Environmental regulation of dormancy, flowering and runnering in two genetically distant everbearing strawberry cultivars

The environmental control of dormancy and its relation to flowering and runner formation is poorly understood in everbearing (EB) strawberry cultivars. We studied the topic by growing plants of the seed-propagated F1-hybrid ‘Delizzimo’ and the runner-propagated ‘Favori’ cultivar in daylight phytotron compartments under short day (SD) and long day (LD) conditions at temperatures of 6, 16 or 26 °C for 5 and 10 weeks. This was followed by forcing at 20 °C and 20-h photoperiod for 10 weeks with and without preceding chilling at 2 °C for 6 weeks. The results showed that dormancy in EB strawberry is regulated by a complex interaction of temperature, photoperiod and chilling in much the same way as known for seasonal flowering (SF) cultivars. Surprisingly, the EB cultivars exhibited the same SD dormancy induction response as SF cultivars, despite their opposite photoperiodic flowering requirements. However, at 26 °C the EB cultivars developed partial dormancy also under LD conditions. As known for SF cultivars, none of the EB cultivars became dormant at 6 °C regardless of daylength conditions, whereas they were increasingly sensitive to SD dormancy induction at intermediate and high temperatures. Similar to SF cultivars, the EB cultivars needed exposure to SD and relatively high temperatures for at least 10 weeks for attainment of the semi-dormant state that is typical for strawberry in general. As reported for SF cultivars, there was a close interrelation between the control of flowering, runner formation and dormancy also in the EB cultivars. ‘Favori’ had an obligatory LD requirement for flowering at 26 °C and was almost day neutral at 16 °C, while ‘Delizzimo’ behaved as a quantitative LD plant at both temperatures, and both cultivars were completely day neutral at 6 °C. Except for the stricter LD control of flowering in ‘Favori’, the overall environmental responses were quite similar in the two genetically distant cultivars. Chilling for six weeks at 2 °C was adequate for complete reversal of the constrained elongation of leaf petioles and flower trusses in dormant plants, but had little or no effect on the degree of flowering and runner formation.acceptedVersio

Growth, yield and fruit quality of tomato Solanum lycopersicum L grown in sewage-based compost in a semi-hydroponic cultivation system

Purpose: Due to environmental concerns, there is a demand to reduce the use of peat as a growing medium for horticultural crops. Simultaneously, there is an interest to recycle organic waste materials in the form of compost. This study aimed to document effects on growth, yield, and fruit quality of tomato plants when cultivated in a sewage digestate-based compost in a subirrigation container system. Materials and methods: The compost used in this experiment consisted of 30% hygienised sewage digestate from biogas extraction and 70% garden waste. The treatments were 100% compost, a peat mix and mixtures of the two in 25/75, 50/50 and 75/25 ratios. Results and conclusion: Considering the contrast in chemical and physical properties of the treatments, variations in growth, yield and quality were expected. The plants differed in leaf area and number of leaves, but there were no differences in yield or quality of the tomato fruits. It is assumed that this is in great part due to the remediating effects of subirrigation with an ideal nutrient solution, and the use of pre-established plants. Further research should focus on benefits of this cultivation system for use in sustainable horticulture in combination with recycled organic waste.publishedVersio

Effects of temperature and photoperiod on photosynthesis in everbearing strawberry

There is little knowledge about photosynthesis in everbearing strawberry cultivars. We therefore grew three everbearing strawberry cultivars in daylight phytotron compartments at temperatures of 9, 15, 21 and 27°C and photoperiods of 10 h (SD) and 20 h (LD). After three weeks, the rates of dark respiration and photosynthesis and their acclimation were measured in 'Favouri'. Photosynthesis of plants grown in the various conditions was measured as CO2-uptake with an infrared gas analyzer at increasing irradiances (50-1000 µmol quanta m‑2 s‑1) and temperatures ranging from 9 to 27°C. In the dark, CO2-production (dark respiration) increased with increasing measuring temperature and was always largest in plants grown at low temperature (9°C) with no significant effect of photoperiod. Photosynthetic CO2-uptake was lowest at almost all irradiances in plants grown at 9°C, and with no clear effect of growth temperatures in the 15-27°C range. At saturating irradiances (500-1000 µmol), CO2-uptake increased with increasing measuring temperatures, reaching a plateau at about 21°C for plants grown at 15-27°C in SD and at 21-27°C in LD. For plants grown at 15°C in LD, the maximum CO2-uptake rate was obtained at 27°C. Light response curves showed that CO2-uptake increased with increasing irradiance and measuring temperatures and that the irradiance effect was markedly enhanced by increasing growth temperature. Maximum uptake rates were lowest for plants grown at 9°C at both photoperiods and highest for plants grown at 15°C in SD. Comparison of plants of 'Altess', 'Favouri' and 'Murano' at 500 µmol irradiance and 21°C revealed no significant differences in photosynthetic efficiency between the cultivars. Generally, the everbearing strawberry cultivars showed considerable photosynthetic plasticity to temperature within the 9-27°C range, although with an overall optimum at 15-21°C.acceptedVersio

Prediction of chemical and sensory properties in strawberries using Raman spectroscopy

publishedVersio

Hagens prydplanter inn på kjøkkenet?

