Ingunn Øvsthus

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(+47) 482 07 250
ingunn.ovsthus@nibio.no

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Ullensvang

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Ullensvangvegen 1005, 5781 Lofthus

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Sammendrag

The mid-early-ripening cultivar ‘Summerred’ is popular among consumers and widely grown in Norway. However, ‘Summerred’ fruit is prone to rapid softening and development of senescence-related disorders, especially senescent breakdown. Calcium can have a significant role in maintaining firmness and delaying senescence of fruits. In a two-year study, foliar application of calcium chloride (CaCl2) was conducted six times, with varying weather conditions between the growing seasons. Fruit was harvested at optimal commercial maturity and stored at 4°C for either 6 or 9 weeks, followed by simulated shelf-life conditions at 20°C. Ethylene levels were monitored during storage to detect ripening discrepancies. At harvest, CaCl2-treated fruit exhibited significantly lower ethylene production compared to untreated fruit, although no differences were observed at the end of the storage period. Senescent breakdown showed significant variability between the two seasons, with an incidence of up to 15% in the first season and nearly no incidence in the second. Senescent breakdown increased with storage duration but was unaffected by foliar CaCl2 application. Real-time PCR analysis of fruit flesh samples revealed increased expression of polygalacturonase and β-galactosidases genes after storage, indicating their involvement in apple softening. Notably, there were no differences in gene expression between CaCl2-treated and untreated fruit after storage. Expression patterns of genes involved in ethylene biosynthesis at harvest were different between the two seasons. Higher expression was observed in the year with greater disorder development, indicating greater maturity at harvest. There were no significant differences in the Streif index between the two years.

Sammendrag

Dette notatet gir en oppdatering av kunnskapsgrunnlaget og relevans for klimatilpasning for de mest sentrale planteproduksjonene, dvs. korn, grovfor, grønnsaker og potet, frukt og bær. Notatet tar utgangspunkt i teksten i ulike fagnotater fra 2016, og oppdaterer beskrivelsene med oppdatert kunnskap relevant for de ulike produksjonene. Økt gjennomsnittstemperatur, økt CO2-konsentrasjon i atmosfæren og en lengre vekstsesong er fordeler som vil kunne utnyttes. På den annen side vil økt nedbør og mer ekstremvær i fremtiden bli utfordringer som må håndteres. Notatet peker på både utfordringer, muligheter og kunnskapsbehov for å lykkes i klimatilpasningsarbeidet.