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To investigate and compare hardwood species based on their carbon (C) and nitrogen (N) storage capacity, a study of the C and N content of the bark and wood of nine common hardwood broadleaves in Novi Pazar, southwestern Serbia, was conducted. Compared with sycamore maple, Norway maple, common ash, common hornbeam, black locust, European beech, Turkey oak, and sessile oak, field maple has the highest C/N ratio in wood (37.05 ± 3.23), representing the best hardwood species for biomass production.

Pigeonpea [Cajanus cajan (L.) Mill.] may have cross- or self-pollination that allows the use of hybrids or improved genotypes by conventional breeding approaches in pigeonpea production. The objectives of this research were to: 1) compare the agronomic performance of a hybrid vs. breeding lines (BLs) developed by pedigree and bulk methods, and 2) determine if there were average and useful heterosis and heterobeltiosis for quantitative traits. The hybrid 13KLAF₁ and UPE-1, UPE-2, UPE-3, UPE-4, UPE-5 BLs, their parents (13KPP-264-05 and ‘Lázaro’), and one early maturity check ‘ICPL 86012’ were evaluated in field trials in Isabela and Lajas, PR. Data of plant height, days to flowering and harvest, seed yield, and weight of 100 dry-seeds were noted for all genotypes. There were no significant differences between 13KLAF₁ and UPE BLs for plant height in both locations. ‘Lázaro’ was late maturity in Isabela (157 days) and Lajas (124 days), as expected. The weight of 100 seeds for all genotypes did not reach values more than 18.5 and 16.3 g such as those observed for 13KPP-264-05 in Isabela and Lajas, respectively. The higher seed yields were observed for 13KLAF₁ (3112 kg·ha⁻¹), UPE-4 (2970 kg·ha⁻¹), and ‘ICPL 86012’ (2739 kg·ha⁻¹) in Isabela, whereas 13KLAF₁ (1599 kg·ha⁻¹) and ‘ICPL 86012’ (1450 kg·ha⁻¹) produced the higher yields in Lajas. The 13KLAF₁ showed an average heterosis and heterobeltiosis of 87% and 60%, and 78% and 30% for seed yield in Isabela and Lajas, respectively. The useful heterosis was >125% in both locations.

Selenium is an essential mineral for both humans and animals. Around 0.5–1 billion individuals globally suffer from selenium deficiency, which can result in a range of illnesses. Hence, the cultivation of selenium-enriched agricultural items can serve as a potent strategy to mitigate selenium deficiency. This study aimed to examine the effect of selenium on the quality, and phytochemical and mineral content of red currant (Red Lake) and jostaberry. The study was conducted in 2022 and 2023. Different doses of selenium (0, 4, and 8 mg⋅kg⁻¹) were sprayed on the fruits three times with 10-days intervals starting from the first formation of the fruits after flowering. Upon completion of the study, various factors were assessed including cluster and berry properties, water-soluble dry matter content, pH levels, titratable acid content, ascorbic acid levels, antioxidant activity, and total phenolics content. The mineral composition of the fruit peel, pulp, and seed was also measured. In jostaberry, the highest values of cluster weight, cluster height, and 100-berry weight were obtained with 8 mg⋅kg⁻¹ selenium application. As the selenium dosage increased, the levels of ascorbic acid, antioxidant activity, and total phenolic content increased, with the highest values determined to be 0.063 mg⋅mL⁻¹, 63.23% DPPH, and 3752.22 mg⋅g⁻¹, respectively, at 8 mg⋅kg⁻¹. In the Red Lake variety, it has been determined that the 4 mg⋅kg⁻¹ dose is effective in terms of cluster weight, cluster width, and cluster height attributes. The highest values for ascorbic acid, antioxidant activity, and total phenolic content were determined to be 0.029 mg⋅mL⁻¹, 53.42% DPPH, and 3117.17 mg⋅g⁻¹, respectively, at the 4 mg⋅kg⁻¹ dose. The selenium content was found to be highest in the peel and pulp of jostaberry at 8 mg⋅kg⁻¹, and in Red Lake, it was obtained at the 4 mg⋅kg⁻¹ application. As a result, an 8 mg⋅kg⁻¹ dose of selenium could be recommended for jostaberry, and a 4 mg⋅kg⁻¹ dose could be recommended for Red Lake.

In this study, we document the primary structural changes that occur during the seed development of Paphiopedilum spicerianum (Rchb.f.) Pfitzer, an endangered species with high horticultural value. Within a defined timeline, our results offer insights into the connection between these structural changes in seeds and their germination percentage. The optimum germination was recorded for immature seeds collected at 180 to 210 days after pollination (DAP), during which the embryos are in the late globular stage and the suspensor begins to degenerate. As seeds continued to mature by 240 DAP, there was a gradual decline in germination. Histochemical staining of mature seeds reveals that only the inner seedcoat and the surface of the embryo exhibit positive reactions to the Nile red stain, suggesting a relatively weak coat-imposed dormancy. This weaker dormancy may contribute to the higher germination observed in mature seeds of P. spicerianum compared with other challenging-to-germinate species. Of the cytokinins examined, 6-(γ,γ-dimethylallylamino)purine (2iP), kinetin (KN), and 6-benzylaminopurine (BA) exhibited a stimulating effect on germination, concurrently enhancing the formation of amorphous protocorms.

