i have been getting seed from a tree i thought to be trifolita but recently been told that it is rusk, the tree fits the discription of rusk in the book hardy citrus for the southeast ,is rusk a good choice for rootstock...the only other choice i have is swingler both are avaliable close by...i live in 9a zone so. ga. ... larry

Rusk is a Ruby orange and trifoliata hybrid, is one of the oldest citranges, having been created by Swingle in 1897 and described and released in 1905. It was named in honor of J. M. Rusk, the first Secretary of Agriculture of the U.S.
It is not normally used as root stock because of the low seed content. It is an attractive ornamental and approaches edidility.
This is from the Citrus Industry, volume 1.
It should be as good a root stock as any of the citranges.

It also produces a more compact tree than would 'Troyer' or 'Carrizo' -- not dwarf like 'Flying Dragon', but definitely smaller than other citranges.

I've read that Rusk makes a particularly good rootstock for mandarins, but is seldom used because it produces so few seeds.

.....Alan.

Larry How would you describe the number of seed in the Rusk .

there were a variation in the number of good because some of the fruit had a large number of undevloped seed,but some fruit would have 2 seed and the next would would 6 or 8,most had 6 or 8 seed,from 5 gal of fruit i got maybe a pint and half of seed but after i washed them and floated off the light seed i ended up with about 2/3 a pint of good seed . I thought rusk didn't have many seed,i don't what is normal seed count for rusk is,i got more seed from swingler because all the seed were mature...do you have some rusk left somebody from the citrus forum called fred wanted a few rusk, do think this may another trifoliate,i may be going to cordeal,ga tueday

I'm as sure that it is Rusk. I sent Fred another message. The Rusk tree was a satsuma when I bought it 25 years ago in flshhhhhhhh . it was one of the first 2 trees that I bought, back then nurseries here didn't carry them.