SEED CROP ENVIRONMENT AND PROCESSING EFFECTS ON SUGAR-BEET (BETA-VULGARIS L.) CERTIFIED HYBRID VARIETY SEED QUALITY

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 var ieties according to breeders' blue prints. Six proprietary monogerm tr iploid 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 pe rformance the subsequent root crop during 1989-1994. Laboratory evalua tion included ploidy level, germination and seed size determination wh ereas the field evaluation included field emergence, root yield and su crose content performance along with observations for annuals, easy bo lters or red table beet contaminants. Local seed lots are of normal mo nogerm triploid varieties and do not show contaminants throughout test ing 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 effe ct on the subsequent root crop yield components. Deviations of Local S eed Lot (LSL) from its corresponding Reference Seed Lot (RSL) ranged f rom 0.8 to -3.3 t ha(-1) root yield and from 0.36 to -0.49% sucrose. S ince these deviations were in the opposite direction for root and sucr ose within varieties they did not result in gross sugar yield performa nce differences. Local seed crop environment and processing effects we re 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 6 8.1% for RSL. Deviations of LSL from RSL for germination and field eme rgence were small and inconsistent. Differences among varieties for se ed size were observed along with a year effect but these differences w ere not associated with germination and/or field emergence. Data showe d 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 mul tiplication.