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Hazelnut (Corylus avellana L.) is a monoecious, dichogamous plant species that flowers in winter and early spring. In traditional hazelnut growing regions, hazelnut cultivars generally express protandry where the male flowers bloom before the female flowers. Nut set requires that compatible pollen be shed when the stigmas of the main cultivar are receptive. In this study, the floral phenology and date of leaf budbreak of five selections and 19 hazelnut cultivars from Europe and North America were observed over 4 yr in southern Ontario, and results were compared with cumulative growing degree days (GDD). In the continental climate of southern Ontario, most cultivars showed protogyny. Flowering dates varied over the years with pollination occurring in a period of 2–3 wk in early spring. These cultivars were classified into early, mid, and late blooming types. A GDD model was a better tool than average daily temperatures to predict the flowering dates of catkins and female flowers. Averaged over years, most of the cultivars in this study have a female bloom that is likely too early for the pollen shed by most of the other cultivars. This would likely impact yields in a commercial orchard. However, ‘Jefferson’, ‘Gene’, and ‘Epsilon’ have late females that are receptive when other cultivars are shedding pollen.

Rapid multiplication of turmeric (Curcuma longa) by micropropagation is needed to produce a continuous source of uniformly sized, high-quality, and disease-free plantlets. Three in vitro experiments were conducted to optimize the medium by evaluating nine media and a full factorial combination (matrix) of two plant growth regulators for direct organogenesis of ‘Hawaiian Red’ turmeric. Two experiments evaluated the media, and the third studied the plant growth regulator matrix. As a result, Driver and Kuniyuki walnut (DKW), Murashige and Skoog (MS), and broadleaf tree basal (BLT) media performed better than woody plant media [Lloyd & McCown woody plant basal medium (L&M), and McCown’s woody plant basal salt mixture (McCown)] for shoot and root formation. The multiplication rate was 18 plants per explant in DKW with 1 mg⋅L−1 6-benzylaminopurine (BAP) and 0.1 mg⋅L−1 1-naphthaleneacetic acid (NAA). After transferring the plants to an ex vitro environment, the survival rate was 97%, and 30% higher than previously reported. DKW produced the highest number of plantlets (with shoots and roots), and BLT produced fewer plants with higher biomass. In the MS media, higher BAP to NAA ratio (2.5 to 0.1 mg⋅L−1) produced the most significant number of shoots; however, the lowest concentration of BAP and NAA (0.1 mg⋅L−1 of both) produced the highest number of rooted plantlets. There are two recommendations for tissue culture of ‘Hawaiian Red’ turmeric. To produce the highest number of plantlets, one should use the higher BAP to NAA ratio (2.5 mg⋅L−1 BAP and 0.1 mg⋅L−1 NAA) for shoot proliferation and then transfer the explants to the root initiation media. However, to reduce the number of subcultures, the explants can be grown in the lowest concentration of both BAP and NAA (0.1 mg⋅L−1) to induce both shoot and root. Although, the number of plantlets (with roots and shoots) will decrease in this method, there is no need for subsequent subcultures and changing of the plant growth regulator combinations.

In recent years, new vineyards have been established in southwestern Ontario. The open water of Lake Erie provides some winter protection for Vitis hybrids and winter-hardy Vitis vinifera L. cultivars in this area. However, winter damage is possible when vines are grown distant from the open water or when lakes are frozen. To better understand the risks to winter survival, the dormancy and chilling phenology were studied over three winters from 2013–2016. Ten dormant canes of two V. vinifera cultivars, ‘Chardonnay’ and ‘Riesling’, were collected weekly from 1 September until 30 March from the mature vines in a commercial vineyard located at St. Williams (Ontario). The canes defoliated in early October, and the endodormancy was completed by the end of December. The cumulative chilling hours (0–7.2 °C) from defoliation until the completion of endodormancy were averaged 606 hours for ‘Chardonnay’ and 665 hours for ‘Riesling’. ‘Chardonnay’ buds were slightly less hardy than ‘Riesling’ to cold temperatures, with a threshold of about −24 °C for ‘Chardonnay’ and −25 °C for ‘Riesling’. Most primary buds of both cultivars died after 16 February 2015, and more than half died after 12 February 2014, due to severe low temperatures of −33.1 and −26 °C, respectively.

