高粱收穫前噴施嘉磷塞對種子含水量及種子發芽之影響

張韻如 蔡文福

國立台灣大學 農藝系

摘 要

本試驗的目的在探討高粱（Sorghum bicolor (L_。) Moench）品種“雜交高粱台中5號”之母本80A 於收穫前噴施嘉磷塞（N-(phosphonomethyl) glycine）對穗上種子含水量、種子發芽及幼苗生長勢之影響。試驗結果顯示收穫前噴施此一除草劑，對高粱植株穗上種子含水量之降低非常有效，雖然愈早噴施及噴施濃度愈高者效果亦愈佳，但會降低種子千粒重及種子發芽後幼苗之生長勢。因此如欲應用在高粱種子生產上，必須在開花後35天（完熟期）才能噴施，且濃度應低於1200ppm。

關鍵詞：收穫前、高粱、發芽、嘉磷塞、種子含水量

Effect of Pre-harvest Spray of Glyphosate on the Drying and Germination of Sorghum Seeds

Yun-Ju Chang and Wen- Fu Tsai

Department of Agronomy, National Taiwan University,

Taipei, Taiwan, ROC

Abstract

The purpose of this experiment was to evaluate the pre-harvest spray of glyphosate [N-(phosphonomethyl)glycine] on the drying and germination of sorghum [Sorghum bicolor (L_。) Moench] seeds. The female parent 80A (male sterile) was planted with the male parent 2R of the hybrid variety Taichung 5. At different maturation stages, the female plants were sprayed with different concentrations of glyphosate. It was found that pre-harvest sprays of the herbicide effectively promoted the dry down of sorghum seeds and did not affect the germination percentage. However, seedling vigor after germination was greatly damaged. The damage was greatest when high concentration of glyphosate (2400 ppm) was sprayed and when treatments were applied 25 days after flowering. Damage decreased as time of treatment after flowering (30, 35 days) increased. It is concluded that the preharvest spray of glyphosate for sorghum seed production can be conducted only at time when seed reaches maturation (35 days after flowering) and with a concentration lower than 1200 ppm in order to avoid any adverse effect.

Key words：germination, glyphosate, pre-harvest, seed moisture content, sorghum