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Open access

Chengyan Yue, Zata Vickers, Jingjing Wang, Neil O. Anderson, Lauren Wisdorf, Jenna Brady, Michele Schermann, Nicholas Phelps and Paul Venturelli

The present study systematically investigated the effects of warehouse and greenhouse aquaponic growing conditions on consumer acceptability of different basil cultivars. A total of 105 consumers rated their liking of three basil cultivars (Nufar, Genovese, and Eleonora), each grown in three conditions (aquaponically in a greenhouse, aquaponically in a warehouse, both with Cyprinus carpio, Koi fish, and grown in soilless medium). We used linear random effect models to investigate consumer preferences for attributes of basil plants grown in different environments by controlling for individual-specific random effects. Participants generally liked the soilless medium–grown and greenhouse aquaponically grown basil plants more than the warehouse aquaponically grown plants. The soilless medium–grown basil had the highest appearance liking and flavor intensity, followed by the greenhouse aquaponic grown and then by the warehouse aquaponic grown. Aquaponically grown cultivars were rated less bitter than soilless medium–grown cultivars.

Open access

Jesús Gallegos, Juan E. Álvaro and Miguel Urrestarazu

The response of root growth in containers has been studied in recent decades. The objective was to evaluate the effect of four types of containers on root and shoot growth. The containers were two shapes, round and square, and in some containers, internal vertical walls (IVWs) were placed that increased the internal container surface area with two substrates: perlite and coir fiber. Seedlings of cucumber, pepper, and tomato were transplanted. Two experiments were performed: vegetative growth and drought stress by partial decapitation and a period without fertigation. After decapitation, preexisting and new leaf area, dry biomass or the leaves, and stem were measured. The results revealed that the type of container had no effect, nor were there significant differences between substrates. The containers with IVWs exhibited an increase in biomass and the root surface. The total contact surface with the substrate of the four container types was closely related to the recorded plant growth. Thus, IVWs not only decrease mechanical problems of roots by preventing spiralling but also favor the production of biomass in vegetable plants and substantially increase the root, enabling the plants to manage water deficit and potentially improve posttransplant stress.

Open access

Job Teixeira de Oliveira, Rubens Alves de Oliveira, Fernando França da Cunha, Isabela da Silva Ribeiro, Lucas Allan Almeida Oliveira and Paulo Eduardo Teodoro

The objective of this work was to investigate the direct and indirect relationships of morphological variables on garlic bulb yield. The primary components of garlic bulb yield, including clove mass, number of cloves per bulb, and bulb diameter and bulb length, are the variables that affect garlic bulb yield directly. Leaf length and growth of a secondary bulb had a negative correlation to garlic bulb yield. Growth of a secondary bulb also had a negative correlation with the number of cloves per bulb and root dry mass. Irrigation with the deficit, applied at the stage of bulb formation, had a positive correlation with garlic yield and a slightly negative correlation with total plant mass, bulb length, and secondary bulb growth.

Open access

Seth D. Wannemuehler, Chengyan Yue, Wendy K. Hoashi-Erhardt, R. Karina Gallardo and Vicki McCracken

DNA-informed breeding techniques allow breeders to examine individual plants before costly field trials. Previous studies with tree fruits such as apple (Malus ×domestica) and peach (Prunus persica) have identified cost-effective implementation of DNA-informed techniques. However, it is unclear whether breeding programs for herbaceous perennials with 1- to 2-year juvenile phases benefit economically from these techniques. In this study, a cost-benefit analysis examining marker-assisted selection (MAS) in a Pacific northwest U.S. strawberry (Fragaria ×ananassa) breeding program was conducted to elucidate the effectiveness of DNA-informed breeding in perennial crops and explore the capabilities of a decision support tool. Procedures and associated costs were identified to create simulations of the breeding program. Simulations compared a conventional breeding program to a breeding program using MAS with low (12.5%), medium (25%), and high (50%) removal rates, and examined different scenarios where MAS had diminishing power to remove individuals as selections reenter the breeding cycle as parent material. We found that MAS application under current costs was not cost-effective in the modeled strawberry program when applied at the greenhouse stage, but cost-effectiveness was observed when MAS was applied at the end of the seedling trials before clonal trials with a removal rate of 12.5%.

