The effects of potential organic apple fruit thinners on gas exchange and growth of model apple trees: A model plant study of transient photosynthetic inhibitors and their effect on physiology and growth

Few fruit thinners have been certified for organic fruit growers. Previous studies have shown that herbicides or shade are capable of reducing photosynthesis and are effective fruit-thinning techniques, although impractical. This project evaluated use of a model plant system of vegetative apple trees grown under controlled conditions to study photosynthetic inhibitors, which could be used as potential organic thinning agents. Various concentrations of osmotics, salts, and oils (lime-sulfur, potassium bisulfite, potassium bicarbonate, sodium chloride, soybean oil) were applied to actively growing apple trees and showed a reduced trend on the rate of apple tree photosynthetic assimilation (Pn), evapotranspiration (Et), and stomatal conductance (gs). From two studies, it was observed that treatments of 2% lime-sulfur (LS) + 2% soybean oil (SO), 4% SO, 8% LS, 5% potassium bicarbonate (KHCO3), and 5% potassium bisulfite (KHSO4) all significantly reduced Pn. The 4% LS + 2% SO, 4% LS + 4% SO, 0.5% sodium chloride (NaCl), and 2% NaCl did not significantly reduce Pn. The response of Et was significantly reduced by 2% LS + 2% SO, 5% KHCO3, and 4% SO. In a second study, trees had reduced Pn, Et, and gs after the application of 4% LS + 4% SO, 2% NaCl, 5% KHCO3, and 5% KHSO4. Stem weight, total plant weight, average leaf weight, and leaf surface area of the treated plants, although reduced, were not significantly so when compared to the control 20 d after treatment

Propagation of thornless blackberries utilizing adventitious shoots from root cuttings

Studies were conducted in early 2003 to determine the effect of root source and length on yield of adventitious shoots from root cuttings and on subsequent plant yield for University of Arkansasdeveloped thornless blackberries. In the first study, roots from ‘Arapaho’ and ‘Apache’ plants grown in an aboveground bed containing commercial potting soil were compared to field-grown roots. Bed-grown roots averaged 6.9 shoots per 15 cm root cutting while field grown roots averaged 3.4. ‘Apache’ produced more shoots/root cutting compared to Arapaho, (5.9 vs. 4.4 shoots/root cutting, respectively). In a comparison of 15- vs. 30-cm-long root cuttings of ‘Apache’, ‘Arapaho’, and ‘Ouachita’, shoot yield of 30-cm roots was higher than that of 15 cm roots, but total yield of shoots per root unit was not increased by the longer root cuttings. Rooting of adventitious shoots neared 100% in both studies, and resulting quality of plants from these shoots was very good. This minor modification to the traditional method of planting root pieces to yield individual plants could lead to a more efficient and productive yield of propagules. The use of adventitious shoots from root cuttings for blackberry plant propagation appears to be a viable method for nurserymen to consider

Evaluation of cover crops in high tunnel vegetable rotation

Organic vegetable production within high tunnels allows for an extended growing season, crop protection, and environmental control. The USDA National Organic Program (NOP) standards mandate evidence that the soil has been maintained and improved over the course of production. Previous studies have indicated the potential of cover crops for reducing competitive vegetation, and improving soil quality, thus resulting in greater plant growth, nutrient uptake, and yield. However, there has been limited work in the confines of high tunnels as part of a tunnel-system rotation. Ten nitrogen-fixing and ten non-legume cover crops were established under a high tunnel and evaluated for their effects on the yield of ‘De Cicco’ broccoli (Brassica oleracea L. var. italica) and ‘Champion’ collards (Brassica oleracea L. var. acephala), aboveground biomass, and plant C and N contents. All treatments received recommended levels of appropriate certified organic fertilizers, water status was maintained, and vegetables received standard organic maintenance for insects and disease. The cover crops hairy indigo (Indigofera hirsuta L.), Catjang cowpea (Viana unguicalata L.), and Sunn hemp (Crotalaria juncea L.) consistently produced higher yields than Tifleaf III hybrid pearl millet (Pennisetum glaucum L.), Dairymaster brown midrib (BMR) hybrid grain sorghum (Sorghum spp.), and Wild Game Food sorghum (Sorghum bicolor L.). Nitrogenfixing legumes produced horticulturally significantly higher yields than the non-nitrogen-fixing grass species. This experiment demonstrated that not all cover crops are equal; they created variation in response. Cover crops provide a viable option for organic producers to maintain or improve soil quality over the course of production

Influence of organic groundcovers on mycorrhizal colonization and symbiosis of organically managed fruit crops