I dagens villahager og parker er det en helt annen sammensetning av planter enn for bare noen tiår siden. I villahagen på 60-tallet var det vanlig å dyrke bær for safting og sylting og frukt for lagring eller konservering til vinterbruk. Utvalget av sommerblomster, stauder, busker og trær har økt, og vi planter andre arter og sorter enn vi gjorde før. I dag velger vi flere arter av trær og busker som ikke er stedegne for Norge, men importert materiale. Det vil si planter som betraktes som eksotiske og annerledes enn det som vokser rundt oss til vanlig. Vi velger kanskje også flere planter for pryd og ikke så mye for nytte lenger, fordi utvalget av grønnsaker, frukt og bær i matbutikkene er stort og alle arter er tilgjengelig hele året. Vi lever et ”hurtigere” liv med mindre tid til å konservere det vi kan høste av naturen. Tidligere hadde konservering av hagens frukt, bær og grønnsaker et økonomisk motiv. Nå er denne typen arbeid noe man gjør for å lage et spesielt produkt eller til en spesiell anledning

Various Factors Affect Product Properties in Apple Cider Production

acceptedVersio

Various Factors Affect Product Properties in Apple Cider Production

acceptedVersio

Climate warming enhances flower formation, earliness of blooming and fruit size in plum (Prunus domestica L.) in the cool Nordic environment

The predicted and ongoing climate warming is expected to affect many aspects of plant development. We analysed data from a 31-year series of observations (1985–2016) on spring phenology and flowering and fruiting performance of three plum cultivars in an experimental orchard at Ås in southeast Norway (59° 40′N; 10° 50′E). Regression analyses revealed a trend of increasing March and April temperature during the study period that was highly significantly (P <  0.001) negatively correlated with the date of full bloom (FB). On average for all cultivars, blooming was advanced by 10 days over the study period. August and September temperature, which also increased significantly during the study period, was closely positively correlated with the amount of flowering in the subsequent spring and also interacted with early spring temperature in advancing blooming time. Investigation of the time of floral initiation in two of the studied plum cultivars revealed that the transition to reproductive development took place in early to mid-August. This finding strongly suggests that the close positive correlation between August-September temperature and the amount of flowering in plum observed in this and other studies, is causally linked to a specific physiological effect of elevated temperature on the flower bud formation process. Increasing March and April temperatures during the last 30 years has advanced blooming and spring phenology in plum and the resulting extension of the growing season has led to increasing fruit size at harvest. We conclude that so far, the ongoing climate warming appears to have been positive for plum production in the cool Nordic environment. However, an increasing risk of frost associated with earlier blooming will represent a potential negative effect of continued warming.publishedVersio

Control of growth cessation and floral initiation in red raspberry (Rubus idaeus L.) cultivars of diverse origin in controlled and natural environments

The aim of the investigation was to assess and compare the environmental limits for growth cessation and floralinitiation in a range of new and established biennial-fruiting red raspberry (Rubus idaeus L.) cultivars of diverseorigin under phytotron and field conditions. The results confirmed that growth cessation and floral initiation inbiennial-fruiting red raspberry are jointly controlled by the interaction of low temperature and short days (SD).When transferred from non-inductive high temperature and long day (LD) conditions to naturally decreasingautumn daylengths at varying phytotron temperatures on 18 August, growth immediately levelled off and ceasedcompletely within 2 weeks in all cultivars at 9 °C. Serial dissections of lateral buds revealed that floral initiationsimultaneously took place. At 15 °C on the other hand, the plants continued growing and remained vegetativeuntil around 15 September when the daylength had decreased to approximately 13 h. The change to 9 °C resultedin an immediate but short-lasting floral induction response that did not bring about initiation in buds situatednear the base of the canes, as was the case at 15 °C. At 18 °C, marginal floral induction took place only in thecultivars ‘Glen Ample’, ‘Balder’ and ‘Vene’, even at photoperiods down to 10 h, whereas at 21 °C, all cultivarsgrew vegetatively regardless of daylength conditions. However, exceptions were some plants of ‘Vene’ and‘Anitra’ that initiated terminal flowers at 18 and 21 °C and flowered directly without chilling (so-called tipflowering). Although some cultivars of Northern origin ceased growing and initiated floral primordia somewhatearlier (at longer photoperiods) than those of more southerly origin, the differences were relatively minor andnot consistent (no latitudinal cline). Results obtained in the field under decreasing autumn temperature anddaylength conditions agreed closely with the results in the phytotron. We therefore conclude that results ob-tained with raspberry in properly controlled daylight phytotron experiments are generally applicable to fieldconditions.publishedVersio

Effect of temperature and photoperiod preconditioning on flowering and yield performance of three everbearing strawberry cultivars

Environmental control of flowering in everbearing strawberry is well known, while the optimal commercial raising conditions for high and continuous yield remains unsettled. We exposed freshly rooted plants of cultivars Altess, Favori and Murano to 9 °C, 15 °C, 21 °C and 27 °C, respectively, at two photoperiods for 4 weeks, and assessed flowering and yield performance. Long days at 15–21 °C enhanced flowering, while short days (SD), particularly at 27 °C, decreased flowering. Runner formation was enhanced by SD, being inversely related to flowering. Yields the next season were highest in plants exposed to 15–21 °C, whereas the seasonal harvest distribution varied. In concurrence with earlier reports, the size of the first fruit flush determined the magnitude of the second flush and the length of the off period when little fruit was produced. The large first fruiting flushes of plants exposed to 21 and 27 °C gave particularly long off periods and small second flushes. Moderate first flushes of plants from intermediate temperatures also resulted in a more evenly distributed harvest and the largest yields. Developing flowers and fruits are strong sinks for photosynthates; therefore, the size of the first fruit flush must be compromised to optimize fruit yield and seasonal crop distribution