Modern techniques for production of seedless vegetables

Muhammad Umair Javid

MS.C Scholar, Institute of Horticultural Sciences, University of Agriculture Faisalabad

Email:umairjavid286@gmail.com

Cell: 00923336629839

A plant is considered to be seedless if it is able to produce a fruit with no seed, traces of aborted seeds or amuch-reduced number of seeds (Voraquauxet al.,2000). Induction of seedlessness in fruits and vegetables is being appreciated due to customer demand, improve aesthetic value and ease in preparation(Pandolfini, 2009). The shelf life of seedless vegetables is expected to be longer than seeded fruit because seeds produce hormones that trigger senescence. This effect has been observed in watermelons, in which seeds are the origin of fruit deterioration(Lukyanenko, 1991). Studies have also shown that seedless tomato fruits are tastier than the seeded variety. Moreover, seedless tomato fruits have been reported to possess 1% more dry-matter content, more sugars,less acidity, less cellulose and considerably high soluble solidsas compared to seeded fruits (Lukyanenko, 1991).

Parthenocarpy, literally meaning virgin fruit, is the natural, artificially induced, or genetically modified production of fruit without fertilization. In the absence of pollination, parthenocarpic plants will set seedless fruit (Gustafson, 1942). Thus, parthenocarpy can be regarded as a primary requirement for the production of seedless fruit(Pandolfiniet al., 2002).

Traditionally seedless watermelonsare produced by crossing a tetraploid (4× = 44) inbredline as the female parent with a diploid (2× = 22)inbred line as the male parent of the hybrid. The reciprocal cross (diploid female parent) does not produce seeds. The hybrid is a triploid (3× = 33) and sterile (Besteet al., 1998). Howeversome problems still exist producing the tetraploid parental line (by treating seedlings with colchicine), finding compatibility between the diploid pollinator and the tetraploid mother plant. Consequently, these difficulties required more time periodfor induction of seedlessness. Moreover Triploid seeds have a thicker seed coat, which decreases their vigour and germability(Yamamuroet al., 1978).Because the current production methods of seedless vegetables are associated withshortcomings, it is necessary to develop a new method to produce seedless vegetables in Short time which would be more convenient for and acceptable to consumer (Sugiyama and Morishita, 2002).

Among the modern existing techniques irradiation is an effective method for introducing nearly complete to complete seedlessness in vegetables. Seedless watermelon can be produced by pollination with partially functional pollens irradiated with gamma rays and x rays at the dose of 600 and 800 Gy (Moussa and Salem, 2010). In cucumber male pollen were irradiated with 0,100,200,300 and 400 Gy caused seedless fruit development, However fruit set percentage was not affected (Lotfiet al., 1999).

Another approach for eliciting seedlessness involves biotechnological research. Auxins andGAs plays important roles in parthenocarpic fruit development. Increased levels of these hormones in the ovary or ovule can substitute for pollination and can trigger fruit development, Researchers have obtained seedless parthenocarpic fruit by elevating the auxin levels in ovules of transgenic eggplant (Solanummelongena L.) and cucumber (Carmi et al., 2003; Goetz, et al., 2006; Yin, 2006).

Genetic approach for the production of seedless fruits is based on the rolBgene of Agrobacterium rhizogenesthat alters auxin sensitivity when expressed in plant. The rolbgene was introduced in tomato under the control of an ovary and young fruit specific promoter. In the rolB transgenic tomato plants, fruits developed without pollination and therefore were seedless (Carmi, et al., 2003).Seedleesnessalso developedby genetically modified parthenocarpic tomato plants(Rotinoet al., 2005).

Conclusion

Traditional polyploidy has been is in use to develop parthenocarpy (seedless) vegetables However, due to different drawbacks regarding commercial feasibility, this method is being discouraged. There is need to develop new technologies for the production of seedless vegetables by using less time to meet the consumer requirment, presently modern techniques are being in usedinclude, Irradiation, Mutation breeding, use of phytoharmones and transgenic approaches for the induction of Seedlessness in vegetables, However several others are yet to be explored.

References:
Beste, E., D.M.Caron, G. Dively, K. Everts, E. Kee, S.D. Walker, J. Whalen, J. Windsor and T. Wooten. 1998. Watermelon Production Guide for Delaware and Maryland, New York, Ithaca. Cornell Cooperative Extension.
Carmi, N., Y. Salts, B. Dedicova, S. Shabtai and R. Barg. 2003. Induction of parthenocarpy in tomato via specific expression of therolB gene in the ovary. Planta 217:726–735.
Goetz, M., A. Vivian-Smith, S.D. Johnson and A.M. Koltunow. 2006. Auxin response factor8 is a negative regulator of fruit initiation in Arabidopsis. Plant Cell. 18:1873–1886.
Gustafson, F.G. 1942. Parthenocarpy: Natural and artificial. Bot. Rev.8:599–654.
Lotfi, M., A. Kashi and R. Onsinejad. 1999. Induction of parthenogenetic embryos by irradiated pollen in cucumber. Acta Hort. 492: 323-328.
Lukyanenko, A.N. 1991. Parthenocarpy in tomato.Pp. 167-178. In:G. Kalloo(ed.)Monographs on Theoretical and Applied Genetics: Genetics Improvement of Tomato. Springer-Verlag. London, U.K.
Moussa, H.R. and A.A.K. Saleem. 2010. Parthenocarpy of watermelon cultivars induced by gamma irradiation. Russ. J. Plant Physiol. 57: 574-581.
Pandolfini, T. 2009. Seedless Fruit Production by Hormonal Regulation of Fruit Set. Nutrients. 1: 68-177.
Pandolfini, T., G.L. Rotino, S. Camerini, R. Defez and A. Spena. 2002. Optimization of Transgene Action at the PostTranscriptional Level: High Quality Parthenocarpic Fruits in Industrial Tomatoes. BMC Biotech. 2: 1–11.
Rotino, G.L., N. Acciarri, E. Sabatini, G. Mennella, R. Lo Scalzo, A. Maestrelli, B. Molesini, T. Pandolfini, J. Scalzo, B. Mezzetti and A. Spena. 2005. Open field trial of genetically modified parthenocarpic tomato: Seedlessness and fruit quality. BMC Biotechnol. 5:321-339.
Sugiyama, K. and M. Morishita. 2002. New Methods of Producing Diploid Seedless watermelon Fruits. JARQ 3: 177-182.
Voraquaux, F., R. Blanvillain, M. Delseny and P.Gallois. 2000. Less is better: new approaches for seedless fruit production. Trends Biotechnol. 18: 233-242.
Yamamuro, K. 1978. Effect of Growth Regulators on Fruit Setting of Watermelon. Bull. Ibaraki Hortic. Exp. Stn. 7: 1–15.
Yin, Z., R. Malinowski, A. Ziolkowska, H. Sommer, W. Plcader, and S. Malepszy. 2006. The DefH9-iaaM-containing construct efficiently induces parthenocarpy in cucumber. Cell Mol. Biol. Lett. 11: 279– 290.
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Organic Foods: Understanding Organic Food Labels, Benefits, and Claim

Organic food has become very popular. But navigating the maze of organic food labels, benefits, and claims can be confusing. Is organic food really healthier? Is it more nutritious? What do all the labels mean? Why is it so expensive? This guide can help you make better choices about which organic foods are healthier for you and better for the environment, and how you can afford to incorporate more organic food into your diet.

