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Open access

Neil O. Anderson, Alan G. Smith, Andrzej K. Noyszewski, Emi Ito, Diana Dalbotten, and Holly Pellerin

The issue of native invasive species management rarely occurs and is fraught with biological, social, and economic challenges as well as posing difficulties in decision-making for land managers. The terminology for categorization of invasive species is examined in the context of their bias(es), which complicates control. An example of a newly determined native species, which is also invasive, is used as an example to navigate control and regulatory issues. Native, invasive reed canarygrass (Phalaris arundinacea L.) occurs throughout Minnesota and most likely the entire midwest region of central United States and Canadian provinces. The species was previously assumed to be an exotic, nonnative Eurasian import but recent molecular evidence supports its status as a native but invasive species. We address how this change to being a native but highly invasive species modifies approaches to mitigate its potential control for state, Tribal, and local authorities. The implications of these new findings will require differential shifts in land managers’ perspectives and approaches for control. Particular differences may exist for Tribal Land Managers vs. departments of natural resources and private agencies. Additionally, regulatory challenges have yet to be decided on how to legislate control for a native invasive species that had been previously assumed as exotic or foreign in origin. These opportunities to change attitudes and implement judicial control measures will serve as a template for other invasive species that are native in origin.

Open access

Jiayi Ji, Zhenglin Li, Ji Tian, Jie Zhang, Yanfen Lu, Xiaoxiao Qin, Jianjun Li, Liqiang Liu, Zhe Gao, Yujing Hu, and Yuncong Yao

Open access

Young Soon Kwon, Soon-Il Kwon, Jeong-Hee Kim, Moo Yong Park, Jong Taek Park, and Jinwook Lee

Open access

Job Teixeira de Oliveira, Rubens Alves de Oliveira, Priscilla Andrade Silva, and Paulo Eduardo Teodoro

To contribute to commercial classification, this work sought to evaluate correlations between fruit mass and other physical characteristics of blackberry fruit, indicating direct and indirect effects of morphology and physical characteristics on blackberry fruit mass. The variables evaluated were the total mass of the blackberry fruit along with its physical components: fruit length, greater transverse diameter, smaller transverse diameter, fruit area, fruit perimeter, and fruit volume. Results of our analyses show that an increase in fruit length, fruit perimeter, and fruit volume reflects an increase in the total mass of the blackberry fruit. Indirectly, greater values of fruit length, greater transverse diameter, and smaller transverse diameter reflect an increase in the perimeter and volume of the blackberry fruit, thus contributing to larger, more attractive fruit.

Open access

Rahmatallah Gheshm and Rebecca Nelson Brown

Saffron is well known as the most expensive spice in the world by weight. It is the dried stigmas of the saffron crocus (Crocus sativus). Besides being well known as a culinary spice, saffron is also important in the pharmaceutical, cosmetic, and dye industries. Saffron crocus is cultivated in a wide range of environments, from the Mediterranean to the Middle East, and even to northern India’s subtropical climate. Saffron crocus is an environmentally friendly and low-input crop, making it a perfect match for low-input and organic farming, and sustainable agricultural systems. The objective of this study was to evaluate the possibility of producing saffron in New England. The study was conducted from Sept. 2017 to Dec. 2019 at the University of Rhode Island. Two different corm planting densities and two winter protection methods were evaluated. In 2018, corm planting density did not affect the number of flowers per unit area or total stigma yields, but flowers from the low-density plots produced significantly (P < 0.05) heavier pistils than flowers from the high-density plots. In 2019, planting density had no effect on flower number, stigma yield, or pistil dry weight. In 2018, flower number, stigma yield, and pistil dry weight were similar to subplots that had been covered with low tunnels the previous winter and subplots that had not been covered. However, in 2019, the plants in the subplots that remained exposed during the winter produced significantly more (P < 0.05) flowers than the plants in the subplots that were in low tunnels for the winter. Saffron yields followed the same pattern, with the unprotected subplots yielding 57% more than the protected subplots (P < 0.05). These data indicate that winter protection is not beneficial for saffron crocus production in Rhode Island. The use of winter protection increases production costs and can decrease yields.

