Tuber yield and quality characteristics of potatoes for off-season crops in a Mediterranean environment.
BACKGROUND
There is little research on evaluating the compatibility of potatoes for double cropping in southern Italy. The aim of this investigation was to assess tuber yield and some qualitative traits of tubers such as skin colour, tuber dry matter content and tuber nitrate content, both in winter-spring and in summer-autumn crops, as influenced by genotype and harvest time.


RESULTS
Yield, skin colour and dry matter content of tubers were higher in the winter-spring crop than in the summer-autumn crop, attributable to the advantageous lag time in spring between solar radiation and temperatures and the disadvantageous lag in autumn. Spunta and Arinda performed well within each crop season, whereas Ninfa showed an important yield loss in autumn. In both off-season crops, delaying tuber harvest until leaf senescence increased yield and improved quality attributes such as tuber dry matter content and skin colour, whereas nitrate contents significantly decreased in the winter-spring crop and increased in the summer-autumn crop. Ninfa showed less tendency than Arinda and Spunta to accumulate nitrate in tubers in both off-season crops.


CONCLUSIONS
It might be advantageous to examine in further research which mechanisms sustain compatibility to the autumn and assess other quality characteristics for the fresh market in the contrasting climatic conditions of the two off-season crops.
Ierna
Anita
A
Istituto per I Sistemi Agricoli e Forestali del Mediterraneo (CNR), Sect. Catania, Str.le V. Lancia, Blocco Palma, I-95121 Catania, Italy. anita.ierna@cnr.it
D018533:Biomass; D016922:Cellular Senescence; D003116:Color; D005838:Genotype; D007558:Italy; D008027:Light; D009566:Nitrates / Q000032:analysis*; D018515:Plant Leaves; D035281:Plant Tubers / Q000737:chemistry / Q000235:genetics / Q000254:growth & development; D012621:Seasons; D011198:Solanum tuberosum / Q000737:chemistry / Q000235:genetics / Q000254:growth & development; D013696:Temperature
D009566:Nitrates