The Effects of Shade on Growth, Development and Yield of a Primocane Fruiting Blackberry, ‘Prime-Ark 45’ to Extend the Market Season

This thesis examines the effects of shade on ‘Prime-Ark 45’ blackberries (Rubus spp.) in greenhouse (GH) and field (FD) experiments aimed at improving fruit production in the southern United States Ozark Plateau region. Primocane blackberry production in the southern United States is limited in acreage of production as well as low yields by high temperatures during the bloom and early fruiting period, resulting in poor fruit set and poor fruit quality. Shade may have the potential to delay bloom and flowering to a more favorable season or by reducing temperatures that cause a poor fruit set and quality. Both the GH and the FD experiment was established in the June 2014 to evaluate the effects of shade on primocane fruiting blackberry growth, physiology and fruiting. The research objectives were experimenting the timing and intensity of shade on the potential for delayed flowering and fruiting. The GH experiment analyzed four treatments using 50% shade cloth: 1) an untreated nonshaded control [CK], 2) unshaded for 29 days then shaded for 30 days [US], 3) shaded for 29 days then shaded for 30 days [SS], and 4) shaded for 29 days and unshaded for 30 days [SU]. Each treatment had 11 single plant replicates. The number of flower buds, flowers, and individual fruits did not vary significantly among treatments in the greenhouse experiment. The last to bloom was the SU, 26 days after the CK on 28 July. These findings are significant because fruit could be shifted to 5 Sept. compared to the CK which would fruit approximately 10 Aug. A FD experiment was conducted to study the effects of various levels and time of shade treatments on ‘Prime-Ark 45’ blackberries. The FD experiment differs from the GH experiment because it included two levels of shade 30% and 50% implemented at different times throughout the growing season. The FD experiment consisted of seven treatments with varying levels of shade and differing dates of treatment implementation: 1) an untreated nonshaded control [CK], 2) early shade 30% [ES30], mid shade 30% [MS30], 4) late shade 30% [LS30], 5) early shade 50% [ES50], 6) mid shade 50% [MS50], 7) late shade 50% [LS50]. The 30% and 50% treatments began 16 June [ES], 1 July [MS] and 15 July [LS]; there were 5 replications per treatment. Growth measurements were taken weekly for both experiments to measure estimated leaf chlorophyll content and leaf assimilation. No significant differences for cane length, cane diameter, node number, internode length, number of lateral branches or number of fruit clusters were observed among treatments. Field treatments ES30, MS30 and ES50 had less fruit than LS treatments during the experiment period. It is possible that flowering and fruiting of the ES treatment could have continued after the end of this experiment due to the delay in flowering and fruiting as observed in the GH experiment. In the future shade should be applied 1 May as opposed to 16 June and could be coupled with season-extending high tunnel systems to protect fruit against freezing autumn weather

Risk Mitigation through Diversified Farm Production Strategies: The Case in Northern Mozambique

Mozambique, like many other parts of the low-income world, faces perennial challenges with food security. With a rapidly growing population and arable land on the decline, sustainable agriculture is vital to managing the already depleted natural resources of Sub-Saharan Africa more effectively while increasing food security. Food security issues for subsistence farmers in most low-income countries are a product of endogenous (crop yields) and exogenous (currency fluctuations as many agricultural inputs are imported) factors. In Mozambique the value of the local currency, meticals, has decreased by approximately 50% since January 2015 compared to the U.S. dollar. While this makes exporting products out of Mozambique more attractive in a relative sense, it negatively effects those industries which rely on imported inputs such as animal feed and inorganic fertilizer. In response to this exogenous currency crisis, research was conducted in Nampula, Mozambique during the summer of 2016 on a method for implementing crop diversification to reduce the risk that accompanies the devaluation of the metical. This research was undertaken on a poultry operation which is heavily dependent on imported maize and soya. Similar to the market structure of the poultry industry in the United States, all birds are grown by individual out growers who typically also have small plots of land to farm. Objectives for the project included 1) perform on-site crop production evaluations, 2) determine profitability for various row crops, and 3) simulate alternative production practices to increase crop profitability. Of the crops grown (tomatoes, maize, and cabbage), maize required the least labor, lowest initial investment, and the highest probability of breaking even. This research concluded that if poultry producers in Mozambique who rely on imported feed grew maize simultaneously it would reduce the dependency on imported maize and reduce income variability associated with exogenous currency fluctuations. Implementing a program such as this could increase revenue streams as well as reduce variability, thereby enhancing regional food securit

