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Since Ferrero SpA established a manufacturing plant in Brantford, Ontario, there has been considerable interest in developing a hazelnut industry locally. One of the issues that needs to be overcome is to supply large numbers of suitable plants rapidly. They can be micropropagated, and then grown in the nursery. Usually, it takes two years to grow suitably sized plants in the nursery. This thesis investigated methods to grow suitably sized plants in one year and evaluated the nursery systems from financial aspect. Hazelnut seedlings were planted in ellepots and plastic pots, and then subjected to three treatments: grown in a retractable roof greenhouse, treated with root pruning technology or grown in outdoor environment. Also, two transplant timings were tested: the fall of 2011 and the spring of 2012. The results showed that pot type did not influence the growth of hazelnut seedlings. The retractable roof greenhouse increased growth and the root pruning technology changed the seedlings root structure but not their growth. Transplant timing did not affect the seedlings growth in the first year in the field. The retractable roof greenhouse has the potential to produce two crops of seedlings in one growing season compared to one crop in the outdoor nursery. The estimated cost per seedling under retractable roof greenhouse was $9.31, which was $1.95 cheaper than outdoor. / Ontario Centres of Excellence and Ontario Ministry of Agriculture, Food and Rural Affairs

Complete vineyard floor cover cropping and root pruning (RP) were evaluated for their ability to regulate excessive vegetative growth and improve berry and wine composition of ‘Cabernet Sauvignon’ (Vitis vinifera L.). Treatments were: tall fescue (Festuca arundinacea Shreb.) ‘KY-31’ and ‘Elite II’, hard fescue (Festuca ovina L.) ‘Aurora Gold’, perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), and an under-trellis herbicide strip combined with KY-31fescue interrows. Compared to herbicide strip/non-root pruned (NRP), Elite II fescue reduced vine pruning weight (kg/vine) 28%, individual cane weight (g) 20%, and canopy leaf layer number 25%. KY-31 fescue/RP lowered vine pruning weights 29% compared to an 8% reduction in pruning weights of vines grown in herbicide strip/NRP plots from 2005 to 2010. KY-31 fescue produced the greatest biomass and stand density. With the exception of a yield reduction in vines grown with KY-31 fescue in 2006, cover crops minimally decreased grape yield. Yearly climatic variation had a greater effect on berry weight and composition (pH, TSS, TA) than did treatments. Limited treatment differences detected in chemical compounds by gas chromatography–mass spectrometry (GC-MS) analysis in wines made from treatment vines in 2010 were correlated to descriptive sensory terms. Cover crop water use, as evapotranspiration, determined by mini-lysimeter (ML), ranged from 3.28 mm/d for KY-31 fescue to 1.52 mm/d for herbicide-treated plots. In 2008, root biomass of vines grown on KY-31 fescue/RP was increased at the 60 to 80 and 80 to 100 cm soil depths compared to root biomass of KY-31 fescue/NRP vines at those depths. Cover crops minimally impacted vine water potential (ΨPD, Ψmd, Ψstem) and grapevine nitrogen levels relative to the herbicide strip, indicating that the grasses were not overly competitive with grapevines. Root pruning and complete vineyard floor cover crops favorably reduced grapevine vegetative growth, although treatment effects diminished over time, possibly in response to redistribution of grapevines’ roots and climatic variation at the site. / Ph. D.

