You ask yourself why am i not getting seed set on some days and seed set on other days? There are several reasons why and some are the hybridizers fault and sometimes Mother Nature just has her way.
Here in Arkansas we have what i have called a pollen bee that steals the pollen from the blooms. When the lilies first start blooming there are no bugs but before long they are very numerous. Are they really a bee, I dont know, i just know they eat pollen. As the temperatures get into the 90s these little theives are hungry. I was watching them this morning and they really liked this red eyed flower as there was 4 on it at one time. Seems they start by landing near the throat of the flower eating the loose pollen and then move up to the anthers and start eating the pollen there. I did catch one that landed on the pistil and worked on that pollen i had just put there. So when you come in from work and go look at the flowers and collect the pollen and its gone here are the Culprits. So get you a piece of Alum foil laid flat and collect the anthers before they open. Put them in the house where its cool and they will open just fine. You can collect the pollen when you get in or at lunch but you will have it. I have an article on our website about saving pollen with pictures listed under forums. http://www.woostergarden.com/
Another common problem is pistil splitting. Maybe you havent noticed but there are several cultivars that do this on a regular basis. When that pistil is splitup you can save your pollen cause you aint gonna set a seed pod there. Another just as bad as splitting is when that pistil is closed off. When it is pointed and not flat, save your pollen. Think of a pistil like a handful of drinking straws in your hand. When the pistil is flat like those ends of straws the pistil can suck down the pollen to the overies and pollinate the seeds. Also when humidity is down the tip of the pistil may be dry. If you will watch your lilies when the anthers start opening and fluffing the pollen the tip of that pistil will have a tiny drop of lubricant to ease the pollen down the pistil. But when the pistil is dry you will not set seeds. If you have 3 blooms on a scape and only 2 have the lubricant on the pistil you will get 2 seed pods.
Also for those wanting to know why some pods have 4 chambers, those are from flowers that were polytepaled(4 petals) and they also had 8 anthers instead of 6. it doesnt mean you will have more seed per pod but you will have 4 chambers.
When i was hybridizing this morning and watching those bugs making a living i was thinking how great this world is that God has created, all things big and small. Jim Elliott