淮北地区小麦产量的变迁与提高产量潜力的途径

淮北地区小麦品种产量潜 力和生产水平都随着年代的推移不断提高。小麦品种产量 潜力的变迁，有两次飞速发展期，即 ５０ 年代和 ７０ 年代；两次 徘徊过程，即 ６０ 年代和 ８０ 年代。小麦生产水平 的变迁，５０、６０ 年代属缓 慢增长期，７０、８０ 年代属突飞猛进期，９０ 年代增 长趋缓。品种产量与生产水平的关系 由 １９４９ 年的 １．８１ 倍上升到 ６０ 年代的 ３．６７ 倍，至 ９０ 年代下降到 １．４ 倍。为了使小麦生产持续 稳定增长，急需培育高产更高产的超高产小麦 新品种。本文还分析了超高产育种的可行 性，提出了性状指标 和主要措施。

Variation and Influence Factors of Yield Gravity Center of Flue-cured Tobacco in Hunan

The variation and influence factors of yield gravity center of flue-cured tobacco in Hunan were studied in 2006-2015 by regional gravity center method and grey correlation analysis. The results showed that the yields of flue-cured tobacco in various areas in Hunan were mainly of the growing with fluctuation type. The yield gravity centers in the whole province and eastern, southern and western Hunan tobacco-growing areas overall moved in the north by west, south by west, west by south, and south by east directions, respectively; and the movements in the south-north direction were in order of eastern Hunan tobacco-growing area 〉whole province 〉western Hunan tobacco-growing area 〉southern Hunan tobacco-growing area, and the movements inthe east-west direction showed an order of eastern Hunan tobecco-growing area〉western Hunan tobacco-growing area〉whole province〉 southern Hunan tobacco-growing area. The main influence factors of the coordinates of the longitudes and the latitudes differed. The main influence factor was planting area in most cities or counties in the whole province, and was per unit area yield in a few cities or counties. It is advised to construct the ＂one main body and two wings＂ development pattern of flue-cured tobacco production in Hunan with southern Hunan tobacco-growing area as the main body and western and eastern Hunan tobacco-growing areas as the two wings.