In This Article:

• What is organic food?
• The benefits of organic food
• Organic farming 
• Organic meat & dairy
• Understanding organic labels
• Cost of organic food 
• Enjoying the benefit of fish without harmful side effects

What is organic food?

Making a commitment to healthy eating is a great start towards a healthier life. Beyond eating more fruits, vegetables, whole grains, and good fats, however, there is the question of food safety, nutrition, and sustainability. How foods are grown or raised can impact both your health and the environment. This brings up the questions: What is the difference between organic foods and conventionally grown foods? Is “organic” always best? What about locally grown foods?

What does “organic” mean?

The term “organic” refers to the way agricultural products are grown and processed. Specific requirements must be met and maintained in order for products to be labeled as "organic".

Organic crops must be grown in safe soil, have no modifications, and must remain separate from conventional products. Farmers are not allowed to use synthetic pesticides, bioengineered genes (GMOs), petroleum-based fertilizers, and sewage sludge-based fertilizers.

What are Genetically Modified Organisms (GMOs)

Genetically Modified Organisms (GMOs) are plants or animals whose DNA has been altered. These products have undergone only short-term testing to determine their effects on humans and the environment.

In most countries, organic products do not contain GMOs.

Organic livestock must have access to the outdoors and be given organic feed. They may not be given antibiotics, growth hormones, or any animal-by-products.

Is organic food more nutritious than non-organic food?

The evidence is unclear. Some studies suggest that, on average, organically grown fruits and vegetables may contain slightly higher levels of vitamin C, trace minerals, and antioxidant phytonutrients than conventionally grown produce. However, other studies have found no nutritional differences between organic and non-organic foods.

The benefits of organic food

Organic foods provide a variety of benefits. Some studies show that organic foods have more beneficial nutrients, such as antioxidants, than their conventionally grown counterparts. In addition, people with allergies to foods, chemicals, or preservatives often find their symptoms lessen or go away when they eat only organic foods. In addition:

• Organic produce contains fewer pesticides. Pesticides are chemicals such as fungicides, herbicides, and insecticides. These chemicals are widely used in conventional agriculture and residues remain on (and in) the food we eat.

Why do pesticides matter?

• Children and fetuses are most vulnerable to pesticide exposure due to their less-developed immune systems and because their bodies and brains are still developing. Exposure at an early age can cause developmental delays, behavioral disorders, and motor dysfunction.
• Pregnant women are more vulnerable due to the added stress pesticides put on their already taxed organs. Plus pesticides can be passed from mother to child in the womb, as well as through breast milk. Some exposures can cause delayed effects on the nervous system, even years after the initial exposure.
• Most of us have an accumulated build-up of pesticide exposure in our bodies due to numerous years of exposure. This chemical "body burden" as it is medically known could lead to health issues such as headaches, birth defects, and added strain on weakened immune systems.

• Organic food is often fresher. Fresh food tastes better. Organic food is usually fresher when eaten because it doesn’t contain preservatives that make it last longer. Organic produce is often (but not always, so watch where it is from) produced on smaller farms near where it is sold.
• Organic farming is better for the environment. Organic farming practices reduce pollution (air, water, soil), conserve water, reduce soil erosion, increase soil fertility, and use less energy. In addition, organic farming is better for birds and small animals as chemical pesticides can make it harder for creatures to reproduce and can even kill them. Farming without pesticides is also better for the people who harvest our food.
• Organically raised animals are NOT given antibiotics, growth hormones, or fed animal byproducts. The use of antibiotics in conventional meat production helps create antibiotic-resistant strains of bacteria. This means that when someone gets sick from these strains they will be less responsive to antibiotic treatment. Not feeding animal byproducts to other animals reduces the risk of mad cow disease (BSE). In addition, the animals are given more space to move around and access to the outdoors, both of which help to keep the animals healthy. The more crowded the conditions, the more likely an animal is to get sick.

Organic farming and locally grown produce

Organic farming refers to the agricultural production systems that are used to produce food and fiber. Organic farmers don’t use synthetic pesticides or fertilizers. Instead, they rely on biological diversity in the field to naturally reduce habitat for pest organisms. Organic farmers also purposefully maintain and replenish the fertility of the soil. All kinds of agricultural products are produced organically, including produce, grains, meat, dairy, eggs, fibers such as cotton, flowers, and processed food products.

Essential characteristics of organic systems include:

• Design and implementation of an "organic system plan" that describes the practices used in producing crops and livestock products.
• Detailed recordkeeping systems that track all products from the field to point of sale.
• Maintenance of buffer zones to prevent inadvertent contamination by synthetic farm chemicals from adjacent conventional fields.

Organic vs. Non-organic Produce
Organic produce: No Pesticides Grown with natural fertilizers (manure, compost). Weeds are controlled naturally (crop rotation, hand weeding, mulching, and tilling). Insects are controlled using natural methods (birds, good insects, traps).	Conventionally grown produce: Pesticides used Grown with synthetic or chemical fertilizers. Weeds are controlled with chemical herbicides. Insecticides are used to manage pests and disease.

Locally Grown Fruits and Vegetables

What is local food? Unlike organic standards, there is no specific definition. Generally local food means food that was grown close to home. This could be in your own garden, your local community, your state, your region, or your country. During large portions of the year it is usually possible to find food grown very close to home at places such as a farmer’s market.

Why people buy locally grown food:

• Financial benefits: Money stays within the community and strengthens the local economy. More money goes directly to the farmer, instead of to things like marketing and distribution.
• Transportation issues: In the U.S., for example, the average distance a meal travels from the farm to the dinner plate is over 1,500 miles. This uses a lot of fossil fuels and emits carbon dioxide into the air. In addition, produce must be picked while still unripe and then gassed to "ripen" it after transport. Or the food is highly processed in factories using preservatives, irradiation, and other means to keep it stable for transport and sale.
• Fresh produce: Local food is the freshest food you can purchase. Fruits and vegetables are harvested when they are ripe and thus full of flavor

Small local farmers often use organic methods but sometimes cannot afford to become certified organic. Visit a farmer’s market and talk with the farmers. Find out how they produce the fruits and vegetables they sell. You can even ask for a farm tour.

