Nitrogen (N) is an essential macronutrient limiting plant growth and quality of leaf-vegetable sweetpotato (Ipomoea batatas Lam). The objective of this study was to investigate the effects of N deficiency and re-supply on growth, physiology, and amino acids in sweetpotato. Two leaf-vegetable sweetpotato cultivars, Pushu 53 and Tainong 71, were subjected to three treatments in hydro-culture: 1) N sufficiency, 2) N deficiency, and 3) N deficiency and subsequently with N re-supply. Compared with N sufficiency, N deficiency caused a decrease in vine growth, carotenoid and chlorophyll content (Chlt), root viability, photosynthesis, and nitrate reductase (NR) activity in both cultivars, but to a great extent in Tainong 71. Whereas N deficiency increased root growth and glutamine synthetase (GS) activity in both cultivars, and the increase in ‘Tainong 71’ was more obvious. Re-supply of N recovered the vine growth, root viability, Chlt, photosynthesis, NR, and GS activity, to a greater extent for ‘Pushu 53’ than for ‘Tainong 71’. N deficiency significantly decreased essential amino acids, including lysine, phenylalanince, isoleucine, tryptophane, leucine, and valine contents and nonessential amino acids, consisting of glutamic acid, aspartic acid, glycine, argnine, and proline content in both cultivars. These results indicated that the light leaf color leafy sweetpotato ‘Tainong 71’ is sensitive to the N availability and the dark green leaf color ‘Pushu 53’ is more tolerant to low N, which appear to reflect the differential response of two cultivars to their different adaptability to N availability.
Meng Wei, Aijun Zhang, Hongmin Li, Zhonghou Tang and Xiaoguang Chen
Roger L. Vallejo and Humberto A. Mendoza
The objective of this research was to determine optimum plot size and number of replications to evaluate yield of sweetpotato (Ipomoea batatas Lam.) clones. The optimum plot size was estimated using the methods of maximum curvature and comparison of variances. The adequate number of replications was determined using the Hatheway method. Using the maximum curvature method, the estimated optimum plot size was 10 basic units (b.u. = six plants or 1.2 m2) for La Molina and San Ramon, and 5 b.u. for Tacna, Peru. Using the comparison of variances method, the optimum plot size was 15 b.u. for all locations tested. The adequate number of replications with a plot size of 15 b.u. was four.
Victor N. Njiti, Qun Xia, Leonna S. Tyler, Lakeisha D. Stewart, Antione T. Tenner, Chunquan Zhang, Dovi Alipoe, Franklin Chukwuma and Ming Gao
Excessive vine growth in sweetpotato has been associated with lower storage root yield. Prohexadione–calcium (Pro-Ca), a plant growth retardant, has been used to reduce vegetative growth and increase harvest efficiency and yield in many fruit and row crops. The influence of Pro-Ca on sweetpotato (Ipomoea batatas Lam.) vegetative growth and storage root yield was evaluated in this study. In 2010 and 2011, the sweetpotato cvs. Beauregard, Porto Rico, O’ Henry, and SC1149-19 were sprayed with 0 and 810 mg a.i./L Pro-Ca in a split plot randomized complete block. Each plot received two sprays, the first at 2 weeks after transplanting and the second at 6 weeks after transplanting. When averaged across cultivars, Pro-Ca significantly (P ≤ 0.05) reduced vine length and vine yield and increased total root yield compared with the control. There was no significant Pro-Ca × cultivar interaction on any trait. Total biomass was not significantly (P ≤ 0.05) different between Pro-Ca-treated and control plants. However, the treated plants had more total root yield, whereas the control plants had more vine yield, suggesting that Pro-Ca treatment affected the distribution of assimilates. Data from this study suggested that it may be possible to use Pro-Ca to manipulate the source-sink relationship for higher storage root yield in sweetpotato.
Arthur Villordon, Christopher Clark, Tara Smith, Don Ferrin and Don LaBonte
tuberous root in sweetpotato plants ( Ipomoea batatas Lam.) Biotronics 23 75 80 Golden, E.A. Duval, J.R. Albregts, E.E. Howard, C.M. 2003 Intermittent sprinkler irrigation for establishment of bare
Rachel A. Itle and Eileen A. Kabelka
and β-carotene contents in white-fleshed African sweetpotatoes ( Ipomoea batatas Lam) J. Sci. Food Agr. 73 301 306 Arias, R. Lee, T.C. Logendra, L. Janes, H. 2000 Correlation of lycopene measured by HPLC with the L*, a*, b* color readings of a
Arthur Villordon, Don LaBonte, Julio Solis and Nurit Firon
homeostasis during lateral development under drought condition Plant Signal. Behav. 4 1002 1004 Sulaiman, H. Sasaki, O. 2001 Studies on effect of planting density on the growth and yield of sweet potato (Ipomoea batatas Lam.) Mem. Fac. Agr. Kagoshima Univ. 37
Malkeet S. Padda and D.H. Picha
247 253 Rabah, I.O. Hou, D.X. Komine, S.I. Fujii, M. 2004 Potential chemopreventive properties of extract from baked sweet potato ( Ipomoea batatas Lam. cv. Koganesengan) J. Agr. Food Chem. 52
William B. Thompson, Jonathan R. Schultheis, Sushila Chaudhari, David W. Monks, Katherine M. Jennings and Garry L. Grabow
micropropagated-certified planting stock. 2nd ed. Dept. Plant Pathol., North Carolina State Univ., Raleigh, NC Nakatani, M. Oyanagi, A. Watanabe, Y. 1987 Holding of cut-sprouts in sweet potato ( Ipomoea batatas Lam.) II. Physiological changes in cut
Gordon J. Lightbourn, John R. Stommel and Robert J. Griesbach
batatas Lam. leaves ( Shahidul et al., 2005 ). Our results demonstrated that the temperature had no affect on the anthocyanin content of leaves from C. annuum plants grown under either low or high light conditions. Different species respond
Arthur Q. Villordon, Don R. La Bonte, Nurit Firon, Yanir Kfir, Etan Pressman and Amnon Schwartz
Notes on the anatomy of the young tuber of Ipomoea batatas Lam Bot. Gaz. 61 388 398 Nakatani, M. Komeichi, M. 1991 Changes in the endogenous level of zeatin riboside, abscisic acid and indole acetic acid during formation and thickening of tuberous