VARIABILITY AND INTERRELATIONSHIP AMONG YIELD AND BULB QUALITY CONTRIBUTING CHARACTERS IN INTERMEDIATE-DAY ONION

A study on variability and inter association between traits in intermediate-day onion cultivars grown from 16 different fields in Changnyeong county, Korea was carried out to establish bulb yield, yield attributing traits and quality characters. The range of variation in yield and average bulb weight was 47.9 to 84.9 t ha^-1, 152.2 to 316.7 g. Variation in minerals ranged from 36.7 to 47.3 g kg^-1 for carbon (C), 1.1 to 1.7 g kg^-1 for nitrogen (N), 0.31 to 0.56 g kg^-1 for sulfur (S), 0.18 to 0.27 g kg^-1 for phosphorus (P), 1.2 to 1.7 g kg^-1 for potassium (K), and 0.23 to 0.37 g kg^-1 for calcium (Ca). The variation in bulb quality was 7.6 to 9.5°Bx for total soluble solids content (SSC), 3.2 to 6.1 mmol kg^-1 for pyruvic acid (PA), 416.3 to 521.5 mg GAE kg^-1 for total phenolic compounds (TP), 171.4 to 378.9 mg QE kg^-1 for total flavonoids (TF), 49.4-70.5 N for firmness, and 0.0 to 11.6%, 8.1 to 71.7% for bulb loss following 3 and 6 months of cold storage. There were significantly positive correlations between yield and fresh bulb weight (0.886) or SSC (0.601), bulb dry matter (DM) and C (0.873), C and Ca (0.529) or SSC (0.541), S and PA (0.523), PA and TP (0.654) or TF (0.559), while there was significantly negative correlation between DM and PA (-0.553) or TP (-0.540), C and TP (-0.535). Bulb yield was poorly correlated with DM, N, C, K, Ca content in bulb.