Dissertations / Theses on the topic 'Strawberries'

5 pp.
Strawberries are easy to grow. They provide the first fruit of the season, and are quick to bear. When harvested fully ripe in the home garden they have excellent flavor. In stores they can be expensive and are often harvested prior to being fully ripe. Various types of strawberries are available. Each type has specific environmental requirements such as temperature and hours of daylight for good production. With the wide range of climatic zones in Arizona it is important to choose the right type of strawberry for your growing conditions.

The Pacific Northwest is recognized for producing high quality strawberries (Fragaria x ananassa Duch.). Unfortunately, these are produced over an extremely short season of no more than 4 weeks. This situation is ideal for the processing market but not the fresh market where an extended season is essential. However, the recently introduced production systems together with the introduction of the day neutral cultivars have the potential to extend the season. The purpose of the present investigations was to examine these systems and the various day neutral cultivars in southwestern British Columbia. The production systems investigated were the waiting bed and the raised hill row. Both systems involve traditional June-bearing (short day) cultivars planted sequentially, resulting in a harvest season of at least 10 weeks. Among the cultivars tested in the waiting bed system, ‘Rainier’ was the most promising and 'Hood' the least; 'Totem' and ‘Shuksan’ gave intermediate responses. In the hill row 'Rainier' was again the most promising. However, in the second year of both systems, when production occurs in the traditional 4 week time period, 'Totem' was the most promising. Comparing the 2 systems, hill rows were more profitable than waiting beds. Day neutral cultivars begin flowering approximately one month after planting, and fruiting occurs from June or early July until October. In these investigations, they were grown at various spacings on raised beds, covered with black plastic mulch and trickle irrigated. The most promising cultivars tested were 'Selva' and 'Tribute' and the most promising spacing was 30 cm.
Land and Food Systems, Faculty of
Graduate

The gut microbiota has been implicated in both health and disease. As such, diet is a significant determinant of gut health, whereby diet induced dysbiosis is associated with cardiometabolic risk. Interestingly, a higher proportion of Firmicutes and a lower proportion of Bacteroidetes are implicated in obesity. Strawberry polyphenols have been shown to reduce cardiovascular disease risk in addition to exhibiting prebiotic activity by increasing probiotic bacteria in the gut. Polyphenols have also been shown to reduce the ratio of Firmicutes to Bacteroidetes. Therefore, dietary modifications such as strawberry consumption may help improve health outcomes through the gut. The objective of this study was to analyze whether 13 g freeze dried strawberry powder (~1 cup/d fresh) consumption reduces the Firmicutes:Bacteroidetes ratio and increases microbial diversity and beneficial bacteria like Lactobacillus and Bifidobacterium. This study was a 5-week free-living diet intervention trial conducted at California Polytechnic State University, San Luis Obispo with expansion to the Eye Medical Center of Fresno. Participants (n=10) had a mean age of 60.5 ± 9.13 years and had a mean body weight of 74.71 ± 10.61 kg. The participants completed a 3-week washout before a 2-week diet intervention. Participants maintained their normal diet throughout the study while eliminating foods high in polyphenols and probiotics. Upon completion of the study, no significant differences were found for body weight (p=0.22) or BMI (p=0.26). Likewise, no significant differences were found for macronutrient, vitamin, or mineral intake except for sugar (p=0.03), vitamin B12 (p=0.03), and fruit (p=0.0014). Bacteria abundance and diversity were not found to be statistically significant following intervention. Since strawberry supplementation was not associated with a significant change in the relative abundance of bacteria with the dose and duration administered, a randomized controlled trial would better determine the effect of strawberry consumption on gut health.

Thesis (Ph. D.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains vi, 74 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 65-70).

Machine vision systems for quality inspection of processing and production lines are associated with increases in productivity, cost savings, and quality control consistency, having become common place in many industries including agriculture. However, automated strawberry quality control has historically been a challenge due to the delicate nature of the fruit’s flesh, making it more prone to damage, bruising, discolouration, and softening than other fruits and vegetables. Previous efforts have been made to grade strawberries using conveyor systems and cameras, generating good or excellent results. However, these methods do not consider the speed at which berries are packed, or the amount of damage-inducing handling required in order to place the fruit on a process line (automated or not), making these systems unsuitable for real-time production. This thesis outlines the research, design, experimentation, and development of an Strawberry Quality Assurance (SQA) vision system which is capable of grading full punnets of strawberries after they have been packed. Fruit is picked from the field, and packaged into containers, before the additional step of being loaded into the quality control vision system and finally, a heat-seal machine which seals the punnets with tamper-proof plastic film. Using this method, the packing workers do not need to slow down, or perform any new tasks, rather the flow of filled punnets is simply diverted to the additional production line. The cameras acquire four images at a rate of up to two per second in order to capture each punnet from above and below (through the transparent plastic) in visible and infrared wavelengths. Visible (RGB) images are used to assess the berry’s colour (ripeness), and visible foreign object likelihood, whilst the infrared images are used for bruise detection. Once the images have been analysed, the system uses an orthogonally directed pneumatic burst of air to eject the defected punnets from the line so that they can be repackaged and reassessed. The initial version of the system used algorithms involving image processing and colour analysis in order to perform under and over ripe detection with good results of 94.7% and 90.6%, respectively, for the multiple instance category. After redesign and upgrade to strobing LEDs and open-source software, machine learning experiments showed that the SVM and unique neural networks underperformed with the best training accuracy results of 84.11% and 76.30%, respectively. Improved performance was found using Resnet-50 pre-trained network in order to extract a feature vector for each image, which is then evaluated by each of the binary classification models. Area Under ROC (AUROC) curves are greater than 80% for both under ripe and foreign object models, whilst the over ripe class score is lower at 58%. The system has entered it’s fifth season as production-ready having already imaged and assessed 290,888 punnets of which 50,270 were rejected, resulting in 17.28% failure rate in total, helping to ensure the consistent quality assurance of production. The successful implementation of the SQA project provides a platform for continuing work including improving performance of the current classifiers, and investigating the potential of improved region-based bounding box method in order to improve visibility for both operator and developer. Data collection and labelling/annotation are performed regularly in order to re-train networks generating improved results, and to reduce inter-seasonal or inter-cultivar concept shift in the models.
Thesis (PhD Doctorate)
Doctor of Philosophy (PhD)
School of Eng & Built Env
Science, Environment, Engineering and Technology
Full Text

The main purpose of this study was to improve the performance of microwave assisted drying. The osmotic treatment was used as pretreatment due to its inherent low energy requirement attributes. The vacuum was applied to microwave drying system to capture low temperature vaporization concepts. The whole process might be called "osmotically dehydrated microwave vacuum drying". Carrots and strawberries were selected to study as a representative of vegetables and fruits, respectively.
The laboratory scale microwave vacuum dryer was setup and the preliminary tests were done with carrots and strawberries. The occurrence of condensation of vapor in vacuum container was found during the drying trials. The location of the open-ended valve which controls the vacuum level was found to have an influence on the condensation. The re-location of valve which allowed air passage to the vacuum container was able to decrease the condensation. The input power for the microwave vacuum drying could not be greater than 1.5 W/g. The continuous use of input power caused the high temperature in the process. The pulse mode (on/off) was recommended for further studies.
Water removal and solid gain of osmotic treatment were considered as factors that affect the dielectric properties dielectric constant (epsilon') and the loss factor (epsilon"). The experiment was set up to investigate the influence of osmotic conditions to dielectric properties. Two osmotic agents, sucrose and salt, were used for carrots; but only sucrose was used for strawberries. The effects of variations in sucrose and salt concentrations, solution temperatures, and length of immersion time on the dielectric properties were studied. The empirical models were generated from response surface methodology (RSM) to predict epsilon' and epsilon" for the various ranges of osmotic conditions considered in this thesis.
As a consideration of the osmotic pre-drying treatment, it was considered appropriate to maximize water loss (WL) and minimize solid gain (SG). The parameter appropriate to study this situation was WL/SG. The optimum conditions of osmotic process to acquire the maximum ratio of WL/SG were investigated. The results of the optimum conditions for carrots were found to be sucrose concentration 50%(w/w), salt concentration 5%(w/w), temperature 20°C and immersion time 3 hours 38 minutes. The optimum conditions for strawberries were found to be sucrose concentration 60%(w/w), temperature 20°C and immersion time 24 hours.
The microwave vacuum drying was then studied as a technique combined with the osmotic pretreatment. The studies were performed on carrots and strawberries. The input power levels 1 and 1.5 W/g with different power modes (continuous, 45s on/15s off and 30s on/30s off) were experimentally studied with a certain condition of osmotic treatment, which was acquired from the previous study. Osmotic treatment prior to microwave vacuum of carrots showed the advantage in most cases; fast drying time, less energy consumption and superior quality aspects except the taste which was affected from the salt. The study of strawberries did not show great advantage of osmotic pretreatment. The drying time and energy consumption of the process with and without osmotic pretreatment were the same but the process with osmotic pre-treatment resulted in better quality of dried strawberries.
The microwave vacuum drying of carrots and strawberries after osmotic pretreatment did not show constant rate period in drying rate curve while the processes without osmotic treatment of strawberries showed longer constant rate period than those observed for carrot drying. According to these phenomena, thin layer models of Lewis and Henderson & Pabis were fitted to the observed data which showed excellent fit for the process without constant rate period, but Page's model was a good fit for both constant rate and falling rate period of microwave vacuum drying.