The global demand for hazelnuts is increasing steadily, driven by increasing use by chocolate companies, pharmaceuticals, health products, and others. North America only produces 5% of the world crop, of which 99% is produced in Oregon (OR, USA). Most available cultivars are adapted to areas with mild winters and thus do not perform well in Ontario (ON, Canada). Our objective was to identify genotypes capable of supporting the newly formed hazelnut industry in southern Ontario. In the last several decades, selections have been identified in ON, New York (NY, USA), and Michigan (MI, USA) that may be better adapted in ON than cultivars from Europe and OR. To test our hypothesis that these new selections would outperform cultivars from Europe and OR in southern Ontario, two trials were performed to evaluate yield, nut quality, and winter hardiness. As hypothesized, selections from ON and NY such as ‘Gene’, ‘Alex’, and ‘Slate’ were winter hardy and highest yielding, followed by ‘Butler’ and ‘Gamma’ from OR; however, these selections did not perform well in other assessed parameters such as nut quality and catkin survivability. Possible explanations for the poor performance of the European and OR cultivars include (i) longer time needed to acclimatize and enter production phase relative to selections from ON, NY, and MI, and (ii) cold susceptibility during the initial establishment phase. The need to allocate resources towards survival probably delays the ability of the European and OR cultivars to enter the production phase. In conclusion, hazelnut cultivars brought from regions with a different climate need to be tested for cold hardiness.

Anthocyanins are a group of water-soluble polyphenolic pigments found primarily in flowers, vegetables, and fruits. These pigments play critical roles in plant and human health. Spectrophotometric methods are a simple and inexpensive way to quantify anthocyanins in plant tissues. Two main spectrophotometric methods have been developed, organic solvent-based, and pH differential methods. Both of these methods are subject to interference from light-absorbing impurities and need to be optimized for different matrixes of different plant materials. Eight methods have been tested in this experiment to quantify anthocyanins in strawberry fruits. Six organic solvent-based methods tested methanol, chloroform-methanol, and MgO in different ratios. The other two methods were pH differential method and a combination of organic solvent-based and pH differential method. Two methods used organic solvents (methanol and chloroform-methanol) were the best in extracting anthocyanin from strawberry fruits. Adding MgO increased the pH of the extract and was less efficient in anthocyanin extraction. All other methods had lower anthocyanin yield compared with methanol and chloroform-methanol methods and are not recommended for strawberry fruit anthocyanin extraction.

Common strawberry cultivars are hermaphrodites, producing both anthers and pistils in their flowers. However, octoploid Fragaria species are trioecious and different genotypes can be female with pi...

The strawberry production season can be extended in Ontario if plantings are protected from adverse weather conditions. At present, dayneutral cultivars developed in California are used for product...

Small fruits are a multi-billion dollar industry in the US, and are economically important in many other countries. However, they are perishable and susceptible to physiological disorders and biological damage. Food safety and fruit quality are the major concerns of the food chain from farm to consumer, especially with increasing regulations in recent years. At present, the industry depends on pesticides and fungicides to control food spoilage organisms. However, due to consumer concerns and increasing demand for safer produce, efforts are being made to identify eco-friendly compounds that can extend the shelf life of small fruits. Most volatiles and essential oils produced by plants are safe for humans and the environment, and lots of research has been conducted to test the in vitro efficacy of single-compound volatiles or multi-compound essential oils on various microorganisms. However, there are not many reports on their in vivo (in storage) and In situ (in the field) applications. In this review, we discuss the efficacy, minimum inhibitory concentrations, and mechanisms of action of volatiles and essential oils that control microorganisms (bacteria and fungi) on small fruits such as strawberries, raspberries, blueberries, blackberries, and grapes under the three conditions.

