Abstract
Cassava is a tropical storage root crop, a source of carbohydrate and alternative energy. It has been classified as “drought tolerant plant” for the whole life cycle, except during the root initiation stage (120-150 DAP). Leaf area index (LAI) is one of the most parameters representing the overall growth and yield prediction in cassava. The aim of this investigation was to validate the physiological and growth performance of cassava in responses to water deficit stress in the field trial as well as to investigate the leaf area index as an important factor to cassava growth and storage root bulking. Leaf relative water content in cassava declined significantly upon a long period of water withholding, and regulated non-photochemical quenching (NPQ), leading to chlorophyll degradation, reduced number of leaves and limited leaf area index (LAI) and loss of storage root yield when compared with well-irrigated plants. Non-destructive leaf area estimation model under water deficit stress condition using spectral reflectance to determine the LAI and VIs was validated. The Ratio Vegetation Index (RVI) was suitable model with high coefficient of determination (R2 = 0.89). However, the RVI as LAI at 150 DAP (120 d water withholding) could be considered as the critical point to indicate cassava growth and yield performance. Based on the results, cassava growth, biomass and yield in the different environments may further be investigated, taking into consideration the genotypic variation and using remote sensing technology for rapid monitoring and accurate and cost-effective data assessment.
 
 *********
 In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue.
 *********
Highlights
Loss in the yield of crops such as cereals, legumes, tubers and root crops due to the drought incidents borne out of global climate change are demonstrated in several regions of the world (Daryanto et al, 2017)
Cassava has been identified as a drought tolerant plant that can withstand the dry season for 4-6 months, depending upon the evaporation rate (Oguntunde, 2005), available soil water (Pardales and Esquibel, 1996), and genotypic variation (El-Sharkawy, 2007; Okogbenin et al, 2013)
It was reported by many physiological studies that net photosynthetic rate, stomatal conductance, transpiration rate and water use efficiency in cassava grown under drought conditions significantly declined when compared with well-irrigated plants (Itani et al, 1999; El-Sharkawy, 2007)
Summary
Loss in the yield of crops such as cereals, legumes, tubers and root crops due to the drought incidents borne out of global climate change are demonstrated in several regions of the world (Daryanto et al, 2017). Cassava has been identified as a drought tolerant plant that can withstand the dry season for 4-6 months, depending upon the evaporation rate (Oguntunde, 2005), available soil water (irrigation schedule) (Pardales and Esquibel, 1996), and genotypic variation (El-Sharkawy, 2007; Okogbenin et al, 2013). It was reported by many physiological studies that net photosynthetic rate, stomatal conductance, transpiration rate and water use efficiency in cassava grown under drought conditions significantly declined when compared with well-irrigated plants (Itani et al, 1999; El-Sharkawy, 2007). Overall growth performances of both shoot and root traits are affected, depending on the level of drought stress (ElSharkawy, 2007; Duque and Setter, 2013)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
