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Location

Message

Date Posted

Tauranga, NZ

Copper?

6/19/2024 1:27:48 AM

Grittyville, WA

Phosphorus could knock out zinc, read the label to see if your fertilizer has zinc. Zinc is one of the minerals that can cause chlorosis, but its just a guess.

6/19/2024 1:38:00 AM

San Diego, CA

Thanks BigYellow. I haven't intentionally added copper, so it could be related. I have amended w/ plenty of micronized rock dust which theoretically has copper covered.

Very interesting observation Gritty. Zinc is a trace mineral in the fert I've applied. The fert is Masterblend 10-52-10, which has trace mounts of both Copper and Zinc.

It could very well be lock-out related. Thank you both!

[Last edit: 06/19/24 2:30:10 AM]

6/19/2024 1:58:22 AM

Tauranga, NZ

My thinking is that high P decreases the availability of Cu. See the Mulders Chart for further context :)

6/19/2024 3:07:57 AM

Grittyville, WA

I believe zinc shows in the new growth so maybe not zinc. Swings in weather (temp, moisture) or maybe the root health, seem to be able to induce chlorosis even if the soil is perfect... I find it all very interesting! I dont know much about copper.

6/19/2024 3:54:22 AM