In soils with high pH, iron is inactivated and bounded to the leaf apoplast developing leaf chlorosis. The inactive iron can be reduced artificially by lowering leaf apoplastic pH with spraying weak acid solutions, providing the symplast absorption of activated iron. The objective of this study was to determine the effect of vinegar spray, as an acidifying substance and iron chelate (Fe-EDTA) on iron nutrition and vegetative growth of grape vines (cv. Thompson Seedless) grown in high pH soils. Four years old grape vines of cv. Thompson Seedless which were grown in high pH soil (pH=8) were selected. Experimental design was a Randomized Complete Block Design (RCBD) with four spray treatments: 1) vinegar (0.8%), 2) iron chelate (0.2%), 3) combination of vinegar and iron chelate (0.8%, 0.2% respectively) and 4) distilled water (control). Vinegar treated plants had higher chlorophyll, active iron (Fe2+) and yield. Vinegar is a by product of grapes that can be easily produced by growers with very little cost and its application has effectively improved plant vegetative growth, yield and mitigated iron deficiency of “Thompson Seedless” grapes. Vinegar is very cheap compared to chelated iron. The vinegar spray has the potential to increases yield without increasing the cost for the growers, ensuring both profitability and sustainability of the production system.

Strawberry is a delicate fruit with short shelf life, primarily due to high nutrient and moisture content anddecay caused by fungi. Traditionally, fungicides are used to control postharvest decay but natural phytochemicals(thymol and carvacrol volatiles) have also shown antimicrobial properties, which can reduce produce wastedue to pathogens. The aim of the study was to test the efficacy of thymol and carvacrol volatiles to controlfungal activity and maintain strawberry fruit quality, packed in two container types (airtight and clamshells).Fungal contamination of strawberries was reduced by thymol and carvacrol in both concentrations (30 & 60ppm) and their combinations. However, weight loss was not affected by the volatile treatments. Titratable acidity(TA) and total soluble solids (TSS) was also affected by volatile treatments. Volatile-treated strawberries hadhigher TA than control fruits. Our results suggest that plant volatiles have the potential to extend the shelf lifeof strawberries after harvest.

The strawberry (Fragaria × ananassa) requires substantial amounts of nitrogen to produce reasonable yields. Wild strawberries (e.g. F. virginiana) grow in soils in the absence of supplemental nitrogen and may possess desirable genes, alleles or expression patterns that support efficient nitrogen uptake and assimilation. The F. virginiana accessions and cultivated materials were used to monitor the accumulation kinetics of five nitrate responsive genes (nitrate transporter, NRT1.1; nitrate reductase, NIA1; nitrite reductase, NiR; ferredoxin NADP reductase, FNR; and transketolase, TK) along with nitrate reductase activity. The results revealed expression patterns that were reminiscent of those observed in Arabidopsis. Wild strawberries exhibited higher transcript accumulation for all genes examined except the nitrate transporter, compared to cultivated materials. Nitrate reductase activity (NRA) did not change in roots but increased in leaves in response to nitrate. Most wild genotypes had higher NRA in aerial tissues compared to cultivated materials. Comparisons of enzyme activity to transcript accumulation kinetics suggest that available nitrate reductase is activated and not likely synthesized de novo, suggesting that some wild accessions may possess enhanced nitrogen assimilation mechanisms. These attributes may be useful to breeding programs in the design of elite plants that may make more efficient use of fertilizers.

Almond is one of the most important nut crops in the world. The origin of almond is central and west Asia. About 30 wild species are identified in this region which represent a rich source of desirable characteristics useful in almond breeding programs. However, almonds express gametophytic self- and cross-incompatibility which affects breeding parent selection. Incompatibility in almond is controlled by a multi-allelic, single gene (S-locus). Recently chemical and molecular methods have been utilized to survey the S-alleles in almond cultivars and closely related species. The restriction fragment length polymorphism method using CAPs protocol was used to determin S-alleles in multiple accessions of wild almond and related Prunus species. Polymerase chain reactions were carried out using one set of degenerate primer pairs (EM-PC2consFD/EM-PC3consRD), and PCR products were digested by five restriction enzymes (TaqI, HinfI, DpnI, ApoI and AluI). The genotypes revealed different cutting paterns. ApoI and DpnI produced the most and the least bandings respectively. AluI, ApoI and HinfI digested the S7. ApoI was the only enzyme which could digest the S9. TaqI, ApoI and HinfI digested the S8 and S12.

