Category Archives: Hydroponics

Pythium: an In-depth Analysis

Previously classified as a fungus, and sometimes called water fungus, Pythium is a type of plant parasite. Since Pythium is a genus, there are dozens of species classified under this name, and they affect all kinds of plants. One thing to keep in mind is that one species – Pythium insidiosum is a pathogen that animals need. However, the other dozens of species are usually parasitic. They are often passed on from the feet of the fungus gnat.

Hydroponic ArugulaThe Commonly Known Root-Rot

The major thing that Pythium is famous for is causing root-rot, something that can do serious damage to plants and rocks. Most of the time, at least in the United States, root-rot is caused by the species Pythium irregulare, P. aphanidermatum, P. ultimum and P. cryptoirregulare. Species of Pythium can be found in all sorts of soils, sand, ponds, streams and sediment beds as well as in the dead roots of last year’s crops. You will almost never get this problem from commercial potting soils but can be easily introduced through walking on your mix or letting your pets roam free on it, as well as by using dirty pots and tools that could contain Pythium.

Symptoms of Pythium

So, what symptoms might you experience if you have a case of the Pythium parasite infesting your plants? There are a number of warning signs to look out for. Here are just a few that should give you a good indication of whether or not you are currently experiencing an infestation from one of the dozens of species of harmful Pythium.

  • The root tips of the plant are brown and dead. Obviously, this will require that you pull up the roots and look at them, but this should be a symptom you should check after you have noticed some of the others on this list.

  • During the day you notice that your plants seem to wilt, but they get better overnight.

  • You notice that some plants are much smaller and not as healthy as the ones around them.

  • Your plants die, but only after turning yellow.

  • There is brown tissue outside of the root and you can pull it off and expose the vascular tissue beneath.

  • If you look at root cells under a microscope, you will notice round spores that have thick walls.

What to do if you Have Root-Rot

Unfortunately, if root-rot has already taken hold, you may not have much success in removing it. Most experts highly recommend that you do everything you can to prevent root-rot in the first place, because once you get it, it can be almost impossible to eradicate. Let’s first discuss what kind of things you can do to prevent root-rot and then talk about some of the things that might work to kill the parasite once it has infested your plants.

Preventing Root-Rot in the First Place

One of the things that you can do to prevent root-rot in the first place is using potting soil that has been pasteurized using heat. What you want is for it to have been heated up to 180 degrees for about 30 minutes. You don’t want any more than that, or any hotter, because it will kill the good bacteria in the soil.

Check your irrigation water carefully if you are getting it from a pond. Pond water can leak sediment through the intake pipe. If you are experiencing a Pythium parasite infection and you think that your irrigation water might be to blame, you should treat it before using it to water your crops or plants. Filtering the water through something like a sand filter will get rid of the parasite before it reaches your crops.

If you are using a flood and drain irrigation system, check your reservoirs. You might have to keep them covered to prevent debris from getting in. You should also pass water through some kind of a filter when it returns so that the potting soil and plant matter can be eliminated from the water before it gets into the reservoir.

Clean all of your tools, pots, benches and anything that could pass on the parasite with a disinfectant. You should also clean your irrigation pipes, reservoir beds, benches and flood and drain floors once in a while as well.

If you have a greenhouse and you have had root-rot from Pythium before, consider adding some type of fungicide to your crop cycle as soon as you can. For example, you can add these bio-agents to potting mix before the transplant, as well as afterward. You might need to apply them more than once and keep in mind that you can’t use pesticides for about two weeks prior to, or after, adding the fungicide to your potting mix.

tomatoes in a glasshouseGetting Rid of Root-Rot from Pythium

If you want to get rid of root-rot after your plants have already been infected, you’ll have a hard road ahead of you. The first thing you want to do is watch out for the warning signs. If your crops or plants seem stunted or have wilted, the first thing to do is check the roots for root-rot. If you do, you may be able to act in time to save your crop. Remove the plant from the container and look for brown roots that are mushy, look for brown lesions on the roots or discoloration. If the roots appear to be decaying, you may have root-rot and if you can detect it early enough, you might be able to get rid of it.

