Effect of natural and artificial chilling in carrot Daucus carota L. at different locations in Kenya. I. Effects on bolting and flowering

SummaryEffect of natural chilling and artificial chilling durations of 2–8 weeks at 9°C on percentage bolting and flowering and on days taken from planting to the two events in carrot cv. Nantes was observed at four locations in Kenya in 1991/92. These were; Juja (1500 m above sea level in a warm Upper Midland (UM) zone) and Molo (2454 m), Kinangop (2558 m) and Marindas (2804 m), all in an Upper Highland (UH) zone. The observation was repeated in 1992/93 but in Juja and Kinangop only. In 1991/92 the lowest bolting and flowering percentage (<25 %) was recorded in carrot plants whose stecklings had received natural chilling at all planted sites while in those whose stecklings had received artificial chilling, bolting and flowering percentage increased with artificial chilling durations within each location. Over 75% flowering was obtained only in those plants grown from carrot stecklings chilled for six and eight weeks within each location and in those given four weeks chilling at Kinangop. In 1992/93, the ...