Growth, developmental, and physiological responses of two sweetpotato (Ipomoea batatas L. [Lam]) cultivars to early season soilmoisture deficit

Gajanayake, B. and Reddy, K.R. and Shankle, M.W. and Arancibia, R.A. (2014) Growth, developmental, and physiological responses of two sweetpotato (Ipomoea batatas L. [Lam]) cultivars to early season soilmoisture deficit. Scientia Horticulturae, 168. pp. 218-228.

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Abstract

Soil moisture deficit at early season is detrimental for sweetpotato growth and development affectingfinal yield. This study investigated the effects of different soil moisture regimes on early season growth,developmental, and physiological responses of two sweetpotato cultivars, ‘Beauregard’ and ‘Evangeline’,grown in a greenhouse environment. Five levels of soil moisture treatments, 0.256, 0.216, 0.164, 0.107,and 0.058 m3m−3of VWC, were maintained through sensor-based soil moisture monitoring, and semi-automated programmed irrigation. Midday leaf water potential (LWP), gas exchange, and fluorescencewere measured weekly from 30 to 50 days after transplanting (DAT). Growth and development of plantswere evaluated through harvesting four plants at 5-day intervals from 14 to 50 DAT. Leaf pigmentsand cell and chlorophyll stability indices were also determined. Midday LWP of sweetpotato declinedlinearly with decreasing soil moisture levels. The photosynthetic rate also declined linearly in Beauregardand quadratically in Evangeline with decreasing soil moisture. Both cultivars had a close associationbetween photosynthetic rate and stomatal conductance over the soil moisture treatments, suggestingthat stomatal closure is a key limitation for the drop in photosynthesis. Chlorophyll concentration wassignificantly lower at extreme soil moisture deficit conditions. Significant difference was found in wateruse efficiency between cultivars and among soil moisture treatments. Rates of vine elongation and leafformation of Evangeline decreased more rapidly than Beauregard with declining soil moisture levels. Alsowith decreasing soil moisture, the shoot biomass declined more rapidly than root biomass. The resultsshowed that maintaining soil moisture closer to field capacity (0.256 m3m−3of VWC) during early seasonis beneficial for early development of both root and shoot system and thus better crop performance. Thedata and the inferences derived from the functional algorithms developed in this study will be useful forcrop modelling, field-level irrigation scheduling, and planting decisions.

Item Type: Article
Additional Information: This work was in part funded by the USDA-NIFA Specialty Crop Research Initiative grant number 2009-51181-06071, the Mississippi Sweet potato Council and the USDA-UVB Monitoring and Research Program, USDA-NIFA-2011-34263-30654, G-1405-2.
Uncontrolled Keywords: Cell membrane thermostability, Drought, Photosynthesis, Pigments, Soil moisture, Transpiration
Author Affiliation: Mississippi State University, 117 Dorman Hall, Box 9555, Mississippi, MS 39762, USA
Subjects: Plant Production
Divisions: Other Crops
Depositing User: Mr Siva Shankar
Date Deposited: 14 Mar 2014 08:29
Last Modified: 14 Mar 2014 08:29
Official URL: http://dx.doi.org/10.1016/j.scienta.2014.01.018
URI: http://eprints.icrisat.ac.in/id/eprint/12871

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