Open access

Michael J. Havey and Sunggil Kim

Hybrid-onion (Allium cepa) seed is produced using systems of cytoplasmic male sterility (CMS) and two different CMS systems have been genetically characterized. S cytoplasm was the first source of onion CMS identified in the 1920s, followed by T cytoplasm that was described in the 1960s. Numerous studies have documented polymorphisms in the organellar DNAs differentiating S and T cytoplasms from the normal male-fertile cytoplasm of onion. There may be additional source(s) of onion CMS that have been described as “T-like” and appear to be more similar to N and T cytoplasms than S cytoplasm. In this study, onion breeding lines from commercial entities were evaluated for molecular markers distinguishing sources of onion CMS. Our results reveal that bona fide T cytoplasm is rarely used commercially to produce hybrid-onion seed, and both S cytoplasm and “T-like” cytoplasm are widely used. We propose that this “T-like” cytoplasm be labeled as “R” cytoplasm because it may have originated from population(s) of ‘Rijnsburger’ onion in the Netherlands. The results of this study also help to clarify inconsistent reports regarding nuclear male-fertility restoration for different sources of onion CMS.

Open access

Thierry E. Besançon, Baylee L. Carr, and Albert Ayeni

Tigernut (Cyperus esculentus var. sativus) is a type of sedge that is quickly becoming popular as a superfood. As demand for tigernut continues to increase, more information is needed to develop weed management strategies for the crop to maximize tuber yield and quality. However, no herbicide is currently labeled for use with tigernut. Experimental trials were conducted in 2017 and 2018 to assess crop safety and control of economically important weeds with preemergence herbicides for transplanted ‘NG3’ and ‘OG’ tigernut. Oxyfluorfen applied alone or mixed with pendimethalin provided excellent control (>85%) of smooth pigweed (Amaranthus hybridus), carpetweed (Mollugo verticillata), and large crabgrass (Digitaria sanguinalis), and it did not cause any tigernut injury, stunting, or yield reduction compared with the weed-free control. However, none of the treatments controlled hairy galinsoga (Galinsoga quadriradiata) satisfactorily 2 months after herbicide application. Bensulide alone or associated with oxyfluorfen caused 14% to 25% stunting of tigernut. Bensulide alone only provided short-term control of broadleaf weeds. Increased weed competition and tigernut phytotoxicity associated with bensulide resulted in a 39% reduction in tuber yield compared with oxyfluorfen alone. Finally, S-metolachlor caused up to 78% stunting and a 68% reduction in vegetative tigernut biomass (on average) compared with the weed-free control. Tuber yield was reduced 55% to 97% after S-metolachlor was applied at transplanting. Oxyfluorfen would provide effective weed control up to 8 weeks after treatment in fields where hairy galinsoga is not a weed of concern and fulfill the requirement of a weed-free period without affecting tuber yield of quality.

Open access

Xiuli Lv, Yuan Guan, Jian Wang, Yanwei Zhou, Qunlu Liu, and Zequn Yu

To reveal the genetic diversity and genetic relationships of China’s Bergenia germplasm, 28 Bergenia accessions from different regions in China were analyzed by 24 intersimple sequence repeat (ISSR) markers. The results showed that 318 sites were amplified in all germplasm, including 307 polymorphic sites, and the percentage of polymorphic sites was 96.54%. Cluster analysis showed that the 28 accessions were divided into three categories, with a similarity coefficient of 0.5475. Bergenia purpurascens was clustered into one category; B. scopulosa was clustered into one category; and B. tianquaninsis, B. emeiensis, B. stracheyi, and B. crassifolia were clustered into one category. The results of the cluster analysis indicated that the 28 accessions were not completely classified by origin. Using the ISSR marker technique to analyze the phylogenetic relationship of Bergenia germplasm is helpful for identifying valuable resources and providing a theoretical basis for the selection of breeding parents.

