[Brian Griffin]

“Yellowing of the areas between the veins (interveinal chlorosis) is usually indicative of manganese, iron or magnesium deficiency. Iron deficiency affects the youngest leaves first, whereas the symptoms of manganese and magnesium deficiency tend to start in the older leaves.

“Nitrogen deficiency causes a more general yellowing or reddening, initially usually of the older leaves, often accompanied by a lack of vigour. With potassium deficiency the yellowing is often more pronounced at the leaf edges.”

https://www.rhs.org.uk/problems/chlorosis

[Merrick]

Yes, chlorosis (yellowing of leaves) can occur as a secondary symptom of aluminum toxicity in soil.

While the primary damage happens to the roots, the resulting inability to absorb nutrients leads to visible deficiencies in the foliage:

Mechanism: Toxic aluminum ions stunt root growth and damage root tips, preventing the plant from uptake essential nutrients like magnesium, iron, and phosphorus, even if they are present in the soil.

Appearance: This nutrient lockout manifests as interveinal chlorosis (yellowing between the leaf veins while veins remain green) or general pale yellowing of older leaves. In rice, it specifically appears as orange-yellow interveinal chlorosis.

Progression: If untreated, the chlorotic areas can die (necrosis), leading to leaf tip death and margin scorch.

I didn't say ONLY aluminum results in chlorosis. But most farmers are competent in controlling their soil pH, so if they see chlorosis it more likely due to one of the thing you point out. But he seems to BLAME his problems on increased aluminum. The video evidence contradicts him. Especially because all the weeds choking out his corn are perfectly healthy.

[Merrick]

And, by the way, several of my go-to chemicals for weeds in my lawn work through chlorosis - many weeds have a different chlorophyll mechanism that fescue, and there are organic compounds that prevent chlorophyll production and photosynthesis in these plants. Triclopyr is an example. But it’s a balance. Too much and you will kill your grass.

So there are potentially many things that result in chlorosis. None of that changes the two inescapable facts that elevated bioavailable aluminum causes chlorosis (none of which is evident in that video) and if you have elevated bioavailable aluminum you are a crap farmer who need to lime his farm.