Use of Nonwoven Polypropylene Covers in Early Crop Potato Culture

Abstract

In view of the high prices obtained for new potatoes, their production is more profitable than other ways of potato usage. Early potato production is associated with considerable risk producers have to take due to high yield variability over years and rapid price decrease as a result of increased supply. The success of potato production for an early crop is dependent to the higher extent on the weather conditions in the initial period of plants vegetation, especially temperature (Nishibe et al., 1989; Sale, 1979). Too low soil temperature retards the emergence and inhibits the initial plant growth. High income obtained from early potato production is possible under conditions assuring early tuber setting and rapid gain of tuber yield, and its marketing when the price is highest. In case of early potato production, its location in regions where vegetation begin early is of high importance. In the regions with delayed vegetation, the crop of new potatoes can be forced by applying perforated polyethylene film or nonwoven polypropylene covers directly on the planted field. The favourable microclimate under the cover faciliates the emergence and futher plant growth and development in the period with less favourable weather conditions for early potatoes (Hamouz et al., 2006; Jenkins & Gillison, 1995; Michaud et al., 1990; Wadas & Kosterna, 2007a). The earlier plant emergence resulted in a more extensive ground cover during early growth and the higher leaf area index (LAI). The growth duration and leaf area determine the amount of solar radiation intercepted by the canopy and influences on the extent of photosynthesis, evaporation, transpiration and final dry matter yield (Gordon et al., 1997; Nelson & Jenkins, 1990). In Europe the covers that were most frequently used in the early crop potato culture were those of perforated polyethylene film (Friessleben, 1984; Hamouz & Rybacek, 1988; Jenkins & Gillison, 1995; Lang, 1984). Widespread availability on the market of nonwoven polypropylene and extensive promotion of these covers have resulted in a frequently reduced perforated polyethylene film with nonwoven polypropylene in the field cultivation of earlies. Polypropylene covers were introduced into agriculture on a large scale in the 1990s. Globally, they are commonly known under the name of nonwoven fabrics (Cholakov & Nacheva, 2009). This material is light, water permeable, transparent and airy. The weight of 1 m2 of nonwoven polypropylene fabric is about 2.5 times lower than the weight of perforated polyethylene film, therefore, the covering does not cause any hinder for plant developing.