Syftet med denna rapport är att sammanställa fakta kring hur åtgärder före och efter trädflytt kan påverka trädets etablering. Rapporten behandlar även vilken inverkan rotbeskärning har på träd och hur nybildning av rötter kan främjas. Rapporten besvarar frågor kring hur ett träd reagerar på att bli flyttat och hur trädart, växtplats och tidigare åtgärder kan påverka resultatet av en trädflytt. Rapporten besvarar även frågor angående vilka åtgärder som kan genomföras, innan och efter trädflytt, för att förbättra trädets etablering på sin nya växtplats, vilken inverkan rotbeskärning har på det flyttade trädet och hur nybildning av finrötter kan främjas. Rapporten är skriven som en traditionell akademisk rapport och är baserad på litteratur som har samlats in från vetenskapliga artiklar, böcker och uppslagsverk. Vid trädflytt förlorar ett träd stora delar, cirka 90 procent, av sitt rotsystem och drabbas av stressymptom. Ett friväxande, sådd i naturen och icke-rotbeskuret, träd kan förlora ännu större delar av sitt rotsystem. Det är viktigt att undersöka om det är ett plantskoleträd eller ett friväxande träd och även vilken trädart som ska flyttas då det kan ha betydelse för hur lyckad trädflytten blir. Genom att utföra rotbeskärning skapas ett kompakt rotsystem som ger en minskad rotförlust. Rotbeskärning främjar även tillväxten av finrötter i rotklumpen, vilket gynnar trädet vid etablering och ger minskad vattenstress. Ofta genomförs en kronreducering för att reducera obalansen mellan krona och rötter. En måttlig kronreducering, mellan 10 och 30 procent, kan gynna trädet. Om trädet ska kunna etablera sig och överleva flytten måste det övervinna stressymptomen. Om ett träd ska kunna bilda nya rötter och ha tillväxt av grenar och skott behöver trädet ha god vitalitet. Bevattning spelar en essentiell roll för trädets överlevnad och etablering. Mulch kan ge god tillväxt av finrötter och bidra till en förbättrad etablering. Rapportens slutsats är att både förberedande åtgärder och efterskötsel har inverkan på trädets etablering och hur väl trädet klarar av att bli flyttat. En korrekt genomförd rotbeskärning bör utföras, en måttlig kronbeskärning av 10-30 procent av kronan bör utföras, träd ska flyttas under sin viloperiod och träd som flyttas bör ha hög vitalitet. Nybildning av rötter främjas av god markfukt, varm jord, jämn bevattning och att mulch läggs på. / The purpose of this report was to put together facts regarding how the measures before and after tree transplanting can affect the establishment of the tree. The report also dealt with the impact that root pruning might have on trees and how regeneration of roots can be promoted. The report answers questions concerning how tree transplanting affects a tree and how tree species, locality and previous measures can influence the effect of a tree transplanting. The reports also answers a question concerning which measures could be performed, before and after tree transplanting, to improve the tree’s establishment in it’s new locality. The last question that this report answers is what impact root pruning has on the tree and how regeneration of fine roots can be favoured. The report is written as a traditional academic report and is based on literature that was collected from scientific articles, books and encyclopedias. A tree loses a large amount, approximately 90 percent, of its root system during the tree transplanting. This causes stress symptoms in the tree. A tree, sown and grown in nature, that has never been root pruned will lose even larger amounts of its root system when it’s transplanted. It’s important to do investigations before tree transplanting. Investigations should be done before tree transplanting to determine what kind of tree, nursery-grown or grown in nature, and what species is about to be transplanted. Both of these aspects may have an influence on how successful the transplanting is. Root pruning can make the root system more compact which reduces root loss during transplanting. Root pruning also increases the amount of fine roots in the root ball which is beneficent during establishment and also reduces water stress. The high amount of root loss causes an imbalance between crown and roots. The crown is often reduced to correct this imbalance and in this report it was proven that a moderate crown reduction is beneficial for the tree. The tree must overcome the stress symptoms to be able to survive and to establish itself. Trees need good vitality to be able to regenerate roots, shoots and branches. Irrigation plays an important part in the establishment and the survival of the tree. Mulch can promote regeneration of fine roots and contribute to an improved establishment. The conclusion of the report is that both preparatory measures and after care has an impact on the establishment and on how successful the transplanting of a tree will be. A correctly executed root pruning and a moderate crown pruning (10 to 30 percentage of the crown) should be carried out. Trees should be transplanted during their dormant season and trees, that are going to be transplanted, should have high vitality. Regeneration of roots is promoted by having good soil moisture, warm soil, even watering and applying mulch.

