The effect of agronomic factors on crop health and performance of winter wheat varieties bred for the conventional and the low input farming sector

Official URL: http://dx.doi.org/10.1016/j.fcr.2020.107822

It has been frequently suggested that varieties bred/selected under conventional farming conditions lack important traits required for optimum performance under low agrochemical input conditions. However, there is limited scientific information about interactions between cultivars bred/selected for the low input vs conventional farming sector and innovative crop agronomic strategies on crop health, yield and quality parameters to support this hypothesis. The main objective of this pilot study was therefore to compare the effect of contrasting fertilisation and crop protection regimes used in organic and conventional farming on crop health and performance parameter in two wheat varieties developed for organic/low input and conventional farming systems respectively. Results indicate that both leaf phenolic and flavonoid compounds, were positively associated with use of the 'long straw' variety Aszita and to a lesser extent composted FYM fertiliser inputs, while they were negatively associated with mineral N-fertiliser inputs, plant N uptake and use of the 'short straw' variety Solstice. On the other hand foliar and ear disease severity were positively associated with plant N uptake, use of the variety Solstice and the use of mineral fertilisers, while they were negatively associated with composted FYM fertiliser inputs, leaf phenolic/flavonoid concentrations and the use of the variety Aszita. Overall findings suggest that low input farming-focused breeding programmes might deliver varieties such as Aszita that have lower yield potential, but have higher grain protein, leaf phenolic concentrations, and foliar disease resistance under low-input conditions. Future studies should investigate whether the higher foliar phenolic levels found in low input varieties are linked to disease resistance and if they are also expressed in the grain.