Start of nute burn or something els

Hi guys new grower here I have a sour diesel autoflower it's at about 4 and a half weeks it's just gone into flower a few days ago but I have noticed slight browning at the tip of one of the oldest leafs just wondered what you guys thought as I have no idea thank you in advance it's in biobizz all mix organic soil with low dose feedings now and then with bio bloom bio grow

Those leaves will die off. Perfectly normal. I’d be more concerned with node spacing. Looks like this one’s got some legs.

Thank you for the reply but over all does it look fairly healthy for an auto I know I have seen some monsters tho. and is the spacing caused by not enough light and bad temps ect and what would you do with it to correct I'm not to concerned about how the plant looks just more as to make it to some kind of smokeable harvest and not have it die on me aha more for the learning you know learning as i grow. Thanks

what lights you useing to grow her? thats some spacing for branch growth, there should be loads more branches and/or closer spaceing between them

Its just a shitty budget one says full spectrum on the box purpley light from Amazon. could it be I kept messing around with the light distance from the canopy I plan on getting a better light next week I have it in a small grow tent with a fan and dehumidifier

what size/wattage is the light? i know blurples have a bad rep, but im sure you can get it closer to the light and get those spaceings much c;loser together.
what height do you have in there and how many hours a day do you have it on? i keep the lights on 24 hrs a day and get real close spaceng

Its on 18/6 its only a small light enough for about 1 square foot I reckon. it says 1000w I'm sure it's gotta be because I kept messing with the distance then. it was about 1 metre away could have been more at one point will those older leaves just die of then is it nothing to worry about.thank you

that will be 100watts maximum at the wall draw. so move it to about 1 ft away. others may say closer, just wait n see.
if you hold your hand underneath it, see if it gets too hot to keep your hand there, if its too hot, its too close.
but ypou should be safe at 1 foot away from the plant. you will get much better growth and much better flowers

The one thing most blurples are usually good for is compact growth in veg..
So it looks and sounds like you've had it way too far away.