Today i noticed a few of my pawpaw trees are showing some very clear issues.
This it the third year of my orchard but first time i’m seeing this.
Also, the symptoms only began appearing a few weeks ago.
These pictures are showing older leaves - younger leaves look totally fine.
I consulted the frequently used document for diagnosing pawpaw nutrient issues, and none of the pictures really look like this; however, the verbal description of potassium deficiency is pretty close (older leaves, yellow margins)
Also, the very well-respected Spectrum Analytic website says this about K deficiency:
The classic and almost universal leaf deficiency symptom is marginal chlorosis of the older plant leaves.
Spectrum goes on to say:
It might also show as a fruit crop that doesn’t quite develop the proper quality or flavor.
While this is a really small sample size, my one pawpaw fruit this year fit this description exactly.
Also searching here, i saw mention of K deficiency causing persimmon fruit drop. My pawpaw dropped i believe prematurely, which also fits.
Now then, to save time let’s assume this is potassium deficiency.
How should it be corrected?
I had the orchard tested this spring with these main results:
Phosphorous 519 pounds/acre
Potassium 194 (listed as “high”)
(these are Mehlich-1 values)
I have known for a while that i need to get my pH down. It actually started 3 years ago at about 7.5 and thru elemental sulfur and compost, it’s come down. I want to get it down even more, to 6 would be wonderful. I’m not sure getting it to 6 will make this issue go away because…
… I have apparently 50x higher Calcium content compared to K. Spectrum Analytics mentions Calcium competes with K. That’s an awful lot of Calcium.
So I guess I don’t know if adding K to the soil will really do anything. I could try foliar feeding, but that’s a hassle.
Part of me is freaking out thinking that I am doomed to have crappy, premature-dropping, gross pawpaws forever