Open access

Cyrus A. Smith, James L. Walworth, Mary J. Comeau, Richard J. Heerema, Joshua D. Sherman, and Randall Norton

A field study was conducted to evaluate tolerance of pecan rootstocks to soil salinity and sodicity. Seven cultivars—Elliott, Giles, Ideal, Peruque, Riverside, ‘Shoshoni, and VC1-68—were selected from a range of geographic regions of origin. The soil of the experimental plot was a poorly drained, saline–sodic Pima silty clay variant. The irrigation water was a moderately saline mix of Gila River and local groundwater with an electrical conductivity of 2.8 dS⋅m–1, containing primarily ions of Na and Cl. Eighty seeds of each cultivar were planted in a greenhouse in late Feb. 2016; 48 seedlings of each cultivar were transplanted into field plots in Feb. 2017. Half the trees received a soil-based application of Zn–ethylenediaminetetraacetic acid (EDTA) at planting. The trees were observed and rated for both vigor and resistance to salt injury on seven separate occasions. Trunk diameter was measured each dormant season. Leaf samples were collected on 9 Oct. 2019 and 6 Oct. 2020, and were analyzed for nutrient content. Zn-EDTA was not found to have a significant effect on growth, vigor, or resistance to salt injury. ‘Elliott’ seedlings exhibited greater tolerance for the alkaline, saline–sodic soil conditions than other cultivars. ‘Giles’ and ‘Peruque’ were most severely affected. Resistance to salt injury (ranging from marginal leaf burn to necrosis of entire leaf), vigor, and growth correlated more strongly with foliar concentrations of Na than Cl or K during 2019. Vigor and growth were not significantly correlated with foliar Na, Cl, or K concentrations in 2020. The foliar K:Na ratio had a nearly equal correlation with resistance to salt injury and a greater correlation with growth than that of Na alone in 2019. However, although the correlation of the K:Na ratio with vigor was stronger than that of Cl or K, Na had the strongest correlation with vigor in 2019. In 2020, the only significant correlation of growth and vigor was with the K:Na ratio. The strongest correlation with resistance to salt injury in 2020 was with foliar Na concentration.

Open access

Laban K. Rutto, Yixiang Xu, Shuxin Ren, Holly Scoggins, and Jeanine Davis

‘Hop’ (Humulus lupulus) cultivar trials were conducted at sites in three Virginia counties (Northampton, Chesterfield, and Madison) in response to demand by the craft beer industry for local ingredients. In 2016, a replicated study involving five cultivars (Cascade, Chinook, Newport, Nugget, and Zeus) was established on an 18-ft-tall trellis system at each site. Weather data influencing infectivity of downy mildew (Pseudoperonospora humuli) and powdery mildew (Podosphaera macularis), two economically important hop diseases, was collected, and to the extent possible, similar cultural practices were applied at each site. Climatic conditions favorable to P. humuli and P. macularis were present throughout the experimental period, and P. humuli infection was widespread at all sites starting from 2017. Among common pests, Japanese beetle (Popillia japonica) was the only one observed to cause significant damage. Unseasonably high rainfall in 2018 led to crop failure at all but the Northampton site, and harvesting was done at all sites only in 2017 and 2019. Yields (kilograms per hectare by weight) in 2017 were found to be ≥45% lower than second-year estimates for yards in the north and northwestern United States. Quality attributes (α and β acids; essential oil) for cones harvested from the Chesterfield site were comparable to published ranges for ‘Cascade’ in 2019, but lower for the other cultivars. More work is needed to identify or develop cultivars better suited to conditions in the southeastern United States. The influence of terroir on quality of commercial cultivars produced in the region should also be examined.