תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםF. H. Alston
Pear cultivars and species were grouped into five classes on the basis of chilling requirement. Class 1 required up to 850 h between 0° and 10°C and each succeeding group required 500–550 additional h of chilling. Cultivars with a high chilling requirement were Fleurissant Tard, Barnet, Roem van Wijngaarden, Frangipane and Red Pear. Low chilling requirements were recorded for Pyrus serrulata, P. calleryana, P. betulaefolia, Doyenné d’Eté, Moonglow, Magness, Beurré Rance and Packham’s Triumph. The number of days to bud burst at 15°C in March was used as a measure of post-dormant heat requirement. Chilling requirement and post-dormant heat requirement were closely related and both were sufficiently related to flowering date for each to be useful as a pre-selection criterion in breeding.
F. H. Alston
Pear cultivars and species were grouped into five classes on the basis of chilling requirement. Class 1 required up to 850 h between 0° and 10°C and each succeeding group required 500–550 additional h of chilling. Cultivars with a high chilling requirement were Fleurissant Tard, Barnet, Roem van Wijngaarden, Frangipane and Red Pear. Low chilling requirements were recorded for Pyrus serrulata, P. calleryana, P. betulaefolia, Doyenné d’Eté, Moonglow, Magness, Beurré Rance and Packham’s Triumph. The number of days to bud burst at 15°C in March was used as a measure of post-dormant heat requirement. Chilling requirement and post-dormant heat requirement were closely related and both were sufficiently related to flowering date for each to be useful as a pre-selection criterion in breeding.
