What do you guys think? Micro or burn...

MtnLivin

Member

• Jan 17, 2019

• #1

Wedding Cake F2 Pheno here and she always shows this tip yellowing on the top leaves only. I'm having a hard time believing its fertilizer burn when no other genetics in a full 7k sqft veg room are showing any signs of burn. Max PPM's are 800-900. I'm leaning towards a micro nutrient issue, but I am having a hard time diagnosing. My colleagues and I will be sending in a leaf tissue test done soon to see what's really going on. In the mean time I would love to hear everyones thoughts. Thank you!

 

I

iTarzan

Well-known member

• Jan 17, 2019

• #2

Skunk #1 is prevalent in many crosses. There was a pheno in the original skunk #1 that had yellow tips or edges of the leaves. It was not a nitrogen problem. It was one of or the best pheno of skunk #1. It was described in Neville's catalog. This could be a genetic trait.

 

Ibechillin

Masochist Educator

• Jan 17, 2019

• #3

What are you feeding with? What medium?

 

Lester Beans

Frequent Flyer

Veteran

• Jan 17, 2019

• #4

Potassium deficiency. Most likely low pH or too much Cal/mag.

Can foliar some kelp or other K product.

 

D

doctahaze

New member

• Dec 7, 2019

• #5

Limited experience, but for what it's worth I grew a humbolt seed company lemon thai kush that looked like your pics here. Yellowing tips early on in veg on upper/newer growth. I dropped the PH of my water from 8+ to 6.5 and the yellowing disappeared. Four other strains in the same soil mix didn't show any symptoms.

 

T

TanzanianMagic

Well-known member

Veteran

• Dec 8, 2019

• #6

That's a zinc lockout, and I agree with DoctaHaze that it is most likely because of a high pH.

https://www.420magazine.com/gallery/data/500/1134Zinc2.jpg
https://www.420magazine.com/communi...lant-and-pest-problem-solver-pictorial.81267/

Micronutrients are locked out at a high pH. Being non-mobile nutrients, damage shows up at the growing tips of the plant. Mobile nutrient (N, P, K, Mg) deficiency/lockout shows up in oldest or middle leaves, and then moves up the plant node by node.

 

Last edited: Dec 8, 2019