Fruits and vegetables where the organic label matters the most
According to the Environmental Working Group, a nonprofit organization that analyzes the results of government pesticide testing in the U.S., the following 12 fruits and vegetables have the highest pesticide levels on average. Because of their high pesticide levels when conventionally grown, it is best to buy these organic:
Apples Bell Peppers Carrots Celery Cherries Grapes (imported)	Kale Lettuce Nectarines Peaches Pears Strawberries

Non-organic fruits and vegetables with low pesticide levels
These conventionally grown fruits and vegetables were found to have the lowest levels of pesticides. Most of these have thicker skin or peel, which naturally protects them better from pests, and which also means their production does not require the use of as many pesticides.
Asparagus Avocado Broccoli Cabbage Corn (sweet) Eggplant Kiwi Mango	Onion Papaya Pineapple Peas (sweet) Sweet Potatoes Tomatoes Watermelon

Does washing and peeling get rid of pesticides?

Rinsing reduces but does not eliminate pesticides. Peeling sometimes helps, but valuable nutrients often go down the drain with the skin. The best approach: eat a varied diet, wash all produce, and buy organic when possible.

Source: Environmental Working Group

Organic meat and dairy

Organic meat, dairy products, and eggs are produced from animals that are fed organic feed and allowed access to the outdoors. They must be kept in living conditions that accommodate the natural behavior of the animals. Ruminants must have access to pasture. Organic livestock and poultry may not be given antibiotics, hormones, or medications in the absence of illness; however, they may be vaccinated against disease. Parasiticide (a substance or agent used to destroy parasites) use is strictly regulated. Livestock diseases and parasites are controlled primarily through preventative measures such as rotational grazing, balanced diet, sanitary housing, and stress reduction.

Organic vs. Conventional Meat and Dairy
Regulations governing meat and dairy farming vary from country to country. In the U.S., these conventionally grown meats and dairy products were found to have the lowest levels of pesticides.
Organic meat and dairy: No antibiotics, hormones, or pesticides are given to animals Livestock are given all organic feed. Disease is prevented with natural methods such as clean housing, rotational grazing, and a healthy diet. Livestock must have access to the outdoors.	Conventionally raised meat and dairy: Typically given antibiotics, hormones and feed grown with pesticides Livestock are given growth hormones for faster growth. Antibiotics and medications are used to prevent livestock disease. Livestock may or may not have access to the outdoors.

What’s in American meat?

It is helpful to understand what the U.S. government allows in feed or to be used in conventional production:

• Dairy cows – antibiotics, pig & chicken byproducts, hormones (for growth), pesticides, sewage sludge
• Beef cows – antibiotics, pig & chicken byproducts, steroids, hormones, pesticides, sewage sludge
• Pigs – antibiotics, animal byproducts, pesticides, sewage sludge, arsenic-based drugs (growth hormones are prohibited)
• Broiler chickens – antibiotics, animal byproducts, pesticides, sewage sludge, arsenic-based drugs (growth hormones are prohibited)
• Egg laying hens – antibiotics, animal byproducts, pesticides, sewage sludge, arsenic-based drugs

Source: Meat, dairy, and eggs buying guide

Understanding organic food labels

What do the food labels such as “organic,” "natural," "free-range," and "non-GMO" really mean? Understanding this terminology is essential when you’re shopping for organic foods.

The most important point to remember is that "natural" does not equal organic. "Natural" is an unregulated term that can be applied by anyone, whereas organic certification means that set production standards have been met. These production standards vary from country to country—in the U.S., for example, only the "USDA Organic" label indicates that a food is certified organic. Similar certification labels are also offered on organic products in other parts of the world, including the European Union, Canada, and Australia.

USDA Certified Organic Food Labels in the U.S.

When you’re shopping for organic foods in the U.S., look for the “USDA Organic” seal. Only foods that are 95 to 100 percent organic can use the USDA Organic label.

• 100% Organic – Foods that are completely organic or made with 100% organic ingredients  may display the USDA seal.
• Organic – Foods that contain at least 95% organic ingredients may display the USDA seal.
• Made with organic ingredients – Foods that contain at least 70% organic ingredients will not display the USDA seal but may list specific organic ingredients on the front of the package.
• Contains organic ingredients – Foods that contain less than 70% organic ingredients will not display the USDA seal but may list specific organic ingredients on the information panel of the package.

Certified Organic Food Labels in other countries

European Union

Australian

Canadian

Meat and dairy labels: other terms you need to know

The organic label is the most regulated term, but when it comes to meat, we often see many other terms used. In order to make informed choices, it is helpful to know what some of these terms mean, although their use can often vary from country to country.

• Natural – In the U.S., this label means “minimally processed” and that the meat can’t have any artificial colors, artificial flavors, preservatives, or any other artificial ingredients in it. Animals can still be given antibiotics or growth enhancers. For example, this term can be applied to all raw cuts of beef since they aren’t processed.
• Grass fed – This term means that the animals are fed solely on a diet of grass or hay. These animals have access to the outdoors. Cattle are naturally ruminants that eat grass, so they tend to be healthier and leaner when fed this way. In addition, grass fed beef has been shown to have more of the healthy omega-3 fatty acids.
• Free range – Again the term “free range” means slightly different things in different parts of the world. Broadly, it means that the animals weren’t confined to a cage and had access to the outdoors. Unfortunately, in the U.S. at least, the animal density can still be very high and the animals may have only short periods outside in an area that’s quite small. Therefore, it is difficult to tell exactly what free range means when you see it on meat packaging in the U.S. You can contact the producer directly for clarification.
• No hormones added – In the U.S. and some other countries where the use of growth hormones is permitted, this term indicates that animals are raised without the use of any added growth hormones. For beef and dairy products it can be helpful, but by law, poultry and pigs cannot be given hormones, so don’t pay extra for chicken or pork products that use this label.

What does "Certified Organic" mean in the U.S.?

Keep in mind that even if a producer is certified organic in the U.S., the use of the USDA Organic label is voluntary. At the same time, not everyone goes through the rigorous process of becoming certified, especially smaller farming operations. When shopping at a farmers’ market, for example, don’t hesitate to ask the vendors how their food was grown.

Source: Organic.org

Tips for keeping the cost of organic food within your budget

Organic food is often more expensive than conventionally grown food. But if you set some priorities, it may be possible to purchase organic food and stay within your food budget. Purchase the organic versions of the foods you eat the most and those that are highest in pesticides if conventionally grown.

