In 1959-61, the total fresh weights of tubers of a late variety increased with increasing plant density up to 70 000-100 000 plants/ha. With denser planting, yields decreased if N was not applied, and there was little or no yield increase with 100 or 200 kg/ha N. The optimal plant density was increased by applying 100 kg/ha N but it was not increased further with higher rates of N. Generally, no favourable interaction of N supply and plant density on yield occurred in early liftings. Weights of

more »

... >35 mm tubers and total dry weights of tubers were generally affected by N and spacing in the same way as total fresh weights. (Abstract retrieved from CAB Abstracts by CABI's permission)