NH4 concentration into nutrient solution may affect fruit quality and as a consequence the storability of tomato fruits

Tomato fruits (Solanum lycopersicum L. cv Belladonna) were grown hydroponically in perlite, in an open hydroponic system,with different NH4-N/total-N supply ratio (Nr) via the nutrient solution. The Nr was set at 0.05, 0.1, and 1.5 on a molar basis. Fruits were harvested at red ripening stage. Several fruit quality parameters (fruit fresh weight, firmness, total soluble solids, acidity, colour, nutrient content as well as total phenolics and carotenoids) were examined, as well as the spectral reflectance characteristics. Fruit firmness maintained in low NH4/total N ratio followed by increased titratable acidity. Total soluble solids reduced in low NH4/total N ratio comparing with the equivalent high ratio. Moreover, tomato lightness increased in low NH4/total N ratio. Fruit fresh weight and chroma (a, b values) did not differ between treatments. Total phenolics and carotenoids (lycopene and ?-carotene) as well as nutritive value (i.e. Mn, B, Zn, Ca content) affected by NH4/total N ratio. Thus, NH4 concentration into nutrient solution may affect fruit quality and as a consequence the storability of tomato fruits. [Acknowledgments: The authors are grateful to the Joint Technical Secretariat of Cross Border Cooperation Programme ?Greece - Cyprus 2007 - 20013? for valuable assistance through the project K3_1_03 ?Hydroflies?. The Project is co-financed 80% by the European Union (ERDF) and 20% by national funds of Greece and Cyprus.] Original title, full list of authors, sources Effect of ammonium:nitrogen ratio on tomato fruit qualityA. Stamatakis1,2, G. Pitsikoulaki1, N. Boretos1, C. Kalaitzidis3, A. Chrysargyris3, N. Tzortzakis31Department of Sustainable Agriculture, Mediterranean Agronomic Institute of Chania, 73100 Chania, Greece2Department of Agricultural Sciences, Biotechnology & Food Science, Cyprus University of Technology, 3603 Limassol, Cyprus3Department of Geoinformation in Environmental Management, Mediterranean Agronomic Institute of Chania, 73100 Chania, Greece, a.chrysargyris@cut.ac.cy V Postharvest Unlimited, ISHS International Conference, 10-13 June 2014, Cyprus, http://web.cut.ac.cy/postharvest/ Picture by galeria.dibujos.net Key words Poscosecha????? postcosecha???? postharvest?????? na-oes? ?? ??? ??????? ?????????????????? post-r?colte?????? ?????????????????????????????????????? na-oogst?????????? post-raccolta???? Obr?bka po?????? p?s-colheita????? ?????????????????????? hasat sonras???? ??????????? Ernte??? ??????????????????????? ????????????????????? postcollita???????? poskliz?ov頠??? ?????? ?? ????????????? nakon branja?? pozberov頠????????????????? obdelovanje zemlje po?? post-colleita????? ????? ?????????? pascapanen????? ?il?onn postharvest??????????? ?????????????? p?c ra?as????????? derliaus apdirbimas po?? lepas tuai????????? ?? ?? ????????????????? post-recoltare??????????? ???????????? ???????????????????????? ??????????????????????????????????? sau thu ho?ch?? ???????????????? zangemva kwenkathi yokuvuna????????????????? Tomate???????????? tomato? tamatie?????? ???????????????????????????? ?????????????????? ??????? tomaat? pomodoro???????? pomidor??????????????????????? ???????????????? domates?????????? ????????????????????????????????????????????????????????????????????????????????????????????????????? ??????????????????????????????????????????????????????????????????????