The best way to get rid of Pythium root-rot is using a fungicide as mentioned in the section on preventing it. If the parasite infection hasn’t reached an unmanageable stage, you might be able to kill it with the fungicide. Some of the products on the market are fungicides that contain these products, which have been shown to be most effective at getting rid of root-rot. However, again, bear in mind that it is much easier to prevent it in the first place than to kill it once it happens.

  • Etridiazole

  • Fenamidone

  • Fosetyl-Al

  • Mefenoxam

  • Pyraclostrobin

The Advantages and Challenges of Hydroponics

Table HydroponicsHydroponics is a form of hydroculture that allows for the more efficient growth of plants and vegetables on a large scale. The idea is simple: you do away with the usual ‘medium’ used for growing and instead submerge the roots of plants directly into a liquid solution packed with the perfect balance of nutrients.

This create a large number of advantages as it allows for plants to be grown in a more flexible manner, while at the same time encouraging more rapid growth with less space and lower cost. At the same time though, it is not a perfect solution as it simultaneously introduces a number of new issues and challenges. In this post, we’ll be examining the strengths and weaknesses of hydroponics in greater detail to assess its usefulness.

How Plants Grow and Thrive

Hydroponics work because plants don’t actually need soil to survive. Plants don’t actually get any nutrients from the soil itself but instead, the soil simply acts as a carrier for nutrients that come from other sources – from biological material scattered by plants and animals.

Normally, the nutrients seep down into the soil and are then dissolved by rain and absorbed by the plants’ roots. At the same time, the soil provides an anchor for the plants, allowing them to remain in place against the wind and other things that might disrupt them. Meanwhile, photosynthesis occurs, powered by the sun and chlorophyll, and allows the plant to produce carbon dioxide, glucose and oxygen.

We’re used to seeing plants grow in soil as this is where they are normally found. And for people growing their own plants, it’s convenient to use a medium that is available in such supply. However, this also presents a number of other problems. For starters, it means the plants need to be grown outside or in pots, which limits the number that can be grown in any space. At the same time, the roots need to spread out to form a large network to ensure an ample supply of nutrients. Success also depends on weather conditions and can be hampered by issues such as pesticides.

How does Hydroponics Work?

Hydroponics meanwhile do away with the need for a medium, instead suspending the plant in one way or another while providing the roots with a water solution that is already rich in nutrients. This is achieved in a variety of ways, depending on the type of hydroponics being used.

For instance, deep water culture means suspending the plants in a plastic container (or otherwise) with the roots able to hang free underneath, submerged in a body of water. DWC is one of the most common forms of hydroponics and if you have ever seen rows of plants growing indoors in white containers, this will likely have been DWC. Aeroponics meanwhile is an alternative approach that uses a fine mist containing moisture and nutrients rather than a body of water. Wicking meanwhile uses a material such as cotton wool in order to draw the solution out from a container where it can then be absorbed by roots suspended above. Wicking is a good ‘entry level’ approach to hydroponics.

There are numerous other forms of hydroponics but suffice to say they all have ultimately the same aim – to provide a steady supply of water and nutrients without the need for soil.

Challenges

One challenge of hydroponics is that the plants also need to be able to get oxygen and carbon dioxide in order to function. In other words, they need air just like animals. Normally, oxygen is acquired through ‘air pockets’ that exist in the soil.

All hydroponic techniques then need to ensure that the plants are getting access to air in one form or another. In the case of something like wicking or aeroponics, this is not an issue. However, DWC will require pumps in order to ensure the water stays oxygenated. An alternative approach is to use ebb and flow hydroponics, which floods the roots with water and nutrients for a brief spell and the drains the fluid away to give them a chance to breathe. In nutrient film technique (NFT), the fluid runs over the top of the roots along a gradient, allowing the roots to get some air while still absorbing the fluid.

