Nature 184, 834 (12 September 1959); doi:10.1038/184834a0

Influence of Site and Season on Agricultural Variety Trials

A. SANDISON

National Institute of Agricultural Botany, Cambridge. May 11.

IN recent work at the National Institute of Agricultural Botany¹ the variation between centres and seasons has been studied in large numbers of cereal variety trials. It was found that the standard deviation of relative yields for wheat, barley and oat varieties in England and Wales is of the order of 10 per cent, when based on results from several centres in one or more seasons, but may be influenced by the actual varieties in trial. Comparable figures for this between trials 'error' have now been obtained for relative yields of roots and dry-matter in fodder beet (12 per cent), dry-matter yields of lucerne from single cuts (11 per cent), yields of maincrop potatoes (14 per cent), and of marketable heads of winter cauliflowers (16 per cent). In the absence of clear guidance from plant physiologists as to the critical conditions determining yield in each crop, attempts to relate these differences in relative varietal performance to particular environmental factors have not often been successful with the 20–40 results usually available for each pair of varieties. There is at present, therefore, little practicable alternative to basing varietal advice to farmers on national average results, although the search for environmental adaptation continues.

1. Sandison, A. , and Bartlett, B. O. , J. Nat. Inst. Agric. Bot., 8, 351 (1958).
2. Salmon, S. C. , Agron. J., 43, 562 (1951). | ISI |
3. Engledow, F. L. , and Yule, G. V. , "Principles and Practice of Yield Trials" (Empire Cotton Growing Coporation, London, 1930).