3个品种莲雾果苗寒冻害等级指标的确定

为减少莲雾寒冻害损失,亟需建立不同品种莲雾果苗寒冻害等级指标。根据大尺度灾情数据记录3种莲雾果苗样本形态,对照形态学标准确定寒冻害等级,结合数理统计和对比方法建立指标。结果确定了3种莲雾果苗寒冻害等级指标。‘大叶’:T_m>4.5℃,无寒冻害;1.5℃m≤4.5℃,轻度;-1.0℃m≤1.5℃,中度;-3.0℃m≤-1.0℃,重度;T_m≤-3.0℃,极重。‘黑珍珠’:T_m>5.5℃,无寒冻害;3.0℃m≤5.5℃,轻度;0.5℃m≤3.0℃,中度;-2.5℃m≤0.5℃,重度;T_m≤-2.5℃,极重。‘紫红’:T_m>5.5℃,无寒冻害;2.0℃m≤5.5℃,轻度;0℃m≤2.0℃,中度;-1.5℃

3 Cultivars of Wax Apple Seedlings: Determination of Cold and Freezing Injury Grade Indexes

The paper aims to establish the cold and freezing injury grade indexes for different cultivars of wax apple seedlings to reduce the loss caused by cold and freezing. Based on large-scale disaster sample data of wax apple seedlings, we determined the cold and freezing injury grade by comparing with the morphological standard, and established the cold and freezing injury grade index combined with mathematical statistics and comparison method. The results showed that: the cold and freezing injury grades of ‘Big Leaf’ were determined as: T_m>4.5℃, no cold and freezing injury; 1.5℃<T_m≤4.5℃, light injury; -1.0℃<T_m≤1.5℃, moderate injury; -3.0℃<T_m≤-1.0℃, severe injury; T_m≤-3.0℃, extremely severe injury; those of ‘Black Pearl’ were: T_m>5.5℃, no cold and freezing injury; 3.0℃<T_m≤5.5℃, light injury; 0.5℃<T_m≤3.0℃, moderate injury; -2.5℃<T_m≤0.5℃, severe injury; T_m≤-2.5℃, extremely severe injury; and those of ‘Purple’ were: T_m>5.5℃, no cold and freezing injury; 2.0℃<T_m≤5.5℃, light injury; 0℃<T_m≤2.0℃, moderate injury; -1.5℃<T_m≤0℃, severe injury; T_m≤-1.5℃, extremely severe injury. In conclusion, the cold and freezing injury grade indexes are of practical significance by artificial climate chamber experiment, geographical transplantation, and historical disaster sample verification.