Probably Rust, Bean Rust. Check out the pics below for comparison and this article for detailed info. Plant resistant cultivars and use fungicides. Dave Here is a link that might be useful: Bean rust pics

An all-at-once harvest might work for bush limas, since all the beans on the plant generally ripen at close to the same time. For pole limas, the harvest is spread out over a longer period. To harvest pole limas, it is best to treat them like common bean shellies, to which they are similar. The pods may - or may not - change color when ripe, depending upon variety. Ripe lima pods also do not soften as much as the ripe pods of common beans, since the hull is more fibrous. The best indicator is a translucence to the pod; if picking with the sun in front of you, shining through the pods, this is more obvious. I grew "King of the Garden" in San Diego, and the pods would usually turn yellowish or brown-spotted when ripe. So does "Sieva". Other limas, such as "Hopi Pole", go from green to brown very quickly, and are more difficult to harvest as shellies. The small limas can go from shelly stage to dry very quickly (a day or two in warm dry weather) so they must be picked often for use as shellies. For "Sieva", the ones I miss are usually enough that there is no need for me to save dry seed intentionally. This year might be an exception to that, though, since flooding has stunted their normally rampant growth. Barring a warm Autumn, I'll be lucky to get more than a couple of meals from a 50-foot row. So much for my first attempt at growing a small-scale commercial seed crop. :-(

"...do you mean put out a lot of lateral runners, or just put out a lot of leaves?" Yes, all of the above. ;-) Both of the limas I mentioned above were initially less rampant than others I've grown, although they took off in late Summer. Of course, with limas, "less" is a relative term, since they are all extremely vigorous. The "1880's Butterbean", after the slow start, eventually filled out nicely. One plant was killed by voles, leaving a 4-foot gap between plants... by the end of the summer, the two neighboring plants had spread into the space, and the gap was hardly visible. Believe it or not, I space most pole limas 24" apart along a 6-foot trellis... and by the end of the season, the vines have filled the trellis in so densely that I can hardly see through them, even at ground level! One year in San Diego, I even spaced "K.o.G." 36" apart, and they still filled in all but the very bottom of the trellis. If the soil is fertile, you don't need many plants to get a good harvest. Last year, the "1880's Butterbean" supplied me with about 30-40 pints of shellies, and several pounds of dried beans, from about a dozen plants. I grew "Christmas" in the 90's (when I still lived in California) along with "K.o.G". For me, "Christmas" was less rampant, with far fewer & shorter lateral runners than "K.o.G.". The majority of the growth was vertical. By the way, the slow-start phenomenon that I mentioned last year extended to all of my pole beans - snaps, limas, yardlongs, and winged beans. It calls into question all my 2007 observations on yield & vigor. Even my sweet corn was less vigorous than usual. I never could figure out whether it was cooler temps, the below-normal rainfall (I irrigate) or some other cause. I suspect that the low rainfall allowed my pH to creep up, since my area has limestone bedrock. I'm curious to see how some of the same bean varieties will perform for me this year. Just wondering... did others have similar experiences with pole beans last year?

Here are links to the leaves of the plant. The pole beans are Kentucky Wonder by Ferry Morse... they are supposed to be disease resistant, so that is baffling me even more. Here is a link that might be useful: Pole Bean Leaf