In aroma analysis, strawberries have always been the favored fruit because of their relatively high content of typical and pleasant aroma constituents. Esters, aldehydes, alcohols and sulfur compounds have been found to be the main aroma components in strawberry. In recent years, two volatile compounds, 2,5-dimethyl-4-methoxy-3(2H)-furanone (DMF) and 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DHF) were reported to contribute heavily to strawberry aroma. These two compounds have been found in all wild strawberries studied, but found only in few cultivated varieties. In this work, three kinds of cultivated strawberries were sampled and analyzed. The three strawberries all belong to the Camarosa variety. They came from different growing areas: Salinas (California), Orrville (Ohio), and Memphis (Tennessee). The volatile compounds of these three strawberries were separated by Gas Chromatography (GC), and identified by Mass Spectrometer Detector (MSD). Column and experimental conditions were optimized for this particular separation. Salinas, Orrville and Memphis strawberries have very similar aroma constituents, however, in slightly differing amounts. Several unique peaks were found in each strawberry, which may well account for the differences in the aroma qualities of the three. 2-Furaldehyde was found in both Memphis and Orrville strawberries, but not in Salinas. It is a key odor compound correlated with woody aroma and it has a low odor threshold value. These two properties make it contribute negatively to the pleasant aroma of Memphis and Orrville strawberries. A compound, 2-furanmethanol, was found only in Salinas strawberries. This compound has a faint burning aroma, however, its high odor threshold value offsets its potentially bad aroma. DMF was found in all three strawberries, but no DHF was detected in any of the three. We propose a possible explanation for the absence of DHF. Ethyl (methylthio) acetate, which is a sulfur-containing compound, was found in both Orrville and Salinas strawberries. This work is the first to report its presence in strawberries of any variety. An external standard method was employed to quantify seven main aroma components found in the strawberry extracts. Aroma values were introduced and then calculated together with sensory descriptions of these compounds. Salinas strawberry was found to have the best aroma quality of the three. These results indicate that the odors of strawberries of the same variety can be different when grown in different geographical areas.
Master of Science

Horticultural producers are in need of efficient and timely techniques for determining crop water requirements. The question of when and how much to irrigate, termed irrigation scheduling, is particularly important for high-value crops such as strawberries (Fragaria ananassa). During the growing season, irrigation scheduling decisions are influenced by climatic variables such as rainfall, temperature and humidity, which directly impact soil moisture levels. A field study was therefore conducted to evaluate two soil moisture sensors for irrigation scheduling of commercial strawberries on a farm in Simcoe, Southern Ontario. Strawberries were grown on raised beds with plastic mulch under two management practices – open field and plastic high tunnels. For each practice, two soil moisture sensors based on time domain reflectometry (TDR) were evaluated. The sensors, Campbell Scientific's water content reflectometer (WCR) and ESI's Gro-point (GP) monitored soil moisture continuously over the growing season (May to October 2007). Soil samples were collected to obtain volumetric water content as a unit of reference for the purpose of comparison and evaluation of the two sensors. Equivalent water depths (EWD) were calculated for an effective strawberry rooting depth of 0.3 m. The calculated EWDs were compared with the grower's irrigation scheduling practices. The study found that the WCR and GP reliably recorded continuous trends in soil moisture throughout the growing season. For the WCR sensor, gravimetric analyses of soil samples showed excellent correlation, resulting in R2 of 0.94 and 0.97 for the open field and plastic high tunnel, respectively. The R2 for the GP sensor was good at 0.88 for the open field but poor for the plastic high tunnels, due to a malfunctioning sensor. The EWDs for the two plots were calculated to be 699 mm for the open field and 711 mm for the plastic high tunnels. A significant fin
Les horticulteurs ont besoin de déterminer avec précision les besoins en eau d'irrigation des cultures. En effet, la bonne gestion de la production et l'obtention d'un meilleur rendement des fraises (Fragaria ananassa) nécessitent la planification de la quantité d'eau à apporter et le jour de l'irrigation. Le climat, la pluviométrie et la variation de la température durant le stade de croissance des plantes sont des variables importantes qui compliquent la tâche de la planification de l'irrigation. La problématique de cette étude s'inscrit dans l'optique d'évaluer l'apport de deux capteurs d'humidité du sol de type TDR (Time Domain Reflectometry) à la planification de l'irrigation des fraises à Simcoe, au sud d'Ontario. Il convient de noter que les fraises ont été cultivées avec la technique du paillis de plastique, en plein champ, ainsi qu'avec la technique du tunnel en plastique. Pour atteindre les objectifs assignés à cette étude, l'utilisation de deux capteurs de type WRC (Campbell Scientific water content reflectometer) et GP (ESI's Gro-point) a permis de suivre d'une manière continue l'humidité du sol pendant le stade de croissance (mai à octobre 2007). Aussi, des échantillons du sol ont été collectés afin d'obtenir la teneur volumique en eau. Cette dernière a été utilisée comme référence et a permis ainsi de comparer et d'évaluer les résultats obtenus à l'aide des différents capteurs. Également, nous avons calculé l'équivalent d'eau en profondeur (EEP) pour une zone racinaire des fraises de 30 cm. Ce procédé nous a permis de comparer l'EEP calculé pour les différentes pratiques d'irrigation adoptées par les producteurs. Les résultats obtenus ont démontré que le WCR et GP représentent la variabilité de l'humidité du sol pendant le stade de la croissance. Pour le capteur WCR, nous avons pu établir une corrélation très intéressante avec l'analyse

Strawberries are a popular fruit with a pleasing color and flavor. However, its delicate tissue and high sugar content makes it highly perishable with visible mold. In this study, we have attempted to test feasibility of different edible coatings for extending shelf life of ‘Chandler’ strawberries subjected to simulated vibrations of local transportation. Six types of coatings were compared based on the quality of treated berries. Curcumin and limonene were used as natural antimicrobials and coatings were prepared from their liposomes and were over-coated with methyl cellulose. One set of each coating type were subjected to the simulated vibration of local transportation. The vibrated samples had lower shelf life than non-vibrated samples, indicating a robust coating which remains intact during road vibrations is required. Based on the number of berries with visible mold, limonene liposomes showed significantly lower fungal growth compared to the control on the 14th day of storage. Titratable acidity and total phenolic contents were also found to be higher in limonene-coated strawberries compared to other coatings. From the findings, further study of liposome coatings of limonene with different particle size and concentration of the lipid bilayer was necessary to characterize the liposome for an effective application in strawberries. To this regard, another study was done with the aim to develop and characterize alginate and limonene liposomes as edible coating materials and to determine their efficacy in shelf life extension and maintaining quality parameters of ‘Chandler’ strawberries. Alginate solution (1.5% w/v) and limonene liposomes prepared from 80% lecithin and 20% PDA were used as edible coating materials. Fungal decay percentage, total yeast and mold counts, headspace atmosphere analysis, total soluble solids, pH, titratable acidity, total anthocyanin content and total phenolics were analyzed to assess fruit quality during 14 days at 4ºC of storage. Days of storage were found to be significant in maintaining the quality of the strawberries. Among the coating types, strawberries coated limonene liposomes were found to be significantly effective in maintaining the lesser respiration rate, lower the change in pH (3.9), and had higher total anthyocyanin (43.849) content during storage. Thus, limonene liposomes were found to be useful for extending the shelf life and maintaining quality of strawberry fruits.

Strawberry plants (Fragaria x annanasa D.) were grown in drip irrigated plots covered with gray/black plastic mulch at the Campus Agricultural Center, University of Arizona, Tucson, AZ. During the 1993-94 season varieties Chandler and Oso Grande were grown while in the 1994-95 season varieties Chandler and Selva were grown. Crop coefficients to estimate crop evapotranspiration for Chandler were determined on calendar day and growing degree day (GDD) basis. For the harvest period, the crop coefficients ranged from 0.35 for early March to 0.6 for early June. GDD were computed using 6 °C as the base temperature and 26 °C as the upper threshold temperature. Although GDD is useful to estimate water needs, it did not predict the starting date of harvest because other factors such as day length, transplanting date, and chilling period are involved. In the 1994-95 season, dry, medium and wet irrigation treatments were established for the Chandler. The well irrigated plants yielded 328 g/plant, equivalent to 21.2 metric tons/ha. The dry treatment received 33 % less water than the medium treatment and resulted 25% less yield. There were no statistical differences in yield between the medium and wet treatments, although the wet treatment received 33% more water than the medium treatment. The Oso Grande and Selva were tested and they yielded 46 and 22% less than Chandler, respectively. The harvest period extended for 70 to 100 days and premium size berries were produced during the first half of the harvesting season.

