain weather changes.

3. Prep your plot: Once the weather is warm enough, you can cut out a garden plot by digging down about four to six inches and then build it up another four inches of mixed soil and compost, said Van Dongen, who also recommends working that soil a bit. “You can get compost from your local garden centre or municipality to enrich the soil. So lay it down and work it in with a fork or cultivator.”

4. Pick your packs: Once the threat of morning frost is gone, you can start transferring starter packs of plants to the outdoors. While you can still plant some things such as carrots, from seeds, starter plants or flowers will practically guarantee you have some outdoor growth this year. “Buying starter plants might cost you say $1.40 for a 4 pack of plants,” said Van Dongen. “It’s a minimal investment for something that you can probably benefit greatly from.”

When you are planting, Van Dongen recommends using a light touch — don’t plant too many seeds or packs. “You have to be careful with how much you plant because if it’s a good year, you don’t know how much you can yield and you feel bad wasting it,” he said. 

5. Maintain your growth: From here on in, it’s maintenance, maintenance, maintenance — that includes monitoring the growth, keeping track of watering your plants, weeding, watching for pests, fertilizing regularly and more. And then come August, you can proudly pick and can that salsa. “That’s what I like about gardening — that sense of accomplishment,” Van Dongen said. “And there’s nothing like going out to your garden and picking a cherry tomato off and eating it. You’re putting your own food on the table.”
Source: Chatelaine 

Biotechnology: Cotton Production Set to Increase

BY ORTON KIISHWEKO, 28 APRIL 2013

RECENTLY, the Ministry of State in the Vice-President's Office (Environment) convened a meeting for stakeholders in the science community to deliberate on how crop genetic engineering can be used in the interest of agriculture and the local people in general.

At the meeting some stakeholders had concerns on whether there is conclusive research findings that show genetically engineered crops have no harm on human beings.

The same week, a renowned Harvard University scholar, Prof Calestous Juma visited East Africa and said biotechnology and genetic engineering have the potential to do for agriculture, what mobile technology has done for the communications sector in Africa.

Prof Juma advocated for the adoption of Genetically Modified Organisms (GMOs), saying they would boost food and income security. He, however, cautioned that it would be detrimental to adopt GMOs without clear, flexible and supportive biotechnology regulations. Prof Juma has authored several books on Africa's development, including The New Harvest, which is arguably today's most authoritative scholarly work on agriculture in Africa.

In his book, he argued that African agriculture is currently at a crossroads, at which persistent food shortages are compounded by threats from climate change. But, as the book argues, Africa faces three major opportunities that can transform its agriculture into a force for economic growth: advances in science and technology; the creation of regional markets and the emergence of a new crop of entrepreneurial leaders dedicated to the continent's economic improvement.

Filled with case studies from within Africa and success stories from developing nations around the world, The New Harvest outlines the policies and institutional changes necessary to promote agricultural innovation across the African continent. Incorporating research from academia, government, civil society and private sector, the book suggests multiple ways that individual African countries can work with others at the regional level to develop local knowledge and resources, harness technological innovation, encourage entrepreneurship, increase agricultural output, create markets and improve infrastructure.

He emphasised the role of technology in transforming livelihoods, insisting that if Africa didn't embrace GMOs in agriculture, the problems like climate change, pests and diseases that have dogged the sector over the years would devour production to shocking levels. He decried the phenomenon of resisting new technologies, saying it won't help Africa to develop. On the safety of GMOs, he compared the current debate to the rumours that were circulated during the early days of mobile technology that the phones would cause brain cancer.

He said instead of focusing on rumours that discredit GMOs, it is prudent for governments to empower institutions to effectively check the safety standards of each product introduced on the market. He said biotechnology had caused a 24 per cent increase in cotton yield per acre and a 50 per cent growth in cotton profit among US smallholder farmers between 2006 and 2008. It raised consumption expenditure by 18% during the period.

He cited another report which said GMO crops that are pest-resistant had suppressed pests even beyond gardens where they were planted to assist farmers who don't grow GMOs. "Biotechnology and in particular GMOs are not per se more risky than conventional plant breeding," he asserted, and explained that genetic engineering would make agriculture more attractive and reduce the number of youth running away from rural areas.

