Garlic Cultivation for High Health-Value

Garlic (Allium sativum L.) is well-known for presenting numerous health benefits linked to the high amount of organo-sulfur compounds, especially aliin, produced in the bulbs. The accumulation of alliin and its precursors in garlic is dependent on both genetic factors and environmental conditions in which the plants are cultivated. Indeed, different organo-sulfur compounds profiles were obtained for several accessions originating from Central Asia when grown in natural conditions in two different climatic contexts. Field trials carried out on three commercial varieties grown under two different climatic conditions of Western Europe confirmed this observation and suggested an important role of the cropping temperature, soil status and water stress conditions. Experiments performed under fully controlled conditions, in vitro and in the greenhouse, showed that sulfur fertilisation as well as light conditions could also have an impact on the organosulfur composition of garlic bulbs. However, the interaction with the genotype has to be considered as spring-varieties and winter-varieties did not react the same way to variations in fertilising and environmental conditions. In the mean time, the effect of increasing mineral sulfur should be considered in relation to other mineral fertilising components, like nitrogen and selenium, as well as to other sulfur sources, from the soil and from the atmosphere, as garlic seems to be able to use atmospheric sulfur. Multiple factors affect alliin accumulation in garlic, so its quality for human health. These factors should be considered when growing garlic for flavour or therapeutic value.