This study investigated the simulated impact and vibration tests on bruise damage and quality of the British strawberries from winter and summer cultivations. The actual transport of food products was also monitored for the vibration and temperature levels in the city and highways. The winter cultivation produced a superior overall quality of 'Elsanta' and 'Sonata' strawberries compared to the summer cultivation. 'Sonata' fruits were more sensitive to vibration damage in the summer cultivation. The packed strawberry punnet of 250 g was tested in impact and vibration tests. The maximum drop height at 750 mm gave a significantly larger wet bruise level of around 40% than other drop heights (p.0.05). The simulated vibration investigated the three frequencies and three exposure times plus control. The vibrated fruits from the most severe of 5 Hz (1.1 g) for 150 sec had significantly higher wet bruises (50-60%) than for other treatments (p.0.05). The bruise damages increased for both simulated tests after storage at 10°C, 70±5% RH for 3 days. The EC value gave a significantly stronger correlation with wet bruise and severity score as compared to puncture, compression and respiration rate measurements (p.0.01). The EC method is suggested for use as a rapid indicator and a predictor for the bruise assessment of strawberries. The vibration and air temperature levels in the refrigerated truck and semi-trailer were monitored. The overall peak frequency of power density was often found at 10-14 Hz. The vertical vibration was the dominant direction during the road transport. The rear-top position gave a stronger root mean square acceleration value. A gradual increase of vibration level occurred after the first drop in city distribute as well as for a smaller load. The range of temperature during food transport was around 2 to 8oC with a set point at 3°C.

The impact of climate change on plant disease is an important concern for agriculture. Tools from natural and social science are used in this interdisciplinary study in an innovative way to assess potential impacts on the UK strawberry sector. Records of agricultural statistics and disease incidence covering a 90-year period were analysed to study agricultural change and the past influence of disease on the sector. Future change in potential disease incidence was then modelled for three of the most common diseases by building probabilistic projections for 2020 to 2080 using the UKCP09 scenarios. Using these disease scenarios, data were collected from strawberry growers, through a national survey and case study work in two contrasting areas of strawberry production, covering around 40% of the UK sector. A number of major outcomes were obtained. The introduction of polytunnels was seen as the most important influence on change in the sector, tripling crop yields and reducing the climatic impact on yield variability. Disease was found to vary spatially and temporally throughout the country, emphasizing the need for development of resistant cultivars, use of pesticides and a change in cultivation methods. Changes in future disease incidence were predicted for all three pathogens, with a high degree of spatial variation. The outcome suggests that the UK Strawberry sector may be vulnerable, not only to the impacts of plant disease, which has affected both the distribution of the sector throughout the UK and profitability of some of the businesses, but especially to pressures arising from other factors such as labour and decreasing profit margins. When coupling these with important policy changes such as the change in the EU Pesticides Directive, a challenging picture emerges for the future of the sector in the UK. Lesson learned from this sector may be applicable to other sectors.

Using 'Redchief' (Junebearer) and 'Tribute' (dayneutral) cultivars, greenhouse and field studies were conducted to determine the effects of defoliation on photosynthesis, growth and yield of the strawberry. From preliminary photosynthesis experiments it was found that both 'Redchief' and 'Tribute' strawberry leaves reached maximum net photosynthesis (Pn) concurrently with full leaf expansion at approximately 8 to l0 days and 4 to 5 days, respectively, after unfolding. By exposing the plants to increasing irradiance it was determined that these cultivars were light saturated at 600 to 700)Ï molâ ¢m^-2s^-1. Neither cultivar showed a consistent diurnal pattern when Pn was monitored hourly over two consecutive days.

Master of Science

Bacterial pathogens on the surfaces of raw produce may be difficult to remove for identification and enumeration. The first part of this project examined whether ultrasonic treatment (40 kHz) of a rinse solution would enhance recovery of Salmonella spp. from various produce surfaces. Strawberries, apples, and cantaloupe were surface inoculated with a five-strain cocktail of nalidixic acid resistant Salmonella spp. Samples were subjected to one of six different treatments using different combinations of agitation methods (manual shaking or ultrasound), diluent temperatures (25°C and 40°C), and agitation times (60 and 120 seconds). After treatment, diluent was spiral plated onto tryptic soy agar supplemented with 50 ppm of nalidixic acid and plates were incubated at 37°C for 48 hours. Results from this study indicate that ultrasonic treatment of a rinse solution did not enhance or diminish recovery of Salmonella spp. from produce surfaces, as compared to manual agitation. The effects of diluent temperature and exposure time appeared to have a significant effect on recovery, depending on the type of produce.

The second part of this project used a computer imaging system to determine the surface area of various types of produce. The imaging system acquired and stored multiple images of the produce samples. From these images, surface fitting and approximation of a 3-D wire frame model were used to calculate surface area. From these measurements, it was determined that there were statistical relationships between surface area and weight. Surface area measurements were used to develop equations to predict surface area from weight measurements.

Master of Science

Net photosynthesis (Pn) and photosynthate partitioning were compared between fruiting and deblossomed strawberry plants. Throughout a six-week fruiting cycle, Pn (leaf area basis), specific leaf weight (SLW), and chlorophyll content were determined at 7-day intervals for an early-formed leaf (old leaf) and for the most recently expanded leaf (young leaf) of fruiting and deblossomed day-neutral plants (cv. Tribute). During the fifth week of the fruiting cycle, Pn of the young leaf was higher for fruiting plants than for deblossomed plants. Pn of the old leaf was not different between treatments during any week. During weeks 4 and 5, the young leaf of the deblossomed plants had a higher SLW than that of fruiting plants; SLW of the old leaf was higher for deblossomed plants during weeks 4-6. The young leaf of the deblossomed plants had a higher chlorophyll content than that of fruiting plants during weeks 1 and 4. Chlorophyll content of the old leaf was higher for deblossomed plants during weeks 1, 2, and 4. There were no differences between treatments for stomatal conductance for CO₂ or dark respiration during any week of the fruiting cycle. In another experiment, deblossoming day-neutral strawberry plants (cv. Tribute) increased the amount of ¹⁴C translocated to the newly-emerging leaves 48 hrs after treatment with ¹⁴CO₂. During weeks 3-6 of the fruiting cycle, leaves of deblossomed plants had a greater total area, dry weight, and total non-structural carbohydrate (TNSC) content than leaves of fruiting plants. Pn on a whole-plant basis was higher for deblossomed plants than fruiting plants. This was largely due to the greater leaf area of the deblossomed plants, since total leaf area was highly correlated with Pn (whole plant basis). Pn (whole plant basis) was highly correlated with total dry weight and TNSC of plants in both treatments. Thus, deblossoming changed Pn and dry matter partitioning of strawberry plants. The additional leaf area and greater Pn rates (whole plant basis) obtained by deblossoming strawberry plants may result in increased yields during subsequent fruiting cycles.
Ph. D.

Master of Science
Department of Horticulture and Natural Resources
Eleni Pliakoni
Intensive specialty crop production within high tunnel systems in the central U.S. has greatly expanded. High tunnel systems, used primarily to protect specialty crops from harsh environmental conditions, improve marketability, and extend fruiting season. High tunnel day-neutral strawberry (Fragaria x ananassa) production in Kansas may by limited due to the high summer temperatures. Evaporative cooling within a high tunnel is a novel technique meant to cool the plant temperature during the hottest months of production. Currently, evaporative cooling is implemented in the early stages during the heavy bloom period. Spring-planted day-neutral strawberry production within high tunnels could provide growers with enhanced yields and marketability, improved storage quality, and late-season prices. This study identifies the optimum cultivars in a plasticulture, high tunnel system with the use of evaporative cooling in regards to yield, quality, storage life, and consumer opinion. The trial was conducted at the Kansas State University Olathe Horticulture Research and Extension Center (OHREC) during 2014 and 2015. Six commercially-available cultivars were evaluated: ‘Albion’, ‘Evie 2’, ‘Monterey’, ‘Portola’, ‘San Andreas’, and ‘Seascape’. Mature fruit (90-100% red) were harvested twice a week and four harvests were evaluated for at harvest and postharvest quality throughout each production year. Storage life was monitored every 24hrs by respiration rate, moisture content and overall visual quality, using a scale from 5 (excellent) to 1 (very poor). Physical and organoleptic quality measurements (texture and color, and soluble solids and titratable acidity) were evaluated every two days throughout storage, and nutritional quality (total phenolic and antioxidant availability) was evaluated at harvest. Our results indicate that ‘Portola’ had the highest yields in 2014 and 2015 at 1.33 lbs/plant and 1.12 lbs/plant, respectively. At harvest, the soluble solids content (°Brix) was highest with ‘Monterey’ and ‘Albion’ (P < 0.0001), while ‘San Andreas’, ‘Monterey’, ‘Portola’, and ‘Albion’ retained firm texture (force(g)) (P ≤ 0.0001). All cultivars maintained their overall visual quality until day 8, with the exception of ‘Evie 2’ and ‘Seascape’. Furthermore, the four cultivars maintained visual quality and had lower respiration rates and moisture content loss (P < 0.001, P < 0.0001, P < 0.05). Throughout storage, ‘Seascape’ had a high respiration rate (P < 0.0001) and low overall visual quality (P < 0.01). Moisture content loss (%) throughout 2014 storage life was less than in 2015 (P < 0.0001) and ‘San Andreas’ and ‘Monterey’ had the least moisture loss throughout both production seasons (P < 0.01). In our trials, evaporative cooling did not affect yield or the incidence of disease. However, the use of evaporative cooling resulted in lower total phenolic levels in both production years (P < 0.0001), and higher respiration rates during storage, as observed in 2015 (P ≤ 0.01). Because of significant year-to-year differences in berry weight (lbs/plant) and size (oz/fruit), further studies are needed to identify the weather effect and best management practices in the region. In Kansas, growing day-neutral strawberries in a high tunnel has potential based on yield and quality of the fruit that we evaluated.