The scholar's position brought into focus the importance of genetic engineering perhaps starting with non-food crops in Tanzania, including cotton. Locally, stakeholders have urged that the government should institute a policy that allows agricultural scientists to conduct research and trials on GMOs in different research centres. The Environmental Management Act does not allow the application of such research and that it should therefore be amended. For example, one of the crops whose future has elicited so much debate is cotton.

Questions have been asked as to whether Bt Cotton can address the challenges in the cotton sector. The Tanzanian cotton sector has undergone dramatic changes since liberalisation in 1994. Stimulated by high producer prices, it has held either its position as either the most or second most important export crop in Tanzania in recent years. An estimated 40 per cent of the entire Tanzanian population is believed to derive their livelihood either directly or indirectly from cotton, grown by as many as half a million of mostly smallholder farmers.

A recent World Bank publication remarks that the sector is unique in that it is marked with too much competition amongst buyers - resulting in higher producer prices yet lower qualities - compared to the other sub Saharan cotton economies. This increased competition- as a trade-off-also resulted in comparatively lower yields, as credit based input provisioning is challenging in an environment where an overcapacity in ginning fuels side-selling.

The earlier South African case is illustrative in that the Tanzanian supply chain put into place via contract farming could serve a similar fate of struggling with recovering the debt and providing subsidized inputs, although measures are developed by the TCB to combat these issues. In addition to low yields obtained in a rain-fed environment, farmers in the sector struggle with lack of access to credit and extension service.

Research in the cotton sector also has been limited with poor seed quality, although the new UK M08 variety - developed at the Ukiriguru Cotton Institute - is planned for release as early as 2013/14. Furthermore, the intense competition has resulted in a comparatively lower cotton quality, as buyers are more focused on securing their quantities for their orders. While the quality is improved by half the ginneries operating roller gins and the entire harvest being hand-picked, the sector continues to suffer from the collapse of the textile industry after liberalization.

On average, only around 20 percent of the ginned cotton is consumed by domestic textile industries. The other 80 per cent are exported, thus revealing a potential source of domestic value addition as an estimated 90 per cent of the profits are obtained abroad (TCB 2010). These challenges were recognised by the Tanzanian Cotton Board as outlined in its Cotton Board Strategy of 2011-2013.

Outside of its domestic domain, the cotton sector is plagued by a range of global structural issues. These include competition from synthetic fibres and a long term decline in terms-of-trade for agricultural commodities (that was reversed in the short-term during the commodity booms in the last few years).

Courtesy: All Africa

HOW TO GET YOUR GARDEN STARTED: PUTTING THE THEORIES TO WORK

Asad Manzoor
Department of Agriculture & Agribusiness Management, University of Karachi (asad@gardener.com)

Most of your garden scheduling has been theoretical. You've given idea to the vegetables you want to grow, what you're going to do with them, and how much you need to cultivate. You've got a plan of how the climate in your spot will influence your final choice of vegetables.

You're starting to understand your microclimate how growing circumstances in your own back garden may differ from the general climate of your region/district or city. Now you're ready to start getting your plans on paper, but as soon as you open the seed catalog, confusion strikes again. You want to grow your own corn, tomatoes, lettuce and carrots…..

Remember, too, that you don't all the time have to play by the rules; you can plant more than one variety of a vegetable and decide for yourself who one is best suited to your palate and your garden. You can also broaden your harvest by planting varieties that mature at diverse times. Experimenting is a good part of the fun of growing a vegetable garden. Selecting the varieties you're going to grow gives you some solid information with which to work .You now know when to plant your vegetables.

With careful scheduling you may also be capable to save garden space and get two or more harvests from the same spot by succession or sequencing planting. After early-maturing crops or Vegetables are harvested, you clear a portion of the garden and replant it with a new crop or vegetable. Plant so that cool-season crops or vegetables grow in the cooler part of the season, and warm-season crops or vegetables can take advantage of warmer weather.