Almond and its related wild species, which are widely distributed in Central and West Asia, have high genetic variation. This is an important source of genetic diversity for crop improvement. In this study a set of 32 SSR and 12 EST-SSR primer pairs were used to determine genetic diversity in 89 accessions of almond and other Prunus species. Most of the accessions (68) were collected from natural habitats of Iran. SSR primers amplified higher numbers of alleles than EST-SSR markers and discriminated genotypes more effectively. Results indicated high diversity among accessions. Observed heterozygosity (Ho) was 0.581. Nei’s index of diversity (He) and average number of alleles per locus (na) were 0.885 and 34, respectively. The mean value of polymorphism information content (PIC) was 0.874. The average Fst (F-statistics index) was 0.271 and the fixation index (Fis) was 0.151. Estimated variance among putative populations (AP) and individuals (AI) and within individuals (WI) were 5, 35, and 60%, respectively, which revealed that most of the variation was distributed among individuals rather than groups. Cultivated almonds were highly similar to P. fenzeliana, which is native to West Asia, supporting the importance of these regions in almond domestication. In the dendrogram of groups, minimum genetic distance was observed between Amygdalus and Orientalis groups from the Euamygdalus section. The Leptopus and Chameamygdalus sections were more distant from almonds than plums. The results also showed Dodecandra (Lycioides) series should be taxonomically classified closer to the section Euamygdalus.

Wild almond species are important genetic resources for resistance to unsuitable condition, especially drought stress. They have been used traditionally as rootstocks in some areas of Iran. So far, 21 wild almond species and 7 inter species hybrids have been identified in Iran. To study seed germination and seedling establishment of some of these species, three separate experiments were designed. In the first experiment, the application of gibberellic acid (GA 3 ) (0, 250, 500 and 750 ppm) for 24 h was studied on germination characteristics of four wild almond accessions after stratification at 5 ± 0.5°C in Perlite media. Germination percentage, index vigor and root initiation factors were different in almond accessions, but were not affected by hormonal treatments. In the second experiment, seeds of another six wild almond accessions were stratified to compare their germination ability. Germination percentage, index vigor and root initiation were different among accessions significantly. In the last experiment, the establishment and vigor of 14 accessions from eight almond species have been evaluated in plastic bags in outdoor conditions. Two ecotypes of Prunus spp. had the highest stem diameter and length at all growing stages. Keywords: Amygdalus, germination percentage, index vigor, root initiation, stem length, stem diameter.

This experiment was conducted to study the effect of salicylic acid addition to nutrient solution and different postharvest treatments on fruit quality of strawberry cv. Camarosa after 7 days at 2°C. Plants were irrigated with two complete nutrient solutions, with salicylic acid (0.03mM) or without salicylic acid as the control. Fruits were then treated with eight different postharvest treatments (25°C water, 45°C water, 25°C or 45°C water containing CaCl₂ (1%), 25°C or 45°C water containing salicylic acid (2mM) and 25°C or 45°C water containing both CaCl₂ (1%) and salicylic acid (2mM)). Fruits which received SA in their nutrient solution had less weight loss and decay and higher firmness. All of the postharvest treatments improved fruit quality characteristics. Fruits dipped in salicylic acid solution had less weight loss, decay and a* (redness) and higher firmness and hue angle than control. Heat treated fruits had less decay and a* and higher hue angle than control. Fruits dipped in CaCl₂ solution had less weight loss, decay and a* and higher firmness than control. Combination of the three postharvest treatments improved firmness, decay, weight loss and vitamin C.

The aim of this study was to evaluate the efficacy of silver nanoparticles (SNP) and essential oils as novel antimicrobial agents in extending the vase-life of gerbera ( Gerbera jamesonii cv. ‘Dune’) flowers. The vase-life of flowers held in a solution containing 5 mg L −1 SNP plus 6% sucrose was found to be significantly higher than with 8-HQC (8-hydroxyquinoline citrate) or control treatments. However, the vase-life was not different to that of flowers held in similar concentrations of silver nitrate. All gerbera flowers held in SNP solutions showed significantly higher relative fresh weight than the control. Vase-life of gerbera flowers was extended by addition of either 50 or 100 mg L −1 carvacrol and either 1 or 2 mg L −1 SNP from 8.3 to 16 d. In addition, the relative fresh weight and solution uptake of gerbera flowers were increased by addition of 100 mg L −1 essential oils and 1 or 2 mg L −1 SNP as compared to that of control flowers. Our results suggest the potential application of essential oils or SNP as novel alternatives to common chemicals used in preservative solutions for gerbera flowers.