This creates an additional complication when using hydroponics however and means the plants being grown will be susceptible to a variety of complications. It only takes a slight error in the system for a pump to stop working for example, potentially suffocating the plants. Likewise, because the light indoors is normally artificial and controlled by a computer, this is similarly prone to error with potentially devastating consequences.

cucumber plant cultivated in greenhouse.Advantages of Hydroponics

Hydroponics has numerous advantages over other methods of growing because it is potentially much more efficient and much more flexible. Hydroponics requires a fraction of the space required by farming or gardening which reduces the strain that this can place on the environment. What’s more, this means that plants can be grown away from their normal habitats, which has a variety of potential benefits.

Moreover, hydroponics enable ensure that plants get a continuous supply of nutrients that are much denser than is possible normally. And because the nutrient solution is so readily available, there is no need for the roots to spread out as they normally would. This means that more plants can be grown in even smaller spaces and at the same time means the plants will tend to grow bigger, stronger and faster.

With lighting and temperature controlled artificially and no threat from pests, there are very few things to limit or interfere with the normal and healthy growth of the plants.
Ultimately, hydroponics can be viewed like a force multiplier (tool that amplifies output) or a form of automation in business. As with automation and force multipliers, hydroponics allows greater yield from a lesser investment and is thereby more efficient. But also like force multipliers, it can magnify errors and mistakes just as well as desirable inputs.

Hydroponics And Its Ramifications

Hydroponic vegetablesHydroponics is a method of growing plants in water by using solutions of nutrients and minerals, without any soil. Perlite or gravel can also be used to steady the plants as they are growing. The practice of growing plants in pre treated water only goes way back to 1627 when Sir Francis Bacon experimented with the practice, and a book about it that he wrote was published a year after his death.

In 1929 a man named William Frederick Gericke got everyone’s attention when he grew tomato plants to heights of over 25 feet by using mineral nutrient solutions instead of regular soil. Gericke was affiliated with the University of California at Berkeley and he came up with the name of hydroponics.

In comparing hydroponics with traditional methods of growing plants in soil there are some interesting factors that present themselves. Early researchers set out to prove that there was no difference in growing plants in soil or by the hydroponics method. It was assumed from the outset that crop yields were similar in both circumstances.

However, hydroponics does have advantages that tradition plant growing techniques that traditional methods does not possess. In hydroponics the roots of a plant has a constant exposure to oxygen as well as having access to as much or as little water as it needs.

One of the most common errors when growing plants in the traditional way is over watering. With hydroponics this does not happen even when large quantities of water are made available to the plants and the plant will use only what it needs, while any excess water can be drained away.

When growing plants in soil, a gardener or a grower has to be very knowledgeable as to when watering is appropriate for different kinds of plants. If a plant is watered too much, it will not be able to access oxygen properly, and too little water will make it difficult for the plant to transport the nutrients that it needs.

An earlier successful utilization of hydroponics happened on Wake Island in the 1930s, as Wake has no soil. The rocky island was a fueling port for Pan American Airlines, and it was used as a place to grow vegetables for passengers. Hydroponics was successfully utilized for this purpose as it was very expensive to bring fresh vegetables in by air.

Hydroponic tomatoesWalt Disney World featured the EPCOT Center which opened in 1982 and introduced the Land Pavilion which showcased a variety of hydroponic features. NASA has done a great deal of experimentation in the hydroponics field, as they are shooting for a plausible hydroponic technique to grow on Mars when that expedition occurs later.

Hydroponics techniques are labeled as having two types of methods, termed as a solution culture and a medium culture. The solution culture technique uses no solid medium for its roots, as they are just immersed in the solution of nutrients.

There are three primary means of solution cultures which are the static solution technique, the continuous flow culture, and aeroponics.

With the static solution culture technique, the plants are grown in containers such as plastic buckets, jars, tubs and tanks. The solution is lightly aerated, or even un-aerated, but in those cases the solution is kept at a low enough level so that the plants receive adequate oxygen. The solution is changed on a periodic basis and the growth is monitored accordingly. The container size is also modified as the plants grow.

With a continuous flow system, the solution of nutrients is made to flow on a continual basis past the roots. This form of hydroponics is much easier to automate as adjustments can be made to a large amount of medium that affects large numbers of plants.