Venture beyond the grocery store. Consider the following ideas for finding organic food:

• Shop at farmers' markets. Many cities, as well as small towns, host a weekly farmers' market, where local farmers bring their wares to an open-air street market and sell fresh produce direct to you. Often you will find items for less than you'd pay in the grocery store or supermarket. Bonus: it's a great opportunity to socialize and get to know like-minded people in your neighborhood who might want to join a Community Supported Agriculture (CSA) farm or start a buying club with you.
• Join a food co-op. Find out whether there is a natural foods co-op, also called a cooperative grocery store, in your area. Co-ops typically offer lower prices to members, who pay an annual fee to belong. However, you do not need to be a member to shop at a food co-op.
• Join a Community Supported Agriculture (CSA) farm, in which individuals and families join up to purchase "shares" of produce in bulk, directly from a local farm. Local and organic!

Organic food buying tips

• Buy in season – Fruits and vegetables are cheapest and freshest when they are in season. You can also find out when produce is delivered to your market. That way you know you're buying the freshest food possible.
• Shop around – Compare the price of organic items at the grocery store, the farmer’s market and any other venue (even the freezer aisle!). Purchase the most economical ones.
• Remember that organic doesn’t always equal healthy – Junk food can just as easily be made using organic ingredients. Making junk food sound healthy is a common marketing ploy in the food industry but organic baked goods, desserts, and snacks are usually still very high in sugar, salt, fat, or calories.

Why is organic food often more expensive?

Organic food is more labor intensive since the farmers do not use pesticides, chemical fertilizers, or drugs. Organic certification and maintaining this status is expensive. Organic feed for animals can cost twice as much. Organic farms tend to be smaller than conventional farms, which means fixed costs and overhead must be distributed across smaller produce volumes. Most organic farms are too small to receive government subsidies.

Enjoying the benefit of fish without harmful side effects

There is a lot of confusion surrounding the healthfulness of seafood. Fish is low in saturated fat and can be a good source of high-quality protein, omega-3 fatty acids, and other essential nutrients. Yet common toxins such as mercury are also found in fish. What does this mean? How much is okay? Which fish are safe?

Each year dangerous quantities of mercury are emitted into the air (an aspect of widespread industrial pollution). When it rains, this pollution goes into our lakes and oceans where it contaminates the fish and shellfish that live there. Seafood can contain harmful chemicals such as mercury, PCBs, chlordane, dioxins, and DDT. This is a problem because eating fish contaminated with mercury, a poison that interferes with the brain and nervous system, can cause serious health problems. The top predators, such as sharks, contain the highest levels of these contaminants. Nursing mothers, pregnant women, women who may become pregnant, and young children have the highest risk, so are advised to avoid all large fish (shark, swordfish, king mackerel, tilefish, etc.).

In recent years there has been a huge decline in many species of fish, caused by unsustainable fishing and farming practices. This means that if changes are not made soon, many wild populations of fish may become extinct.

Sustainable seafood choices

Seafood can be part of a healthy diet if you know what type of fish to choose. There are a number of smartphone apps and downloadable wallet-cards for you to keep on hand to use in the grocery store or a restaurant. These guides are updated often and contain the latest information on healthful and sustainable seafood choices. Find links in the Resources section below.

Source: HelpGuide

Hydroponic: Lettuce garden in plastic bottles

I have no land to grow a garden, But I do have windows that get plenty of sunlight.  I wanted a compact, low maintenance way of quickly growing lettuce and other small, fast growing plants.
My goals were:
cheap: I'm not looking to spend much money on this project, so cheap is good, and free is better. After all, that's why we're doing it ourselves, right? I got pretty much all my materials from recycle bins at work or other household items. The few things you would have to buy cost less than $10, and provide enough material for many of these bottles.
It's easy: No expensive tools or equipment, no expertise, just scissors, and an "exacto knife" or other sharp pointed blade.
low maintenance. Once you set it up, it requires no watering, no fertilizing,
no electricity: There are no air or water pumps. The roots get oxygen by forming aerial roots above the surface of the water as the water level drops.

The materials are easy to find: anybody, anywhere can find the materials for this project. You can use almost any kind of plastic bottle with relatively smooth straight sides, from 24 oz up to 2 litre bottles and beyond. Water bottles, Soda bottles, fruit smoothie bottles, square bottles, round bottles, whatever. The growth media is made from easy to find products, for $5 you can buy enough to fill hundreds of these bottles. I've also been experimenting with using water from a fish tank as fertlizer, with good results so far.
It works: So far it's been working great. the plants are healthy and are growing quickly. The roots look healthy and are not rotting or showing signs of lack of oxygen. The leaves are nice and green and show no signs of nutrient deficiencies. A hydroponic system should work as well or better than a soil based system, otherwise, what's the point.
It's compact. the smaller bottles take up about 3 inches of a windowsill, and the larger (2 liter) bottles take up only 5 inches, so you can fit several in a window. You can also hang bottles to use the vertical space of the window. I'm still working on an easy way to hang them. When I get it right I'll post that part. too.

Step 1: Materials Needed

Materials needed
A plastic bottle: Any size larger than 23 oz. Large 2L bottles work very well, but smaller bottle work fine for small plants like lettuce. you're only growing these for about a month, so it doesn't need to be huge. Also, the sides must be fairly straight and smooth, especially near the "shoulder". Bottles with lots of grooves or ridges don't work well. I've used round bottles and square bottles, they both work fine. Bottles with slightly thicker and stiffer plastic work quite well.
A Shower Scrunchie: one of those plastic mesh shower sponge thingies. they consist of about 10 feet of mesh, which is actually a hollow tube of mesh folded and tied into a compact shape. One of these is enough mesh to make dozens of grow bottles.
Scissors: nothing fancy.
a knife: a very sharp utility knife or exacto knife with a sharp tip.
aluminum foil: To protect the roots from direct sunlight. I grew one plant for a few weeks without the foil, and it didn't seem to really harm the roots, but they did grow away from the sun, rather than growing straight down like the others. You are also likely to develop a problem with algae if the roots and liquid media is exposed to direct sunlight, and this will quickly consume the nutrients and foul the water. You could probably use something that looks nicer, if that's important to you.
(update: after a few more weeks, the plants without foil around the water reservoir did develop serious algae problems, and were noticeably smaller than the ones that were covered)
tape: regular clear office tape.
Seeds: I'm using lettuce, because it's fast growing, and has a shallow, fibrous root system. Bibb lettuce apparently works very well, although I'm using a red leaf lettuce. Try other things, and let me know how they work. larger plants would obviously require larger bottles. A packet of lettuce seeds contains hundreds of seeds, so you don't need to buy a lot, and share the extras.
Growth media: You could buy ready made hydroponic growth media, but it's expensive. You can easily make growth media from store bought fertilizer and epsom salts, with home made egg shell extract for calcium and micro-nutrients.  A small box of fertilizer costs about $3, and box of epsom salts is about 99 cents. You only use a tiny bit of each, so even the smallest box of fertilizer can make enough media for hundreds of grow bottles. Egg shells are basically free, assuming you eat eggs once in a while. A single egg shell dissolved in lemon juice will be enough micronutrients for several bottles.

