Let's play identify the nutrient deficiency!

Hey guys, first year hop grower here in NC. Strongest rhizome has turned out to be what I think is Cascade (may have mixed them up) but over the past week noticed some spots on the leaves turning yellowish.

Karma points for anyone who has advice or thinks they know what it is (already been to http://5e.plantphys.net/article.php?ch=t&id=289 - looks like many options).

Thought it could be aphids but haven't seen any in a while. Thinking I may just need some basic organic fertilizer.

What are you fertilizing with and what is the irrigation routine?

Too much water? We've had a lot here in new England over the last month and some of my second years look like that.

I have one of my hop plant that looks like that... Its a tettnanger. I use 3-3-3 fertilizer, ounce a week water with a compost tea and every two weeks use liquid organic nitrogen miracle grow. I dont think it's a deficiency. These plants grow so fast there are just imperfections in some of the leaves. Thats my belief at least.

I haven't fertilized them at all actually.

I normally water them about twice a week unless the weather takes care of that. Had several fairly heavy rain storms over the past week or so.

I never water mine and just let nature handle it. I have mulch down so the soil stays nice and moist all the time.

Doesn't look like a deficiency at all. I would either say you have some sort of leaf sucking insect involved or they have been burned by water on the leaves due to watering mid day or something.

My hops all have little bits of stuff like that and they seem to be happy so I wouldnt worry about it!

kellanv said:

Doesn't look like a deficiency at all. I would either say you have some sort of leaf sucking insect involved or they have been burned by water on the leaves due to watering mid day or something.

My hops all have little bits of stuff like that and they seem to be happy so I wouldnt worry about it!

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Soooo - watering should be at dawn or dusk? Didn't realize water on the leaves could cause burns.

Yes, the water acts as a lens and focuses the beam of light.

jazzyfool said:

Soooo - watering should be at dawn or dusk? Didn't realize water on the leaves could cause burns.

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Urban Legend...unless it is hot water from a hose or a drip system. I water my hop plants and soaked the leaves in 100 degree heat. The water cools the plant and evaporates for the most part.

watering during the day does not cause leaf damage

http://www.puyallup.wsu.edu/~linda chalker-scott/horticultural myths_files/Myths/Leaf scorch.pdf

There is a reason golf courses water the grass on hot days--it cools the plant down. If the reverse was true all the fairways and greens would die!

So if it's not nutrient deficiency and not leaf burn from watering then...

I used insecticidal soap and some organicide a week ago to take care of some aphids but I used them right before sunset - would these have caused the discoloration?

Looks like a magnesium deficiency to me. A little bit of epsom salts should fix that right up.

jazzyfool said:

So if it's not nutrient deficiency and not leaf burn from watering then...

I used insecticidal soap and some organicide a week ago to take care of some aphids but I used them right before sunset - would these have caused the discoloration?

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Who said it's not nutrient deficiency? I bet it's the rain along with lack of nutrients. People apply fancy soil mediums with manure or compost or miracle grow or whatever and the rains often leach out the nutrients before you figure out what happened. Fertilize and water it in.

It doesnt look like a nutrient deficiency. Chlorosis is usually more uniform and will later lead to necrosis. Could be very early stage magnesium as stated.

I was probably a bit short in my answer but chlorinated water, foliar fertilizer salts, soaps, pesticides etc can all lead to burn especially on hot days when plants are stressed. Water by itself won't likely burn.

All the same, watering off peak will be more efficient due to less evaporation.

Standing water, pooling in one area, for extended periods of time.

If it's not that, then your N-P-K is off...

jazzyfool said:

I haven't fertilized them at all actually.

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bobbrews said:

Standing water, pooling in one area, for extended periods of time.

If it's not that, then your N-P-K is off...

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Ok - should I do a soil test or just go ahead and get some 10-10-10 fertilizer and dose it? Any brands recommended?

I like a 3-1-2 ratio of N-P-K.... plants biological makeup follows that ratio so anywhere in that ballpark should perform better than an even 10-10-10.

And I know a lot of folks are adamant about organic fertilizers, but they don't work immediately. It takes time for the soil microbes to break down organics. If you want immediate results, use a weakly, weekly dose (pun intended) of synthetic fertilizer following a 3-1-2 ratio... with all of the minor nutrients as well. Osmocote is a good brand.

BigJay13 said:

There is a reason golf courses water the grass on hot days--it cools the plant down. If the reverse was true all the fairways and greens would die!

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I think the drawback with watering mid-day is that you can waste water if it evaporates before it soaks in. I prefer to water my garden in the morning so it soaks in before it gets too hot, but the sun and any breeze dry off the leaves before they get fungal infections (hops can get mildew; tomatoes can get other kinds of fungus).

Keeping the leaves dry with good air circulation is one reason that people trim down their bines...which reminds me, my Cascade hill is starting to get overgrown again.