Yellowing leaves near main cola

Hey Rollitup fam,

First time grower here... I have an auto flower green crack that is a couple weeks from harvest (I think) lol.

Ive started noticing some of the leaves at the top yellowing and turning brown at the tips - there’s also brown tips all around.

Is this nute burn? I’m growing in BioBizz light mix, and feeding BioBizz nutrients.

If it’s not, what is it?

Thanks so much for the help - so excited to hopefully smoke my own grown flower!

Magnesium deficiency. Advanced. Likely needs calcium too.

Looks kinda hungry

Thanks for the help guys! I have CalMag, any advice on how much I should use per litre on my next feed?

You got your answers on the leaves but I'm commenting on your statement: "I have an auto flower green crack that is a couple weeks from harvest (I think) lol".
Two weeks isn't enough for that plant, based on the white pistils. Those buds are maybe half done. You should wait until all the white pistils turn reddish brown and shrivel back into the buds. You'll see the calyxes swell and the trichomes will mature (need a loupe to see the trichomes and be sure to check the trichs on the buds, not the leaves). Best bet is to post a photo every week or so and ask other growers before chopping.

It's nutrient burn hump ya face

Ha. Yeah, more like 6 weeks left...plants always take longer than newbies seem to expect. I was the same myself, and always harvesting too early as a result.

Check out my latest chernobyl grow if you want to see an example of how buds look as they mature. I'm going to try to take a regular photo of the same bud from week 6 of flowering through to harvest. Currently on Week 8ish..expecting to chop in 1 or 2 weeks.

True indeed, oh Flush em with half strength nutes

Thanks for all the feedback guys! Will try flushing first and keep an eye on them!

Sad times, plant is now looking like this...

Can anyone now confirm whether this is nute burn or deficiency?

Is there anyway of salvaging this?

The top leaves are definitely burnt from the light. Unhealthy leaves will always fry quicker than healthy leaves.

The rest of the symptoms are a bit of a mix though.

Given that you seem to be displaying signs of deficiency (based on the colour of leaves) as well as signs of nute burn...I would suggest that pH or waterlogging issues are the most likely culprit....Some issue that will block a range of nutrients.

The interveinal chlorosis looks most like Zinc or Iron deficiency, but it's not likely you're actually missing those nutes, just that they are being blocked, potentially for one or both of the reasons I mentioned.

My general advice is to avoid soil that is marketed as "for cannabis", and to avoid nutes all together in soil. Just buy good "houseplant" peat or potting mix and a big bag of wormcasting. Mix them together 60/40 or 70/30 and just water until harvest. No bother, no stress, no multicoloured leaves (until just before harvest, when you want them).