Risk Mitigation through Diversified Farm Production Strategies: The Case in Northern Mozambique

Mozambique, like many other parts of the low-income world, faces perennial challenges with food security. With a rapidly growing population and arable land on the decline, sustainable agriculture is vital to managing the already depleted natural resources of Sub-Saharan Africa more effectively while increasing food security. Food security issues for subsistence farmers in most low-income countries are a product of endogenous (crop yields) and exogenous (currency fluctuations as many agricultural inputs are imported) factors. In Mozambique the value of the local currency, meticals, has decreased by approximately 50% since January 2015 compared to the U.S. dollar. While this makes exporting products out of Mozambique more attractive in a relative sense, it negatively effects those industries which rely on imported inputs such as animal feed and inorganic fertilizer. In response to this exogenous currency crisis, research was conducted in Nampula, Mozambique during the summer of 2016 on a method for implementing crop diversification to reduce the risk that accompanies the devaluation of the metical. This research was undertaken on a poultry operation which is heavily dependent on imported maize and soya. Similar to the market structure of the poultry industry in the United States, all birds are grown by individual out growers who typically also have small plots of land to farm. Objectives for the project included 1) perform on-site crop production evaluations, 2) determine profitability for various row crops, and 3) simulate alternative production practices to increase crop profitability. Of the crops grown (tomatoes, maize, and cabbage), maize required the least labor, lowest initial investment, and the highest probability of breaking even. This research concluded that if poultry producers in Mozambique who rely on imported feed grew maize simultaneously it would reduce the dependency on imported maize and reduce income variability associated with exogenous currency fluctuations. Implementing a program such as this could increase revenue streams as well as reduce variability, thereby enhancing regional food securit

The effects of shade on primocane fruiting blackberries in the field

Primocane fruiting blackberry production in Arkansas is limited by heat during the flowering and early fruiting season. Shade could be used to delay flowering and fruiting to more favorable growth period. This study was designed to test three levels of shade (0% [control], 30% and 50% shading) applied at three times during the growing season that examined the growth, development, physiology of flowering, and fruiting of ‘Prime-Ark® 45’ blackberries. The seven treatments were as follows: 1) an untreated control (CK), 2) early shade 30% (ES30), mid shade 30% (MS30), 4) late shade 30% (LS30), 5) early shade 50% (ES50), 6) mid shade 50% (MS50), and 7) late shade 50% (LS50). The 30% and 50% treatments were implemented 16 June (ES) and left on for 95 days, 1 July (MS) and left on for 80 days, and 15 July (LS) and left on for 66 days. All shade was removed 19 Sept. 2014. Foliar gas exchange using CIRAS®-3 portable gas exchange monitor and estimated chlorophyll content (Minolta SPAD®) were measured weekly. Beginning at maturity, fruit was harvested biweekly to determine fruit yields per plot. Plant growth was measured destructively at the end of the study period. The cumulative berry weight was greatest for LS50 and LS30 which was not different from the CK or MS50, while ES30, MS30, and ES50 berry weights were significantly less. The cumulative marketable weights were greatest for LS30 and CK, while ES30 and MS30 were less than the CK. Shade altered flower and fruit production, but was not found to result in higher fruit quantities compared to the control. Some ES treatments reduced cropping compared to LS treatments