La culture de la fraise (Fragaria x ananassa Duch.), l’une des plus importantes productions horticoles au Canada, fait face à des défis importants pouvant affecter la productivité et la qualité des fruits. Par conséquent, cette étude se concentre sur l'utilisation des biostimulants les plus prometteurs pour les fraises pouvant améliorer le microbiote du sol, le développement, la productivité et la qualité des fraises produites sous abris. Deux expériences en blocs aléatoires complets ont été réalisées en serre et sous grands tunnels. Dans l'essai en serre, nous avons étudié l'effet de 14 traitements sous gestion conventionnelle (7 traitements) et biologique (7 traitements). Pour le système de culture conventionnelle, les traitements consistaient en: 1- Témoin (sans biostimulant), 2- Extrait d'algue, 3- Trichoderma harzianum souche T22, 4- Rhizoglomus irregulare, 5- Combinaison d'Azospirillum brasilense, Gluconacetobacter diazotrophicus et Bacillus amyloliquefaciens, 6- Mélange des traitements 4 et 5, et 7- Formulation à base d'acide citrique. Pour le système de culture biologique, les traitements biostimulants étaient: 8- Témoin (sans biostimulant), 9- Extrait d'algue, 10- Rhizoglomus irregulare, 11- Combinaison d'Azospirillum brasilense, Gluconacetobacter diazotrophicus et Bacillus amyloliquefaciens, 12- Mélange des traitements 10 et 11, 13- Mélange des traitements 10 et 11 à faible fertilisation, et 14- Formulation à base d'acide citrique, dans une conception de blocs aléatoires complets avec cinq répétitions. D'autre part, dans un essai sous grands tunnels, nous avons étudié six traitements 1- Témoin (sans biostimulant), 2- Rhizoglomus irregulare, 3- Combinaison d'Azospirillum brasilense, Gluconacetobacter diazotrophicus et Bacillus amyloliquefaciens, 4- Mélange des traitements 2 et 3, 5- Formulation à base d'acide citrique et 6- Formulation à base d'acide citrique et lactique à l’intérieur d’un dispositif expérimental en blocs aléatoires complets de quatre répétitions. Nos résultats ont montré que les paramètres d'activité du sol étaient plus élevés sous une gestion de culture biologique, bien que les traitements de biostimulants n'ont pas augmenté l'activité microbienne du sol par rapport à leurs contrôles respectifs, à l'exception de la combinaison de mycorhizes et de bactéries pour des plantes cultivées conventionnellement sous grands tunnels. Pour les deux expériences, les biostimulants n'ont pas influencé significativement la performance photosynthétique des feuilles. Cependant, les biostimulants ont eu un impact sur le développement des plantes et certains paramètres de croissance. En serre, les mycorhizes sous régie biologique et le traitement de mycorhizes et de bactéries sous régie conventionnelle ont diminué le nombre de tiges florifères par rapport aux plantes témoins. En revanche, tous les biostimulants ont augmenté la croissance des plantes cultivées sous grands tunnels. En serre et sous régie conventionnelle, le rendement des plantes traitées avec l'acide citrique a été supérieur à celui des plantes témoins, tandis que l'acide citrique et une combinaison de mycorhizes et de bactéries sous régie biologique a augmenté le rendement. Sous grands tunnels, aucun effet significatif sur le rendement n'a été observé. Le traitement de mycorhizes et de bactéries a augmenté la teneur des fruits en ºBrix, en polyphénols et en anthocyanines des plantes cultivées en serre et sous régie biologique, tandis que Trichoderma a augmenté la teneur en polyphénols et en anthocyanines des fruits sous régie conventionnelle. Aucun effet des biostimulants sur le contenu des fruits en ºBrix et polyphénols n'a été observé sous grands tunnels, tandis que tous les biostimulants ont augmenté la teneur en anthocyanines des fruits. D'après cette étude, nous pouvons conclure que certains biostimulants ont montré des effets bénéfiques, permettant ainsi d’améliorer la performance agronomique de la fraise en termes de croissance, de rendement et de la qualité des fruits de plantes cultivées sous abris. La variabilité observée entre les deux systèmes de production confirme l'importance de la validation de ces résultats sous différentes conditions de croissance et saisons de production.
The strawberry (Fragaria x ananassa Duch.) is one of the most important horticultural crops in Canada. However, several challenges limit the productivity and quality of this crop. Therefore, this study focused on using the most promising biostimulants that can improve soil microbiota, plant development, crop productivity, and berry quality in the greenhouse and high tunnels. In order to study different biostimulants treatments, a greenhouse and high tunnel experiments were carried in a complete randomized block design with five or four replicates. For the greenhouse trial, we studied the effect of 14 treatments under conventional (7 treatments) and organic (7 treatments) growing management. Studied treatments for the conventional growing system consisted of 1- Control (without biostimulant), 2- Seaweed extract, 3- Trichoderma harzianum strain T22, 4- Rhizoglomus irregulare, 5- Combination of Azospirillum brasilense, Gluconacetobacter diazotrophicus and Bacillus amyloliquefaciens, 6- Mixture of treatments 4 and 5, and 7- Citric acid-based formulation. For the organic growing system, the biostimulant treatments were: 8- Control (without biostimulant), 9- Seaweed extract, 10- Rhizoglomus irregulare, 11- Combination of Azospirillum brasilense, Gluconacetobacter diazotrophicus and Bacillus amyloliquefaciens, 12- Mixture of treatments 10 and 11, 13- Mixture of treatments 10 and 11 with low fertilization, and 14- Citric acid-based. For the high tunnel experiment, six treatments were compared: 1- Control (without biostimulant), 2- Rhizoglomus irregulare, 3- Combination of Azospirillum brasilense, Gluconacetobacter diazotrophicus and Bacillus amyloliquefaciens, 4- Mixture of treatments 2 and 3, 5- Citric acid-based formulation, and 6- Citric and lactic acid-based formulation. Our results showed that soil activity parameters were higher under organic crop management compared with the conventional one, although biostimulant treatments did not increase soil microbial activity compared with their respective control, except for the combination of mycorrhiza and bacteria of high tunnel conventionally grown plants. For both experiments, biostimulants did not influence significantly leaf photosynthetic performance. However, biostimulants did impact plant development and some growth parameters. Compared with control plants, our results showed that the number of flowering stalks decreased for greenhouse organically grown plants treated with mycorrhiza and for conventionally grown plants treated with the combination of mycorrhiza and bacteria. On the other hand, all biostimulants increased the growth of plants grown under the high tunnels. Concerning yield parameters, conventionally grown plants treated with citric acid produced higher total and marketable yield compared with control plants, while the marketable yield of organically grown plants was higher in the plants treated with citric acid and the combination of mycorrhiza and bacteria. In contrast to the greenhouse experiment, no yield effect was observed for high tunnel plants. In terms of berry quality, Trichoderma increased the polyphenol and anthocyanin content of conventionally grown berries, while a combination of mycorrhiza and bacteria increased the ºBrix, polyphenol and anthocyanin content of organically grown plants compared with control. No effect of biostimulants on ºBrix and polyphenols were observed for high tunnel plants compared with control, while all biostimulants increased berry anthocyanin content. From our study, we can conclude that some biostimulants may improve strawberry performance in terms of growth, yield, and fruit quality. The lack of a significant difference between biostimulant treatments, due to large variability, confirms the importance of validating these results under different growing conditions and production seasons.

