宁夏引进美国黑核桃生物学特性的研究

2011—2012年对宁夏引进的10年生美国黑核桃9个优良株系及1株普通核桃的物候期、生长特性及开花结实习性进行观测及研究。结果表明，美国黑核桃4月中旬至5月上旬开始萌动，4月中下旬至5月中下旬开花；品系间雄花期最多相差11 d；雌花期最多相差20 d。枝条表现出明显的二次生长，春梢7月上旬停止生长，于8月上旬开始抽出秋梢。8月下旬至9月下旬果实成熟，同时枝条停止生长，9月下旬开始落叶。

Biological Characteristics of 9 American Black Walnuts Introduced to Ningxia

Biological characteristics,such as phenology,growth,flowering,and fruiting of 9 cultivars of 10-year-old American black walnuts introduced to Ningxia were examined in 2011-2012.One cultivar of common walnut (Juglansm mandshurica) was used an the control.The bud-break of American black walnuts began in the middle of April to the middle of May,flowering began in the middle of April to the late of May. The flowering period differed among 9 cultivars with the most discrepancy of 11 days in the male flowers and 20 days in the female flowers.Shoots showed an obvious secondary growth.The spring growth stopped in early July,and autumn growth was in early August.The fruit ripening was in late August to late September,at that time shoots started to stop growth.Defoliation began in late September.