Open access

Chunxian Chen and William R. Okie

Open access

Weiping Zhong, Zhoujun Zhu, Fen Ouyang, Qi Qiu, Xiaoming Fan and Deyi Yuan

The normal development of anthers and the formation of functional pollen are the prerequisites for successful pollination and fertilization. In this study, we observed dynamic changes in inflorescence and anther development in the chinquapin (Castanea henryi) using stereomicroscopy, light microscopy, and transmission electron microscopy. We found that cytokinesis during meiosis in microsporocytes was of the simultaneous type, and that the tetrads were mainly tetrahedral. Mature pollen grains contained two cells with three germ pores. The anther wall was of the basic type and composed of epidermis, endothecium, middle layers, and tapetum. Mature anthers had no middle layer and tapetum. The tapetum was of the glandular type. At the early microspore stage, a large number of starch granules appeared in the endothecium, which was deformed at the late microspore stage. Lipid droplets appeared in tapetum during the early microspore stage, and a few lipid droplets were still found during tapetum degeneration. The mature pollen accumulated a large amount of starch and lipids. These findings demonstrated that the anther wall provides nutrients and protection for pollen development. There is relatively stable correspondence between the external morphological characteristics of male flowers and internal structure of anther development.

Open access

Travis Wayne Shaddox and Joseph Bryan Unruh

Wetting agents are commonly applied to golf putting greens to manage soil moisture. Speculation has arisen regarding the influence of wetting agents on golf ball roll distance. The objective of this study was to determine the influence of wetting agents on golf ball roll distance, putting green surface firmness, and volumetric water content in sand-based putting greens. This study was conducted during the 2018 growing season in Jay, FL and Ft. Lauderdale, FL on ‘TifEagle’ hybrid bermudagrass (Cynodon dactylon × C. transvaalensis) putting greens. Treatments were applied to plots (2 × 3 m) in a randomized complete block design using four replications, and included seven wetting agents and an untreated turfgrass control. The study area was irrigated at 80% of the previous week’s reference evapotranspiration. Ball roll distance, firmness, and volumetric water content (VWC) were recorded weekly and pooled by month. Wetting agents did not lead to an increase in ball roll distance, firmness, or VWC during any month in Jay or Ft. Lauderdale. Inversely, in Jay, polyoxyalkylene polymer resulted in decreased surface firmness during October and November compared with untreated turfgrass. VWC was reduced as a result of some wetting agents in Ft. Lauderdale in February, September, November, and December, and resulted in no influence on VWC in Jay. The coefficients of determination of surface firmness and ball roll distance in Jay and Ft. Lauderdale were significant (P < 0.001) and were 0.12 and 0.08, respectively. This indicates that ball roll distance can increase as surfaces become firmer. However, this study found no evidence that wetting agents increase ball roll distance on sand-based putting greens.

Open access

Jacob H. Shreckhise, James S. Owen Jr., Matthew J. Eick, Alexander X. Niemiera, James E. Altland and Brian E. Jackson