Thesis (MScAgric)--University of Stellenbosch, 2002.
ENGLISH ABSTRACT: Historically root diseases have been a production-limiting problem for the strawberry industry worldwide. In the Western Cape Province of South Africa the most serious root disease is black root rot, which causes losses of up to 30%, annually. The aims of this study were to investigate aspects of the etiology and epidemiology of this disease in the Western Cape, and to provide information that can be incorporated in an integrated disease management strategy. In Chapter I a summary of published information on this disease is presented. Disease symptoms include severe stunting of plants, which have black, rotted, reduced root systems. Even though this disease is of great economic importance, the etiology remains unresolved. However, soilborne fungal root pathogens, particularly Pythium and Rhizoctonia spp. have been implicated as major role players. Control of this disease, as well as the other root diseases affecting strawberries, has relied on soil fumigation with broad spectrum chemical fumigants, in particular methyl bromide. However, due to the ozone depleting action of methyl bromide it was decided at the signing of the Montreal Protocol to remove this chemical from the market. This action has caused great demand for alternative measures to control root diseases on many crops including strawberries. Development of integrated disease management strategies is dependent upon a more complete understanding of the etiology, biology and ecology of the disease complex. In Chapter 2 fungal pathogens associated with diseased plants were isolated and Koch's postulates were carried out. The most frequently isolated fungal pathogens were Pythium irregulare, Rhizoctonia spp. and Cylindrocarpon destructans. Two morphotypes of Rhizoctonia were isolated viz. a brown and a white type. Pythium irregulare was isolated more frequently in July than in September, and was not isolated at all in November. Rhizoctonia spp. were present at all sampling dates but were more frequently isolated in November than at the other times. All the fungi that were tested were pathogenic and caused root lesions. Cylindrocarpon destructans and Coniella fragariae did not have a stunting effect on the plants. These results confirm a major role for Pythium and Rhizoctonia in the black root rot complex and suggest that there is a complimentary seasonal variation in occurrence between these two pathogens. The Rhizoctonia species and anastomosis groups of isolates obtained from diseased strawberries in the Western Cape Province were determined, and their pathogenicity and relative virulence assessed. Both binucleate and multinucleate types were recovered from diseased roots and identified as R. fragariae and R. so/ani, respectively. All isolates of R. solani were members of anastomosis group (AG) 6, whereas three AG types were identified among isolates of R. fragariae, viz. AG-A, AG-G and AG-I at a relative occurrence of 69%, 25%, 6% respectively. All Rhizoctonia isolates were pathogenic to strawberry, but R. solani (AG 6) was the most virulent causing severe stunting of plants. This is the first species confirmation and AG type identification of Rhizoctonia taxa causing root rot of strawberries in South Africa. An assessment of the presence and quantity of black root rot pathogens associated with soils prior to fumigation and post fumigation with methyl bromide, was made in Chapter 4. Isolations were also made from nursery plants to determine whether any black root rot pathogens were in the plants before transplanting. Results demonstrated that after fumigation the soil was free of all pathogenic fungi associated with the disease. However, the main pathogens involved in black root rot, viz. Rhizoctonia fragariae, R. solani and Pythium spp. were isolated from nursery plants. The fact that the plants are already infected with these pathogens renders the prospects for control of this disease difficult. Further studies are urgently required to develop production practices that can be included in disease management programmes. In vitro studies were carried out to determine the ECso values of different fungicides for isolates of Pythium irregulare, Rhizoctonia fragariae AG-A, AG-G and AG-I and R. solani AG 6. Benomyl, fludioxonil and tolc1ofos-methyl were used in these tests. Field trials were also conducted using these fungicides. In Chapter 5 it is shown that in general application of fungicides improved the yield and did not affect the survival rate of strawberry plants. Fludioxonil showed potential for short-term use. Applications of fungicides that targeted specific fungal genera were not sufficient to control the disease. Seasonal fluctuation of Pythium and Rhizoctonia spp. became apparent with the occurrence of Pythium being relatively high early in the season but low late in the season. Conversely, the occurrence of Rhizoctonia was low at the beginning of the season but high late in the season. In the short-term there is potential for fungicide applications as part of an integrated disease management strategy, but the economic feasibility of this practice needs to be assessed. In this study the major pathogens causing black root rot were identified in the Western Cape Province of South Africa, and important information regarding the epidemiology of the disease was reported. These results can be incorporated in an integrated management strategy to reduce losses of strawberry production, attJibutable to black root rot.
AFRIKAANSE OPSOMMING: Wortelsiektes is wêreldwyd 'n produksie-beperkende probleem vir die aarbeibedryf. . Swartwortelvrot, wat jaarliks verliese van tot 30% veroorsaak, is die belangrikste wortelsiekte in die Wes-Kaap Provinsie van Suid-Afrika. Die doelwitte van hierdie studie was om aspekte van die etiologie en epidemiologie van die siekte in die Wes- Kaap te ondersoek en inligting wat in geïntegreerde siektebestuurstrategië ingesluit kan word, te voorsien. In Hoofstuk 1 word 'n opsomming van gepubliseerde inligting aangaande die siekte uiteengesit. Siektesimptome sluit ernstige verdwerging van plante met swart verotte en verkleinde wortelstelsels in. Alhoewel die siekte van groot ekonomiese belang is, is die etiologie grootliks onbekend. Grondgedraagde wortelpatogene swamme, spesifiek Pythium en Rhizoctonia spp., is egter as belangrike rolspelers geïdentifiseer. Tot dusver het die beheer van hierdie siekte sowel as ander wortelsiektes van aarbeie berus op grondberoking met breë spektrum chemiese berokingsmiddels, spesifiek metielbromied. As gevolg van die osoonafbrekende aksie van metielbromied is daar egter tydens die ondertekening van die Montreal Protocol besluit om dié middel van die mark te verwyder. Hierdie besluit het 'n groot aanvraag na alternatiewe beheermaatreëls vir wortelsiektes van verskeie gewasse, insluitende aarbeie, veroorsaak. Die ontwikkeling van geïntegreerd siektebestuurstrategieë is egter afhanklik van 'n meer volledige begrip van die etiologie, biologie en ekologie van die siektekompleks. In Hoofstuk 2 is die patogene swamme wat met die siekte geassosieer word, geïsoleer, en is Koch se postulate uitgevoer. Die mees algemeen geïsoleerde patogene swamme was Pythium irregulare, Rhizoctonia spp. en Cylindrocarpon destructans. Twee morfotipes van Rhizoctonia is geïsoleer, nl. 'n bruin tipe en 'n wit tipe. Pythium irregulare is meer dikwels in Julie as in September geïsoleer, maar glad nie in November nie. Rhizoetonia het tydens alle monstertye voorgekom, maar is meer dikwels in November geïsoleer. Al die swamme wat getoets is, was patogenies en het letsels op die wortels veroorsaak. Cylindroearpon des true tans en Coniella fragariae het nie'n verdwergingseffek op plante gehad nie. Hierdie resultate bevestig die dominante rol van Pythium en Rhizoctonia in die swartwortelvrot kompleks en dui op 'n komplementêre seisoenale variasie in die voorkoms van hierdie twee patogene. Die Rhizoctonia spesies en anastomose groepe (AG) van die isolate geisoleer vanaf siek aarbeiplante in die Wes-Kaap Provinsie is bepaal, en die patogenisiteit en relatiewe virulensie is beraam. Sowel tweekernige as multikernige tipes is vanaf siek wortels geïsoleer en respektiewelik as R. fragariae en R. so/ani geïdentifiseer. Alle isolate van R. so/ani was lede van anastomose groep 6, terwyl drie AG tipes, nl. AGA, AG-G en AG-I onder die R. fragariae isolate geïdentifiseer is met relatiewe voorkomste van 69%, 25%, 6% respektiewelik. Alle Rhizoctonia isolate was patogenies op aarbeie, maar R. so/ani (AG 6) was die mees virulente en het ernstige verdwerging van plante veroorsaak. Hierdie is die eerste bevestiging van spesies en identifisering van AG tipes van Rhizoctonia taksa wat wortelvrot van aarbeie in Suid Afrika veroorsaak. In Hoofstuk 4 is 'n beraming van die voorkoms en hoeveelheid swartwortelvrot patogene geassosieer met grond voor, en na beroking met metielbromied, gemaak. Isolasies is ook vanaf kwekeryplante gemaak om te bepaal of enige swartwortelvrot patogene voor oorplanting in die plante teenwoordig was. Die resultate het getoon dat grond na beroking vry was van alle patogeniese swamme geassosieër met die siekte. Die hoof patogene betrokke in die swartwortelvrot kompleks, nl. Rhizoctonia fragariae, R. so/ani en Pythium spp. was egter in die kwekery plante teenwoordig. Die feit dat plante reeds met hierdie patogene geïnfekteer is, maak die vooruitsigte vir die beheer van hierdie siekte moeilik. Verdere studies word dringend benodig vir die ontwikkeling van produksiepraktyke wat by siektebestuursprogramme ingesluit kan word. In vitro studies om die ECso waardes van die isolate van Pythium irregulare, Rhizoctonia fragariae AG-A, AG-G en AG-I en R. so/ani AG 6 vir die fungisiedes benomyl, fludioxonil en tolclofos-metiel te bepaal, is uitgevoer. Hierdie fungisiedes is ook in veldproewe getoets. In Hoofstuk 5 is getoon dat aanwending van fungisiedes die opbrengs verbeter het en nie die oorlewing van aarbeiplante beïnvloed het nie. Fludioxonil het potensiaal vir korttermyn gebruik getoon. Die aanwending van fungisiedes wat spesifieke swamgenera teiken, was nie voldoende om die siekte te beheer nie. Seisoenale fluktuasies van Pythium en Rhizoctonia spp. het duidelik geword met die relatief hoë voorkoms van Pythium vroeg in die seisoen, maar lae voorkoms laat in die seisoen, terwyl die voorkoms van Rhizoctonia laag was aan die begin van die seisoen, maar hoog later in die seisoen. In die korttermyn is daar potensiaal vir fungisiedtoedienings as deel van 'n geïntegreerde siektebestuurstrategie, maar die ekonomiese haalbaarheid van hierdie praktyk moet bepaal word. In hierdie studie is die hoof patogene wat swartwortelvrot van aarbeie in die Wes-Kaap Provinsie van Suid-Afrika veroorsaak geïdentifiseer, en belangrike inligting rakende die epidemiologie van die siekte is aangeteken. Hierdie resultate kan in 'n geïntegreerde bestuurstrategie geïnkorporeer word om verliese van aarbeiproduksie, toeskryfbaar aan swartwortelvrot te, verminder.

