Effect of cold temperature durations of onion sets in store on the incidence of bolting, bulbing and seed yield

Growth, bolting and yield of garlic (Allium sativum L.) in response to clove chilling treatment

“…In the untreated control, where the cloves were kept at ambient temperature (20 • C), the bulbs matured late. The findings agree with the research of Aura (1968), Butt (1968), Palilov (1969) and Khokhar et al (2007) on onions; under low storage temperatures (0-7 • C), the vegetative cycle is reduced and bulbing is accelerated, while under high temperatures (18-30 • C), both bulbing and ripening are delayed.…”

“…Therefore, the most important floral induction factors in garlic should be variety, bulb storage duration and temperature, and photoperiod and growth temperature (Pooler and Simon, 1993). Chilling treatment during bulb storage has been researched significantly on Allium and Lilium (Le Nard and De Hertogh, 1993;Bandara et al, 2000;Khokhar et al, 2007;Lee et al, 2007Lee et al, , 2008Mojtahedi et al, 2012Mojtahedi et al, , 2013Lucidos et al, 2014), but chilling treatment on bulbs as a substitute for plant vernalization has rarely been reported. The results of Karaguzel and Baktir (2013) indicate that cold treatments and their durations had significant effects on the flower stem length, flower stem diameter and flowering time of Allium robertianum Kolmann; the best results were obtained from bulbs stored at 10 • C for a 30-day period in a heated glasshouse, while the earliest flowering was observed in bulbs stored at 5 • C for 60 days in the glasshouse.…”

“…Though the effect of sole chilling treatment on cloves is not equal to that of green plant vernalization, the results provide evidence for the actual possibility of the vernalization application to produce garlic bulbs or fresh garlic scapes in warm season or area. Several researchers have reported the early maturity of garlic and onions after a pre-planting low-temperature treatment (Satti and Lopez, 1994;Khokhar et al, 2007). Bandara et al (2000) found that increasing the chilling treatment period up to 45 days increased the bulb yield, while a further increase in the treatment period reduced the yield.…”

“…Trevaskis et al (2007) reported that several weeks of cold exposure were often sufficient to promote flowering, but longer durations could accelerate flowering to a greater degree, up to the point when the vernalization response became saturated. It was reported that the optimum conditions to fully vernalize onion cultivars were under low-temperature (-11 • C) treatments for 7-90 days (Khokhar et al, 2007). The role of lowtemperature storage for growth and development in other bulbs has also been well demonstrated (Mojtahedi et al, 2012(Mojtahedi et al, , 2013.…”

Effect of Planting Density and Spacing on Growth and Yield of Onion

“…It requires proper vernalization temperature for early flowering and higher yield of bulb (Kabir et al, 2008). For flower induction it requires low temperature (Khokhar et al, 2007). Onion induce flowering in temperature ranging from 5°C -13°C, inflorescences growth temperature between 20°C -25°C (Serkara et al, 2017).…”