Companion (we can also say friendly plants) planting is another way to twice upon plantings pace. This you do by planting short-term crops or Vegetables between plants that will take a longer time to mature. The short-term crops or Vegetables are harvested by the time the longer-season crops or Vegetables need the extra room. A good example of this is to plant radishes between rows of tomatoes; by the time the tomatoes need the space, the radishes will be gone.

Weeds Control in Upcoming Era

Asad Manzoor
Department of Agriculture and Agribusiness Management University of Karachi
asad@gardener.com

In the upcoming era, weed control methods currently being intensively researched will allow prolonged weed control options away from herbicides and mechanical methods in agricultural, horticultural and nonagricultural weed management. Biological control by insects and plant disease producing micro organisms, foretelling modeling of weed/crop relations, and the use of herbicide antidotes, more viable crops, allelopathy, and genetic engineering/modify will become more widespread as their consistency is enhanced.

The generally purpose of additional approaches is to find out innovative, more environmentally suitable and friendly weed management methods/techniques that not only control weeds successfully, but advance our understanding and knowledge of weed ecology/biology and permit us more sustainable management of the agro ecosystem. Biological control of weeds by insects and plant disease organisms has had significant achievement in several weed management situations, and current research will direct to supplementary uses of natural agents. Significant biological research involves the potential introduction of natural control species commencing an invasive weed species site of origin (Watson, 1993). The use of herbicide antidotes (Hatzios and Wu, 1996) to defend crop plants has been doing well for some herbicides in some crops—for example, chloroacteamide herbicides in corn and sorghum. One of the supreme recent changes in weed control has occurred through the genetic transformation of crops with herbicide-resistant genes and the incorporation of herbicide resistance through conventional breeding. In 1999 and 2000, more than 50% of the U.S. soybean acreage and more than 30% of the corn acreage was planted to cultivars resistant to one of several herbicides. Genetic engineering offers marvelous potential in all areas of weed science for enhanced understanding of plants and of weed control. Genetic engineering, along with current advances in sequencing the genome of Arabidopsis (and in the future, other plants), will allow a clear understanding of specific gene function.

Such knowledge will authorize gene manipulation and modification in our agricultural activities, such as the finding of genes that add to weediness, competitiveness, allelopathy, dormancy, or a plant’s being a perennial, with functions (Weller et al., 2001; Gressel, 2000). Genes of interest in weed control methods once revealed may then be engineered into crops or used to manipulate weeds to achieve a wanted effect in crop productivity and reduced weed influences. One area in especially where genetic engineering may play a role is allelopathy. Allelopathy (Rizvi and Rizvi, 1992) results from any direct or indirect inhibitory or stimulatory effect by one plant (including microorganisms) on another through the production and release into the surroundings of a chemical compound. Although no marketable breakthroughs have yet occurred in engineering plants to produce higher concentration/amount of allelochemicals, rather a few such genes have been recognized in Arabidopsis. Genetic engineering of crop plants or cover crops with genes for allelochemicals could allow key strides in rising plants helpful in weed management. The future for weed control is thrilling, as there are many opportunities for challenging fundamental and applied approaches for weed management in our environment (Hall et al., 2000).

References:

Gressel, J. 2000. Molecular biology of weed control. Transgenic Res. 9:355–382.
Hall, J. C., L. L. van Eerd, S. D. Miller, M. D. K. Owen, T. S. Prather, D. L. Shaner, M. Singh, K. C. Vaughn, and S. C. Weller. 2000. Future research directions for weed science. Weed Technol. 14:647–658.
Hatzios, K. K., and J. Wu. 1996. Herbicide safeners: Tools for improving the efficacy and selectivity of herbicides. J. Envir. Sci. Health. B31:545–553.
Rizvi, S. J. H., and V. Rizvi. 1992. Allelopathy: Basic and Applied Aspects. Chapman and Hall, London.
Watson, A. K., ed. 1993. Biological Control of Weeds Handbook. WSSA Monograph Ser. #7.WSSA, Lawrence, KS.
Weller, S. C., R. A. Bressan, P. B. Goldsbrough, T. B. Fredenburg, and P. M. Hasegawa. 2001.The impact of genomics on weed management in the 21st century. Weed Sci. 49:282–289.