Nitrogen plays a major role in the growth and yield of strawberry. For optimizing nitrogen fertilizer application, it is necessary to understand the response of strawberry to nitrogen supply. The objective of this study was to determine the effect of nitrate supply and plant size on strawberry nitrate uptake and nitrate reductase activity (NRA). Strawberry plants cv. Selva were grown under growth chamber conditions in nutrient solutions containing 0, 0.1, 0.25, 0.7 or 4 mM nitrate. Cumulative nitrate uptake increased with the increase in nitrate supply. Increasing nitrate concentrations from 0 to 0.25 mM decreased leaf NRA; however, further increases to 4 mM nitrate restored NRA to activities observed at 0 mM nitrate. The activity of NADH- and NADPH-dependent NR was similar at every external nitrate concentration. Activity of NR was greater in the smallest plants and decreased as plant size increased. However, increasing external nitrate concentration increased nitrate uptake, but had not the same effect on nitrate reductase activity, showing that NRA and nitrate uptake are not necessarily correlated.

Vitis riparia (Michaux) is native to North America and tolerates the local weather and soil conditions of south-western Ontario in Canada. A survey was done on V. riparia to elicit the distribution of pests on the species in central south-western Ontario. Eight hundred and forty four genotypes of V. riparia were observed throughout the sandy soils of five counties in Ontario (Brant, Elgin, Middlesex, Norfolk and Oxford). The location of the selected vines was labeled in the Geographic Information System (GIS). The ArcGIS program was used to make maps of the distribution of the wild grape pests, Phylloxera, Japanese beetle, Filbert gallmaker, Cane Filbert gallmaker, Tumid Filbert gallmaker and Tube Filbert gallmaker midges in those areas. The results show that the density of pests on V. riparia is more severe in some areas than others. Phylloxera and Japanese beetle were the major pests observed. Phylloxera was most prevalent and Japanese beetle least prevalent in Elgin County. The gallmaker midges were found in low densities throughout the area. The distribution of Phylloxera could be related to the soil type, and the distribution of Japanese beetle and Tumid gall midge to the land use. With Phylloxera, it appears that they prefer poor drainage soils which do not dry out readily. Whereas, Japanese beetle and Tumid gall midge prefer undisturbed soils where they can overwinter successfully.

Most researches concerning real-time system scheduling assumes scheduling constraint to be precise. However, in real world scheduling is a decision making process which involves vague constraints and uncertain data. Fuzzy constraints are particularly well suited for dealing with imprecise data. This paper proposes a fuzzy scheduling approach to real-time system scheduling in which the scheduling parameters are treated as fuzzy variables. A simulation is also performed and the results are compared with both EDF and LLF scheduling algorithms. The latter two algorithms are the most commonly used algorithms for scheduling real-time processes. It is conculded that the proposed fuzzy approach is very promising and it has the potential to be considered for future research.

Gerbera vase life is most often terminated by stem bending and breaking or petal wilting. Effects of vase solutions containing 1 mg L –1 silver nanoparticles with or without 6% sucrose on gerbera ‘deep purple’ vase life, relative fresh weight, relative solution uptake, stem bending or breaking, stem end discolouration and ethylene production by petals, stem ends and stem necks were evaluated. The combination of SNP plus 6% sucrose increased vase life by 8 days compared with the deionised water control. Petal wilting and stem break were decreased by SNP plus 6% sucrose compared to the control. SNP plus 6% sucrose treatment enhanced ethylene production by petals, stem ends and stem necks during vase life. However, there were no obvious adverse effects of this increased ethylene on vase life parameters. Overall, results suggest that 1 mg L –1 SNP plus 6% sucrose has commercial potential as a vase solution for cut gerbera flowers.