Students’ Perceived Barriers, Benefits & International Programmatic Preferences

Study abroad experiences can change college students by contributing to their development of self-awareness, communication skills, and ability to navigate the unknown. The objective of this study was to determine students’ perceived barriers, benefits, and preferences for international programs (IP). Undergraduate students in large-enrollment, required courses by major, and all freshman orientation undergraduate courses in Bumpers College were targeted and all grade classifications were represented (n = 672). Based on a five-point Likert-type scale (1 = completely disagree to 5 = completely agree), students reported “cost is too high” (M = 3.93, SD = 1.00) and being “too busy with school” (M = 3.54, SD = 1.10) as the barriers keeping them from participating in an IP. Using the same Likert-scale, students reported “socially/culturally learn more about a host country” (M = 4.61, SD = 0.67) and “life-changing opportunity” (M = 4.60, SD = 0.66) as the most influencing benefits. Students were most interested in short-term, faculty-led programs (n = 234, 27.2%) with a length of two to three weeks (n = 224, 30.7%) during summer session I (n = 307, 39.4%). Students reported they would like to learn more information about future IPs through email (n = 278, 34.8%), classroom visits (n = 111, 13.9%), and their academic advisors (n = 108, 13.5%). Assessing student’s barriers, benefits, and preferences for IPs will guide Bumpers College program development. It is important to focus IP efforts on students’ needs and interests, while also providing meaningful, engaged learning in all environments

Effect of timing of shade on growth, development, physiology, and fruiting of a primocane fruiting blackberry in a controlled environment

Primocane blackberry production in the upper south is limited by high temperatures during the bloom and early fruiting period, resulting in poor fruit set and poor fruit quality. Shade may have the potential to delay bloom and flowering to a more favorable season. A greenhouse study was established to evaluate the effects of shade on primocane blackberry growth, physiology, and fruiting. Single rooted plants of ‘Prime-Ark® 45’ were planted in 12-liter pots and grown in a greenhouse at the University of Arkansas System Division of Agriculture, Agriculture Research and Extension Center, Fayetteville, Arkansas. At approximately 0.25 m in height, one of the four following treatments was imposed with eleven single plant replications: 1) an untreated control (CK), 2) unshaded for 29 days then shaded for 30 days (US), 3) shaded for 29 days then shaded for 30 days (SS), and 4) shaded for 29 days and unshaded for 30 days (SU). Plants in the SU treatment were significantly taller than the SS and CK. Dry weight of leaves was consistent for all treatments except for SS which was significantly lower than the others. The CK bloomed first followed by US and SS. The last to bloom was the SU, 26 days after the CK. In conclusion, there was a delay of ‘Prime-Ark 45’ flower formation when 50% shade cloth was implemented and removed in the SU treatment. Further research needs to be completed to find the optimal intensity and timing of shade implementation that will improve fruit set in the southern region

Releases of Asian houbara must respect genetic and geographic origin to preserve inherited migration behaviour:evidence from a translocation experiment

Maintaining appropriate migratory strategies is important in conservation; however, translocations of migratory animals may alter locally-evolved migration behaviours of recipient populations if these are different and heritable. We used satellite telemetry and experimental translocation to quantify differences and assess heritability in migration behaviours between three migratory Asian houbara (Chlamydotis macqueenii) breeding populations (640 km range across eastern, central and western Uzbekistan). Adults from the eastern population migrated twice as far (mean = 1,184 km ± 44 s.e.) as the western population (656 km ± 183 s.e.) and showed significantly less variation in migration distance than the central population (1,030 km ± 127 s.e.). The western and central populations wintered significantly further north (mean: +8.32°N ± 1.70 s.e. and +4.19°N ± 1.16 s.e., respectively) and the central population further west (-3.47°E ± 1.46 s.e.) than individuals from the eastern population.These differences could arise from differing innate drive, or through learnt facultative responses to topography, filtered by survival. Translocated birds from the eastern population (wild laid and captive-reared, n= 5) migrated further than adults from either western or central recipient populations, particularly in their second migration year. Translocated birds continued migrating south past suitable wintering grounds used by the recipient populations despite having to negotiate mountain obstacles. Together, this suggests a considerable conserved heritable migratory component with local adaptation at a fine geographic scale. Surviving translocated individuals returned to their release site, suggesting continued translocations would lead to introgression of the heritable component and risk altering recipient migration patterns. Conservation biologists considering translocation interventions for migratory populations should evaluate potential genetic components of migratory behaviour

Effects of brownification and warming on algal blooms, metabolism and higher trophic levels in productive shallow lake mesocosms

