Home » The Light Factor: Health and Light

The Light Factor: Health and Light

Welcome to Book of the Week – a weekly feature of an Acres U.S.A. published title offering you a glimpse between the pages! Get the Book of the Week email newsletter delivered directly to your in box! This week’s Book of the Week feature is Eco-Farm by Charles Walters. 

Many plants grow poorly as long as the soil fails to warm up. During this period in early spring, very little nitrogen is served up by proteins in the soil’s organic matter. One can see pasture grasses literally starved for want of nitrogen. Then one day the soil wakes up, and the landscape is painted green overnight.


Ambient air temperatures also figure in plant performance. Photosynthesis comes to a halt at night because the chloroplasts settle down for a sleep of sorts. There is a word for this—photoperiodism—and scientists who use that word speak of daily rhythms, biological clocks, and the like. USDA scientists H. A. Bortwick and S. B. Hendricks found, as early as 1948, that red and far-red light—that is, visible light almost in the infrared part of the spectrum—regulates plant growth. They found a protein which runs the light switch in plants, so to speak. They proved that the molecule styled phytochrome is triggered by light. It presides over the plant life process—its germination, flowering, growth. Even in sleep, respiration and burning of sugar continues.

Good Iowa farmers will tell you that they can hear the corn grow at night, and they can. Entomologist and philosopher Phil Callahan has watched bamboo growing. “After a good electrical storm you can sit down level with the fresh little bamboo shoots and actually see them get longer” Callahan said. But when air temperatures soar beyond endurance, respiration and sugar burning are affected simply because too much sugar is lost.

“Light exerts a profound effect on plants and on all animal life,” John Ott once told Acres U.S.A. readers via the medium of a taped interview. His two books. My Ivory Cellar and Health and Light furbish and refurbish this thesis. “Sunlight is a broad, continuous spectrum peaking a little in the bluegreen. It then cuts off abruptly in the ultraviolet at about 2.900 angstroms because of the filtering effect of the earth’s atmosphere,” Ott wrote in Health and Light. An angstrom is a unit of length so small it demanded a name of its own. Technically speaking it is one ten-billionth of a meter, and is used in optics and to measure light, something a farmer hardly concerns himself with. Yet a farmer has to be concerned with light.

Using time-lapse photography, Ott has been able to show the streaming of protoplasm with cells of a living plant leaf. This has to do with the photosynthesis we discussed in the first lesson of this book. Air, water, sunshine and a few earth minerals make it possible for plants to create food energy in the presence of an appropriate temperature.

But when the sun sets, photosynthesis stops. Long periods of cloudy weather and faltering sunlight intensity not only affect plant life, they help nature decide which plants can survive in climes with long and short days. Modern technology, particularly weather modification and industrial development, has a profound effect on sunlight availability, ergo crop production. The consequences of inserting carbon black and other nucleating agents into the atmosphere by climate and weather modifiers escapes instant comprehension. But the result of heavy and concentrated industrialization has been a matter of record. The Smithsonian Institution in Washington, D.C. has reported a 14% loss of overall light intensity over the past 60 years. Mount Wilson observatory in California has published figures to the effect that all farm acres have lost 10% of average sunlight intensity during the last 50 years, and 26% reduction in the ultraviolet part of the spectrum. Some virus problems and aphids brought on in part by inadequate sunlight have in fact been controlled by placing light reflective aluminum foil on the ground beneath the plants.

Poultry growers have long realized that the light in a chicken’s eye stimulates the pituitary and thereby increases egg production. Ott says the pituitary is the balancewheel of the entire glandular system, not only in chickens, but in men as well.

Indeed, Git’s experiments tell us something we ought to know, even if we can do little about it. In one experiment he photographed chloroplasts within Elodea grass as they responded to different wavelengths of light energy. When the Elodea grass was exposed “to the full spectrum of all the wavelengths of natural sunlight, all the chloroplasts would stream in an orderly fashion around and around from one end of the cell to the other. However, if the sunlight was filtered through ordinary window glass that blocked most of the ultraviolet, or if an ordinary incandescent microscope light which is lacking in the ultraviolet part of the spectrum was used, some of the chloroplasts would drop out of the streaming pattern and remain immobile near the center or off in one comer of the cell of the leaf.”

Under red light, chloroplasts would drop out of the streaming pattern or take a shortcut, not touching all the bases. But when the color filters were removed, the chloroplasts would go back to their normal streaming procedure.

About the Author:

Charles Walters founded Acres U.S.A. and completed more than a dozen books as he edited the Acres U.S.A. magazine, while co-authoring several more. A tireless traveler, Walters journeyed around the world to research sustainable agriculture, and his trip to China in 1976 inspired others. By the time of his death in 2009, Charles Walters could honestly say he changed the world for the better.

More By Charles Walters:

Browse the Charles Walters Collection for all of his titles and works.

Similar Books of Interest: