Manganese deficient cucumbers?

[Chuck Ketcham]

Last year I grew cucumbers for the first time in an EarthTainer. I used a 6:2:1 grow media ratio rather than the traditional 3:2:1 as per the recommendation on this thread:

http://www.tomatoville.com/showthread.php?t=29567

After a while, I noticed the leaves didn't look right, so I searched the web looking for the reason. I found a picture on the Texas A&M cucurbit problem solver page that looked exactly like my cucumbers. Here is the link:

http://aggie-horticulture.tamu.edu/v...se-deficiency/

This says that the cucumbers were suffering from a manganese deficiency. It also goes on to say that high PH soils often induce manganese deficiency by holding manganese in an insoluble form.

That doesn't seem right to me for two reasons:

1) My soil should have been a LOWER PH due to the high peat moss content (6:2:1 ratio). I did add some Espoma Garden Lime (2 cups) as per the Earthtainer Construction Guide, but I wouldn't think this would cause a highly alkaline soil.
2) I added 3 cups of Ferti-lome Tomato and Vegetable Food (7-22-8) which already has manganese as an ingredient.

So, could my problem be something else other than a deficiency in manganese?

Thanks.

[Ed of Somis]

C...hard to say without pics and full explantion. I grew cukes for the first time ever last year. They did pretty well. My main issue was aphids. I used 5 gal nursery pots...that seemed large enough. I may have over-fertigated if anything. This year I painted the sides white...to cut the temps down inside the pot.

[JamesL]

Chuck,
I grow cukes Earthtainer style as well. Other than the leaf issue you described, what other problems did you have? Any production or other plant or fruit issues?
I am sure I have pics someplace of leaves looking very similar. Wasn't too focused on it as it didn't really affect production.
How were you fertilizing and with what product?

[drew51]

Manganese can be hard for plants to absorb. Any added was probably locked in the soil and unavailable to the plant. The best solution is a foliar spray of manganese sulfate.
magnesium deficiencies also kinda look like manganese. In that case Epsom salt foliar spray.

Are you sure it was not powdery mildew? If it was it would have killed the plant without treatment, and maybe even with treatment.

[Chuck Ketcham]

If powdery mildew looks anything like the picture shown here:

http://aggie-horticulture.tamu.edu/v...owdery-mildew/

Then, no it was not powdery mildew. On the other hand, I am a new gardener and don't have much experience with identifying plant problems.

I will say that my leaves looked exactly like the picture linked in the original post, which is why I asked about manganese deficiency.

Even with the leaves in this condition, the plants produced quite well for a time.

Then later on in the season, I had a terrible problem with aphids (black in color, not the usual white). I tried spraying with home-made insecticidal soap, which didn't work out too well, as the leaves started drying out and curling, and the plant stopped production too early.

My initial thought was that the initial leaf disorder and the subsequent later aphid infestation were two separate ailments.

Now I must concede that it was possible I only had one problem, the aphids, that just went unnoticed until far too late. It's hard to say.

Anyway, is manganese deficiency a common ailment? And is it usually prevented with the foliar spray mentioned?

[drew51]

I have only ever seen a manganese deficiency on fruit trees. So not sure how common on melons? I never had it on my melons. Use Bonide all seasons oil for the aphids, it also stops powdery mildew. Spray a couple times 7 days apart or sooner if aphids still visible.
The foliar spray will help, it's the best way to get manganese to any plant. You could actually combine the manganese with the oil. Dose for manganese sulfate is about 1 tbs per gallon. Available on Amazon. It's cheap, and you will have a lifetime supply.
It's probably illegal for me to send, I have more than I could ever use.