Accumulation and utilization efficiency of potassium in ramie varieties

Difference in nutrient utilization efficiency of genotypes of crops is attracting more and more attention of plant nutrition and breeding scientists. This experiment was carried out to reveal whether genotypic variation of potassium (K) utilization efficiency exists in ramie [Boehmeria nivea (L.) Gaud.], by measuring K concentrations and accumulations in different organs in relation to the dry matter and fiber productivity of six field growing ramie varieties with evident dissimilarity in growth vigor. Potassium concentration decreased in leaves, petioles and seeding organ, but increased in stem wood and in the raw fiber of high raw fiber yield (RFY) varieties at the late growth stage. For different parts, stem bark attained the largest K concentration, followed in order by petiole, stem wood, seeding organs, raw fiber and leaves. Potassium concentration of stem wood, bark and raw fiber, respectively, demonstrated positive and significant correlation with RFY. Potassium utilization efficiency declined by harvest time. The results suggested that the ramie varieties with high biomass and RFY and K consumption such as Xiyeqing can be planted under the condition of abundant K resource, while Nindu-Ramie variety may be used as high K efficient genetic resource for its ratios of RFY (g) and biomass (g) to K consumption (g) are over 25 and 114, respectively, in spite of its low biomass and RFY.