Growth performance of Bur oak (Q. macrocarpa Michx.) and Red oak (Q. rubra L.) under salinity conditions was assessed by growing seedlings in the presence of increasing levels of NaCl. Salinity reduced root growth in both species, although its repressive effect was more pronounced in Red oak. Exposure to 75 mM NaCl for three weeks almost arrested root growth in Red oak, while it reduced it only by 40 % in Bur oak. Red oak roots showed extensive necrosis and limited branching. Salinity also induced leaf injury, which at a NaCl level of 25 mM was less severe in Bur oak possibly due the higher expression of dehydroascorbate reductase (DHAR) and ascorbate peroxidase (APX), enzymes participating in the detoxification of reactive oxygen species (ROS). Salinity also altered nutrient uptake and accumulation in root and leaf tissue. Compared to Red oak, the relative calcium level in Bur oak roots exposed to increased salinity remained elevated, while an opposite trend was observed in leaf tissue. This was in contrast to nitrogen and potassium, the relative level of which was higher in Red oak leaves grown in the presence of NaCl. The better performance of Bur oak root tissue under salinity conditions was ascribed to structural modifications of the root system with maturation of casparian bands and suberinization occurring closer to the root tip. These structures are known to act as barriers enhancing ion selectivity. Collectively this study demonstrates that relative to Red oak, Bur oak is more tolerant to NaCl induced salinity conditions. / February 2017

La fixation symbiotique d’N par les légumineuses est très sensible aux ravageurs, provoquant des dommages sur les racines nodulées, avec un impact sur la fixation d’N et la croissance qui demeure mal connu. Nous avons alors analysé la réponse adaptative de la fixation symbiotique et de la croissance du pois Frisson sauvage et 3 de ses mutants hypernodulants P64, P118 et P121, respectivement mutés sur les gènes SYM28, SYM29 et NOD3, à une ablation de la moitié du système racinaire, en fin de phase végétative. La réponse adaptative a été mesurée 8 jours après ablation, dans des conditions d'alimentation en carbone par la photosynthèse variées. A 380 ppm, le mutant P118 a montré la plus faible diminution de l’activité spécifique de fixation (-17%) suite à l’ablation comparé au sauvage et aux 2 autres mutants (-36% à -62%) associé à une accélération chez les mutants P118 et P121 et un maintien (sauvage et P64) de la croissance des nodosités. A 150 ppm, suite à l’ablation, l’activité spécifique de fixation symbiotique par les nodosités a été diminuée (sauvage), maintenue (P64 et P118) ou augmentée (P121), associée à une accélération (sauvage et P121) ou un maintien (P64 et P118) de la croissance des nodosités. A 750 ppm, l’activité spécifique de fixation a diminué suite à l’ablation pour tous les génotypes, associée à un ralentissement (P64), un maintien (P118, sauvage) ou une faible accélération (P121) de la croissance des nodosités. Les résultats montrent une plus grande capacité de la fixation symbiotique des mutants hypernodulants (P118 et P121 essentiellement) à résister au stress provoqué par l’ablation. / Symbiotic N fixation of legumes is very sensitive to environmental stresses, like pea pests damaging nodulated roots. However, the impact on their N uptake capacity and plant growth has not been studied so far.We analyzed the adaptive response symbiotic N2 fixation and plant growth of pea wild type Frisson and hypernodulating mutants P64, P118 and P121 mutated respectively on genes SYM28, SYM29 and NOD3 to root pruning of half the root system at the end of the vegetative stage. The adaptive responses of pea: cv. Frisson and 3 of its hypernodulating mutants were compared under varying carbon supplies from photosynthesis.At 380 ppm, mutant P118 showed the lowest decrease of the specific activity of N fixation (-17%) following root pruning compared to the wild type and the 2 others mutants (-36% to -62%), associated to an acceleration (P118 and P121) and a maintained (wild type and P64) nodule growth. At 150 ppm, following root pruning, specific activity of N fixation of nodules decreased in wild type, was maintained in P64 and P118 and increased in P121. At 750 ppm, specific activity of N fixation of nodules decreased for all genotypes following root pruning, associated to a maintained nodule growth in wild type and P118, a slower growth in P64 and acceleration in P121.Our results showed a greater capacity of hypernodulating mutants P118 and P121 to withstand the stress induced by root pruning of half the root system.