Effects of Agronomic Management and Climate on Leaf Phenolic Profiles, Disease Severity, and Grain Yield in Organic and Conventional Wheat Production Systems

Abstract

Agricultural intensification over the last 40 years has increased cereal yields, but there is very limited information on the effects of intensification practices (e.g., nondiverse rotations, mineral NPK fertilizer, and pesticides) on crop health and quality. Results from the study reported here suggest that the use of mineral NPK fertilizers reduces phenolic acid and flavonoid concentrations in leaves and increases the susceptibility of wheat to lodging and powdery mildew, when compared to composted FYM inputs. In contrast, the use of herbicides, fungicides, and growth regulators reduces lodging and foliar disease severity but had no effect on phenolic acid and flavonoid concentrations. The use of composted FYM inputs also resulted in a significant grain yield reduction and not substantially reduced the severity of opportunistic pathogens such as Septoria, which remain a major yield limiting factor unless fungicides are used and/or more Septoria resistant varieties become available.

Effects of Production Region, Production Systems and Grape Type/Variety on Nutritional Quality Parameters of Table Grapes; Results from a UK Retail Survey

“…A recent systematic review and meta-analysis reported that organic crops on average have higher concentrations of phytochemical/antioxidants and higher antioxidant activity [14]. Long-term field experiments on arable crops linked the higher phenolic concentrations and antioxidant activity in organic compared to conventional wheat to a lower and/or more balanced supply of nitrogen when organic instead of mineral N-fertilizers are used [15]. However, there is still considerable controversy on whether and to what extent organic table grapes have higher phenolic, anthocyanin and/or antioxidant levels, because several previous comparative studies, reported contrasting results on composition differences between organic and conventional table grapes or grapes of specific varieties [12,[16][17][18][19][20][21][22].…”

Effect of Different Combinations of Phosphorus and Nitrogen Fertilization on Arbuscular Mycorrhizal Fungi and Aphids in Wheat

“…It also plays a key role in the energy metabolism of photosynthetic processes [50]. A study on wheat found that P fertilizer reduced the concentration of phenolic acid and flavonoids in leaves [51]. The reason may be due to a reduction of AMF colonization in the soil in the presence of relatively high amounts of P. Many reports demonstrate that the content of P in soil is negatively correlated with AMF [16,17] and affects the secondary metabolism of the host.…”

Phenolics and Carotenoid Contents in the Leaves of Different Organic and Conventional Raspberry (Rubus idaeus L.) Cultivars and Their In Vitro Activity

“…Phenolic compounds are well known as “natural pesticides”. In organic agriculture, plants produce more phenolic compounds in the leaves because use of synthetic pesticides is forbidden [19,20]. In the present experiment, the authors want to investigate how cultivation methods effect the content of biologically active compounds in raspberry leaves.…”