Seed crop environment and processing effects on sugar beet (Beta vulgaris L.) certified hybrid variety seed quality

Abstract

The effect of the local seed crop environment on yield performance and seed quality characteristics of the sugar beet root crop was studied along with the effectiveness in multiplying proprietary sugar beet varieties according to breeders' blue prints. Six proprietary monogerm triploid hybrid varieties, multiplied, processed and marketed in Greece on licence by Hellenic Sugar Industry, were each tested using two seed lots produced from the same mother stocks. For each variety, two seed lots of each seed crop season were tested for laboratory and field performance the subsequent root crop during 1989-1994. Laboratory evaluation included ploidy level, germination and seed size determination whereas the field evaluation included field emergence, root yield and sucrose content performance along with observations for annuals, easy bolters or red table beet contaminants. Local seed lots are of normal monogerm triploid varieties and do not show contaminants throughout testing showing that local field multiplication practices are correct and pollen control was effective to secure varietal purity. Data indicated a small but inconsistent variety dependent seed crop environment effect on the subsequent root crop yield components. Deviations of Local Seed Lot (LSL) from its corresponding Reference Seed Lot (RSL) ranged from 0.8 to -3.3 t ha(-1) root yield and from 0.36 to -0.49% sucrose. Since these deviations were in the opposite direction for root and sucrose within varieties they did not result in gross sugar yield performance differences. Local seed crop environment and processing effects were observed for germination and field emergence. LSL's on average had 91.0% germination and 68.4% field emergence as compared to 92.4% and 68.1% for RSL. Deviations of LSL from RSL for germination and field emergence were small and inconsistent. Differences among varieties for seed size were observed along with a year effect but these differences were not associated with germination and/or field emergence. Data showed that quality characteristics could be manipulated through processing to secure the high seed quality standards required. It was concluded that local seed growing practices were carried out appropriatelly and the environmental control was effective resulting in reliable seed multiplication.