Step 2: Start your Seeds

I started my seeds in plastic egg cartons filled with soilless seed starting mix. I transplanted them to the grow bottle when they had a few real leaves. You could probably just directly start the seeds in the completed grow bottle. This would be easier on the seedlings and would prevent transplant shock.
Don't want to spend money on seed starter mix? take a shovel, trowel, or your hands, and go outside. There's an awful lot of soil out there in the woods, and nobody's going to miss a few handfuls of it. This is slightly cheating if you're a real hydroponic purist, since technically hydroponics doesn't use soil, but I won't tell if you won't
To make the egg carton seed starter, just go buy some eggs, the fancy ones in the clear plastic carton. You'll use egg shells in your growth media, and eggs are tasty, so nothing goes to waste. The plastic carton has three folding sections; two "egg cup" sections that cradle the eggs, and one flat lid. 
Cut the flat lid off, and use it as a tray to hold water. Then poke some holes in each of the egg cups to let water drain out. use the other section of egg cups as a lid, to form a dozen tiny greenhouses. Water it once, plant the seeds, and leave them alone for a week.

Step 3: Cut the bottle

Cut the top off the bottle about half an inch below the "shoulder" of the bottle. The exact height will vary from bottle to bottle. As long as you cut at the level where the sides are straight, and not the part where the bottle narrows towards the neck, you should be fine.  Leave about half an inch of straight side on the "top" part of the bottle, so that it will grip the sides of the "bottom" when you flip it over.
Trace the line with a marker placed on an object of the correct height, such as a stack of books.
Carefully puncture the plastic with the blade and cut along the line. Go slowly, it's easy to cut a crooked line if you go too fast.
You may want to cut a pull tab on one side, so that you can easily remove the top.
Cut a dime sized air hole (or several) about an inch below the top. This provides air flow to the bottom root chamber. It also allows you to add or remove water once the system is set up. A turkey baster works well for adding water, and you can remove water by simply pouring it out this hole. You can cover the hole with tape for transportation to prevent spills.

Step 4: Cut the cap

Cut a hole in the cap, but leave the threads alone. Use a sharp exacto knife, and be extreeeeemly careful.
Place the cap upside down on a book, with one edge just a bit over the edge. hold it firmly in place and make sure no part of your hand is under the cap, just in case the knife pokes through too far.
Poke with the exacto knife down through the inside of the cap, at the edge. You'll notice that the blade will cut in one direction.
Keep poking the blade through, about a blade width away from the previous cut, so that the blade cuts back towards the previous slit.
I told you to be careful, so don't come crying to me if you cut yourself. You've been warned.

Step 5: Add the mesh to the cap

Take your mesh shower scrunchie and cut the string that holds it together so the whole thing can be unwound. Cut off a bit of the mesh, just a few inches, and stretch it over the mouth of the bottle. Then screw the cap on over that. Cut away the excess. You should end up with a funnel capped with mesh at the mouth. This will keep the plant and support media from falling into the water.

Step 6: Make the aerial root support basket

Your plant's roots need support, especially the roots that will be above water. Without support the aerial roots will clump together and won't absorb as much oxygen. Take the long tube of mesh and tie a knot in one end. pull the knot tight and cut off the excess. Cut off about 6 inches of mesh, so that you have a mesh bag with a knot at the bottom.

Step 7: Mark water level

Put the whole thing together to see how it all fits, and to figure out your water level.Place the mesh basket around the upside down funnel, so that the mesh hangs loosely, about an inch below the mouth of the funnel. Don't pull it up tight against the funnel, you want some space between the funnel and the root support mesh. Now press the funnel down into the base so that the mesh basket is held in place between the funnel and the base. If everything fits together well, mark the side of the bottle at the the level of the mouth of the funnel. The easiest way is to just pour some water in until the mouth of the funnel is just barely touching the water.

Step 8: Make hydroponic fertilizer growth media.

If you are making hydroponic growth media from fertlizer, here's the recipe I've used, with pretty good success so far.
in 1 L (32 oz) water, dissolve:
1/8 teaspoon bright blue name brand plant food which shall remain nameless.
1/16 teaspoon epsom salts. you can get this at any drug store. Get the plain kind without any aloe or mint or fragrance or other additives.
5 drops egg shell extract (see below)
(second update: I've updated the media recipe to half the strength of the previous recipe. I've been using the half strength recipe (shown above) for a few weeks, and the plants are now large, healthy, and are growing very quickly.)
For calcium and micronutrients we will use eggshell dissolved in lemon juice, which produces calcium citrate, and a bunch of other dissolved elements. This also helps buffer the pH, since growth \ media tends to get too basic (high pH). Egg shell contains calcium, magnesium, and all the other micronutrients needed by plants, in approximately the right proportions. How convenient!

Take an eggshell, leave the membrane intact, and let it dry. Then crush it as finely as you can, membrane and all. Then dissolve it in lemon juice using these measurements:
1/2 teaspoon of dried powdered eggshell
The juice of half a lemon (about 1 1/2 tablespoons).
Leave it overnight in a covered glass or jar to dissolve. It's ok if it's a bit gritty or some of it doesn't dissolve.
This is enough for 2 L of growth media, so only add half (about 1 tbsp) if you are making a 1 litre batch.
I'm still experimenting with using fish tank water, so I'll post another instructable if that works out. So far so good. In fact, the bottles with fish tank water seem to have more extensive root systems.
(update on fish water)
The fish water experiment had unusual results. the plants grown in fish tank water had very extensive roots, but significantly less leaf growth. I'll have to collect more data to see if this is just by chance or an actual effect of the growth media.

Step 9: Assemble the grow bottle

If you are transplanting from seedlings, gently scoop out your seedling with a bit of seed starter meda around the roots and place the root ball into the funnel, and gently press it down into the bottle cap. Remove excess soil if it won't fit. You should only have enough media to hold the stem upright, maybe an inch deep, just enough to fill the bottle cap.
pour a bit of water into the funnel and let it drain out though the mouth (into a bowl or something). This will flush out some of the particles that would otherwise cloud your water. It also helps to flush the roots down through the mesh.
If you are starting the seeds in the funnel, just fill the cap with about an inch of seed starter, soil, sand, or vermiculite and plant the seed. I know that technically starting seeds in dirt, or anything resembling dirt, is not pure hydroponics, but I don't really care. If you are a real hydroponic purist, start the seeds in vermiculite, peat, rock wool or whatever you prefer.
once your seeds or plants are in the funnel, fill the base with growth media up to the line you marked in step 7 and assemble the bottle.

