Submitted to: HortScience
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/1/2004
Publication Date: 3/1/2004
Citation: Parris, N., Douds, D.D., Dickey, L.C., Moreau, R.A., Phillips, J.G. 2004. Effect of hydrophilic zein films on the growth of tomato plants and evaporative water loss. Hort Science.39(6).p.1324-1326. Interpretive Summary: Materials presently used as ground cover in agriculture to control weeds or reduce water evaporation, such as plastic sheeting, are expensive to use because of additional costs of removing and disposing of the material after the growing season. In this study, we produced biodegradable zein films made from a semi-purified zein extract (Zein isolate) we prepared ourselves from corn and compared those to films made from commercial zein. Films were used to cover the soil surface of plastic pots in which tomato seedlings were grown. Films made entirely of the commercial zein degraded within a week and had little effect on water loss or plant growth. Films from the zein isolate degraded after two months and both retarded water loss and enhanced plant growth relative to controls without films. Farmers and horticulturists would especially benefit through both reduced water usage and increased plant growth. Future work will focus on blending both commercial zein and the zein isolate to produce films timed to degrade when the water loss from the soil surface is no longer significant.
Technical Abstract: The effect of ground cover films prepared from zein on the growth of tomato plants and corresponding evaporative water loss was investigated in greenhouse experiments. Zein is an alcohol soluble protein isolated from corn. Films were prepared both from an experimental zein isolate (a zein-lipid mixture) and from commercially available purified zein. Films made entirely of the commercial zein degraded within a week and had little effect on water loss or plant growth. However, results indicated there was a significant decrease in water loss from the growth media for pots covered with films made of the zein isolate compared to controls without films. In addition, plants mulched with zein isolates low in free fatty acids were 18% taller and 28% greater in mass compared to controls. Zein isolate films appear to be a viable replacement for polyethylene sheeting as ground covers.