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Root Characteristics and Yield of Greenhouse-Grown Cucumber in Continuously Cropped Soil

The cucumber (Cucumis sativus L.) production in greenhouse-grown reacted an important on vegetable supply. An experiment was conducted, during the 2001-2002 and 2002-2003 cropping seasons, November 2001 to the early July 2002 in the first season, and October 2002 to early July 2003 in the second season, in a solar greenhouse on the Loess Plateau in Yan’an, Shaanxi, Northwest China, to study the root characteristics, growth and fruit yield of cucumber as affected by growing in soils that have been continuously cropped cucumbers for 0, 1, 4, and 8 years. The results showed that the number of cucumber roots, root length, root dry weight, plant height, and leaf number decreased, but root diameter increased as the duration of continuous cropping increased. The fresh fruit productivity was the highest on the soil with 1year cropping history and decreased as the duration of continuous cropping increased to 4 years or more. Root number, root length, and root weight were correlated positively with yield whereas root diameter was correlated negatively with yield. The results emphasized the point that 4 years duration of continuous cropping is an important warning time for greenhouse cucumber production. If the duration of continuous cropping was beyond 4 years, poor root growth and decrease in yield of the cucumber would start appearing. In order to promote root development and increase fruit productivity, beyond 4 years of continuous cropping should be avoided in cucumber production management.