5 Tips for Growing Early Spring Greens

By Shannon Cowan

Although the arrival of spring in some parts of the country brings welcome gardening weather, other regions are still waiting for those warmer temperatures to begin. Wherever you live, growing greens in in your garden or greenhouse can help you get a jumpstart on the season and enjoy delicious salads that haven’t travelled miles to your table.

Unlike many vegetables which require warmer temperatures to germinate, most greens are “cold hardy”, meaning that you can plant them long before the last frost. But just planting your greens doesn’t ensure a healthy crop. Here are a few tips to help you achieve success when cultivating early spring greens in your garden.

1. Ensure your soil is ready

The seeds of most greens will germinate at temperatures as low as 40 degrees F, which means you can begin planting as soon as the soil has thawed and is dry enough to rake smoothly. Overly wet soils may rot your seed, so if you live in an area with a high water table or copious rainfall, be sure you aren’t rushing the season. A good way to test your soil for readiness is to squeeze a fist full in your hand. If the soil forms a ball that separates easily or crumbles through your fingers, it’s dry enough to begin planting. If the soil forms a ball that doesn’t separate when jiggled, wait a few more days and try again.

If your soil is too wet, consider installing raised beds to improve early-season growing conditions. Raising your beds 12-24” above the ground is often all you need to improve soil conditions and ensure adequate drainage. You can also install sub-drainage or ditches if your space is large enough to warrant the cost.

Lastly, if your soil is too wet because of a high clay content, consider improving soil quality by adding some sand and organic matter such as compost and rotted manure. The ideal soil type for growing vegetables is sandy-loam.

2. Provide adequate nutrients for healthy growth

Like all plants, lettuces and other salad greens require nitrogen, phosphorous and potassium to grow. However, in salad greens the bulk of the plant’s energy is used up making green leaves. For this reason, these plants rely most heavily on nitrogen for healthy production. Fertilizing your soil with finished compost or rotted animal manure before planting is one way to deliver nitrogen to your plants’ roots. We also top dress with compost after the seeds have emerged (if planting in rows) or water with diluted fish fertilizer or compost tea. Other sources of nitrogen include organic alfalfa or kelp meal worked into the soil before planting.

3. Keep soil evenly moist

One of the mistakes many gardeners make when growing early greens is overwatering. Although the soil is warming up along with the air, those cold spring temperatures mean less evaporation. While some experts advocate misting your greens, particularly before germination, we’ve found a light watering twice per week is enough to quench our plants’ thirst and ensure strong, healthy development. Frequency will depend on your soil (whether it is sand, clay, or loam), the temperatures in your region, and whether your crop is outside or in a greenhouse.

4. Provide primary and secondary cover

To get a head start on the season, you can plant greens in a greenhouse or hoop tunnel a full month before their outdoor planting dates. You can also go one step further: although seeds grown in a greenhouse already benefit from warmer-than-average temperatures, an extra layer of protection can speed growth and improve germination. In The Winter Harvest Handbook, Eliot Coleman describes how floating row covers (a thin layer of light-permeable cloth) can substantially increase the temperature and relative humidity of a growing area inside a greenhouse. This “double coverage” modifies the climate enough to spur on growth and protect plants from unexpected dips in temperature. Lightweight, floating row covers are now widely available at most garden suppliers. After starting a selection of early greens in our greenhouse, we cover our seeds for the first few weeks after planting to speed germination and maintain an even soil moisture early in the season.

5. Choose cold-hardy varieties

Although most greens are tolerant of the cold, some are more likely to germinate and thrive in unpredictable, swinging temperatures than others. Arugula, spinach, kale, cress, mustard greens, and corn salad are all good choices for an early spring sowing. In most locations, lettuces will germinate in a greenhouse in early spring. Though they may grow more slowly than other greens at the beginning of the season and they require protection from hard frosts, lettuces add bulk and sweetness to the mix. Keep in mind that most lettuces require light to germinate, so a thin covering of soil is all they need to get started. See our list below of favorite cold-hardy greens below for more details.

