Early-maturing potato cultivars (Solanum tuberosum L.) grown in many subtropical and tropical regions are typically packed and shipped without curing. The objective of this study was to evaluate two early-maturing potato cultivars (‘Fabula’ and ‘Red LaSoda’) grown under four nitrogen fertilizer (NF) rates and harvested at three intervals after vine kill for effects on tuber physical and compositional quality at harvest and during storage. NF was applied through fertigation (0, 112, 224, or 336 kg·ha−1) and compared with granular NF application (224 kg·ha−1). The tubers were harvested weekly after vine kill (H1, H2, and H3) then evaluated for quality at 7 and 14 days during storage at 10 °C/80% to 85% relative humidity (RH). ‘Fabula’ tubers from H1 had the highest cumulative weight loss (3.6%) after 14 days of storage (season 1), while those from both H1 and H2 were highest (4.4%) in season 2, regardless of NF application method or rate. Tuber firmness increased by 1.5 newtons (N) for tubers from H1 after 7 days storage, and again by 0.76 N after 14 days for tubers from H2 and H3. Periderm dry matter content (DMC) for H1 tubers increased to 13.9% after 7 days, regardless of fertilizer treatment, in contrast to those from H2 or H3 where DMC remained constant throughout storage (10.6% and 11.4%, respectively). For ‘Red LaSoda’, cumulative weight loss in season 1 for H1 tubers was 2.2% after 14 days storage, whereas that for H2 and H3 tubers averaged 0.7%; this trend was similar for season 2. Periderm DMC significantly increased with increased storage time; that for H2 tubers was highest (19.6%) after 14 days. In both cultivars, tuber ascorbic acid content (AAC), soluble solids content (SSC), and total titratable acidity (TTA) remained constant throughout the 14-day storage period. Periderm maturity of ‘Fabula’ and ‘Red LaSoda’ potatoes had a greater effect on tuber physical and compositional quality during storage than the fertilizer rates or application methods. Fertigation at NF rates of 112, 224 or 336 kg·ha−1 was comparable with conventional granular NF application for growing high-quality tubers with acceptable postharvest life. Growing tubers at 112 kg·ha−1 nitrogen via fertigation has the potential to reduce both irrigation water usage and fertilizer runoff during the production cycle.
We thank the Florida Department of Agriculture and Consumer Services (FDACS) for partial funding of this project. We also acknowledge the support of the North Florida Potato Growers Association, the University of Florida/IFAS Hastings Research and Extension Center and the UF Horticultural Sciences Department. We appreciate the field and laboratory assistance of Joel Reyes-Cabrera, Adrian Berry and Scott Taylor.
BurtonW.G.1989The potato. 3rd ed. Longman Scientific & Technical Essex UK
BussanA.J.2003Physiological processes of potato tuber maturation. Proc. of Wisconsin Ann. Potato Mtg. 16:47–50
DahlenburgA.P.MaierN.A.WilliamsC.M.J.1990Effect of nitrogen on the size, specific gravity, crisp colour and reducing sugar concentration of potato tubers (Solanum tuberosum L.) cv. KennebecAustral. J. Expt. Agr.301123130
Dahlenburg,A.P.Maier,N.A.Williams,C.M.J.1990Effect of nitrogen on the size, specific gravity, crisp colour and reducing sugar concentration of potato tubers (Solanum tuberosum L.) cv. Kennebec301123130)| false
HalfordN.G.MuttucumaruN.PowersS.J.GillattP.N.HartleyS.ElmoreJ.S.MottramD.S.2012Concentrations of free amino acids and sugars in nine potato varieties; Effects of storage and relationship with acrylamide formationJ. Agr. Food Chem.601204412055
Halford,N.G.Muttucumaru,N.Powers,S.J.Gillatt,P.N.Hartley,S.Elmore,J.S.Mottram,D.S.2012Concentrations of free amino acids and sugars in nine potato varieties; Effects of storage and relationship with acrylamide formation601204412055)| false
MakaniM.N.2014Postharvest quality of ‘new’ potatoes: Effects of improved water and fertilizer use efficiency during production and application of ‘rapid curing’ during storage. University of Florida Gainesville PhD Diss
MakaniM.N.SargentS.A.ZotarelliL.HuberD.J.SimsC.A.2015Irrigation method and harvest time affect storage quality of two early-season, tablestock potato (Solanum tuberosum L.) cultivarsSci. Hort.197428433
Makani,M.N.Sargent,S.A.Zotarelli,L.Huber,D.J.Sims,C.A.2015Irrigation method and harvest time affect storage quality of two early-season, tablestock potato (Solanum tuberosum L.) cultivars197428433)| false
ZotarelliL.DittmarP.J.RobertsP.D.WebbS.E.2015aPotato production Chapter 13 p. 233–251. In: P.J. Dittmar et al. (eds.). 2015–16 Vegetable production handbook for Florida. Vance Pub. Lenexa KS. EDIS Publication HS733
ZotarelliL.RensL.R.CantliffeD.J.StoffellaP.J.GergelaD.BurhansD.2015bRate and timing of nitrogen fertilizer application on potato ‘FL1867’. Part I: Plant nitrogen uptake and soil nitrogen availabilityField Crops Res.183246256
Zotarelli,L.Rens,L.R.Cantliffe,D.J.Stoffella,P.J.Gergela,D.Burhans,D.2015bRate and timing of nitrogen fertilizer application on potato ‘FL1867’. Part I: Plant nitrogen uptake and soil nitrogen availability183246256)| false