Place the mesh root support bag around the upside down funnel, so that the mesh hangs loosely, about an inch below the mouth of the funnel. Don't pull it up tight against the funnel, you want some space between the funnel and the root support mesh. Now press the funnel down into the base so that the mesh basket is held in place between the funnel and the base.
Cover the area below the water level with foil to block some of the light. I just loosely wrap a skirt of foil and loosely tape it, so I can remove it to check the roots.

Step 10: Care and feeding

Once assembled, this system should require almost no care at all. You will not need to water or feed it. The shape of the funnel will keep the plants upright as they grow, but you might want to rotate the bottle so they don't lean towards the sun and get lopsided.
The water level should drop once the plant starts consuming water. This will expose the upper part of the roots, which is good. You want the roots to be able to breathe.  The air hole allows just enough air flow for the roots to breath, without letting them dry out. The exposed upper roots will not dry out, because the enclosed air space above the water is extremely humid. You should quickly see this area get fogged with condensation.
let the roots stay submerged until the roots extend through the mesh bag by a few inches. this will ensure that the aerial roots do not cling together.  If the water level doesn't drop fast enough, pour out a bit of water so that the upper part of the roots are above water. the roots should be about 1/3 exposed.

Step 11: Update

Update:
OK, so it's been about a few weeks since I posted this project, and it's gone fairly well. When I posted, the plants were relatively young, only about a 10 days old, with three or four leaves. They are now quite large, and I've actually picked and eaten some tasty lettuce.
Here's what I've learned.

• Algae is the enemy: If light shines on your growth media, it will quickly be overgrown with algae. This will not necessarily kill the plant, but it will quickly deplete the nutrients in the media and slow the growth of your plant. It also looks gross to have a bottle of green goo in your window. So wrap the bottle tightly in foil, top to bottom, including the funnel. You could also probably sterilize the media by microwaving it and allowing it to cool. That will kill most bacteria and algae.
• Watch your water levels and roots: When the plants get large, they start to consume large amounts of water. In a mature lettuce plant, they can suck up half an inch of water per day. You will need to top off the water level every few days, (I use a turkey baster) or the roots will be left high and dry, and the plant will quickly wilt and die. If you see a plant looking droopy, check to see if the roots are still touching the water. When topping off media, just add water, no need to add new fertilizer unless the leaves are looking yellow, and in that case it's probably best to completely change the media.
• Half strength media works fine. The media recipe I included is a bit too strong. I've been using a half strength recipe and it's worked well. So for a litre/quart of media that would be 1/8tsp fertilizer, and a tiny pinch of epsom salts (a few crystals), and a drop or two of eggshell extract. I'm going to revise the recipe in the original instructable.

Hydroponics for Home Gardeners

By: J. Raymond Kessler Jr., Extension Specialist, Associate Professor; J. David Williams, Department Head and former Extension Specialist; and Robyn Howe, Undergraduate Student, all in Horticulture, Auburn University

For centuries, civilizations throughout the world have experimented with soilless gardening, from the ancient Babylonians to the Aztec Indians. Marco Polo spoke of China’s magnificent floating gardens, and there is documentation that the Egyptians practiced primitive hydroponics. It was not until the 1930s, however, that this “new” form of gardening began to receive notice due to the notable experimentation of Dr. W.E. Gericke of the University of California. Gericke, often called the “father of modern hydroponics,” coined the term hydroponics, which literally means “working with water.” Since that time, many developments have been made, and hydroponic gardening continues to grow and thrive in popularity and usage.

Hydroponics is, simply put, growing plants without soil. The discovery was made years ago that it was not the actual soil that plants need to grow is the mineral nutrients held by soil particles or those unleashed through the action of bacteria and worms. The nutrients slowly dissolve in the surrounding soil-water solution, and the roots then absorb the nutrients from the soil-water. All plants have the same basic needs whether they are grown in soil or not. When the plant’s nutritional needs are met, soil is no longer necessary. In fact, the soil may harbor pathogens and other organisms that could harm the plant. In hydroponics, all the nutrients are supplied in a water solution that passes over the roots or floods around them at regular intervals. Plants often grow faster in a hydroponic system because nutrients are immediately available and therefore can be assimilated faster.

When experimenting with hydroponics, as with all other gardening techniques, it is important that the gardener know the basic physiology of the plant that is, how the plant works. Plants use their roots to draw in water and minerals that are trans-ported upward into the leaves. They also take in oxygen and release carbon dioxide in respiration.

The leaves absorb energy during the day from sun-light and take up carbon dioxide from the air. The water from the roots, the carbon dioxide, and the light energy combine to form carbohydrates such as sugar. The plant then releases oxygen back into the atmosphere. These actions, aided by the nutrients gleaned from absorbed minerals, complete the process of photosynthesis, providing the energy and raw materials for growth. At night, the process reverses in the leaves. Carbohydrates break down, releasing the energy needed to create new leaves, stems, and roots, and carbon dioxide is released.

Plants, much like human beings and animals, re-quire water, air, food, light, and warmth in order to perform these essential physiological processes and, as a result, to grow and reproduce. The basic hydroponic system should fill the needs of the plant’s roots just as the earth would by providing support, oxygen and carbon dioxide exchange (via the substrate), and water and nutrients (via the nutrient solution). Adequate light and warmth complete the minimal requirements for successful hydroponic plant growth.

Substrate

In order to serve as a suitable replacement for soil, the substrate must be capable of supporting the root system and holding moisture and nutrients. It should be inert, free of insects and diseases, and not easily broken down. Also, the substrate should allow adequate aeration of the roots and have good drainage qualities. Plants need sufficient access to oxygen in the air in order to grow and take up water and nutrients. Poor drainage can lead to de-creased growth, stunting, wilting, and discoloration of the leaves and, in the worst cases, “drowning.”

Several commonly used substrates are coarse sand (ask for washed river sand), gravel, perlite, coarse vermiculite, and rock wool. Perlite and coarse vermiculite are good choices because they are sterile, uniform, and readily available in garden centers. Sand and gravel also work well but should be washed thoroughly before planting to remove lime or other impurities.

Water

Mature plants process a surprisingly large amount of water. For instance, a fully grown to mato plant may use up to 2⁄3gallon of water a day. An inadequate water supply is the most limiting factor to plant growth. Water deficiencies can cause the plant to spend all its available energy on developing an extensive root system, the result being a small, stunted shoot. For this reason, it is important that the media be flooded, and subsequently drained, one to three times daily or as often as necessary to keep the roots moist.

