Abstract:
An experiment was conducted to find out the influence of vernalization on bolting
efficiency and bulb production of different varieties of cluster onion. This research was carried
out during the period from February to June 2023 at the Experimental area, Faculty of
Agriculture, University of Jaffna, Kilinochchi. Three onion varieties (MICLO1, ARLCLO2,
ANKCLO1) and an advance breeding line (TVM6) were used with vernalization and
nonvernalization of bulbs. Treated Bulbs and untreated bulbs were planted in field using
Randomized Complete Block Design with three replications. Agronomic traits (First Flower
initiation days, 100% Flowering Days, Number of flowers per umbel, Number of Flower stalk
per plant, Width of umbel(cm), Number of Seed per umbel, Number of bulbs per plant, Dry
bulbs weight(g)) were recorded in different treatments from sampled plants. Data were analyzed
using SAS application. Analyzed data revealed that the onion varieties responded differently for
bolting and bulb formation. Overall, the study found that vernalization improves flowering
ability, flower presence in umbels and umbel size, Mainly Floral characteristics were influenced
by vernalization with cultivars. The varieties responded differently for bolting and bulb
production. Varieties ARLCLO2 and MICLO1 were shown suitability for bulbs harvests with
yields having varying bulbs traits while breeding TVM6 (76 Flowers/Plant) and variety
MICLO1(54 Flowers/Plant) were found to be the best for bolting. as well as MICLO1(134
seed/umbel) and TVM6 (125 seed/ umbel) for true seed production.in Kilinochchi.