An increase of dissolved organic carbon (DOC) in inland waters has been reported across the northern temperate region but the effects of this on whole lake ecosystems, often combined with other anthropogenic stressors like nutrient inputs and warming, are poorly known. The effects of these changes on different component of the ecosystem were assessed in an experiment using twenty-four large (3000L) outdoor mesocosms simulating shallow lakes. Two different temperature regimes (ambient and ambient +4 °C) combined with three levels of organic matter (OM, added as filtered peaty water), simulating the DOC increase that is predicted to take place over the next 4 to 21 years were used. Neither temperature nor OM had significant effects on net ecosystem production, respiration or gross primary production. Phytoplankton chlorophyll a concentration was not significantly affected by warming, however in summer, autumn and winter it was significantly higher in mesocosms receiving intermediate OM levels (July–Feb DOC concentrations 2–6 mg L−1). Summer cyanobacterial blooms were highest in intermediate, and lowest in the highest OM treatments. OM concentration also influenced total macroinvertebrate abundance which was greater in spring and summer in mesocosms with intermediate and high OM. Fish abundance was not significantly affected by OM concentration, but abundance was greater in ambient (55 fish subsample−1) compared to heated mesocosms (17 fish subsample−1) and maximum abundance occurred two weeks later compared to heated mesocosms. The results suggest that changes in OM may have a greater effect on shallow lakes than temperature and that phytoplankton, especially cyanobacteria, benefit from intermediate OM concentrations, therefore, nuisance algal blooms might increase in relatively clear shallow eutrophic lakes where DOC concentrations increase

The European 2015 drought from a hydrological perspective

In 2015 large parts of Europe were affected by drought. In this paper, we analyze the hydrological footprint (dynamic development over space and time) of the drought of 2015 in terms of both severity (magnitude) and spatial extent and compare it to the extreme drought of 2003. Analyses are based on a range of low flow and hydrological drought indices derived for about 800 streamflow records across Europe, collected in a community effort based on a common protocol. We compare the hydrological footprints of both events with the meteorological footprints, in order to learn from similarities and differences of both perspectives and to draw conclusions for drought management. The region affected by hydrological drought in 2015 differed somewhat from the drought of 2003, with its center located more towards eastern Europe. In terms of low flow magnitude, a region surrounding the Czech Republic was the most affected, with summer low flows that exhibited return intervals of 100 years and more. In terms of deficit volumes, the geographical center of the event was in southern Germany, where the drought lasted a particularly long time. A detailed spatial and temporal assessment of the 2015 event showed that the particular behavior in these regions was partly a result of diverging wetness preconditions in the studied catchments. Extreme droughts emerged where preconditions were particularly dry. In regions with wet preconditions, low flow events developed later and tended to be less severe. For both the 2003 and 2015 events, the onset of the hydrological drought was well correlated with the lowest flow recorded during the event (low flow magnitude), pointing towards a potential for early warning of the severity of streamflow drought. Time series of monthly drought indices (both streamflow- and climate-based indices) showed that meteorological and hydrological events developed differently in space and time, both in terms of extent and severity (magnitude). These results emphasize that drought is a hazard which leaves different footprints on the various components of the water cycle at different spatial and temporal scales. The difference in the dynamic development of meteorological and hydrological drought also implies that impacts on various water-use sectors and river ecology cannot be informed by climate indices alone. Thus, an assessment of drought impacts on water resources requires hydrological data in addition to drought indices based solely on climate data. The transboundary scale of the event also suggests that additional efforts need to be undertaken to make timely pan-European hydrological assessments more operational in the future

Malaria vector research and control in Haiti: a systematic review

BACKGROUND: Haiti has a set a target of eliminating malaria by 2020. However, information on malaria vector research in Haiti is not well known. This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti. METHODS: A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO. The following search terms were used: malaria, Haiti, Anopheles, and vector control. RESULTS: A total of 132 references were identified with 40 high quality references deemed relevant and included in this review. Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control. In the last 15 years (2000–2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti. Overall, the general literature on malaria vector research in Haiti is limited and dated. DISCUSSION: Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola. However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination