Pheno Hunter

I agree I would not top an auto. just LST.

I woudln't top an autoflower. just train it. DLI is the primarfy factor for yield. Training just distributes it more evently when done well. The goal of that is less proportional larf of total yield, imo.

Topping I would do after 3 weeks and stop training HST at 1212. LST during stretch should be OK but not longer. Much success and Happy Growing

A zinc, maganese or sulfur deficiency can all start out looking like this .Give your plant a dose or three of soluble mineral mix/trace element mix that are available from any decent garden centre and that should help your plant. Apply it to the roots, do not rely on foliar feeding ever!

The appearance of iron deficiency is similar to magnesium deficiency. Darkness starting from the inner part and lighter outer parts indicate iron deficiency.

Some of the other micros can mimic Mg deficiency or look similar to it. https://420life.com/wp-content/uploads/2021/10/Marijuana-Leaf-Deficiency-Chart-scaled.jpg here is a leaf chart to compare it to. the product your useing in the feeding regime. Meigs Sul-Cal-Mag, does it list what version of the S Ca and Mg it is providing? Given you are feeding it this regularly it should not have any issues with Mg. Unless it is in a form unavailable to the plant like Magnesium oxide. I am guessing it is calcium nitrate or citrate and the S and Mg are in epsolm salt form but they could also be in nitrates or citrate or just sulphate. Hopefully the package give you a breakdown. It also looks like in week3 their was a top dressing done but I don't see this in the notes or the nutrient profile on the diary. Are you fully mixing it into the top layer? What are you feeding these plants outside of CaMg and RHIZOTONIC? They 100% need other macros and micros. just curious how you are providing them. Might be part of the problem. Might not be. Good Luck!

21-28 days depending if the defoliation didn't delay it. Yes, it is viable immediately.

The flowers will open by themselves and drop pollen. Pollen can be used as soon as it drops. You can also, after the first few flowers open, cut the stalks off, hang them upside down in a paper bag and collect pollen that way. After being cut off, the male flowers will "after ripen" and open and drop pollen once mature enough after harvest. This method makes containing the pollen extra simple..........wait 4-5 days after placing them in the bag, then open the bag carefully and there should be a pile of pollen at the bottom of the bag. Apply the pollen with a small paint brush or small, very fine make up brush..........do not use Q-tips, the pollen will stick to them and not transfer to the female flowers. If you only get a small amount of pollen, it can be mixed with fine flour at up to 80% flour and 20% pollen and you will still get 100% fertilization. I have been doing this for many years now and it works perfectly. Pollinate the freshest, newest female calyxes with the whitest and juiciest pistils only, at the base of the buds....... it will take 4-6 weeks for the seeds to fully mature. You will know the seeds are mature once the calyx dries up, splits open and then you will be able to see a shiny dark brown seed inside the calyx. Waiting patiently for the seeds may seem difficult, the flowers will be well over ripe and generally unsmokable, but seed production only happens this way.