Getting The Best Bloom From Your Trees

[Millet]

Relatively low temperatures (night 50 to 55F and day 59 to 65F) promotes flowering in citrus. Also, increasing the exposure to chilling temperatures from 2 to 8 weeks increases the number of floral shoots and flowers per shoot, resulting in a concentrated spring bloom which in turn synchronizes both the fruit development, maturity and harvest.  While in ground outdoor trees must rely on the weather,  winter water deficit stress can be imposed on out door citrus trees of all cultivars to compensate for inadequate exposure to low temperatures during mild winters.  In door and greenhouse trees can easily be temperature controlled to produce the above results.   

[will2358]

Thanks Millet for the info. You always have such great information.

[brian]

Any strategies for *reducing* bloom/fruit set for trees that overproduce?  For example, my Nordmann kumquats produced massive quantity of small fruits this year, while half the number of larger fruits would be preferred.  Pruning flowers off isn't really feasible as there are so many and spread throughout the canopy.

[Bomand]

About the only way to do a good job is to thin by hand and pole thinning. Fruit set and production depends on the availible carbohydrates to the blooms and fruit. Plenty of available carbs usually indicates a healthy tree. I wait till tiny fruit are set, pinch them between thumb and finger and gently twist them off. Use a pole to reach a canopy and strike the supporting branches with enough force to shake the tiny fruit off. I find that removing 1/3 of the small fruit will usually do the trick. You then will get fewer but bigger and better fruit. I hate to thin but find it necessary at times. Be sure to time it when the fruit are tiny.  Some of us have the idea that fruit thinning leads to an alternate bearing tree.....I am not one of them. As far as I know Nordman is not a citrus that lends itself to alternate bearing unless....there is a nutritional problem with the tree.0

[Millet]

What Bomand writes will certainly work, and many people do exactly as Bomand has written.  Of course the best situation would be to retain all the fruits that Brian's tree produces, but at the same time have his tree produce  larger sized fruits.  Thus the best of both worlds. This is done all the time in commercial groves.  1st spray the tree with low biuret urea 1.5 months prior to the expected bloom date.  This spray greatly helps in the bloom and also the retention of fruit. Then after the tree blooms and sets the fruit, spray the tree again with low biuret urea. This 2nd spray  increases fruit size.  It does this by extending the cell division stage of fruit development, increasing fruit size. To achieve the best results both solutions should be between 5.5 and 6.5 pH. Both low biuret urea sprays are made up by dissolving 100 grams of urea per gallon.  Therefore, if Brian would spray the tree with the 2 sprays the tree will retain most all of the fruit and at the same time give Brian his wish of larger fruit..

[brian]

I will have to order some urea powder and give this a try, I never have it in hand when you post the spray timing reminders

[sunny]

I will have to order some urea powder and give this a try, I never have it in hand when you post the spray timing reminders

It should be low biuret urea, not normal one.

In my notition book i wrote that we need 1 teaspoon low biuret urea in 1 gallen water...so is that wrong? 100 gram is much more.

My citrus bloom well and we never have those cold temperatures, i also water them every day.

[brian]

I can't actually find any 0.25% biuret urea for sale... any suggestions on where to buy it?

All the sources I find are 0.5% biuret or above

[Vlad]

This is what I got on Amazon: https://www.amazon.com/gp/product/B007OAYGEA/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

[brian]

Their spec sheet says 0.5% biuret which I think is a bit high for citrus.

https://n.b5z.net/i/u/10066364/f/Urea_-_Spec.pdf

Product Name: Urea Prilled
Grade: Agricultural
Order Code: URPRLAG
SDS No.: 301


Biuret, Wt. % 0.5 max.

[Millet]

I've used .5% biuret as a foliar spray on citrus, and had no problems.  I used it on Cara Cara, Ponkan, Valentine Pummelo, Marsh Grapefruit and Saint Teresa Lemon.

[brian]

Thanks, I will try this