ANALYSIS OF GROWTH OF IRRIGATED RAPE

Abstract

Irrigated Polish rape (Brassica campestris L. cv. Span) and Argentine rape (B. napus L. cv. Zephyr) were harvested at 1-wk intervals at Lethbridge, Alberta and separated into leaves, stems, pods, and seed. Leaves reached maximum dry weight on 8 July for Span and 15 July for Zephyr and then senesced completely or to low levels. Maximum plant dry matter, which ranged from 312 to 1,174 g/m2, occurred in the last half of August. Although total dry weight increased substantially during the period that leaf dry weight was decreasing, crop growth rate also decreased, indicating that leaves were an important source of photosynthates for plant growth.