<sod>Generally grown as a [[Hardiness (plants)|hardy]] annual, lettuce is easily cultivated, although it requires relatively low temperatures to prevent it from flowering quickly. It can be plagued with numerous [[Micronutrient deficiency|nutrient deficiencies]], as well as insect and mammal pests and fungal and bacterial diseases. ''L. sativa'' [[hybrid (biology)|crosses]] easily within the species and with some other species within the ''Lactuca'' genus; although this trait can be a problem to home gardeners who attempt to save seeds, biologists have used it to broaden the [[gene pool]] of cultivated lettuce varieties. World production of lettuce and [[chicory]] for [[calendar year]] 2010 stood at {{convert|23620000|MT|sp=us}}, over half of which came from China.<eod>
<sod>Generally grown as a [[Hardiness (plants)|hardy]] annual, lettuce is easily cultivated, although it requires relatively low temperatures to prevent it from flowering quickly. It can be plagued with numerous [[Micronutrient deficiency|nutrient deficiencies]], as well as insect and mammal pests and fungal and bacterial diseases. ''L. sativa'' [[hybrid (biology)|crosses]] easily within the species and with some other species within the ''Lactuca'' genus; although this trait can be a problem to home gardeners who attempt to save seeds, biologists have used it to broaden the [[gene pool]] of cultivated lettuce varieties. World production of lettuce and [[chicory]] for [[calendar year]] 2013 was 24.9 million [[tonnes]], over half of which came from China.<ref name=faostat/><eod>