Favorite Cold-Hardy Greens

The following greens will germinate and thrive in cool temperatures. We start a variety in our greenhouse in early spring to use in salad mixes, making sure to select for texture, colour, and nutrients. We also sow directly into the garden in consecutive plantings spaced 2-3 weeks apart to ensure a continuous harvest.

Arugula

(Also known as “rocket”) is an easy-to-grow early spring green that will germinate in the coldest spring soil, earlier in a greenhouse. Sow in rows or broadcast the seed evenly, but thin to 4-6” (10-15 cm) apart after emergence or the plants will bolt prematurely. When the plants do produce flowers, you can prolong production by pinching them off.

Beet Greens

Are great for color. The bright red-and-green combination adds brilliance to salads and tastes delicious when harvested at the baby-green stage (less than 4” or 10cm). Like other early greens, beets can be sown in a greenhouse as soon as the soil can be worked. Cool temperatures will intensify the colour in some varieties.

Claytonia

Or “Miner’s Lettuce”, has long been considered a weed in North America, but its succulent texture and tolerance for cold temperatures has made inroads with gardeners and upscale restaurants over the last few decades. Its small, white flowers are equally edible and add interest to salad mixes.

Corn Salad

(Also known as mȃche) is a favorite cool-weather crop with a mild, nutty flavour. Harvest the outer leaves or cut the entire inner rosette and watch it regrow. Although corn salad takes as long as lettuce to mature (about 50 days), it germinates faster and earlier, making it a great addition to early salads.

Edible Chrysanthemum

(Or shungiku) is an early green with Asian origins. Harvest the leaves or the edible flowers for a mildly bitter addition to salads and stir fries.

Kale

Is a year-round staple at our house, but one of our favorite ways to eat this calcium-rich plant is as a baby green in a mixed salad. If planted in spring, kale will germinate at soil temperatures at 40° F or higher. In a greenhouse, kale will produce quickly and flesh out salads with its vast array of colours and textures. We prefer Red Russian for our salad mix—its purple veins and frilly edges add a touch of fancy to any meal. Harvest the outer leaves of each plant when they are no more than 4” (10cm) long and sow more thickly than you would for mature plants.

Lettuce

Is a staple in any salad, but the vast array of varieties available today mean choices in colour, texture, and flavour. One thing to keep in mind if growing lettuce in a greenhouse is that some varieties will hold better than others into the heat of summer, ensuring a longer harvest and a steady supply. If you would like to keep your plants going after the weather warms up (or while waiting for those outdoor plantings to begin producing), choose a bolt-resistant variety (one that will not go to seed quickly). Oak leaf lettuces such as Salad Bowl have performed incredibly well in our greenhouses over the years. Other favorites include Red Sails and Lovelock.

Mustard Greens

Mustard greens, such as Mizuna, Giant Red, and Tah Tsai add spice to salads and can also be cooked in stir fries or soups. All belong to the Brassica family (the same family as broccoli, cabbages, and arugula), which means they share some of the same pests. Unlike broccoli and cabbages, however, mustards grow quickly and then go to seed. Although you can plant them outside your greenhouse in the coolest of temperatures, greenhouse growing ensures an earlier, more even harvest.

Pea Greens

Pea greens include the top 3-4” (7.5-10 cm) of any edible pea plant. I first encountered pea greens while working on an organic greens farm where workers harvested the leafy, vining tops rather than waiting for the pods to develop. Pea greens are only tender enough if you harvest them when plants are young. Cut the entire plant top once or twice before trellising and allowing to mature for your pea crop.

Sorrel

Sorrel stands out as a must-have in our garden. As one of the few perennial greens available today, sorrel produces first in the spring when most other greens are just going into the ground as seeds. Sorrel’s large and delicious leaves have a distinct, lemon flavor. They make a great edition to any salad or sandwich.

