Ask Erik

Erik,
I was recently given a bouquet of orchids. I would like to preserve them. Is this possible and if it is, how do you do this?
Thank you for your time, Anita.

Anita,
You may want to keep them as "fresh cut" flowers for a while before drying, so I will provide a couple of tips for both. To preserve fresh cut plant material, you basically do the opposite of what makes them grow. Cooler temperatures will slow down the dehydration (wilting) process as the rate of transpiration and bio-reactions are reduced. The transpiration rate will also be further reduced with an increase in humidity, however, only to a degree. The flower petals will wither if they come into direct contact with condensed moisture (for example a coarse spray). Very high humidity levels will also deteriorate the flowers, upper limits will vary from species to species, but I am sorry I don't have any specific data for orchids. Prepare a solution for the plant stems before re-cutting flowers and immersing. The stems should be re-cut immediately prior to submersing in the solution, to prevent an embolism (air bubble) from entering the vascular tissue, breaking the osmotic column of solution in the stem, causing the cut flower to whither. Commercially available cut flower preservation solution concentrates are common and available. Just add the powder to water as per the recommendations. Anything that decreases the amount of oxygen in the water while raising the sugar content works well. Believe it or not, some commercial floral wholesalers use a solution of water and 7-UP in their flower buckets.
If simply drying flowers (as opposed to curing plant products), hang them up to dry in a dark, enclosed area with a low to moderate humidity level. A low velocity circulation fan should help keep the air from stratifying. Increase carbon dioxide levels if you have the means. You can store the dried flowers in glass jars with air tight seals, even choosing a decorative glass container as it can make for a nice conversation piece. If you have bottled CO2, you can gas the containers the moment before sealing. If you keep this vessel out of the light and away from temperature extremes and lots of movement, the flowers should look very much like their former selves for many years.
Sincerely, Erik Biksa.

Hi there Erik, this is my question for you:
I have been growing orchids using the hydroponic passive system, and have become very interested in the advantages of the use of potassium silicate. I have read the article included in volume 1 number 2 of your magazine, and quite a lot of similar articles.
As a matter of fact, I now have plenty of potassium silicate at 40 % concentration, and what I will appreciate is if you can supply the recommended doses of potassium silicate both for the nutrient solution as well as for foliar spray. Also, how often should it be used? Every time you feed the plants? Once a month? I want to use it, but without approaching toxic levels!
Best regards, JLB.

Thanks for your question.
The information I have suggests that silicate levels should be about 250 ppm (milligrams per liter) in the nutrient solution for a positive response from the plant. So, roughly 625 milligrams (0.625 grams) of a 40% silicate solution per liter of nutrient solution would be required to achieve silicate levels of 250 ppm (250 / (40/100))=625. This will also likely raise the pH of the nutrient solution, so it may require some adjustment to get it back to pH 5.5 to 6.5. As I have highlighted in the past, potassium silicate is generally manufactured with equal molecular weights of potassium hydroxide and silicic acid. The two compounds are held in a relatively unstable bond to create potassium silicate. You cannot keep this as a liquid concentrate with other nutrients, as adverse reactions will occur. Also if the pH of the nutrient solution is not pH 5 to 6, the potassium silicate may deteriorate becoming unavailable to plants and possibly clogging your nutrient delivery lines.
There are naturally occurring deposits of plant available silicate found in nature. There are several products on the market that are blended from these sources with rare earth minerals. This also provides additions of necessary micros, and possibly beneficial sub-micro elements. As this type of plant-available silicate occurs naturally, it tends to be more stable in the nutrient solution. As a note of caution, when you purchase products from natural sources, you inherit other materials native to the site of origin which may include sodium.
I think that when using silicate in a natural and plant-available form it could be used with each irrigation if prepared as a mild nutrient tea (inside a small fine woven bag inside your nutrient tank). If applying potassium silicate at the levels discussed, you may want to apply with the nutrient solution every week or two, or as growth rates dictate.
I am not really sure that I would like to use potassium silicate as a foliar spray as it may clog the stomata. The stomata are the tiny openings on the leaves' surface that exchange compounds, most often used for gas exchange.
Sincerely, Erik Biksa

Erik,
My plants are all weak from thrips. Will clones ever be the same (strong vigor)-Or should I start from scratch. And how do I get rid of them?
Thank You, David.

