Climatic Requirements for Growing Sweet Corn

Corn is a warm-season crop that requires high temperatures for optimum germination and rapid growth. At planting, soil temperatures of 21-27°C are best and should not be below 10°C for standard sweet corn, or below 16°C for supersweets. Frost injures sweet corn at any stage of growth and even long and cool spring weather or early warm weather, can also cause ear abnormalities like appearance of ear in tassel and vice-versa.

Soil moisture must be continuous throughout the growth period and is especially critical from silking through kernel growth. Leaf rolling is a symptom of moisture stress. Water stress at silking leads to poor pollination, which shows up later as missing kernels. Kernels at the end of the ear may not develop (poor tip fill) or whole rows of kernels may not develop along the cob due to moisture stress. With temperatures above 35°C or hot, dry winds at silking, tip fill is especially poor. In rainy or very damp weather, pollen sticks to the tassel and pollination may also be poor, leading to poor seed set.