过去数年在品种的引用上存在着一些问题。如七十年代在“左”的思想影响下,不少地区不经试种盲目大量引种,一方面造成一些危险病虫传播蔓延,在生产上造成一定的损失;另一方 In the past few years there have been some problems with the quotation of varieties. In the seventies, under the influence of the “leftist” ideology, a large number of places were introduced blindly and in large numbers without trial and error. On the one hand, some dangerous pests spread and caused some losses in production. On the other hand,