HARMFUL EFFECT OF WORKED-DOWN WINTER WHEAT ON SPRING-SEEDED WHEAT AND RAPESEED

Abstract

Where winter wheat (Triticum aestivum L. ’Norstar’) was worked-down on 1 May and the plots reseeded to spring wheat immediately, no detrimental effect on yield of spring wheat was found. However, delaying this action until 15 May reduced the yields of spring-seeded wheat because of the harmful effect of decomposing winter wheat and late seeding. Moisture depletion by winter wheat was eliminated as a causative effect by light irrigations during May. Yields of rapeseed (Brassica campestris L. ’Candle’) were not so severely reduced by worked-down winter wheat. The harmful effect was significant only with 30 May cultivation and seeding date.Key words: Phytotoxicity, Triticum aestivum, Brassica campestris, worked-down