The relationship of preharvest sprouted seed and seed treatment to emergence and yield of winter wheat (Triticum aestivum L.) in the Eastern Free State

The deleterious effects of preharvest sprouting on wheat (Triticum aestivum L.) baking quality are well known, but limited information is available on field performance of sprouted seed and plants grown from sprouted seed. A field trial was planted in two consecutive years with the cultivar Tugela-D N to determine the effects of sprouting severity and fungicide seed treatme nt on germination, emergence and yield of plants from sprouted seed. The sa me seed was used in 1996 and 1997 to determine the effect of storage of pre harvest sprouted seed. Germination percentage and emergence were reduced in proportion to sprouting severity of seed. Seed treatment had no significan t effect on germination in either year, although triadimenol, and to a less er extent tebuconazole, caused coleoptiles to shorten significantly. Sprout ing also reduced biological yield. The germination percentage of carried ov er preharvest sprouted seed was dramatically decreased in the following sea son, and consequently the emergence percentage was reduced by almost 60% in 1997.