Aeroponics uses a method that keeps the roots in an environment that is saturated in a mist or an aerosol of the nutrient solution. The roots are literally suspended in a growth chamber where they are systematically sprayed with a fine mist of the nutrients. This technique has been very successful for tomato and potato production, micro-greens and leaf crops.

In the medium culture, the roots of the plants will rest in some sort of medium, such as perlite, rocks, and similar types of medium. Plants have a constant battle against gravity and when they are grown in other environments other than the soil, the actually mature more rapidly.

Which medium to actually use is one decision that hydroponic growers have to make. Clay pellets have been successfully uses as has growstones, which are made from glass waste as it holds a good bit of air and water.

Coco peat is another medium used, as it is the material that is left over after all of the fibers have been removed from the shell of the coconut.

Perlite is a volcanic rock which has been heated to extremely high temperatures, and is formed into very lightweight glass pebbles. Other medium are used with great success, as new medium are being tested on a regular basis.

The nutrient solutions that are used in hydroponics contain micro organisms and fertilizer. There are various lighting systems that are employed to provide the adequate light that the plants need to grow.

Hydroponics has enabled the growth of plants to occur just about anywhere the system can be set up, both indoors and outdoors. The flexibility and the fact that much more can be grown in smaller spaces is revolutionizing the way we think of growing and harvesting plants on a very large scale.

The Biggest Natural Pests and Threats for Indoor and Hydroponic Plants

When you grow plants indoors and especially using hydroponics, you will find that your plants are naturally at far less risk of pests and insects as compared with growing them outdoors. Slugs are no longer a threat and the same is true for caterpillars to some extent.

However this does not mean that your indoor plants are going to be completely safe and there are still a number of different pests that can wreak a lot of damage should you let them. Here we will look at some of the most common culprits when it comes to your indoor gardening.

Common Plant Pests

Aphids

Plant pestsAphids are the first pest that will spring to mind for many people when it comes to indoor gardening and for good reason. These little critters are highly common, easy to see and unfortunately not very easy to control. They can be any color and will often appear on the underside of leaves clustered into a group. If the problem gets bad, then you might even notice a sticky honeydew appearing on the plant.

The best natural treatment for aphids is ladybirds. Of course you may not want to fill your home with ladybirds either though, so an alternative is to use pesticides containing malathion or diazinon.

Spider Mites

Spider mites are almost invisible and often only visible with a magnifying glass – a good reason to occasionally check your plants.

A sign that you might have spider mites is that the plant begins losing its normal green color. It may then look bronzed or somewhat washed out and there may also be a fine webbing covering the undersides of the leaves. Controlling mites is difficult and you should isolate the plant at the first sign of infestation. Spray it weekly with an insecticide soap – or even regular water and soap. Be vigorous as the mites can reproduce once every 3-7 days. Spider mites aren’t insects so insecticides don’t always work.

Scale Insects

Scale insects too often go unnoticed allowing them to build up in number. They are oval, brown and look a little like limpets with slight shells. The shells protect them against pesticides but they can be killed by dousing with alcohol using a cotton bud.

Mealybugs

Mealybugs look like white bunches of cotton or fluff and can be mistaken for diseases. They are often found on the undersides of leaves, on stems or at the base of leaf joints. The best way to kill them is with a little alcohol – so dip a Q-tip into some and then dab a little on the affected area.

Whitefly

The whitefly is so named as adults will look literally like white flies. These are larger than many of the other pests on this list which makes them unsightly and unfortunately they can fly and so travel between plants. This also makes them very hard to kill with insecticide. Kill off the adults manually if you can and then use insecticidal soap to remove any infants.

Soil Insects

Soil insects live in the soil and may be seen burrowing when you go to water your plants. The adults can crawl or fly around on the surface of the plant but they don’t actually do much harm. In large quantities they may cause wilting in which case drenching the soil with insecticidal soap can often provide a solution. Of course you don’t need to worry about soil insects if you use hydroponic gardening.

Thrips

Thrips are light brown and slender insects that look a little like weevils. They’re quite unpleasant when seen but are hard to spot as they’re very small. They distort leaves though through a process called ‘rasping’ and this can leave behind scars. Spray with insecticidal soap.

