Plant quality adapted to a modern and sustainable Norwegian strawberry and apple industry

PlantQuality aims to increase the apple and strawberry industry's access to high-yielding, healthy plant material, and thereby improve the competitiveness and profitability in all stages of production. The knowledge needs concern strategies for a predictable, effective and market oriented production of uniform, high yielding, healthy plants at a low cost, by means of basic research on plant and plant pathogen development under different climatic and cultivation conditions. Scenario analysis of the economic and social impact an improved access to superior plant material will have on the strawberry and apple industry are analysed. Experiments have been performed in controlled climate with plants of several strawberry cultivars to increase the understanding of how temperature and photoperiod are interacting on growth and development. We have shown that the locus TERMINAL FLOWER1 (FaTFL1) is a strong repressor of flowering in strawberry. This finding provide breeders with a new breeding target; producing cultivars with lowered FaTFL1 expression level could expand the flowering and fruiting season of strawberries. Three papers on plant quality and flowering responses in strawberry are published in 2016. In collaboration with NORGRO and plant producers, four field trials with plant qualities from Norway and Holland have been conducted. Results are published in articles in growers magazines and in international journals. A master thesis at NMBU on the subject will be defended in 2017. Experiments to study the effect of temperature on growth and development of apple cultivars have been performed in the project period. A Master thesis on apples was defended at NMBU in 2015, and the results are published in a scientific journal in 2016. Important project goals are to increase our knowledge, and develop means to control two serious plant pathogens (apple proliferation phytoplasma and strawberry powdery mildew). To increase our basic knowledge of the epidemiology, and find practical means to control the fungi, a Postdoc is engaged. The same fungicides used during propagation of planting material are used in strawberry fruit production, thus increasing the risk of fungicide resistance. PlantQuality has revealed resistance among isolates of Podosphaera aphanis, the fungus causing strawberry powdery mildew, against two groups of fungicides. 36 isolates of P. aphanis where analyzed by sequencing genes. 17 isolates indicated resistance against sterol inhibitors, 3 against strobilurines and 9 against both fungicide groups. This strongly indicates that there is fungicide resistance among isolates of powdery mildew in Norwegian strawberry production. A spray trial in a greenhouse with isolates from a strawberry plant producer showed reduced effect against powdery mildew when compounds from both fungicide groups were used. PlantQuality is aiming to find alternatives for chemical treatments against powdery mildew. There is special focus on treatments with UV light, heat therapy of transplants and sprinkler irrigation. Additional work is being carried out in other projects in Norway, Europe and USA, where people from the project team participate. In trials with sprinkler irrigation, four 1-minute treatments per day have provided as good effect as regular fungicide applications. Treatments with UV and heat are now being adapted to practical growing conditions. Controlled transmission experiments have been performed on the apple root stock B9 using the hawthorn psyllid (Cacopsylla melanoneura), which is known as one of the potential vectors of apple proliferation in Europe. Experiments have been carried out in 2015 and 2016. The psyllids that were used in the experiments were collected from fields, highly infected with apple proliferation phytoplasma in Hardanger and Sogn. Experimental plants will be followed up for 0.5-1.5 years to find any transmission. Moreover, hawthorn psyllids have been collected from selected orchards in Hardanger, Sogn, Lier and Telemark including the plant collections at Njøs and Lier Bygdetun. This will yield data on the amount of apple proliferation phytoplasma infection in the insects and phenology data for when the insects arrive in spring and when their activity peaks. The phenology study will be part of a master thesis at the University of Bergen as well as a study to see if psyllids are attracted to infected trees within a field. All results will be edited and published in 2017. We have performed a qualitative market analysis of the Norwegian market for apple trees and strawberry plants, based on interviews with stakeholders, and consultation documents from the official process which ended in the opening up for imports of apple trees and strawberry plants. Data gained in 2013-2015, will be published in a NIBIO report in 2017.

PlantQuality aims to increase the apple and strawberry industry's access to high-yielding, healthy plant material, and thereby improve the competitiveness and profitability in all stages of production. The knowledge needs concern strategies for a predicta ble, effective and market-oriented production of uniform, high-yielding, healthy plants at a low cost, by means of basic research on plant and plant pathogen development under different climatic and cultivation conditions. Scenario analysis of the economi c and social impact an improved access to superior plant material will have on the strawberry and apple industry will be analysed in context of value chains, organisation of markets, rules and legislations, agricultural politics and socio-economic develop ment. By understanding factors controlling growth, growth termination and flowering in apple, differences in plant development between strawberry genotypes as responses to photoperiod, temperature and plant nutrition, combined with means to control two se rious plant pathogens (apple proliferation phytoplasma and strawberry powdery mildew), the plant producers will obtain grow-how of high quality plant material. The fruit and berry producers will acquire information about marked structures, get access to t he best climate adapted genotypes and plant qualities on the marked, and protocols on plant establishment and plant qualities used to extend the season and increase yield. PlantQuality will provide a cost efficient production of strawberry and apple plant s, to make Norwegian plant production economically sustainable for the future market. To accomplish this, we have assembled a national and international team of accomplished scientists covering the disciplines of plant physiology, molecular genetics, plan t pathology, entomology and economy. Our project is forward-looking with benefits for the industry and the consumers 5-10 years ahead.