From the anecdotes on this site they are indeed prolific producers. I've heard differing opinions on the quality of the fruit, but consistently folks have said it is a prolific producer. Jellyman is probably the best person to respond to this question since he has been growing Doyle for quite some time.

Bud:

In Northern Virginia, on the 6b/7a dividing line, Doyle produces massive amounts of blackberries, with no disease or other problems at all.

I can't tell you if there is a difference in chilling requirements between Doyle and Triple Crown, but it's worth a shot. Triple Crown produces pretty well here too, but Doyle will outproduce it about 5 to 1, with a picking season that is longer by around 10 days. Doyle has larger berry panicles.

Don Yellman, Great Falls, VA

Jellyman, what's the quality of the Doyle like? The Triple Crown is divine, when I get them. How good are the Doyles?
Thanks, ThisBud

Thisbud:

Doyle berries are very good. For a long time we thought they were slightly smaller than the TC that I also grow (and of course later-setting berries are smaller), but last season they seemed just as large when picked in the same part of the season.

I am not one for hair-splitting on the subject of "flavor", which is mostly in the mouth of the consumer. If it looks like a blackberry and tastes like a blackberry, I call it a blackberry. If you close your eyes, you won't be able to tell the difference between a fully ripe Doyle and and an equally ripe Triple Crown. Having said that, I don't think a climate like San Diego is ideal for growing any blackberry.

Don Yellman, Great Falls, VA

Thanks very much, Don. I thought I'd try the blackberries because I've had such phenomenal luck with boysenberries. I wish I knew more about the genetic relationship between blacks and boyses. Maybe they're not as closely related as I thought?

I grow Doyle berries but I live in Indiana. I have 5 plants that produced 60 qts the first year. 125 the next, l45 the next, and 175 last year. very heavy producer.

Wikipedia has some information on Boysenberries. It might be helpful if you want to learn a bit more. Here is a clip:

"A boysenberry is a cross between a raspberry and the Pacific blackberry. For a berry, this is a very large fruit (8.0g), with large seeds and a deep maroon color."

"In the late 1930s, George M. Darrow of the USDA began tracking down reports of a large, reddish-purple berry that had been grown on the northern California farm of a man named Rudolph Boysen. Darrow enlisted the help of Walter Knott, a Southern California farmer who was known as a berry expert. Knott hadn't heard of the new berry, but he agreed to help Darrow in his search for the berry."

I love the Boysenberry story.

gurgler, thanks so much for the Rudolph Boysen/George Darrow story. I'll read the rest of it on Wikipedia. Strange (and fascinating) to me that two cane fruits that don't do so well in my area, blackberries and raspberries, should cross and produce a boysenberry that does phenomenally well here. All hail the boysenberry. In the words of Paul Simon,
"I prefer boysenberry more than any ordinary jam. I'm a 'Citizens for Boysenberry Jam' fan."

I suggest growing roseborough. they can be had from brambleberry farm.
they have disease free plants and very cheap maybe try Kiowa as well. I got
some from Simmons but they were riddled with anthracnose so had to quarantine them. They make up to quarter size berries of wonderful sweetness. Brazos is tart so I don't go there. Humble might be good too if
you can find.
I remember looking in wonder at a blackberry garden in Oceanside where I lived
long ago. I lived in a long 2 story apt. close to the beach with an inside 'court"
and tikis out front. you may know of it. Anyway they sure were growing
blackberries!! I am using serenade and others from gardens alive along with
copper and now captan spray after bearing and have been doing fine. By all
means for it. also check with Californina Rare Fruit growers for info. good luck. :)