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