Soilless substrates are routinely amended with dolomite and sulfate-based micronutrients to improve fertility, but the effect of these amendments on phosphorous (P) in substrate pore-water during containerized crop production is poorly understood. The objectives of this research were as follows: compare the effects of dolomite and sulfate-based micronutrient amendments on total P (TP), total dissolved P (TDP), orthophosphate P (OP), and particulate P (PP; TP − TDP) concentrations in pour-through extracts; to model saturated solid phases in substrate pore-water using Visual MINTEQ; and to assess the effects of dolomite and micronutrient amendments on growth and subsequent P uptake efficiency (PUE) of Lagerstroemia L. ‘Natchez’ (crape myrtle) potted in pine bark. Containerized crape myrtle were grown in a greenhouse for 93 days in a 100% pine bark substrate containing a polymer-coated 19N–2.6P–10.8K controlled-release fertilizer (CRF) and one of four substrate amendment treatments: no dolomite or micronutrients (control), 2.97 kg·m−3 dolomite (FL); 0.89 kg·m−3 micronutrients (FM); or both dolomite and micronutrients (FLM). Pour-through extracts were collected approximately weekly and fractioned to measure pore-water TP, TDP, and OP and to calculate PP. Particulate P concentrations in pour-through extracts were generally unaffected by amendments. Relative to the control, amending pine bark with FLM reduced water-extractable OP, TDP, and TP concentrations by ≈56%, had no effect on P uptake efficiency, and resulted in 34% higher total dry weight (TDW) of crape myrtle. The FM substrate had effects similar to those of FLM on plant TDW and PUE, and FM reduced pore-water OP, TDP, and TP concentrations by 32% to 36% compared with the control. Crape myrtle grown in FL had 28% lower TDW but pour-through OP, TDP, and TP concentrations were similar to those of the control. Chemical conditions in FLM were favorable for precipitation of manganese hydrogen phosphate (MnHPO4), which may have contributed to lower water-extractable P concentrations in this treatment. This research suggests that amending pine bark substrate with dolomite and a sulfate-based micronutrient fertilizer should be considered a best management practice for nursery crop production.

Open access

Amanda Bayer

Reduced irrigation (RI) can be used to reduce irrigation volume as well as to control plant growth. The timing and duration of RI applications can affect overall plant growth and flowering. Knowledge of plant response to RI can allow growers to control growth and plant form. The objective of this study was to quantify flower and overall plant growth of ‘PAS702917’coneflower (Echinacea purpurea) and ‘Helbro’ sneezeweed (Helenium hybrida) in response to RI. A soil-moisture sensor automated irrigation system was used to apply four irrigation treatments: RI and well-watered (WW) controls (25% or 38%) and two alternating treatments to apply RI for either the first 2 weeks (25% followed by 38%, RIWW treatment) or final 4 weeks (38% followed by 25%, WWRI treatment) of the 6-week study. For the sneezeweed experiment, RI was reduced to 20%. For coneflower, peduncle length was greater for the WW (36.8 cm) and RIWW treatments (35.7 cm) than the RI (27.0 cm) and WWRI treatments (26.6 cm). Shoot dry weight, compactness, leaf area, and flower number were not significant. For sneezeweed, WW plants were taller (57.2 cm) and had greater shoot dry weight (49.8 g) than plants in other treatments. WW plants also had more flowers (99) than WWRI (63) and RI (67) plants, which were more compact. Total leaf area did not differ between treatments for either species. Total irrigation volume was greatest for WW plants (5.2 and 15.1 L/plant for coneflower and sneezeweed, respectively), with RI at any point during the experiment resulting in water savings.

Open access

Nan Tang, Xiuting Ju, Yafan Hu, Rulong Jia and Daocheng Tang

Scale propagation is a cost-effective and time-saving reproduction method for lily bulb production. The effects of different incubation temperatures and plant growth regulators on the scale propagation of Lilium davidii var. unicolor were investigated. The results showed that temperature influences the scale rot incidence rate, speed of scale differentiation and bulblet formation, as well as the size of bulblets. The optimum temperature for scale propagation of L. davidii var. unicolor was 30 °C. Scales incubated at 30 °C showed a lower rot incidence and faster differentiation and produced larger bulblets. The application of gibberellic acid (GA3), 1-naphthaleneacetic acid (NAA), and 6-benzylaminopurine (6-BA) had no significant influence on the differentiation rate of scales. GA3 application reduced the incidence rate of scale rot. However, treatment with 50 mg/L NAA and 2 mg/L 6-BA significantly increased the rot incidence rate in the second week of propagation. Both treatments with 100 mg/L NAA and 100 mg/L GA3 produced a higher number of bulblets than their controls after 6 weeks of incubation. GA3 at 100 and 150 mg/L increased the diameter of bulblets, resulting in more large bulblets (grade 1) and fewer small bulblets (grade 3). 6-BA did not facilitate propagation by scaling.