Drought Resistant Corn
Tips & Techniques to Grow Corn in a drought
|The only true drought resistant plants are those that evolved in a dessert environment. deep-rooted Desert Trees survive months without rain by extending their roots deep into underground aquifers. Cactus have the ability to subsist on minimal moisture and store more in their fibrous membranes.|
There is no such thing as Desert Corn, but there are a number of heirlooms, hybrids and "yikes !" - GMOs that perform better than the rest of the pack under desert and drought conditions. They are drought tolerant, but not drought resistant.
"Non-GMO drought-tolerant varieties are already deployed to several million farmers with yield improvements reported to be about 20-30 percent." 
Dupont released multiple versions for resistance to drought, regional adaptations and disease resistance. Once again this corn is not available to Home Gardeners and only on a limited basis to Commercial growers.
In addition to selecting the correct varieties of corn, you as the gardener will have to make up the difference that Mother Nature is withholding. Diligence is rewarded with a bountiful harvest - damn the drought full speed ahead !
Iochief Sweet Corn is available and has been a reliable and consistent producer of sweet corn under adverse conditions for decades. It is an older hybrid that is hardy and drought tolerant. Iochief is readily available to home gardeners.
Black Aztec Corn is a variety grown by the ancient Aztecs and Mayans dating back Centuries. It is drought tolerant in the sense that it will generally survive a lack of water, and produce seed for the continuation of it species. However the seed it produces when stressed is not of the highest quality. The trick to growing palatable Black Aztec corn lies in harvesting while it is immature, the kernels will be white instead of blackish purple.
Mature Black Aztec corn is still good for grinding into flour or corn meal. For sweet corn it is best used while it is young and white before it hardens and turns black.
Corn with high concentrations of Starch are best used for corn flour, cornmeal, and so forth. It can also be used as a ornamental corn. It does not serve well as edible fresh corn, unless of course your a chicken or pig.
Blue Giant Dent Corn has attributes very similar to Oaxacan Green and the "butcher" varieties. It is grown in Mexico and vicinity and generally used for tortillas and corn chips. Blue Giant does not fare well in windy locations. A Similar variety is Hopi Blue Corn.
Bloody Butcher is another variety of Dent Corn that fares well under drought conditions. It can be eaten fresh but you have to catch it an opportune time, and there is a very short window of only a few days.
Once the silk begins to darken and you can pierce a kernel with your finger nail and see its juices flow out - it's ready. If you miss the window of opportunity it is still good for roasting or cracking but doesn't taste very good fresh. A Similar variety is Daymon Morgan's Kentucky Butcher.
There are a number of tactics to help corn plants prosper under drought conditions.
3. Add another 3 to 4 inches of organic mulch around the base of plants to help with moisture retention.
4. It is believed - although not proven beyond the shadow of a doubt that adding aspirin to the water when you plant tomatoes will enhance their ability to cope with drought as well as disease resistance. "The basic premise is that salicylic acid (the original active ingredient in aspirin) triggers plants to activate their version of an immune system, leading to an improved ability to fight off disease and fend off stresses like drought or cold."  .
5. Dusting the roots with mychorizzae is another well advised option when planting. Mychorizae are a naturally occurring beneficial fungi that attach themselves to plant roots creating a symbiotic relationship.
Mychorizae penetrate the root systems of most plants in nature. They are helpful in providing improved uptake of water and nutrients from the soil. They help protect the roots from harmful pathogens and disease and help to reduce the effects of mineral Build Up on plants.
Trichoderma is another beneficial fungus that colonizes root systems. They prevent harmful fungi from entering the same root system, stimulate root development, and improve the plant's adaptability to environmental stress.
6. Dry farming is a technique which can help reduce water usage when need be. Water your plants as you normally would when they are young. Shortly after the ears set stop watering them completely. You'll end up withe smaller ears. This tactic does not work well under extreme heat conditions - extended dry periods above 90 F. and works better with non sweet corn varieties.
7. Interplant properly. Using the proper companion plants for corn will aid the development of both plants. See Corn Companion Plants
A. Cucumber as well as squash provides for a living mulch, helpful in soil moisture retention. "the vines [cucumber] growing with corn helps to anchor corn and discourages raccoon's "Cucumbers are offensive to raccoons, so it's beneficial to plant it alongside corn. Corn seemingly protects the cucumbers against the virus that causes wilt." Carrots Love Tomatoes: Secrets of Companion Planting for Successful Gardening - L.Riotte
8. Silicon is proven to enhance drought and heat tolerance in plants. No - I am not talking about putting silicone caulk on your plants ! Silicon is a very abundant natural element that is present in soil, in fact it comprises nearly 1/4 of the Earths Crust. It strengthens the cellular walls, improving the plants tissue strength, overall health, vitality and productivity and is advantageous to drought tolerance in plants. It can be applied as foliar spray or as a soil addendum. See - Silicon for Drought Gardening
1. Genuity DroughtGard Hybrids Monsanto
3. Aspirin water for plant disease? Penn Live