Start Planning Now For A Good Spring Citrus Crop

[Millet]

Know that if you grow citrus trees inside a warm house or greenhouse during the winter months you will need to be SURE to start following citrus flower bud induction conditions during November for the coming year's bloom. Citrus grown in warm homes or greenhouses need to receive approximately 850 hours of temperatures below 68F(between November and Christmas +-) to set a heavy crop of flower buds. If the trees are continually grown at higher temperatures the buds will poorly develop as flower buds, but rather as leaf producing buds. It is the 850 hours below 68F that differentiates the buds from foliar (leaf) buds into flower buds. After the 850 hours of below 68F temperatures, which is sufficient for flower bud induction to occur, then give the trees 7-12 days of temperatures greater than 75 to 80 degrees F. which will trigger flower bud growth and bud swelling. This should give you a good crop fruit. Conversely, if you do not want flowers thus no fruit but would rather produce a lot of stem and leaf growth (to enlarge the tree) then keep the temperature above 68F at all times. - Millet

[cory]

Millet, is that consecutive hours of temperatures below 68°F?

Thanks,
Cory

[Millet]

Accumulative hours. - Millet

[jcaldeira]

Thanks, Millet. 

In more tropical environments, where chilling hours are not possible for citrus, water stress from dry conditions tends to induce flower buds.

[Mark in Texas]

And how do you induce leaf production?  Made a thread on this issue recently.  http://tropicalfruitforum.com/index.php?topic=13298.0  This lime tree keeps pushing flowers/fruit and at the same time dropping leaves without new leaf replacement.

[cory]

Thanks Millet.  Glad to know.  Accumulative is not so hard to provide for me then in my greenhouse that can warm up higher for a few hours during the day.

Cory

[Millet]

Mark at this time of year does, or did before leaf fall, the Lime tree's leaves receive direct sun shine? If so it sounds like WLD (Winter Leaf Drop)- Millet

[Mark in Texas]

Mark at this time of year does, or did before leaf fall, the Lime tree's leaves receive direct sun shine? If so it sounds like WLD (Winter Leaf Drop)- Millet

No direct sun Millet. It's under Palram's DynaGlas SolarSoft85 which is facing north and is very light limiting this time of the year.  Come spring that whole roof section from end to end is getting Clear corrogated.

Speaking of Palram Dynaglas, a word to the wise, and caution.  I got samples just for fun and using a light meter measured their SolarSoft 85 against the 90 and the Clear.  The Clear and 90 were to spec as advertised - 93% LT and 91% LT respectively.  The 85 which is what I have on the roof was 65% LT, not 85% LT as (falsely) advertised.  I wrote my sales rep who says he took the samples to Greentek, the distributor, and had them tested according to ASTM code by Palram.  Needless to say all I got back was anecdotal evidence, my "test was flawed"....general bullshit.  I told them they are conducting fraud and you can see how it went from there......

Well, looks like I'm in for another fruit drop.