Light

The amount of light required varies from plant to plant. Most fruiting plants such as corn, tomatoes, and peppers need 8 to 10 hours of sunlight a day. If these plants are grown indoors, an artificial light must be used to provide high light intensity without causing the temperature to rise above acceptable levels. This situation may be difficult to achieve. On the other hand, many ornamental and foliage plants require less sunlight than fruiting plants do and therefore perform very well indoors. One common error in applying hydroponics is trying to grow plants in reduced light when full sun is required.

Temperature

Warm-season plants perform best when the temperature is between 70 and 80 degrees F during the day and 60 to 70 degrees F at night. Cool-season plants generally require temperatures approximately 10 degrees lower than those suitable for warm-season plants. Above or below this range, plant growth will slow dramatically. Therefore, it is important that these temperatures be maintained whenever possible.

Nutrients

The key ingredient in the recipe for successful hydroponic gardening is the nutrient solution. In traditional soil-based gardening, the plant receives fertilizer from the slow breakdown of organic materials and the release of mineral nutrients in the soil. Hydroponic systems provide readily available, water-soluble minerals directly to the roots in a complete and balanced solution, thus eliminating the need for soil.

There are sixteen elements needed for plant growth. Plants extract several of these elements, such as oxygen, carbon, and hydrogen, from water and air. The rest of the elements must be supplied through the nutrient solution.

The primary macronutrients are nitrogen (N), phosphorus (P), and potassium (K). The secondary macro-nutrients are calcium (Ca), magnesium (Mg), and sulfur (S). These distinctions are made based on how much of each nutrient plants need. Micronutrients, or trace elements, such as iron (Fe), manganese (Mn), boron (B), molybdenum (Mo), zinc (Zn), copper (Cu), and chlorine (Cl) are used in very small amounts by plants, hence the name micronutrients. Micronutrients are sometimes present as impurities in the water and in the solid substrate.

Nitrogen

Nitrogen is central to the development of new leaves and stems as well as to overall growth and performance. An overabundance of nitrogen causes soft, weak growth and possible delay of fruit and flower production. Symptoms of nitrogen deficiency are yellowing leaves and weak, spindly growth.

Phosphorus

Phosphorus is used by the plant in photosynthesis and in the production of flowers and seeds. It also encourages strong root growth. When phosphorus levels are low, the older leaves begin to turn deep green and develop brown or purple dis-coloration. Other symptoms may be stunted growth and chlorosis, or yellowing, of the lower leaves.

Potassium

Potassium is necessary during all stages of growth, particularly during fruit development. It is involved in the manufacture of sugars, starches, and chlorophyll. Potassium helps the plant make good use of air and water by regulating stomatal openings in the leaves and also helps build strong roots. Deficiency symptoms are mottling and yellowing of older leaves, generally along the margins, and flower and fruit drop.

Calcium

Calcium is used by the plant in the manufacture and growth of cells. It also acts as a buffer for excess nutrients in soil. Calcium deficiency is recognizable by the curling and stunting of young leaves and dieback of the shoot tip. Too much calcium can stunt the growth of a young plant.

Magnesium

Magnesium is fundamental in the absorption of light energy and is central to the structure of the chlorophyll molecule. Symptoms of magnesium deficiency include curled leaf margins, yellowing of older leaves (veins remain green), and, eventually, bright green coloration of the growing tips.

Nutrient Solutions

The elements needed for successful hydroponic growth are widely available in premixed form from gardening catalogs, garden centers, fertilizer companies, and hydroponic supply companies. Most hydroponics amateurs will rely on these commercially available mixes rather than preparing their own solutions at home.

However, for those enthusiasts who are willing to mix their own, the extra time and effort may offer more precise nutrient combinations for specific plants, as well as provide an opportunity for experimentation. Many nutrient solution recipes have been developed, some for general use and others for specific plants, and no one recipe is better for all plants than another. Hydroponic nutrient solutions contain several water-soluble, nutritive salts that can be purchased at fertilizer companies, green-house supply companies, and chemical companies.

The primary and secondary macronutrient salts are usually mixed in a large volume of water at a concentration ready to use on plants. The micronutrients are mixed as separate concentrated solutions that are then added in a measured amount to the macronutrient solution.

To make your own solution, mix 10 gallons of macronutrient solution according to the recipe in either Table 1 or Table 2. Nutrient solution No. 1 is more appropriate for slow-growing plants and plants growing under low light intensity, such as foliage plants. Nutrient solution No. 2 is more appropriate for rapidly growing plants and plants under high light intensity, especially vegetables. Next, mix the following two micronutrient solutions, and add each to the macronutrient solution.

• Mix 7.6 grams (11⁄4level teaspoons) of boric acid (H3BO4) and 0.6 grams (1⁄10teaspoon) of manganese chloride (MnCl2• 4H2O) in 1 quart of water.

Use 1⁄2cup of this solution for 10 gallons of macro-nutrient solution.

• Mix 3 grams (1⁄2level teaspoon) of chelated iron (NaFe EDTA) in 1 quart of water. Use 1 3⁄5cup of this solution for 10 gallons of macronutrient solution.

After mixing the nutrient solutions together, check the pH. (Meters for measuring pH can be purchased from garden and hydroponic supply companies.) Most plants grow well in a slightly acidic solution with a pH of 5.5 to 6.5. If the solution is too alkaline (pH greater than 7.0), add a few drops of white vinegar per gallon, stir, and recheck the pH. If the solution is to acidic, add a small amount of baking soda per gallon to increase the pH. Continue rechecking and making adjustments until the desired pH level is reached.

The nutrient solution can be reused for 10 to 14 days when applied one to three times a day. At the end of this period, flood the substrate with clean water and drain it several times to wash out any accumulated materials. Mix and add a new solution.

Simple Hydroponic Systems

The simplest hydroponic system for beginners is a non recycling system consisting of a well-drained container filled with an acceptable A larger-scale version of the recycling method involves using a container that has a hose and an outlet an inch or two from its base. The container must be raised off the floor and tilted so that the nutrient solution drains through the outlet into a receptacle. These simple hand-fed methods work best with small-scale systems. For larger systems, a submersible pump can be used to pump the solution back into the container from the receptacle substrate. The nutrient solution is mixed, and then it is applied one to three times daily, using a simple watering can. The excess solution drains away and is lost.

A more economical technique is the recycling method, which involves collecting and reusing excess solution. The simplest version of this technique involves placing a large dish under the plant container to catch the solution and then pouring the solution back over the plant at regular intervals.

In addition to the systems that require a substrate, there are non aggregate methods such as water culture and aeroponics. In water culture, the plant’s roots are kept submerged in the nutrient solution. The plants are supported by a grid of wire, rope, or string or by coarse screening. This method, however, introduces aeration problems and re-quires an aquarium pump to bubble oxygen into the nutrient solution.

