gabriola garden

Wednesday, May 02, 2007

Chlorotic Tulips Used to Fetch Outrageous Prices

We went away for three days and asked a neighbor to keep an eye on our garden. When we came home, our many, many tulips were flourishing, except for a red variety that Sara first planted over four years ago. Last year it had perfectly healthy blooms. Now they appeared streaked with white, irregular lines.

At the same time, Sara discovered a few aphids on one of our roses. After a few hours of research on the Internet, I came up with the answer. The aphids and the streaked tulips were interconnected. Our red tulips had been infected with Tulip Breaking Virus (TBV), also known as Tulip Mosaic Virus, the most common viral infection of tulips. This virus, along with many others, is vectored or transmitted by aphids.

“Broken” tulips at one time were considered rare and extremely valuable in parts of Europe. One bulb in the early seventeenth century sold for the price of a house. It’s hard to believe, but paintings of broken tulips by some of the Dutch Masters were cheaper to buy than the bulbs themselves.

Since the cause of the chlorotic streaking was unknown, in those days people believed that it was the result of planting the bulbs at an unsuitable depth, applying too much manure, using too rich or too poor soil, or inclement weather.

It’s only in the last eight decades that the virus infection has been recognized as the true cause. The variegated color scheme on the tulip petals is caused by an irregular distribution of anthocyanin. Today, the virus’ DNA has been mapped and it can easily be detected and identifies by serological and molecular techniques.

The best way to deal with this viral infestation is removing and destroying all the affected bulbs, before the aphids can spread the virus to any other vulnerable plants, such as lilies.

Sara has some daylilies growing in the same garden patch as our broken tulips, so she’s thinking of digging them up and putting them into pots so they can be safely removed from the vicinity of the infection. It’s a good idea not to plant tulips again in the same soil for at least a year.

As far as the aphids go, a thorough spraying of Scorpion Juice is warranted. This very effective Advanced Nutrients product has protected most of our plants by imparting an induced systemic resistance to most pathogens and pests throughout our garden.

However, the tulip bulbs in question were old and of a strain extremely susceptible to viral infections. Most of our tulips are doing just fine and are unaffected by the virus or the aphids. This is due largely to our regular spraying with Scorpion Juice.

We also mix Barricade into our watering tank. Barricade is a Potassium Silicate product that strengthens the cell walls of all our plants and makes it extremely hard for insects and pathogens to penetrate this line of defence.

Since we feed all our plants organically, we hesitate to use any chemical insect repellent. The most we ever do is perhaps a mild soap solution to wash away spider mites and their webs or to keep aphids at bay. There are safe soaps on the market that do not hurt plants.

My first thought when I saw the chlorosis on the tulips was iron deficiency, but since we feed our plants a fish based, 100% organic fertilizer, Iguana Juice Grow and Bloom, I was puzzled. Aren’t fish supposed to be high in iron? They I checked the ingredients and saw that it also had kelp extract in it, which definitely has a high iron content.

Another product that we mix into our watering solution is Sensi Cal Grow, which is replete with a whole array of micronutrients, including iron DPTA, iron EDDHA, and iron EDTA. So the idea of iron deficiency was soon ruled out by me.

Just think, if we lived in 1637 in Amsterdam we could sell one of our chlorotic bulbs and buy a house for the price of it! Even in those days this was considered folly, and cartoons of the period lampoon the excesses of the tulip market, which soon went bust because so many speculators tried to make a quick buck.

posted by Tim at 8:40 PM


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