Spinach

Spinach is another early staple that fleshes out salad mixes and adds vital nutrients to meals. We harvest our greenhouse spinach at the baby-green stage, taking the outer leaves and allowing plants to regrow. Spinach does best in fertile soil that is well-drained and warmer than 35° F. Sow early, but remember that spinach will go to seed in a greenhouse as soon as the weather warms up. Although you can sow outside almost as soon as the soil can be worked, we’ve found a greenhouse crop of spinach out-produces its outdoor cousins by up to 4 weeks, making both plantings worthwhile.

Favorite Spring Mixes:

If space is limited, consider growing a selection of greens to suit your palate. Here are some of our favorite blends organized by taste:

Mild:

Looseleaf lettuce (e.g. Salad Bowl or Red Salad Bowl), Butterhead lettuce (Buttercrunch), Romaine lettuce (Freckles or Conquistador), spinach, claytonia, beet greens, pea shoots.

Spicy:

Looseleaf lettuce (choose one red and one green variety), Romaine lettuce, arugula, tah tsai, mizuna, edible chrysanthemum (shungiku).

Tangy:

Looseleaf lettuce, Romaine lettuce, arugula, claytonia, kale, corn salad, beet greens, sorrel.

A Final Word

Growing spring greens for salad mixes is a satisfying way to get started in the garden before long days and warmer soil temperatures arrive in full force. It’s also one way to save money and improve the quality of your salads with just a little bit of effort.

About Shannon
Shannon Cowan is a writer and editor whose novels and articles are published in the United States and Canada. She and her family are currently building a green home and converting six acres of semi-rural brush into a working farm. She blogs about their adventures at www.agreenhearth.com.

Source: EarthEasy

5 Easy to Grow Mosquito-Repelling Plants

Before reaching for the chemical sprays, try planting these easy-to-grow plants which have natural mosquito-repelling properties…

As the outdoor season approaches, many homeowners and outdoor enthusiasts look for ways to control mosquitoes. With all the publicity about the West Nile virus, mosquito repelling products are gaining in popularity. But many commercial insect repellents contain from 5% to 25% DEET. There are concerns about the potential toxic effects of DEET, especially when used by children. Children who absorb high amounts of DEET through insect repellents have developed seizures, slurred speech, hypotension and bradycardia.

There are new DEET-free mosquito repellents on the market today which offer some relief to those venturing outdoors in mosquito season. But there are also certain plants which are easy to grow and will have some effect in repelling mosquitoes from areas of your home and garden.

Here are five of the most effective mosquito repelling plants which are easy to grow in most regions of the US:

1. Citronella

Citronella is the most common natural ingredient used in formulating mosquito repellents. The distinctive citronella aroma is a strong smell which masks other attractants to mosquitoes, making it harder for them to find you. Although citronella is used in many forms, such as scented candles, torches and citronella ‘scented’ plants, the living plant is more effective because it has a stronger smell.

Citronella is a perennial ‘clumping’ grass which grows to a height of 5 – 6 feet. It can be grown directly in the ground in climate zones where frost does not occur. If grown in the garden or near the patio, it should be planted in the ‘background’, behind small decorative flowers and shrubs. In northern climate zones citronella can be grown in a large pot or planter, ideally with casters, so it can be rolled indoors during winter.

Gardening centers usually sell citronella as small plants in pots, ready to transplant to a larger pot or into raised garden beds on the ground. Once established, new plants can be propagated in early spring by splitting large clumps into smaller sections and replanting the new ‘starts’ in pots or other areas of the garden. Citronella plants are considered low maintenance, like most grasses, and they do best in full sun and well-drained locations. Periodic applications of nitrogen-rich fertilizers will ensure vigorous growth, but this treatment only needs to be applied once a year, preferably in early spring.

When purchasing citronella, look for the true varieties, Cybopogon nardus or Citronella winterianus. Other plants may be sold as ‘citronella scented’, but these do not have the mosquito repelling qualities of true citronella.

2. Horsemint

Also known as Beebalm, Horsemint is an adaptable perennial plant which repels mosquitoes much the same as citronella. It gives off a strong incense-like odor which confuses mosquitoes by masking the smell of its usual hosts.