One simple version of water culture for a single plant consists of using a pint- to quart-sized glass or plastic bottle or jar that has a stopper or lid with two holes in it. The stem of a young plant is passed through one hole so that the plant is held above the nutrient solution and the roots are in the nutrient solution. The plant’s stem is surrounded with cotton for support. The nutrient solution is aerated by an aquarium pump. The plastic tube from the pump is passed through the second hole in the lid and into the nutrient solution. The container is covered with aluminum foil to keep light off the root system.

In aeroponics, the plant’s roots are suspended in air and are regularly misted with a fine spray of nutrient solution. Misting must occur often enough to cover the roots with a constant film of nutrient solution at all times. The misting chamber must be kept dark so algae does not grow and compete with the roots. This method requires more mechanical and electrical sophistication than the previous methods do. The methods that use a substrate are generally less expensive, are easier to transplant from, and have fewer difficulties than the water or aeroponics methods do.

Getting Started

It is important that the beginner keep in mind that hydroponics is not the perfect solution to all gardening woes. There are pros and cons to both traditional soil-based gardening and hydroponics. One major disadvantage of hydroponics is the commitment of time and energy necessary for success. Soilless gardening is much more exacting than traditional gardening and may overwhelm the novice gardener if too complex a system is implemented.

Begin with a small project such as an herb garden to get a feel for hydroponics, and, as your knowledge and comfort increase, move on to a more elaborate system.

^{Source: Alabama Cooperative Extension System}

Cultural Methods of Vegetable Disease Control

Most vegetables are susceptible to one or more diseases. You can, therefore, anticipate disease problems sooner or later in your vegetable garden. By following good cultural practices and taking preventive measures, your chances of garden failure due to disease problems can be reduced.

Garden site selection is important to pro-duce high yields of healthy vegetables. Trying to grow vegetables on a poor site is one of the main causes of garden failure. Although few people will have ideal garden sites, they should select the best site available.

Garden sites should not be within the drip line of large trees. Avoid planting near black walnut trees, since they produce a root sub-stance that is toxic to certain vegetables, especially tomatoes. The garden site should be slightly sloped to provide good water and air drainage through the soil.

Excess soil moisture can damage vegetable roots, as well as promote root diseases caused by certain fungi. Air movement through the garden is also important to help dry the foliage, thus reducing the chances of fungal and bacterial infections. Garden sites with good air drainage are less likely to be damaged by late frosts.

Most garden vegetables require full sunlight for maximum production. Sunlight also hastens drying of foliage. Soil tillage should be done early enough, prior to planting, to allow decomposition of raw organic matter such as manure or green plant material. This usually requires about six weeks under warm temperatures and longer at low temperatures. Organic material that has not decomposed can be a source of disease organisms and can also promote development of certain diseases such as root and stem rots. Applying nitrogen fertilizer before plowing or tilling green plant material into the soil will hasten its de-composition.

Crop rotation will help prevent the buildup of disease-causing organisms in the soil. Some disease causing organisms affect one vegetable or group of vegetables, but may not affect an-other. Several vegetables of the same family, such as squash, cucumbers and cantaloupes, may be affected by the same disease. Therefore, it is not a good practice to grow plants of the same family in rotation. Table 1 gives crop groupings for rotation to control soil-borne diseases. At least a three-year rotation is suggested for vegetable crops.

Sanitation is very important in controlling vegetable diseases. Many disease-causing organ-isms survive the winter in plant debris, cull fruit or plant stubble left in the garden. Any practice that will eliminate these overwintering sites for fungi, bacteria, viruses and nematodes will reduce the occurrence of disease problems the following year. Removal or plowing-under of crop stubble and trash helps destroy overwintering populations of disease organisms. Some disease-causing organisms are able to survive the off season on contaminated equipment or containers. Equipment that has been used in disease-infested vegetable gardens or containers used in handling diseased vegetables should be disinfested before being used again.

Disease-free seed and transplants are a must in vegetable production. Seed should not be saved from diseased plants. Always buy seed from a reputable dealer, since you normally cannot tell from their external appearance if seed are contaminated with disease-causing organisms.

Certain geographical areas, such as the arid western states, can produce disease-free seed because of climatic conditions. Seed from these areas should be stipulated in your seed orders. Gardeners starting their crop from transplants should, likewise, insist on disease-free plants.

Seed treatments vary, depending on the crop as well as the disease to be controlled. Some disease-causing organisms are carried on the surface of seed and can be controlled by a simple fungicide treatment. Fungicides are not effective against those organisms carried beneath the seed coat.

Fungicides applied to seed also give young seedlings some protection from soil-borne disease organisms as they germinate and emerge. Such treatments, however, do not control organisms that attack the plant after the seedling stage.

A seed treatment is usually applied by the company from which the seed is purchased. Home-grown seed can be treated at home with relative ease. Thiram or Captan fungicides can be used as seed treatments on most vegetable crops. Use these protectant fungicides according to instructions on the label. For small quantities of seed, such as packets, apply sufficient fungicide to coat the seed surface. Simply place a small quantity (comparable to the size of a match head) in the packet, reclose and shake to coat the seed with the fungicide.

Planting dates can be an effective tool in reducing diseases of vegetables. Okra, for in-stance, requires warm soil for good germination and growth. If planted when the soil is still cold, the seeds will rot, or if they do germinate, they will probably develop damping-off or stem rot. Some crops, such as corn and beans, should be planted as early as the weather permits to escape severe virus infections. Aphids that transmit viruses are usually at lower population levels early in the season.

Mulches can be used to conserve moisture, keep fruit clean and prevent diseases. Mulches reduce fruit rot on crops, such as strawberries, tomatoes, squash, cucumbers and melons by preventing direct contact with the soil. Mulching will reduce splashing of soil onto lower fruit and foliage by rain.

Staking or trellising tomatoes, pole or half runner beans and cucumbers will prevent soil contact with the foliage and fruit. Air circulation will be better if these plants are trellised, thus promoting better drying of foliage and reducing diseases. Pesticides can be more effectively applied to trellised plants.

Watering can influence the development and severity of many foliage diseases. Wet foliage is favorable for the development of most diseases. To reduce infections, apply irrigation water to the soil rather than the foliage. If water must be applied to the foliage, then it should be done in late morning or mid-afternoon to allow the foliage to dry before evening.

Maintaining uniform soil moisture can re-duce problems such as blossom end rot of pe-pers and tomatoes. Excessive soil moisture can result in increased root and stem rot diseases. It is best to work in the garden when the foliage is dry to reduce disease spread. Bacterial diseases of tomatoes, beans and other crops are readily spread on hands and clothing of workers when the foliage is wet.

Use of resistant varieties is one of the most economical ways of controlling vegetable diseases. Resistant varieties should be used in areas where diseases are present or where the soil is known to be infested with disease-causing organisms. Resistant varieties should be used even when rotation is practiced.