highly significantp < 0.001
Multi-site variety trials with six contrasting spring wheat varieties carried out on organic farms located in three contrasting pedo-climatic zones of the UK also identified very highly significant ( p < 0.001) interactions between site/environment and variety for (i) grain and protein yield, (ii) major yield-determining parameters such as Septoria and yellow rust severity and (iii) processing and nutritional quality parameters [ 57 ] ( Table 6 , Table 7 and Table 8 ).