Samer Abou Hamdan^(1)* and Bayan Muzher^{( 1)}

(1). Pome and Grapevine Division, General Commission for Scientific Agricultural Research (GCSAR), Syria.

(*Corresponding author: Eng. Samer abou hamdan E-mail: abuhamdansamer@yahoo.com)

Received: 12/07/2020                                Accepted: 22/08/2020

Abstract:

The research was carried out at the Pome and Grapevine Division in Sweida Governorate_ General Commission for Scientific Agricultural Research GCSAR_during 2016 and 2017 on the pear variety Conference Pyrus communis var. Conference that introduced by the General Commission for Scientific Agricultural Research in order to determine the environmental requirements, and study the influence of temperature on the development of flower buds and fruit ripening, and the date of consumption maturity according to the environmental, physical, and chemical indicators and connect them with sensory tests at each harvest date. The results showed that Conference variety requires from 900 to 1200 winter chilling hours to obtain the highest percentage of opened flower buds, and the study area achieved the need of this variety in the two seasons, and the temperature had an effect on the length of duration of phenological stages of the flower buds, and the increase of temperature accelerated the onset of flower buds, and reduced the period between these stages particularly the white stage and the full bloom. The variety requires between 165 and 178 days for consumption maturity with a thermal accumulation of 2225-2287 thermal units, and the best maturity indictors were at the harvest time 25/9 when the fruit weight was 252.3 g, fruit firmness 5.4 kg/cm², starch degree 4.5-5.6, and the percentage of soluble solids and total sugar increased to 14.72% and 12.04% respectively, and the percentage of titratable acidity decreased to 0.17%, as well as the results of sensory tests showed that the early harvested fruits didn^‘t reach the good quality for consumption, and their structures were improved as the fruits matured, and all of them were between good and outstanding by the time of 25/9.

Key words: Pear, Conference variety, Chilling hours, Phenological stages, Maturity indicators.

Full paper in Arabic: PDF