ABSTRACT
In plants with alternate phyllotaxy, the leaves are arranged either in the left-or right-spiralled direction around the stem, and the angular deflection between two consecutive leaves is usually 137.5° accordingly, a particular plant is called left-handed (clockwise) and right-handed (counterclockwise), respectively. This spirality is not genetically determined, but fruit-yield is often associated with the foliar arrangement in some species. This chapter deals with a review of the following crops that show yield in relation to leaf handedness in coconut palm, oil palm, date palm, Dioscorea species, certain legumes, and Solanceous taxa. The various explanations and hypotheses proposed have been discussed and reviewed.
