Maize (Zea mays L.) is grown year-round by seed companies in controlled environments to continually advance new germplasm, unimpeded by season. During winter months, maize seedlings can exhibit a physiological disorder in which newly emerging leaves from the whorl become tightly wrapped, resulting in necrosis and preventing new growth from emerging, hereafter referred to as leaf fusing. These symptoms have been recognized as a calcium deficiency in maize. Experiments were conducted to test hypotheses of light as an environmental catalyst to induce maize leaf fusing and that supplemental light emitting diode (LED) lighting or changes to soil substrate, could remediate leaf fusing in low light conditions.

Light intensity did induce leaf fusing, with a P-value < 0.001; the low-light treatment resulted in 68 % of plants with leaf fusing, while only 15 % showed leaf fusing in the high-light treatment. Substrate type did not have an effect on leaf fusing. The addition of supplemental lighting under low light conditions did, however, remediate leaf fusing symptoms. Plants grown under a low-light + LED treatment, using a 660 nm deep red LED light, reduced leaf fusing with 27 % of plants showing the disorder compared with 71 % in the low-light treatment.

To avoid the calcium disorder in maize seedlings, environmental factors that influence plant growth rate must be balanced with environmental conditions that promote calcium movement to the point of newest growth. Low light intensity, coupled with other environmental conditions promoting plant growth, result in greater instances of leaf fusing in maize. Additional light intensity, through the use of supplemental lighting, can be used as a tool to reduce leaf fusing in maize.