Ants

Ants don’t directly harm plants but in fact ‘farm’ for honeydew using mealybugs and aphids. In large quantities though they can damage root systems by borrowing into the soil. Again, insecticidal soap drenched into the soil will normally provide a solution. Having lots of ants on a plant is often a sign that the plant isn’t healthy though and it may have other problems.

Spraying flowersTips for Preventing Pests

Using the above information you should be able to identify and combat specific types of infestations affecting your plants. Meanwhile though, there are also some more general tips you can use to prevent the majority of infestations before they occur and to prevent the spread of insects.

The first tip is to make sure you always use clean pots and planters when you re-pot a plant and that you use sterile potting soil wherever possible. Using garden soil can risk bringing in all kinds of insects.

If you have a new plant, then you should isolate it for about a month while looking for signs of infection or disease. This is especially important if the plant came from a garden center where it could very easily pick up problems – just as children pick up knits from kindergarten. The same also goes for plants that you might have kept outside temporarily during summer. Isolation prevents any problems that one plant has from spreading to the other plants you own – and so of course it’s also a good idea to move plants as soon as you notice signs of an infestation.

Another tip is to occasionally ‘bath’ your plant. A little soapy water and a soft cloth can help you prevent a surprising number of problems. This also gives you a great opportunity to examine your plant. Remember that some pests can only be seen under a magnifying glass, so take a closer look!

Finally, make sure to generally look after your plant and to keep it healthy. Like humans, plants are less likely to get ill if their natural defenses are high. Regularly feeding your plant, watering it and giving it plenty of light are all things that can help it to thrive and thus reduce the chances of it becoming ill.

Stay vigilant, keep some pesticide to hand and act quickly. Follow these three rules and you should find that pests are rarely a problem for your indoor gardening!

Hydroponics and pH

Many people believe acidity shouldn’t be a factor in hydroponics because it’s something that only happens in soil. In reality, it’s just important if not more to monitor and adjust acidity in hydroponics as in your backyard garden. If the water doesn’t have the proper levels of pH, then the crop will not grow properly.

young tomato plantThe Basics Of pH

pH measure the overall acidity of a substance on a scale of 1-14. If the water has a high concentration of hydrogen ions, then it is acidic and will register between 1-6.9. If it has more hydroxyl ions, then it’s alkaline and will measure between 7-14. For hydroponics, the levels should be somewhere between 5.5 and 6.5 for most crops. pH levels below 5 and above 7.5 will likely kill the plant.

The acidity of the water makes a difference in how the plant will absorb necessary nutrients. Everyone wants succulent fruit and colorful vegetables, but that isn’t going to happen if the plant can’t absorb the iron, nitrogen, etc. In hydroponics, the nutrients are in the solution and can precipitate out and stick to the walls of the chamber, if the pH is off. If it’s not suspended in the solution, then the plant can’t absorb it.

How To Measure pH

Measuring pH can be as simple or complicated as you want. The simplest and least expensive is to use testing strips. The strips have a dye that reacts to the pH of the water and will change color. Compare the color to those listed on a chart, and you can determine the rough pH level. The downside is it lacks accuracy given that there are many variables in the solution that can cause the strips to be off color and you’re “eye-balling” it rather than getting an actual reading.

A liquid test involves putting solution into a vial and adding a few drops of the dye. The entire solution will change color and then compare it to a color chart. The color is more defined, so it’s a more accurate than the paper.

A pH reader can give an actual number and involves placing an electrode into the water and taking a reading. This is the most expensive option, but the most accurate. The only downside is the meter must be calibrated regularly or else it may provide an inaccurate reading.

cucumber plant in greenhouse.Changing pH

If the pH balance is off, then it must be adjusted. There are products designed for hydroponics that will raise or lower the pH, but the general rule is that if it’s too acidic, then something alkaline must be added and vice versa. Be very careful adding acids and other chemicals to the hydroponics as it can not only harm your plants if not done carefully, but also cause serious injury to the hydroponic gardener.

pH balance is often overlooked by many with devastating consequences because they don’t believe it applies to hydroponics. It’s a vital and simple measurement that could mean the difference between a bumper crop and complete ruin.

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