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Chinese Agricultural Science Bulletin ›› 2013, Vol. 29 ›› Issue (4): 94-98.doi: 10.11924/j.issn.1000-6850.2012-2617

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Comparative Studies of Chilling Requirement and Covering Time of Forcing Cultivation of Different Pear Cultivars in Nanjing

  

  • Received:2012-07-26 Revised:2012-08-14 Online:2013-02-05 Published:2013-02-05

Abstract: In order to research suitable pear varieties for forcing cultivation in Nanjing and the proper time for covering, During 2011-2012, the chilling requirement of 37 pear cultivars and varieties growing in Nanjing, model were determined using Utah model, 0-7.2℃model and≤7.2℃model ,respectively. The results showed that the lowest chilling requirement was‘Atago’, which needed 207 C.U tested by Utah model. Relatively, some cultivars such as‘Tangshansu’,‘Yali’,‘Sha 01’,‘Liuyuesu’,‘Zaomeisu’had higher chilling requirement. The chilling requirement of different cultivars ranged greatly, but most cultivars ranged 300-700 C.U. It was found that the Utah model was much more suitable to describe the changes of dormant course of pear buds in Nanjing. The maturity and origin of certain cultivars were not related to their chilling requirements. The climate in winter is temperate in Nanjing with small day average range. It was early January for early and middle matured cultivars with chilling requirement below 400 C.U to cover film to increase temperature. And the proper time to cover film for early matured cultivars which had chilling requirement of 400-700 C.U was early February.