Chapter 19 - Environmental Factors Controlling Carbon Assimilation, Growth, and Yield of Papaya (Carica papaya L.) Under Water-Scarcity Scenarios

Abstract

Crop growth and yield, as well as crop quality, are expected to be affected by global climate change. Therefore, a high degree of uncertainty remains regarding food production and security under future climate scenarios, which, in addition to global warming, will include altered pest and disease incidences, as well as changes in the magnitude and (seasonal and yearly) distribution of rainfall, leading to increased flooding and drought incidences worldwide. Water scarcity has a tremendous potential to be harmful for papaya producers given the high water requirements of this crop. Depending on its duration and intensity, water scarcity might lead to situations of water deficit, which in turn affects key physiological processes such as stomatal conductance and photosynthesis. Knowing how papaya (Carica papaya L.) responds to environmental factors (water, light, and temperature) is important for developing management strategies to optimize fruit yield and quality. The objective of this chapter is to present current research knowledge related to the effects of water, light, and temperature and their interactions with the photosynthetic process and whole-plant physiology of papaya. We demonstrate that environmental factors studied profoundly affect the productivity and physiology of papaya. In the papaya, damage to photosynthetic carbon assimilation due to environmental stress, including water deficits, can reduce biomass production, and net carbon assimilation, which can influence growth, fruit yield, and fruit quality. Therefore, as drought conditions are expected to become more frequent worldwide due to climate change, understanding the effects of water deficits on papaya physiology, especially the photosynthetic processes, will be critical to maintaining productivity of this crop under water-limiting conditions. With improved, science-based management, growers will optimize photosynthetic carbon assimilation and increase papaya fruit productivity and quality.