Two field studies were conducted to assess the potential benefit of arbuscular mycorrhizal (AM) inoculation of elite strawberry plants on plant multiplication, and fruit yield, under typical nursery conditions, in particular soils classified as excessively rich in P. To study plant productivity, five commercially in vitro propagated elite strawberry cultivars ('Chambly', 'Glooscap', 'Joliette', 'Kent', and 'Sweet Charlie') were not inoculated with AM fungi or were inoculated with either a single species (Glomus intraradices), or a mixture of species (G. intraradices, Glomus mosseae, and Glomus etunicatum). AM inoculation was found to impact strawberry plant productivity in a soil with excessive P levels. The AM fungi introduced into the field by inoculated mother plants established a mycelial network in the soil through colonization of the daughter plant roots, however, persistence of colonization was determined to below (<12% in inoculated plant roots). In soils excessively rich in P, individual crop inoculation may be the only option for management of the symbiosis, as the host and non-host rotation crops, planted prior to strawberry production, had no effect on plant productivity or soil mycorrhizal potential.
To study the impact of AM inoculation on fruit production, three commercially grown strawberry cultivars (Glooscap, Joliette, and Kent) were not inoculated with AM fungi or were inoculated with either G. intraradices or G. mosseae. AM fungi impacted the fruit yield, with all inoculated cultivars producing more fruit than noninoculated cultivars during the first harvest year. The percentage of root colonization could not be used to explain the differences in total fruit yield during the first harvest year, or the increase in total fruit yield the second harvest year.
We wished to examine the effects of various P treatments on C metabolism within the intraradical mycelia (IRM) of the fungus. Specific primers were developed for the Glomus intraradices glucose-6-phosphate dehydrogenase (G6PDH) gene. Real-time quantitative reverse transcriptase polymerase chain reaction (QRT-PCR) was used to measure the gene expression of the G. intrarardices G6PDH gene in response to external P conditions of colonized transformed carrot roots. The results showed a significant down-regulation of G6PDH in the IRM of G. intraradices when cultures were grown in a high P (350 muM P) medium compared to those grown in the low P (35 muM P) medium. The down-regulation may suggest a reduction in the C flow from the host to the fungus. There was no effect on G6PDH expression following a two-hour incubation with additional P applications (No P, low P and high P).

No Brasil o morangueiro (Fragaria x ananassa Duch), representa um papel sócioeconômico de grande importância nas regiões Sul e Sudeste, constituindo-se num importante produto para consumo in natura e para indústria de alimentos. No entanto, o cultivo intensivo e muitas vezes com práticas culturais inadequadas tornam praticamente inevitável o controle químico de pragas e doenças, constituindo-se, o morango, num dos produtos com maior carga de agrotóxico. Nesse sentido, a produção de alimentos mais saudáveis, isentos de resíduos tóxicos, vem crescendo no mercado nacional e internacional demandando o desenvolvimento de tecnologias mais sustentáveis. O trabalho foi desenvolvido, nos anos de 2007 e 2008, na área experimental da UTFPR - Campus Dois Vizinhos com objetivo de avaliar o comportamento agronômico e as alterações bioquímicas de morangueiros em sistema de cultivo orgânico em função da aplicação de diferentes concentrações de calda bordalesa, calda sulfocálcica e biofertilizante supermagro, o delineamento experimental utilizado foi blocos ao acaso com 4 repetições contendo 16 plantas por parcela. O primeiro experimento realizado em 2007 foi um fatorial misto 3x4 sendo, fator A (qualitativo) constituído pela calda bordalesa, a calda sulfocácica e biofertilizante supermagro e o fator B (quantitativo) representado pelas concentrações de 0,5;1,0;2,0;4,0% e a testemunha onde se aplicou água. A freqüência de aplicações foi a cada 7 dias. No segundo experimento no ano de 2008, os tratamentos foram um fatorial 5x3, onde o fator A foi representado pelas caldas (calda bordalesa a 1%; calda sulfocálcica a 1%; biofertilizante supermagro a 4%, alternância de aplicação de caldas nas mesmas concentrações e a testemunha) e o fator B pelas cultivares (Camarosa, Camino Real e Albion). As avaliações realizadas no primeiro experimento foram: número de frutos por planta, produtividade, massa média, análises físico-químicas dos frutos (firmeza de polpa, acidez titulavel, sólidos solúveis totais - SST, aspecto visual e avaliação degustativa), avaliações de doenças de mancha-de-micosferela e mancha-dedendrofoma e análises bioquímicas em tecidos foliares (proteínas, aminoácidos, açúcares totais e redutores, fenóis totais e atividade de peroxidases). No segundo experimento, foram avaliados os mesmos parâmetros agronômicos, bem como as análises bioquímicas de açúcares totais e redutores, proteínas e atividade da enzima fenilalanina amonialiase. Os dados foram submetidos à análise da variância pelo programa SISVAR e seus resultados submetidos a comparações de médias e regressões. As caldas bordalesa e sulfocálcica, bem como o biofertilizante supermagro interferiram positivamente no número de frutos, massa média e produtividade do morangueiro. Concentrações acima de 1,0% de calda bordalesa e sulfocálcica causaram manchamento dos frutos, limitando seu emprego. O supermagro não apresentou restrição sendo que as melhores respostas agronômicas foram observadas nas maiores concentrações. A firmeza de polpa manteve-se mais elevada em função da aplicação das caldas. A aplicação das caldas e do supermagro interferiu no controle de doenças com redução da severidade da mancha-de-micosferela. A aplicação das caldas não interferiu na qualidade organoléptica dos frutos na pós-colheita, não sendo observado sabor estranho nos mesmos.
In Brazil, the strawberry (Fragaria x ananassa) represents a socio-economic importance in South and Southeast, becoming an important product for fresh market and food industry. However, intensive cultivation and often with inadequate cultural practices make it practically inevitable chemical control of pests and diseases, being the strawberry, one of the products with the highest pesticide load. In this sense, the production of healthier foods, free of toxic waste, is growing in national and international market demanding the development of more sustainable technologies. The study was conducted in the years 2007 and 2008 at the site of UTFPR - Campus Dois Vizinhos to evaluate the agronomic performance and biochemical changes of strawberry in organic cropping system according to the application of different concentrations of bordeaux mixture, lime sulfur and fertilizer supermagro, The experimental design was randomized blocks with four replications containing 16 plants per plot. The first experiment was conducted in 2007 with a 3x4 mixed factorial, factor A (qualitative) consisting of Bordeaux mixture, the spray and fertilizer sulfocácica supermagro and factor B (quantitative) represented by concentrations of 0.5, 1.0, 2.0 , 4.0% and the control where water was applied. The frequency of applications was every seven days. In the second experiment in 2008, the treatments were a 5x3 factorial design, where the first factor was represented by grout (1% Bordeaux mixture, lime sulfur at 1%; biofertilizer supermagro 4%, alternating application of grout at the same concentrations and control) and factor B by cultivars (Camarosa, Camino Real, and Albion). The evaluations performed in the first experiment were: number of fruits per plant, yield, average weight, physical-chemical characteristics of fruits (firmness, acidity, soluble solids - TSS, visual appearance and evaluation gustative), assessments of disease micosferela spot and stain dendrophoma and biochemical analysis in leaf tissues (proteins, amino acids, total and reducing sugars, total phenolics and peroxidase activity). In the second experiment examined the same parameters agronomic and biochemical analysis of total and reducing sugars, proteins and enzyme activity of phenylalanine ammonialyase. The data were subjected to analysis of variance by SISVAR program and its results submitted to mean comparisons and regressions. The Bordeaux mixture and lime sulfur and fertilizer supermagro interfered positively in the number of fruits, average weight and yield of strawberry. Concentrations above 1.0% Bordeaux mixture and sulfur caused staining of the fruit, limiting its use. The supermagro showed no restriction being that the best agronomic responses were observed at higher concentrations. The fimness remained higher depending on the application of grout. The application of the grout and supermagro interfere with disease control with reduced severity of the stain micosferela. Applying the grout does affect the flavor of the fruit after harvesting, were not noticed strange flavor to them.

Янчевський, П. П. Дослідження розвитку рослин суниці садової за використання різних систем зрошування : випускна кваліфікаційна робота : 201 "Агрономія" / П. П. Янчевський ; керівник роботи К. М. Кудряшова ; НУ "Чернігівська політехніка", кафедра аграрних технологій та лісового господарства. – Чернігів, 2021. – 56 с.
У кваліфікаційній роботі наведено формування високого врожаю рослин суниці, досягається за допомогою дотримання правил та правильної техніки вирощування. Дослідження ґрунтувалось на оцінці факторів та вимог технології вирощування, оцінці біологічної цінності рослини, основі отримання екологічно чистої ягоди, доступності елементів живлення, застосуванні мінеральних добрив. Під час досліду визначили особливості та цінності ягоди, виявили потенціал збільшення врожайності суниці, та отримання якісного врожаю.
In the qualifying work is given the formation of a high yield of strawberry plants is achieved through compliance with the rules and proper cultivation techniques. The study was based on the assessment of factors and requirements of cultivation technology, assessment of the biological value of the plant, the basis of obtaining ecologically clean berries, the availability of nutrients, the use of mineral fertilizers. During the experiment, the features and values of the berry were determined, the potential for increasing the yield of strawberries and obtaining a quality harvest was revealed.

