WHATS UP WITH FOXTAILING

IVE NOTICED WHEN I LOOK AT PICTURES OF BUDS ON FORUMS AND EVEN THE PICTURES THAT SEED BANKS POST FOR THEIR SEEDS. THAT ALMOST ALL HAVE FOXTAILING. BUT THE REASON I AM ASKING THIS IS . ALMOST EVERY STRAIN I GROW STARTS FOXTAILING RIGHT AT 4 WEEKS FLOWERING ( ALMOST TO THE DAY). I HAVE GONE TROUGH FORUM AFTER FORUM AND REALLY FOUND NO ANSWER. I HAVE BEEN GROWING FOR A FEW DECADES AND I HAVE HAD EVERYTHING DAILED IN FOR I LONG TIME. SO I REALLY DONT WANT TO HERE ABOUT HEAT AND ALL THAT OTHER BS. IN THE LAST 4 OR 5 YEARS IT IS REALLY GETTING OUT OF HAND. IS IT REALLY GENETICS ?
SORRY IF THIS HAS BEEN ANSWERED BEFORE. BUT I COULD NOT FIND A ANSWER.....................................................................

STAY HIGH...TO FLY RIGHT......................................................:

Back in the day, foxtailing was normal.

I believe it was commercial concerns and the turn towards 'rock hard nugs' that drove foxtailing to be seen as undesirable.

I've always liked it myself!

Higher temperatures will cause some varieties to foxtail much more also.

I play with lights just for fun sometimes. At one end of the bud room is a 600 watt 10K color temp in a triangle with a pair of 400 watt 4K color CMH's.
Plants at this end foxtail more than the plants under a pair of 400 watt Black Dogs and three each 230 watt Dwarf Stars. The biggest difference is the infrared output.
Out of curiosity I put 150 watts of 850 nm near infrared on for two hours every morning and night and the foxtails increased.
Adding 200 watts of 730 nm far red added to the foxtails as well but a smaller amount.

This fits with foxtails being heat caused if it is radiated heat. Not sure is piped in hot air would have the same effect, my curiosity did not extend that far.

A trend I notice in LED's is many are adding far red and a few are adding near infrared to the output. This would tend to make more foxtails if used.
Some Indica plants would not foxtail under any conditions I set, but most would and some Sativa's foxtail even with ideal lighting.
So lighting does add to the foxtails but is far from the only variable.