Ground covers have the potential to impact the crop rhizosphere biology, which includes organisms such as arbuscular mycorrhizal fungi (AMF), which in turn affect the crop host plant through symbiosis. There has been evidence that a ground cover that provides a suitable environment for colonization of AMF and subsequent symbiosis could be a tool in organic fruit production. The objective of this research was to compare colonization of AMF in strawberry plant (Frageria x ananassa cv. Radiance) and apple rootstocks (Malus x domestica, cv. M. 26) grown in a greenhouse affected by various ground cover treatments. Inoculation was achieved by mixing BioOrganics™ Endomycorrhizal Inoculant directly into soilless media according to label rates. Following a dormancy period, plants were treated with one of the following ground cover treatments: 1) city-generated urban green-compost (GC), 2) shredded white paper, 3) urban refuse wood chips or 4) an untreated control. The GC ground cover significantly increased percent colonization of AMF compared to other ground covers; however, AMF infection did not affect plant biomass, root volume, root surface area, root diameter, or leaf area. The AMF suppressed root length; plants inoculated with AMF had shorter roots but similar root volume to compared to non-inoculated plants. The GC treatment may have disproportionately contributed more nutrition by media composition of a smaller particle size and a decreased lignin, cellulose, and hemicellulose content compared to other ground cover treatments. Though the ground covers in this study had no effect on symbiotic AMF benefits, long-term studies with mature host plants could reveal a correlation between ground cover media and symbiosis

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

Food accessibility related to the Double Your Dollar Program

The Double Your Dollar (DYD) Program is a program that gives Supplemental Nutrition Assistance Program (SNAP) beneficiaries and Senior Farmers Market Nutrition Program (SFMNP) participants match dollars to spend at local farmers markets. The DYD’s goal is to incentivize healthy eating among individuals of low income and promote spending at farmers markets. Food insecurity affects over 60,000 individuals in Washington and Benton counties in Arkansas. The aim of this study was to assess how the DYD program impacted users’ food accessibility and how the program could be improved for the future. A survey was used to address basic demographics, type, frequency, and change of food purchases, and customer shopping patterns. Eighty DYD users were surveyed at farmers markets in Washington and Benton counties. The results indicated that the vast majority of current DYD users had increased purchases of fresh fruits and vegetables, which is a marker for improved nutritional status. The main motivations for shopping at the farmers market included the ability to buy fresh, healthy, and quality foods. This study indicates that food assistance programs such as DYD could be replicated throughout the country to improve local food accessibility and, as a result, potentially improve nutritional status among individuals of low income. Future studies should assess the awareness of the program within the community since this study only assessed those already participating

Propagation of thornless Arkansas blackberries by hardwood cuttings

Effects of auxin application and cutting location on canes on adventitious root development in hardwood cuttings of three Arkansas thornless blackberry cultivars were studied. Dormant canes were collected from one-year-old plants of ‘Apache’, ‘Arapaho’, and ‘Navaho’ and stored in a cold room until February. Two- or three-node cuttings were taken from the canes at apical, mid, and basal locations along the cane and were placed under intermittent mist in a perlite-filled greenhouse bed. Cuttings were either untreated or treated with auxin indole-3-butyric acid (IBA), applied as a liquid quick dip at 0.3%. In general, cutting diameter was greatest for basal and smallest for apical cuttings. Significant interactions were observed for cultivar and cutting location and for cultivar and auxin treatment for rooting. ‘Apache’ with auxin treatment had the highest rooting percentage, and ‘Arapaho’ and ‘Navaho’ with auxin the lowest. For cuttings that rooted, auxin treatment increased the root rating, representing root system development, for ‘Apache’ and ‘Navaho’ but had no affect on ‘Arapaho’

Herbicide-Resistant Soybeans in Arkansas: Lessons Learned and Future Direction

In Arkansas Delta soybean production, glyphosate resistant (GR) Palmer amaranth has significantly impacted weed management. The incidence of herbicide resistant (HR) weeds has farreaching crop science, economic, and communications implications, which have been explored by the corresponding expertise of our research team members to form a comprehensive literature review. The review was used to develop policy recommendations to address current and future HR genetically modified (GM) crop use and the associated issues. The review of crop science research indicated an overall increase in herbicide application, as well as an increase in weed management programs focused around glyphosate rather than the application of multiple herbicides. The review also revealed some management methods have potential to resolve the problem, including alternating herbicide application, avoiding sub-lethal rates, using “burn down” herbicides prior to planting, crop rotation, tillage, and zero tolerance weed policies. The use of fewer herbicides rather than multiple types creates a monopolistic edge for the companies producing those few herbicides, allowing greater market control. Crisis communication methods, including developing internal readiness, conducting needs assessments, developing a relevant message, and conveying the message through appropriate channels, can be used to develop a response to the issue that will best communicate necessary information to the target audience. The team used these findings to formulate policy recommendations, which include management, economic, and communication plans that may provide a starting point to address the issue

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

Maintaining a way of life: trials and tribulations of farmers’ market families

Never before in our nation’s history has there been so many ways for consumers to purchase food. From grocery stores, to super centers such as Wal-Mart and Costco, convenience stores, online purchases, community supported agriculture (CSA), and farmers’ markets, Americans have a multitude of venues to choose from. Although many Americans currently purchase their foods from grocery stores, a growing number of them are buying locally at their farmers’ markets and from CSAs. As the sustainability movement takes a greater foothold in the American household, local products and local foods are becoming ever more important and prevalent. Yet with all of the statistics surrounding local agriculture, the human element is often lost. A majority of small farmers and their spouses, often the ones who sell at a local level, have to work full time both on and off farm to support their families and farms. This case study examines the professional lives of five local farm families who choose to sell their products at the Fayetteville, Arkansas farmers’ market. It seeks to understand farmers’ reasons for farming and selling locally, as well as their biggest challenges and rewards. In addition, it seeks to fill gaps in literature regarding farmers’ motivations for selling at a local level