I am in the humid subtropics but we get pretty regular droughts in Australia. Last spring we went for about 7 months without any real rain.
I have trialed just about every grain you can imagine here, but we have clouds of birds of many different species. Amaranth does OK but the germination is finicky (needs high nitrate in soil to get going?) and the yield isnt high enough to be considered a staple. I have a strain of white maize I have developed that is fairly bird resistant but not super reliable since we need wet weather to get it going and dry to harvest a decent quality product, which only happens about every second year. Planting a big crop and getting nothing half the time is pretty off putting. Rice also stands up to birds surprisingly well, and doesnt suffer as much from wet at harvest, but I need to find a simple way to hull it to justify scaling up. Genetic diversity available in rice is pretty limited here as well. Dry legumes also suffer from inconsistent wet/dry cycles, plus a nasty sucking bug that ruins most species, but luckily lima beans have proven themselves worthwhile and I recently found a source for wider genetics to work with. I am also developing seed pumpkin strains from a few different moschata types that grow like weeds here. The low tech production of a high value product that stores easily in a humid climate is a big plus.
Tuber crops seem to be the place to focus for me, though they have issues as well. Potatoes grow really well through our late summer/autumn when we normally get good rain, but storing tubers in our warm climate all through spring and summer without refrigeration is very difficult. Some years I can also grow a spring crop, but if we get a spring drought then I can lose all my stock. I was hopeful of figuring out a way to grow strains from seed to get around this but I am still experimenting. Sweet potato grow very well here but our cracking clay soil makes weevils a major issue, so the crop cannot be relied upon. I am experimenting with other Ipomoea species. Even cassava has a hard time with bandicoots digging up the roots before harvest (even in high cyanide forms). Luckily winged yams and canna do really well here. I am breeding canna and collecting yam diversity to try producing seed. If I can't breed a crop I don't consider it to be a long term staple to rely on. Cocoyam, taro, Calathea allouia and Maranta arundinacea will always only be minor subcrops for this reason. I am considering becoming a starch extraction specialist, since the same equipment that purifies starch from canna can also be used on Typha roots at a different time of year. I am also starting work with Plectranthus as a tuber crop, but need to find a source of P. esculentus to really get going as P. rotundifolius is a bit too water dependent/tropical to do well here.
We also have a few tree staple crops. I am trialing chestnuts but it might be too humid for them to be a major crop here, but preliminary results are pretty good. They mature quickly so I might be able to get somewhere with them. We also have a legume tree called black bean (Castanospermum) that produces huge starchy seeds. They are also packed with toxins that can be removed by roasting and soaking in running water as the natives did. I reckon I could do starch extraction on them instead, similar to how mung beans are turned into starch in Asia, as a way to detoxify instead. We also have the massive bunya nut tree (Araucaria bidwillii) that I am collecting local diversity from, hoping to cross with the related parana pine from Brazil in the future to domesticate the genus. I am also trialling Schotia from south africa, which has fairly large starchy seeds that are meant to be edible after roasting. Macadamia grows like a weed here and I am planting lots of them as an oily nut crop.