LEFT: Ears of corn are completely untouched by insect pests when a little mineral oil is applied to their silks as soon as those silks begin to show well. This corn was planted early. Note the big, plump ears: those ears were supposed to grow seven inches long but many ran over eight. ABOVE: As soon as the silks on your ears of corn dry out, peel back the husks of a trial ear or two to test maturity. Better yet, pull an ear and take a bite. When kernels are bright yellow, sweet, milky and crisp your corn is at its peak condition and should be picked immediately. Remember that hybrid corn ripens all at once and ? when it's ready ? you must be prepared to harvest, freeze, can or sell your crop. A delay of only a day or two can produce tough, dry, starchy kernels. The corn shown above is lochief, which takes about 85 days to mature its big nine-inch ears. lochief is especially resistant to drought and is a good variety to plant in hot, dry climates.