DETERMINATION OF BLACK WALNUT (JUGLANS NIGRA) HARVEST DATE WITH DUROMETER MEASUREMENTS

2005 ◽  
pp. 529-531
Author(s):  
M.R. Warmund ◽  
M.V. Coggeshall
2020 ◽  
Vol 20 (1-2) ◽  
pp. 131-136
Author(s):  
Natalya I. Zimenkina ◽  
Vladimir A. Kurkin

Significance. Black Walnut (Juglans nigra L.) is a species of trees of the Walnut family (Juglandaceae). This plant of the genus Walnut (Juglans L.) has not been sufficiently studied unlike other species e.g. Juglans regia L. This medicinal plant raw material is quite perspective, its preparations have antimicrobial, general tonic effect. We can use its leaves, unripe fruit, and the bark. However they are not widely used in medicine. In order to introduce the plants of the Walnut genus to the State Pharmacopoeia of the Russian Federation (RF State Pharmacopoeia), it is necessary to conduct of pharmacognostic studies, to develop product specification file to confirm the identification and quality of medicinal plant raw materials. The aim of this study is to develop a method of quantitative determination of flavonoids in the bark of the black walnut (Juglans nigra L.). Materials and methods. Material of the study was black walnut bark, stocked during the sap flow period (April) in 2018. The bark was skived up to 15 cm long and 23 cm wide. The bark was air-dried with the protection from direct sun light. The end of the drying was checked by the brittleness of the bark. Results. The methods of the quantitative determination of flavonoids in walnut bark has been developed. We used the differential spectrophotometry taking into consideration state standard sample of rutin at the analytical wavelength of 416 nm. The error of a single determination with a confidence level of 95% is 1.20%. Conclusion. We used the developed technique and analyzed a number of samples of black walnut bark. The content of total flavonoids in the plant raw material is 5.13 0.02% (as calculated on rutin). The flavonoid content should be at least 4.0%.


HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 691-695 ◽  
Author(s):  
Scott A. Brawner ◽  
Michele R. Warmund

Eastern black walnuts (Juglans nigra L.) were collected weekly in September and October to identify a method to determine the optimal harvest date and to develop a quantifiable color classification system for kernels. Husk hardness, measured by a durometer, decreased over a 5-week period. During the collection periods, the greatest percent kernel for ‘Emma K’, ‘Kwik Krop’, and ‘Sparrow’ was recorded when durometer values (i.e., force measurements) of husks were 5.2, 5.5, and 3.4 N, respectively. Husk softening was also detected using the denting method, but the perception of denting did not consistently correspond with a specific husk hardness value. Of the three cultivars, ‘Kwik Krop’ kernels were the most difficult to visually sort into light, medium, and dark colors. Kernel LCH sum (L* + chroma + hue angle values), measured by a handheld spectrophotometer, provided a reliable color classification for all black walnut cultivars in which light kernels had LCH sums ≥150, medium kernels had sums of 149 to 126, and dark kernels had values ≤125.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 352
Author(s):  
Joshua L. Sloan ◽  
Francis K. Salifu ◽  
Douglass F. Jacobs

Intensively managed forest plantations often require fertilization to maintain site fertility and to improve growth and yield over successive rotations. We applied urea-based “enhanced-efficiency fertilizers” (EEF) containing 0.5 atom% 15N at a rate of 224 kg N ha−1 to soils under mid-rotation black walnut (Juglans nigra L.) plantations to track the fate of applied 15N within aboveground ecosystem components during the 12-month period after application. Treatments included Agrotain Ultra (urea coated with a urease inhibitor), Arborite EC (urea coated with water-soluble boron and phosphate), Agrium ESN (polymer-coated urea), uncoated urea, and an unfertilized control. Agrotain Ultra and Arborite EC increased N concentrations of competing vegetation within one month after fertilization, while neither Agrium ESN nor uncoated urea had any effect on competing vegetation N concentrations during the experiment. Agrotain Ultra and Arborite EC increased δ15N values in leaves of crop trees above those of controls at one and two months after fertilization, respectively. By contrast, Agrium ESN and uncoated urea had no effect on δ15N values in leaves of crop trees until three months after fertilization. Fertilizer N recovery (FNR) varied among ecosystem components, with competing vegetation acting as a sink for applied nutrients. There were no significant differences in FNR for all the urea-based EEF products compared to uncoated urea. Agrium ESN was the only EEF that exhibited controlled-release activity in this study, with other fertilizers behaving similarly to uncoated urea.


