Worker motivation large extent determine productivity and efficiency human resource use in an organization. This paper presents a statistically validated exploratory and empirical study, based on instruments made from experiences that seek to determine the influence of motivation on labor productivity in fruit packing plant (plums and nectarines) in the area central Chile. Three approaches from the side of the content theories of motivation Maslow, Herzberg and Alderfer are compared to establish which of these theories best explain the motivation of agricultural workers in the process of fruit packing respect to labor productivity. Motivation factors were characterized successfully by a factor analysis model; the "working conditions" was the motivation factor negatively affecting labor productivity. This factor includes the criticism or orders received from the fruit packing plant manager, availability and cleanliness of the bathroom, fresh water availability for drinking and protection elements. It was also found that empirically identified motivational factors are explained by content theories of motivation, both Maslow's Hierarchy of Needs theory as Alderfer's ERG (existence relatedness and growth) theory.