Greenhouse and field studies were conducted to determine the effects of shade on photosynthetic, growth and yield responses of "Redchief" strawberries. Plants were exposed to 0 , 30 , 47 and 63 percent shade in the greenhouse. Net photosynthesis (Pn) as measured under the shade treatments demonstrated a curvilinear decrease. Pn as measured under saturating light levels of 790 μ-tmol· m-2 · s·1 began to decrease in plants grown under 30 percent or higher shade levels. Light saturation curves for leaves expanded in full sun and then transferred to shade treatments for seven days showed a decrease in Pn saturation rate and light saturation point at 63 percent shade. Saturation curves for leaves expanded under the shade treatments exhibited a decreasing trend in saturation rate and point at all shade levels. Heavy shade (63%) reduced leaf thickness and depth of the palisade cell layers. Individual leaf area was not affected by shade treatments. As percent shade increased, total plant dry weight decreased linearly as did specific leaf weight. Shade treatments of 0, 30, 63 or 95 percent were applied over field-grown plants either in the fall during flower bud initiation, or in the fall and spring, during flower bud initiation and spring vegetative growth. Berry number was reduced as percent shade increased. Plants shaded only in the fall had higher berry number than plants shaded both in the fall and spring. Berry weight was also reduced as percent shade increased. Sugar concentration, pH and titratable acidity were not affected by shade levels or time of shade application.
Master of Science

Il settore agro-alimentare sta diventando un notevole business per le industrie a causa del crescente interesse per il concetto di sicurezza alimentare e della necessità di nutrire il mondo globale. In particolare, il Regno Unito ha investito considerevoli risorse nella ricerca e nello sviluppo per ottimizzare la produttività: questo lavoro di tesi si inserisce in quest’ambito. In particolare le soluzioni meccatroniche analizzate, vertono su due diversi casi di studio: • la progettazione di un’innovativa linea di confezionamento per le fragole; • sviluppo di una piattaforma mobile per il test del suolo. Il primo progetto, in collaborazione con Berry Gardens, azienda leader nel Regno Unito nel commercio della frutta rossa, consiste nel ri-progettare una linea di confezionamento fragole. Partendo da un attuatore di Bernoulli, lo studio preliminare si è concentrato sulla progettazione di una nuova generazione di manipolatori in grado di minimizzare i danni sul prodotto, con annessi relativi test per valutare le sue potenzialità. Inoltre, è stata sviluppata una stazione di trattamento UV in grado di trattare fragole su entrambe le superfici per massimizzare l’effetto di decontaminazione. Infine è stata presentata la soluzione finale della linea di confezionamento. Il secondo progetto, in collaborazione con l'università norvegese University of Life Sciences, ha come obiettivo quello di assemblare una piattaforma composta dal robot mobile Thorvald II sviluppato dall'Università norvegese, e un robot cartesiano, prodotto dalla società SMC, al fine di costituire una piattaforma mobile autonoma per l’analisi del suolo. Entrambi i progetti sono stati sviluppati presso l'Università di Lincoln, Regno Unito, con la collaborazione di School of Engineering, School of Computer Science, Lincoln Institute for Agri-Food Technology (LIAT) e di partner industriali dell'Università.

The current approach taken in horticulture is to use films that block UV radiation as studies have shown that blocking UV reduces insect pest population as well as the spread of diseases. However, blocking UV radiation can have a negative impact on aspects of quality since a number of studies have shown that increasing UV radiation can increase secondary compounds in plants such as health beneficial phenolics. Therefore a key aim of the study was to investigate the effect of increasing UV transmission on aspects of quality of two contrasting crops (lettuce and strawberries) in relation to growth and development. UV radiation had an inhibitory effect on lettuce growth whereas it promoted the synthesis of phenolic compounds. UVB (280-320 nm) accounted for the greatest increase in secondary products and the greatest reduction in yield suggesting that there could be a direct benefit to commercial production associated with the use of highly UV transmissive films. However, this study showed that the beneficial effects of UV transparent and UV blocking films can effectively be combined in a production system. The reduction in yield in response to UV radiation equId be primarily due to high metabolic cost of phenolic compounds as well as to internal shading to some extent due to the high anthocyanin accumulation. An increase in UV transmission increased early fruit production, hastened fruit colour development, increased firmness and increased the secondary compounds in strawberry fruit. This study showed that the increase in secondary compounds of commercial strawberry cultivars grown under highly transmitting films was not as profound as in the case of lettuce. However, wild strawber'ry species not only showed greater response to UV radiation compared to commercial cultivars but also had a significantly higher phenolic content. No inhibitory effects of natural levels UV radiation was observed on net photosynthesis and photosystem II suggesting that phenolic compounds may have effectively protected the photosynthetic apparatus.

The work in this project aimed to shed light on the basis of high temperature induced reductions in cropping in everbearing strawberries. This would enhance the understanding of the physiology of this response in everbearing strawberries, and contribute to the development of practical methods to alleviate its severity on a commercial scale. Two physiological components have been revealed by the research: first, the reduction in flower production following a high temperature episode. Secondly, post-anthesis flower abortion and the potential importance of pollen performance. In flowers which were emerging under high temperatures, pollen showed reduced germination capacity. This is suggested to be a contributory factor to the observed post-anthesis flower abortion, which resulted in significant proportions of flowers not setting fruit. As a result, the final crop did not reflect the number of flowers produced by the plant and there was a high temperature-induced cropping trough. As far as practical methods are concerned, the interaction of other environmental factors with temperature was not found to alleviate the adverse effects of high temperature on cropping. The factors studied were vapour pressure deficit in the growth environment, and osmotic potential of the substrate (electrical conductivity of the feed solution). Crop load reduction (Le. truss removal) was also studied as a potential means of alleviating high-temperature induced cropping troughs, but the cropping patterns of treated plants did not differ significantly from those of the non- treated plants. Finally, poly tunnel cooling technologies were evaluated and it was found that forced air ventilation incorporated into a tunnel with a light diffusive cladding material with a degree of internal shading up to 35% could provide temperature control. This therefore could provide the potential to reduce temperature inside polytunnels and so ameliorate cropping troughs following periods of high summer temperatures.

Fresh strawberries have grown into a multi-billion dollar industry over the last few decades in California. Botrytis cinerea or grey mold, is the worst pathological disorder affecting strawberry fruit causing cull rates of up to 30% in the worst seasons. Strawberry fruits are fragile and have a short shelf-life making timely harvest, cooling, and marketing an absolute necessity. The current industry standard is to ship strawberries in an overwrapped CO₂-enriched headspace pallet in refrigerated trucks at 33 °F. However, B. cinerea has the ability to grow at very low temperatures and continues to plague the strawberry industry during postharvest storage and retail sale. Postharvest treatments available for strawberry preservation and disease management have been severely limited due to the reluctance to spray or wash the fruit. Consumers are also demanding produce that is free from synthetic chemical residues. Recent research with plant essential-oil volatile compounds has indicated that they have significant anti-fungal activity. Very little information is available regarding the use of essential-oil compounds for postharvest treatments on California strawberries to reduce the incidence of B. cinerea. The primary objective of this study was to investigate the potential for synergy to control B. cinerea through the combined application of volatile treatment constituents with uniquely different modes of action. Strawberries were acquired from commercial growers in the Santa Maria area of California on the day of harvest. Volatile essential-oil compounds were diluted in ethanol and applied to sachets which were then affixed to the inner lids of randomly selected clamshells. Clamshells were individually overwrapped with a micro-perforated 1-mil polyethylene film. The marketable shelf-life, percent rotted fruit, headspace atmosphere, postharvest quality, and sensory analysis were determined during 14-21 days storage at 40°F. The combination of ethanol (495.5 ppm), methyl jasmonate (4.5 ppm), citral (30 ppm), linalool (30 ppm), and vanillin (30 ppm) was the most effective formula to reduce rot and increase shelf-life overall and strawberries treated with 600 ppm of this blend maintained acceptable organoleptic quality. Applying high levels (750 ppm or more) of this formulation resulted in phytotoxic calyx desiccation after only 3 days at 40°F. However, moderate amounts (300-600 ppm per package) did not desiccate the calyx until 7-11 days of storage allowing sufficient time to market and consume the berries before the effect would be noticeable. A blend of essential-oil volatile compounds has the ability to significantly reduce postharvest losses from B. cinerea, can be applied without spraying on or washing fruit, and can be derived from natural sources. Additional Index Words: Methyl jasmonate, carvacrol, thymol, citral, linalool, vanillin, Induced Acquired Resistance.

