Rain spreads crop diseases, according to an article in ScienceDaily 20 November 2017.
Previous research has shown that raindrops can spread microscopic pathogens, i.e. disease causing bacteria, viruses and fungi. A team of researchers at the Department of Biomedical Engineering and Mechanics at Virginia Tech have now studied how the spread actually happens, using laser light and high speed photography of drops falling on a surface laden with microscopic particles.
Previous studies had shown that splashing from raindrops spreads microscopic particles. The new study found two other mechanisms – vortex rings and elastic collision. Vortex rings spread out in a circle from where a drop lands on the plant surface. Elastic collision is like the effect you get when a billiard ball hits another ball that is part of a tightly packed group, where all the balls in the group are dislodged.
To test their results they released a drop onto wheat plants infected with rust fungus, and found that nearly all of the satellite droplets from a single drop contained at least one rust spore.
Sunghwan Jung explained a possible application of their findings: “We are trying to characterize how far these pathogens are flying from one plant to the others, then we can suggest what is the optimal distance or array of the crops in the field”.
He went on to comment: “Since wheat provides roughly one quarter of the world’s food supply, spreading pathogens can cause a big problem in terms of the grain yield every year. Minimizing pathogenic damage by taking into account mechanisms of dispersal and optimal crop array can not only protect the wheat crop from continued yield loss, but protect the entire agricultural systems from continued pathogenic spread”.
Editorial Comment: Rain is essential today for crops to grow, and therefore to feed the world, and is God’s provision for us (e.g. Acts 14:17). However, this study is a reminder that in this fallen world, rain is only the second best way to provide water for plants. Genesis tells that that in the beginning the earth was watered by a rising mist, rather than by rain (Genesis 2:6). This would have gently watered the ground and the plants, and settled the dust and other particles without flinging them around, and therefore would not have spread ‘pathogens’ or damaged soft leaf surfaces as it does to my tomato crops. After Noah’s Flood the water cycle changed, and from then on most places in the world are dependent on rain to water the plants, which as this new study shows has ‘downsides’.
Sunghwan Jung’s comments are a good application of the original mandate given to human beings to have dominion over the earth. This is not (and never was) a licence to mindlessly and selfishly exploit the earth as some sceptics like David Attenborough have accused Christians of, but the responsibility to use the resources of the earth wisely. To do this we must study the earth, understand how it works, and use its resources to provide for people and honour our Creator with thanks and praise for His provision. After Adam sinned, God did not withdraw the original command, but told Adam that from then on exercising dominion would become hard work. Therefore, Jung’s application of his study to help farmers plant their crops in a way to minimise the spread of pathogens is a good application of dominion.
One of the reasons that exercising wise dominion has become difficult is the degeneration of the living world, so that some microbes have become pathogens, i.e. cause disease. They were not that way in the original very good world. For more information see the Creation Research DVDs Did a Good God Make Bad Bugs?, and The Real History of Worms and Germs. These available from the Creation Research webshop here.
Evidence News vol. 17 No. 21
13 December 2017
Creation Research Australia
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