On December 18, 2005 I planted a one year old Marisol Clementine tree grafted on Kinkoji rootstock, inside my greenhouse. The tree is planted into a raised bed, placed on the ground, so the tree will be growing in the ground. The raised bed is artifically heated with heat cables (thanks for Citrus Joe's help) that are buried at two different depths in the soil keeping the soil at 72F at all times. The night time air temperature is maintained at 60F. I keep the day time humidiity between 50 to 60 percent. An aluminized reflector wall was built behind the tree reflecting the winter sunlight back onto the north side of the tree's canopy, while the sun's rays shine light on the south side of the tree. Additionally, a seperate aluminium reflector is on the tree's west side, only from sunrise to 12:00 noon to reflect the sun's energy as it rises in the east. Then, from 12:00 noon until sun set, the east aluminized reflector is placed on the east side of the tree to amplify the western afternoon sun. This is all done to maximize the low sun light during the winter months (year around summer tropical plus conditions). I'm going to get the east and west reflectors mechanized so I don't have to do it manually. Soil water levels are monitered weekly (Saturday mornings), and always watered with warm water. It has now been 24 days that the tree has been in the ground, and yesterday (1-08-2005) I noticed HUNDREDS of new flushes have started, and in every area and on every side of the tree, litterally on every single branch and twig. I plan to take a picture to the tree's growth every three months (Dec., March, June & Sept.) for the first five years (GOD willing). I will be keeping a daily log of everything related to the tree's growth. Reason for test is: 1st., For fun and to learn. 2nd., to see how fast I can get the tree to grow in a five year period. 3rd., to see the maximum amount of fruit that can be successfully harvested betwen the initial planting of a Marisol Clementine through the 5th season. - Millet

I am going to abandon the east and west aluminized reflector sheilds after the 1st of March as they will not be needed for extra tree growth. Citrus trees reach their MAXIUM photosynthesis production at levels of only 1/3 full sunlight. So stronger sunlight will not increase the amount of photosynthates (the trees food source) that the tree will produce. However, ADDITIONAL photosynthesis, can be brought about by LONGER periods of light on the foliage. Therefore, I have installed a HID light source to increase the "day" length to 14 hours per day. Therefore, at this time of year, gaining an additional five hours of photosynthesis. I will leave the rear aluminized reflector to reflect additional light energy to the north (shaded) portion of the canopy. The tree has started to flush a lot of new growtn, however, these additional leaves will not and cannot export any photosynthates to the tree (for additional growth) until they become fully expanded (approx. 60 days) - Millet

sounds fascinating and very cutting-edge, Millet. I read everything twice. Looking forward to your findings, and perhaps pics, if you can get to them later on. -Vince

I installed a 120V, 2.6 amp, 250 watt, Metal Halide Lamp today above the Maraisol Clementine tree's foliage. According to the directions the tree's foliage must be slowly hardened off to the light emiting from the MH lamp. The lamp must be first placed 3-1/2 feet above the tree, then the lite can be lowered down 6 inches closer to the tree's leaves every other day until the light is 1-foot above the tree. Metal Halide lamps emit the closed thing to natural sunlight that is available. Metal Halide light is in the blue spectrum, which is the spectrum that causes foliage growth. The light is on from 4:30PM until 10:00PM which will give the tree a 15 hour "day." - Millet

Millet,
Do you have a back up generator in case of a power failure? :shock:

Makes me wish we could store excess sunlight during the day and distribute it during the night. Some plants require night period in order to grow, at least from what the former operator of Phytotron has told me.

I have been studying in my quest to grow the Merasol Clementine in frozen Colorado record time. I came across a 1987 USDA Agricultural Research Service research project of growing Citrus aurantium L (sour orange) seedlings in a elevated CO2 atmosphere . The elevated CO2 atmosphere was maintained at 300-ppmv ABOVE ambient air. Briefly the results were: 1). After 2 years, the above ground biomass (total weight) of the CO2 treated trees were triple the weight of the untreated trees growing in ambient air. 2). Fruit production of the CO2 enriched trees started 1 year earlier. 3).The mean annual daylight photosynthetic rate of the CO2 enriched foliage was double that of the ambient air grown trees. At 88F and 300ppmv extra CO2 enrichment the photosysthesis of the leaves was 75 percent greater than trees grown at the same temperature in non-CO2. At 95F the photosynthesis was 100 percent greater, and at 108F with the extra 300-ppmv CO2 the rate of photosynthesis was 200 percent better than trees grown at the same temperature in ambient air. Interestingly the upper limiting temperature that stops leaf photosynthesis in citrus leaves is normally 95F, but when grown in an elevaed C02 atmosphere, citrus leaf photosynthesis increases until a temperature of 108F (13 degrees higher - from 95 to 108). The photosynthesis of trees grown in ambient air pretty much stops at 95F. 4). C02 enrichment also increased the leaf size linerally as temperature rose to an increase of 40 percent larger leaves at 95F. 5).The branch growth following bud burst of the C02 enriched trees was ENORMOUS compared to that of tree growth in ambient air rreaching a peak of 6 times greater growth length. 6). Citrus leaves of an age of 2 years or greater fall throughout the year. The ratio of leaf drop from C02 enriched trees to those of ambient air grown trees was 1:3. During October the ratio of leaf fall was 2:7. I am going to have to build a clear plastic growth chamber around the Marisol Clementine so that the tree can grow in a raised C02 atmosphere to acheve the enormous benefits that C02 provides. So now the tree has extra daylight length, extra soil heating, and soon an elevated C02 atmosphere. I wonder about gibberellic acid sprays, however I would be afraid to spray a "mature" grafted tree as Giberillic acid can revert mature citrus trees back into juvenility. I'll hope to get some expert advice on this. If the gibberellic acid would give a great deal of tree growth, and only prolong juvenility for a year or so it might be worth it. - Millet