CAPES
O objetivo deste trabalho foi avaliar o efeito dos eliciadores acibenzolar-S-metil (ASM) e da proteína harpina em pré e pós-colheita na indução de resistência a Botrytis cinerea, causador do mofo-cinzento em morangos, e sobre outros agentes infestantes. Quatro experimentos foram conduzidos, dois deles em pré-colheita, e outros dois em pós-colheita. No primeiro experimento (1) em pré-colheita, conduzido em casa-de-vegetação, testou-se dois produtos à base de harpina (ProActTM 2,5 g L-1 com 1% do i.a., e Messenger® 0,75 g L-1 com 3% do i.a) e um à base de ASM (Bion® 500WG 0,5 g L-1 com 50% do i.a.), mais a testemunha (água destilada). Após 24 horas da segunda pulverização dos tratamentos foi realizada inoculação do fungo B. cinerea (105 conídios mL-1). Neste experimento foram avaliadas: produtividade, incidência e severidade da mancha-de-dendrofoma, flores abortadas, incidência de ácaros e incidência de frutos com mofo-cinzento, além do teor de proteínas totais, atividade da enzima fenilalanina amônia-liase (FAL), fenóis totais e taxa de assimilação de CO2. No segundo experimento (2) em pré-colheita, foram testadas doses de harpina (ProActTM 100, 200 e 300 mg L-1) e de ASM (Bion® 500 WG 100, 200, 300 e 400 mg L-1), mais a testemunha (água destilada). Após 24 horas da primeira aplicação dos tratamentos foi realizada inoculação de B. cinerea (104 conídios mL-1). Neste experimento foram realizadas avaliações para os parâmetros de produtividade, incidência de podridões e taxa de assimilação de CO2. Além disso, após a quarta aplicação dos tratamentos, foram coletados frutos para um dos experimentos (4) em pós-colheita. Foram realizados mais dois experimentos em pós-colheita, e o terceiro experimento (3) foi conduzido em parcelas subdivididas, com e sem ferimentos nos frutos. Os frutos foram pulverizados com ASM (Actigar® 50WG 5,0 mg do i.a. mL-1), dois produtos comerciais contendo proteína harpina (80 mg do i.a. L-1 - ProActTM e Messenger®) e uma testemunha (água destilada). Para o quarto experimento (4), frutos tratados em pré-colheita com 100, 200 e 300 mg L-1 ProActTM (1% de harpina), e 100, 200, 300 e 400 mg L-1 de Bion® (50% de ASM), mais a testemunha (água destilada). No experimento 3, os tratamentos foram aplicados por meio de pulverização e 12 horas após efetuou-se a inoculação do fungo B. cinerea (105 conídios mL-1). Após 48 horas da inoculação os frutos foram avaliados quanto à área lesionada e firmeza de polpa. Foi coletada amostra do material vegetal para análise do teor de proteínas totais e da atividade da FAL. Os frutos do experimento 4 foram colhidos do experimento 2, depois da quarta aplicação dos tratamentos. Após a desinfecção em HCl (1%) os frutos foram inoculados com o fungo B. cinerea (105 conídios mL-1) e passadas 96 horas foram avaliadas a área lesionada e a firmeza da polpa. Nos experimentos em pré-colheita foi observada indução de resistência à B. cinerea pelos eliciadores, inclusive com efeito de doses. No experimento 1, verificou-se maior atividade da FAL e maior acúmulo de fenóis totais, sendo estes parâmetros relacionados à redução da porcentagem de frutos podres e a menor incidência e severidade da mancha-de-dendrofoma. Em pós-colheita, no experimento 3, houve redução de área lesionada por B. cinera mediante aplicação dos eliciadores. A atividade da fenilalanina amônia-liase aumentou em relação à testemunha e foi relacionada ao maior controle do mofo-cinzento, como também, à maior firmeza de polpa. No experimento 4, também houve a redução da área lesionada, bem como o aumento da firmeza de polpa com o aumento das doses de ambos os produtos. As doses 300 e 9 400 mg L-1 de ProActTM e Bion®, respectivamente, apresentaram os menores valores de área lesionada e a dosagem de 200 mg L-1 de ambos os produtos apresentou maior firmeza de polpa.
The objective of this work was to evaluate the effects of elicitors acibenzolar-S-metil (ASM) and harpin protein in pre and post harvest in the induction of resistance against Botrytis cinerea, responsible to the gray-mold in strawberries, and about other infestent agents. Four experiments had been led, two of them in pre harvest, and other two in post harvest. The first experiment (1) in pre harvest, was carried out in a greenhouse. It was tested two products from harpin protein (ProActTM 2,5 g L-1 with 1% of i.a, and Messenger® 0,75 g L-1 with 3% of i.a) and one from ASM (0,5 Bion® 500WG g L-1 with 50% of i.a), more the control (distilled water). 24 hours after the second spraying of the treatments was carried through inoculation of B. cinerea (105 conidia mL-1). To this experiment we had also been evaluated: productivity, incidence and severity of the one leaf blight fungus (Dendrophoma obscurans), percentage of aborted flowers, incidence of mites and percentage of fruits with the gray-mold, beyond the content of total proteins, activity of the phenylalanine ammonia-lyase enzyme (PAL), total phenols and the CO2 assimilation rate. In the second experiment (2) in pre harvest, doses of harpin (ProActTM 100, 200 and 300 mg L-1) and of ASM had been tested (Bion® 500 WG 100, 200, 300 and 400 mg L-1), more the control (distilled water). 24 hours after the first application of the treatments inoculation of B. cinerea (104 conidia mL-1) was carried through. In this experiment evaluations for the productivity parameters, percentage of putrid fruits and the CO2 assimilation rate had been carried through. Besides that, after the fourth application of the treatments, had been collected fruits for one of the experiments (4) in post harvest. Two experiments had been led more, in post harvest, the third experiment (3) was led in subdivided parts, with and without wounds in the fruits. The fruits had been sprayed with acibenzolar-Smetil (Actigar® 50WG 5.0 mg of i.a. mL-1), two commercial products having harpin protein (80 mg of i.a. L-1 - ProActTM e Messenger®) and one control (distilled water). The fruits of experiment 4 had been harvested of experiment 2, after the fourth application of the treatments. To the fourth experiment (4), fruits in pre harvest with 100, 200 and 300 mg L-1 ProActTM (1% of harpin), and 100, 200, 300 and 400 mg L-1 of Bion® (50% of ASM), more the control (distilled water), were evaluated in post harvest. In experiment 3, the treatments had been applied by means of spraying and 12 hours after the B. cinerea fungus was inoculated (105 conidia mL-1). After 48 hours of the inoculation the fruits had been evaluated as for the injured area and pulp firmness. Sample of the vegetal material was collected for analysis of the total proteins content and the activity of the PAL. After the disinfection in HCl (1%) the fruits had been inoculated with B. cinerea fungus (105 conidia mL-1) and passed 96 hours had been evaluated the injured area and the firmness of the pulp. In the experiments in pre harvest the induction of resistance against B. cinerea was observed by the use of elicitors, including with effect of doses. In experiment 1, it was verified bigger activity of the PAL and bigger accumulation of total phenols, being these parameters related to the reduction of the 11 percentage of rotten fruits and the smaller incidence and severity of the one leaf blight. In post harvest, in the experiment 3, there was reduction of injured area by B. cinerea through the application of the elicitors. Plants sprayed with the elicitors increased the activity of phenylalanine ammonia-lyase and it was related to the biggest control of the gray mold, as well as, the biggest pulp firmness. In experiment 4, there was also had the reduction of the injured area, as well as the increase of the pulp firmness with the increase of the doses of both the products. The doses of 300 and 400 mg L-1 of ProActTM and Bion®, respectively, had presented the smaller values of injured area, and the dosage of 200 mg L-1 of both the products presented greater pulp firmness.

This project investigates the impacts of nutrition merchandising on consumers’ willingness to pay for local tomatoes and strawberries. The data come from survey of Kentucky and Ohio residents in June 2011. Two thousand one hundred twelve individuals from Kentucky and Ohio were surveyed, to find out the impact of selfawareness of health benefits and health benefits information on their willingness to pay. The consumers were offered one of the three survey versions. The versions varied by how much nutrition information was provided to the consumer related to both strawberries and tomatoes – otherwise identical. A had the most, B had text only, and C omitted any nutritional benefits. This nutrition preamble was offered just before doing a payment card willingness-to-pay experiment. Standard demographic data were also included. The goal of the study was to see if and in what way the provision (or nonprovision) of this information, as well as consumers’ own knowledge of nutritional benefits of local foods, their beliefs and lifestyle influenced their willingness to pay for these local products.

Strawberries are considered an important crop in California where in 2018 it was in the top 5 valued fruit and vegetable commodities valued at $2.84 billion accounting for 88% of the total U.S. production. Strawberry production can be severely impacted by soilborne pathogens that can affect strawberry roots, crowns and leaves which can result in plant mortality. As much as 50 to 60% mortality can occur in one field. Pathogens responsible for such losses include Colletotrichum acutatum (syn.C. nymphaeae), Macrophomina phaseolina and Verticillium dahliae. With the phaseout of methyl bromide, host resistance and an understanding of host-pathogen interactions can play an important role in control of these diseases. A two-year study was conducted in order to evaluate host resistance of anthracnose in 105 cultivars and elite breeding lines developed by six strawberry breeding programs. Cultivars and elite breeding lines were inoculated using three local isolates in both years. All breeding programs provided genotypes that had a wide range of anthracnose susceptibility ranging from 0 to 100% mortality during both years. In both years an average of 78% of all the plant mortality occurred by 1 January. From the 105 cultivars and elite breeding lines, 30 cultivars were common to both years. Of these 30 cultivars, nine of them differed in their disease susceptibility between experiments by more than 20%. This suggests that several years of field evaluation may be necessary to determine susceptibility to anthracnose. Popular cultivars that represent the spectrum of susceptibility are Monterey (susceptible), Festival (moderately resistant), and Sensation (resistant). A second study was conducted toevaluate pathogen colonization of resistant and susceptible strawberry cultivars, testing interactions among crown and root plant tissue and two sampling timings. These cultivars were challenged with two soilborne pathogens, Macrophomina phaseolinaand Verticillium dahliae,over two years. Existing qPCR protocols for M. phaseolina and V. dahliae were used in order to quantify how much pathogen DNA was detected in crown and root samples. For the 2016-2017 V. dahliae trial there were significant effects for cultivar. Cultivar Benicia had significantly higher pathogen DNA compared to resistant cultivars Marquis, UC-12 and Camino Real. Susceptible cultivar BG 1975 had significantly less pathogen DNA compared to resistant cultivars San Andreas and Petaluma. In the 2017-2018 V. dahliaetrial pathogen DNA amount was not significantly different based on cultivar, plant part colonization, or the sampling period. In the 2017-2018 M. phaseolina trial all three of the fixed factors, cultivars, plant part colonization and sampling period were statistically significant. Cultivar ‘Sweet Ann’ had a significantly higher level of M. phaseolinaDNA in the early vs. the late sampling.