Performance evaluation of short-day onion (Allium cepa L.) germplasm

A field experiment was conducted at Spices Research Sub-Centre (SRSC), Bangladesh Agricultural Research Institute (BARI), Faridpur, Bangladesh during 2019-2020 to find out promising onion line/s. Twenty-five onion germplasm with BARI Piaz-1 and BARI Piaz-4 (as check) were evaluated in a randomized complete block design in the trial. The results revealed that onion lines/varieties studied differed significantly on yield attributes, yield and quality of onion. The genotype AC Bog 413 had superior performance in incidence of bolting (2.36%), disease severity (13.66%), bulb diameter (BD-4.98 cm), individual bulb weight (IBW-36.76 g), multiplier bulb (0.22%), days to maturity (103.33 days) and yield (25.37 t/ha) over the recommended varieties-BARI Piaz-1 and BARI Piaz-4. The AC Bog 413 gave 66.33 & 22.57% higher IBW, 72.70 & 27.04% higher bulb yield, 98.33 & 98.29% lower split bulb and 90.74 & 91.03% lower bolting than those of BARI Piaz-1 and BARI Piaz-4, respectively. The AC Bog 413 matched with the disease severity category 2 while BARI Piaz-1 and BARI Piaz-4 matched with the category 4 under 0-5 scale. However, the BARI Piaz-1 had higher dry matter (DM) content (17.32%), higher TSS content (18.00 °brix) and stronger pungency (5.00) than those of AC Bog 413 (15.53%, 14.50 °brix, & 4.00), respectively. The values of DM content, TSS content and pungency score for BARI Piaz-4 were 15.66%, 14.59 °brix and 4.00, respectively. Simultaneously BARI Piaz-1 and AC Bog 413 exhibited firmer bulbs (9.00) than that of BARI Piaz-4 (8.25) under 0-9 scale. The skin and flesh colour of bulbs were identified as bronze red & white for BARI Piaz-1; red & white for BARI Piaz-4 and pink red & reddish for AC Bog 413, respectively. The variety BARI Piaz-4 and AC Bog 413 showed torpedo shape of bulb while BARI Piaz-1 showed flat shape of bulb. The AC Bog 413 showed the lowest storage loss (29.94%) among the genotypes/varieties followed by BARI Piaz-1 (35.53%), AC Bog 435 (36.09%) and BARI Piaz-4 (37.38%). The genotypes AC Bog 426 and AC Bog 430 also exhibited good performance in bolting (16.90, 19.75%), split bulb (15.66, 10.75%), disease rating (33.33, 19.66%), BD (4.01, 4.00 cm), IBW (28.66, 28.43 g), DM content of bulb (18.66, 19.69%), days to maturity (112.33, 99.33 days), yield (19.42, 19.39 t/ha), shape (flat, flat), firmness (9.00, 9.00), skin colour (bronze, bronze) and flesh colour (white, white), respectively. Finally, the genotypes AC Bog 413, AC Bog 426 and AC Bog 430 were found to be promising line/s to the recommended onion varieties (BARI Piaz-1/BARI Piaz-4) in most characters measured