David,
This is an area of some debate, but let's starts with the thrips. The most common types of thrips infesting indoor crops are Greenhouse thrips (Heliothrips haemorrhoidalis) and the Western Flower Thrip (Frankliniella occidentalis). Mature greenhouse thrips are between 1.3 to 2 millimeters in length, while the western flower thrip tends to mature at about 1 millimeter in length. The western flower thrip tends to lay its eggs into the tissue, especially in dense floral clusters, so the yellowish eggs are rarely seen.
During a brief period when the eggs hatch, the larvae of the western flower thrip may be present in the soil. Hypoaspis mites are a large predatory mite that will feed on the larvae before they can emerge as adults and can persist in the growing medium for a respectable period of time. They are applied at a rate of 20 mites per square foot of growing space (640 per four' x eight' table) about every three weeks. Amblyseius (Neoseiulus) cucumeris are predatory mites that attack a variety of immature thrips on the plant. They should be applied at a rate of about 30 mites per square foot of growing area every week to maintain control. This should be continued for five to eight weeks after the first release. If they run out of prey to consume, they will feed on pollen.
Obviously, you cannot use insecticides if you decide to enlist biological predatory insects. If you have been spraying previously as a control measure, you will need to wait a week or so before applying the beneficial insects. You can always introduce a couple of "tester" bugs too see if an insecticide is persisting.
Synthetic and natural pyrethroids offer some control as contact sprays. Diluted neem oil applied as a contact spray or soil drench will also help to knock-back thrip populations.
Chitosan applied as a spray helps to strengthen plants against insect attacks, in part by increasing the thickness of plant cells. This helps to make it more difficult for the thrips to pierce the plant tissue. Now, as for the clones. If the strain is of no particular value to you, or if you are able to re-acquire disease and insect free stock it would be best to discard the infected plants. Thrips pierce plant tissue to feed. In doing so, they are vectors for the spread of disease.
If the plants are weakened by the attack, and have not been infected with any viral diseases it is possible to retain plant vigour, although a period of time in optimal growing conditions without pests or disease will be required before you can begin to take clones again. Often a cutting is only as good as the moment in the donor plants life it was taken from. Remember that the plants genotype (genetic make-up) is not easily altered, while the plants phenotype (physical appearance) is influenced by the environment acting on the genes.
Sincerely, Erik Biksa

Hi,
I was wondering about the article you wrote on fulvic acids and the effect on taste on the fruits after the last week of spraying. Can you please let me know if it will affect the taste on the finishing product or if there is any worry on consumption? Also, how many drops is 1ml? Reason why I ask is because my friend wanted to add 35% hydrogen peroxide to his soil garden. Also, does he have to worry about it affecting his nutrients?
Thank you for your time love those articles!

Thanks for your question and the kind words.
If you are using a premium quality fulvic acid at the recommended dilution rates you will see improved quality in floral and fruit crops. In floral crops where inflorescence develop (flower buds along the branches or stems to form a larger flower) over applications of premium quality fulvic acids will promote stem elongation. That is why the general recommendation is that if you are unsure of your strain's response to fulvic, you should apply it at the roots through the vegetative stage and only once as a light spray towards the final week before harvest for improved cropping. Fulvic acid is found in some dietary supplements as it makes nutrients available for absorption along the wall of the large intestine. Be aware that not all fulvics on the market are not fulvic acids, or may contain higher levels of heavier weight fulvic chains which are typically thought to be less bio-active.
I believe there are about five drops per milliliter. Since this is not the best unit to measure volume with (as droplet sizes can vary) try filling a teaspoon while counting drop by drop. Divide the number of drops by five ( the number of milliliters in a teaspoon). Now if your formula calls for five drops per gallon and you need to mix ten gallons you will know how much to add in terms of milliliters.
Some people are really into the H2O2 (hydrogen peroxide), but I do not believe that it is necessary or even beneficial in nutrient solutions, although it has merits in pre-treating the make-up water for nutrient solutions. Chealtes and complexes may become oxidized if applied in the solution, which may lead to a nutrient imbalance or may harm beneficial soil microbial life. Keep the medium or nutrient solution well aerated for plant available oxygen at the roots. There are devices being developed which diffuse dissolved oxygen into the nutrient solution that reportedly achieve incredible dissolved O2 levels that remain available for a sufficient period to benefit the rhizosphere (root zone). For prevention and control of root related pathogens try a product such as Flora Shield which acts as an enzymatic inhibitor, controlling microbial population levels.
Cheers, Erik Biksa