Horsemint is a fast growing, shade-tolerant and drought-resistant plant which reaches a height and width of 2 – 3 feet. It does well in dry, sandy soil and can tolerate salty conditions, which is why it is often found in coastal and beach areas. Horsemint seeds can be sown indoors in trays for later transplanting, or sown directly into the ground in late summer in colder climate zones. Midwest and Eastern growing zones are favoured for growing horsemint.

Mature horsemint plants can be divided in spring and fall by dividing into small sections and transplanting into permanent locations. Horsemint can also be planted in pots for moving indoors in cold climate zones.

Horsemint leaves can be dried and used to make herbal tea. Its flowers will also attract bees and butterflies to your garden.

3. Marigolds

Commonly grown as ornamental border plants, marigolds are hardy annual plants which have a distinctive smell which mosquitoes, and some gardeners, find particularly offensive. Marigolds contain Pyrethrum, a compound used in many insect repellents.

Marigolds prefer full sunlight and reasonably fertile soil. Although marigolds can be planted from seed, starter plants are inexpensive and readily available at most garden centers. Although an annual, marigold will often reseed itself in favourable conditions, or the gardener can easily collect seeds for future germination. Established plants will need to be thinned, and flowers should be dead-headed to promote additional blooms.

Potted marigolds can be positioned near entrances to your home and any common mosquito entry points, such as open windows. The smell may deter mosquitoes from going past this barrier. While marigolds can be used as border plants around the patio, we do not advise putting marigolds on the patio table since the bright blooms may attract wasps.

Besides repelling mosquitoes, marigolds repel insects which prey on tomato plants, so you may want to plant a few marigolds in your tomato bed for added protection.

4. Ageratum

Also known as Flossflowers, Ageratum emits a smell which mosquitos find particularly offensive. Ageratum secretes coumarin, which is widely used in commercial mosquito repellents.

Ageratum is a low-lying annual ornamental plant which reaches heights of 8 – 18”, and is easily recognized by its blue flowers, although there are varieties with pink, white and violet blooms. This plant will thrive in full or partial sun and does not require rich soil. It is often displayed in rock gardens where low-lying plants are favoured.

Although the leaves of Ageratum can be crushed to increase the emitted odor, it is not advisable to rub the crushed leaves directly on the skin.

5. Catnip

Catnip is a natural mosquito repellent. In August 2010, entomologists at Iowa State University reported to the American Chemical Society that catnip is ten times more effective than DEET, the chemical found in most commercial insect repellents. According to Iowa State researcher Chris Peterson, the reason for its effectiveness is still unknown. “It might simply be acting as an irritant or they don’t like the smell. But nobody really knows why insect repellents work.”

In the laboratory, Peterson put groups of 20 mosquitoes in a two-foot glass tube, half of which was treated with nepetalactone, a biologically active characteristic constituent of catnip. After 10 minutes, only an average of 20 percent – about four mosquitoes – remained on the side of the tube treated with a high dose (1.0%) of the oil. In the low dose test (0.1%) an average of 25% – five mosquitoes – stayed on the treated side. When the same tests were conducted using DEET (diethyl-meta-toluamide), approximately 40 to 45% – eight to nine mosquitoes – remained on the treated side. A ten-fold higher concentration of DEET was required to obtain results similar to those of the Catnip.

Catnip, Nepeta cateria, is very easy to grow. This perennial herb is related to mint, and grows readily both as a weed and a commercially cultivated plant in most areas of the US.

While catnip will repel mosquitoes in close proximity to the plant, some people apply crushed catnip leaves or catnip oil for more robust protection. Bear in mind, however, that cats will respond to you similarly as they would respond to the plant itself. Cat owners may want to choose an alternative plant for repelling mosquitoes.

While the plants mentioned in this article have been shown to have mosquito-repelling properties, there are environmental variables that can mitigate their effectiveness. A breeze may direct odors in the opposite direction if advancing mosquitoes, reducing the plant’s effectiveness. New formulations of non-toxic mosquito repellents are commercially available, and are advised for people who want to enjoy the outdoors without the annoyance of persistent mosquitoes.

Source: EarthEasy