2013 ◽  
Vol 59 (4) ◽  
pp. 453-463 ◽  
Author(s):  
Rosa C. Goodman ◽  
Juan A. Oliet ◽  
Guillermo Pardillo ◽  
Douglass F. Jacobs

1968 ◽  
Vol 57 (10) ◽  
pp. 1674-1677 ◽  
Author(s):  
Umesh C. Bhargava ◽  
Bertis A. Westfall

Metabolites ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 58 ◽  
Author(s):  
Khanh-Van Ho ◽  
Zhentian Lei ◽  
Lloyd Sumner ◽  
Mark Coggeshall ◽  
Hsin-Yeh Hsieh ◽  
...  

Black walnut (Juglans nigra L.) is one of the most economically valuable hardwood species and a high value tree for edible nut production in the United States. Although consumption of black walnut has been linked to multiple health-promoting effects (e.g., antioxidant, antimicrobial, anti-inflammatory), the bioactive compounds have not been systematically characterized. In addition, the associations between different black walnut cultivars and their health-promoting compounds have not been well established. In this study, the kernels of twenty-two black walnut cultivars selected for nut production by the University of Missouri Center for Agroforestry (Columbia, MO, USA) were evaluated for their antibacterial activities using agar-well diffusion assay. Among the selected cultivars, four black walnut cultivars (i.e., Mystry, Surprise, D.34, and A.36) exhibited antibacterial activity against a Gram-positive bacterium (Staphylococcus aureus), whereas other cultivars showed no effect on the inhibition of this bacterium. The antibacterial compounds showing the strongest activity were isolated with bioassay-guided purification and identified using a metabolomics approach. Six antibacterial bioactive compounds responsible for antimicrobial activity were successfully identified. Glansreginin A, azelaic acid, quercetin, and eriodictyol-7-O-glucoside are novel antibacterial compounds identified in the kernels of black walnuts. The metabolomics approach provides a simple and cost-effective tool for bioactive compound identification.


2011 ◽  
Vol 57 (No. 3) ◽  
pp. 107-113 ◽  
Author(s):  
L. Šálek ◽  
P. Hejcmanová

The black walnut (Juglans nigra L.), an introduced species into the Czech Republic, is planted for its production of valuable timber. A systematic study of the black walnut growth rate at different localities and consequently the creation of standard volume tables under Central European conditions therefore appear to be of high relevance. The aim of our study was to reveal the black walnut growth pattern in its pure stands in two riparian forests along the Morava and Svratka River (Strážnice locality and Židlochovice locality, respectively). To describe and to compare relationships among diameter at breast height (dbh), tree height and age, we used a forest management plan and measured 573 and 670 trees in pure sample stands at Strážnice and Židlochovice, respectively. We found out that the measured mean DBH and mean height were consistently higher in Strážnice, however the relationships of DBH to height, age to DBH, and age to height showed the same pattern at both localities. The mean heights of trees were 16.3, 24.1, 28.7, 31.9, and 34.5 m in 20, 40, 60, 80, and 100 year age classes and were consistently taller in comparison with other, mainly European, regions. Therefore our results suggest the high potential of black walnut in timber production in riparian forests in the Czech Republic, mainly in the South Moravian region.


2017 ◽  
Vol 63 (No. 3) ◽  
pp. 136-148 ◽  
Author(s):  
Hrib Michal ◽  
Podrázský Vilém ◽  
Matějka Karel ◽  
Viewegh Jiří

The article analyses the influence of black walnut on forest phytocoenosis in South Moravian forests and assesses how its representation may affect the understorey vegetation of the forest ecosystems. In July 2014, 31 relevés were processed in the South Moravian forests. These were stands of pure black walnut (Juglans nigra) as well as black walnut with small-leaved lime (Tilia cordata), along with neighbouring autochthonous stands (pure ash – European and narrow-leaved), oak (summer oak), or their mixtures. Ellenberg’s indicator values reveal differences in the plant communities under black walnut comparing those under native tree species for the variables nitrogen, soil reaction and temperature. In addition, total cover is significantly higher under walnut. Other differences are visible from the detrended correspondence analysis ordination. The study also confirmed that in the stands of black walnut the preference of some species is suppressed, for example Brachypodium sylvaticum and Poa nemoralis in alluvial forests and Melica uniflora in hilly forests.


Sign in / Sign up

Export Citation Format

Share Document