boron deficiency in pansy plugs

[terry]

The last few years I have really struggled with boron def. in pansy plugs, so this year I have started to add a boron supplement. The problem is that I don't know how much to add. I saw on several edu sites that .75 0z/100 gal of Borax was the correct amt-but it never says how many times-or is it just once? I started with the boron applications when the pansies were starting to put out true leaves. I have been adding  .40 oz/100 gallons water of borax to the fert mix and gradually fertilizing more as they grow larger, increasing the ppm of the fert (20-10-20 mostly, switching to 15-2-20 occasionally) but not the borax amt. I think that I may be using too much because I am fertilizing them every day now (seeds started 8/9), but I am seeing a lot of boron def. in the plugs. This late germination is mostly D. Cool water and D. Primrose, and while I have found that blue is the biggest problem when it comes to b. def, I am seeing it in the primrose as well.

Usually its been the extreme heat when germinating that causes the boron def (that I can see), but this year the heat was not as big an issue in August as previous yrs.

If the plug is exhibiting a b. def-will it ever come out of it with continuing boron applications or should I discontinue the borax? 

How many times do you guys apply boron to your plugs and at what stages?

Thanks in advance for all the help you can give.

[Eric Rohloff]

Your Boron problems are probably not low Boron in the media but elevated ph blocking its availability. Make sure your ph is 5.8 or lower.:)

[terry]

Eric-I should have said that the ph is about 5.8. The leaves are nice and green-no blocked iron, I think it is Boron def.

[Eric Rohloff]

Check your E.C. to make sure that's not above 1.2. Higher E.C.'s can add to the Boron problem.

If your media ph is 5.8 fully drench (some leaching) with a .5 ppm of Boron with water having a ph of around 4.5.  Follow with a rinse of water with a ph of 5.4-5.6.  Check E.C. again before next watering to see if fertilizer will be needed. Apply a .25 ppm once a week or about .125 ppm constant.

[terry]

Thank you so much Eric-I think the E.C. levels are too high and that is the culprit. Will drench right now. I always really appreciate the help that you give.

So if I were starting from scratch-you apply .25 ppm/weekly from stage 2 onwards? That is what is not really clear from the edu sites. Or is the ppm suggestion low because I have already added so much?  The sites say 6ppm-just not how many times or when in the growing stage to do it.

[Eric Rohloff]

You can go all the way up to 6 ppm one time as a corrective. Make sure you rinse really good especially if you doing it with extremely low ph water. I usually apply .125 -.25 ppm constant. Remember this saying, "When in doubt leach it out".;)

[Paul Westervelt]

We apply supplemental Boron every two weeks the entire time the crop is one the ground. For rates and other support info, I high recommend contacting the folks at J.R. Peters. Jack, Cari and their team are excellent. There are probably other great labs too, but I'm a Jack's fan - they've never steered me wrong. Good luck!