Checkerboarding, opening the brood nest, etc.

[Zoot]

If one employs any of these techniques in an effort to keep a big 2nd year hive unsplit - what happens typically after the main flow (assuming there was no swarm and one obtained a good crop of honey and harvested it)? I would envision a really substantial colony at that point. Would a late summer split be feasable or is it likely that such a hive could be managed on through the fall and winter into the next spring?

[Michael Bush]

>Would a late summer split be feasable or is it likely that such a hive could be managed on through the fall and winter into the next spring?

If it's really booming at the end of July a split can work well here.  Where you are you might be able to push that to the beginning of August.

[Brian D. Bray]

There are 4 essentials considerations in swarm control:

• Bees busy building comb will usually not swarm
• Hives with plenty of room to give the queen as much room as she wants to lay eggs and house hatching brood will usually not swarm
• Hives with plenty of room to house honey storage will usually not swarm
• Hives with proper ventilation are less likely to swarm

If done properly a hive can be build up very strong during the 1st honey flow.  A split (nuc) at the end of that flow will mimic the swarm--be sure to place the old queen in the nuc for added effectiveness of mimicking a swarm and the new queen in the parent hive.  The hatching brood in the parent hive will maintain the strength of the hive to that prior to the split by the time the 2nd flow begins. This means a split in late April, May, or June just as in nature but controlled.  The original hive will still produce well and continue to grow as long as your swarm management practices are maintained. It will produce more than it would if only a portion of swarm control concepts are used and a swarm were somehow avoided.
Swarm management is an all year around consideration.
The split will also produce a harvest using the same techniques. 
Using proper swarm management techniques you can have twice as many strong hives at the end of the season as what you started with and twice as much honey harvest than you would have with just the one hive, even if swarming were avoided.

[Zoot]

continuing with this theme - as the summer progresses beyond the first flow and if one decides to do a split (or create a nuc) at that time or even later is it more advisable to consider requeening the old hive as opposed to letting the bees do it themselves?

[Michael Bush]

If you are looking at needing a queen during the spring buildup (and if you don't care that much about local genetics) then buying one will make a difference in the honey crop as you'll lose 24 days of brood rearing raising a new one.

In the summer, after the flow, it doesn't make much difference in the crop (since that's past) and works fine to let them raise their own.