Health and quality of the root system are imperative to ensure the successful establishment of a citrus tree after transplant from the nursery into the field. Containerized citrus production in enclosed nurseries restricts root growth and can result in root circling and intertwining. This may hinder root expansion and result in root girdling after transplant, negatively affecting tree establishment and growth. The root structure of a transplanted citrus tree can also be affected by the container type used in the nursery. Containers with root-pruning properties like chemical pruning or air pruning reduce root circling and may produce superior root systems compared with regular, nonpruning containers. The aim of this study was to evaluate the effects of different nursery containers on root physiological and morphological traits and plant performance over 15 months of growth in the nursery. Three container types, chemical pruning containers, air-pruning containers, and standard nursery containers, were compared. The chemical pruning containers were standard citrus nursery containers with a mixture of copy hydroxide [Cu(OH)₂] and copper carbonate (CuCO₃) [10% copper (Cu)] applied to the inner wall. Pruning occurs upon contact of the roots with the Cu on the wall of the containers. The air-pruning containers were custom-sized Air-Pots in which pruning occurs on holes in the wall of the containers upon contact of the roots with the air. Two rootstocks, US-812 and US-942 (Citrus reticulata × Poncirus trifoliata), were included for comparison in the nongrafted stage and 12 months after grafting with ‘Valencia’ orange (Citrus sinensis). Chemical root pruning positively influenced tree height, shoot mass, leaf area, rootstock trunk diameter, and the nonfibrous root biomass. No differences among container types were observed for the fibrous root biomass, but chemical pruning produced more roots that were finer with a higher specific root length and a higher respiration rate. In contrast, air pruning produced more roots that were thicker compared with the other containers. Most of the leaf nutrients were lower in trees grown in the chemical pruning containers compared with the standard containers, except for Cu and zinc (Zn), which were highest in the former. Trees growing in air-pruning containers were not significantly different in growth from trees growing in standard containers.

Goosegrass, Eleusine indica (L.) Gaertn., is a serious weed in bermudagrass, Cynodon spp. Rich., golf and sports turf. Reduction of canopy gaps such as divots might discourage goosegrass establishment because turf canopy reduces sunlight that could stimulate goosegrass seed germination. The objective was to compare goosegrass seedling emergence and growth under different conditions of bermudagrass canopy, including bare soil and divots of different ages, and the effect of fertilization rates. The first experiment compared surface treatments. Goosegrass seeds were planted monthly for 12 months in bare soil and divoted pots in a glasshouse. Initial goosegrass seedling emergence was large in the first month after planting, 23% in divots and 20% in bare soil, compared with only 9% emergence from canopy. Reduced emergence occurred from 2 to 8 months in canopy, divots, and bare soil. Cumulative goosegrass emergence was 44% in divots, 40% in bare soil, and 31% in canopy. In a second experiment, goosegrass seeds were planted in divots 0, 2, 4, 6, 8, and 10 weeks old. Divots were visibly closed within 4 to 6 weeks. By 9 weeks after seed planting, goosegrass seedling emergence was reduced 72% after planting in 10-week-old divots compared with fresh, 0-week divots. Goosegrass continued to emerge through all 63 weeks observed after seed planting. High fertilization rate, 123 g N/m²/year, from 10 to 63 weeks reduced cumulative late seedling emergence 34%, compared with half-rate fertilization, probably due to denser canopy under high fertilization. In a third experiment, goosegrass seedlings planted in closed bermudagrass canopy grew 90% less, in root and shoot fresh and dry mass, compared with seedlings planted in divots. Across all experiments, goosegrass emergence and growth were reduced by increased canopy.

Blue honeysuckle (Lonicera caerulea) is a circumpolar species complex with representatives in Europe, Asia, and North America. Although honeysuckles (Lonicera spp.) from Eurasia have a history of invasiveness in North America, farmers and homeowners are interested in growing nonnative blue honeysuckle hybrids because of their edible blue fruits. To assess whether these cultivars and closely related native blue honeysuckles (Lonicera caerulea subsp. villosa) might have similar growth and fecundity, we planted five nonnative cultivars of blue honeysuckle and five native genotypes in a common garden in Orono, ME, USA, along with invasive red-fruited honeysuckles [Tatarian honeysuckle (Lonicera tatarica) and European fly honeysuckle (Lonicera xylosteum)] for comparison. Rooted cuttings were planted into a field plot in Jun 2016 and fully maintained during the first season; thereafter, maintenance consisted of weeding once annually. Seventy-three percent of native blue honeysuckle plants survived to the end of the study, whereas survival and growth of nonnative cultivars were more robust. In 2021, nonnative cultivars had an average height of 81 cm and width of 86 cm, which were 2.8 times the height and 2.9 times the width of surviving native plants. The estimated canopy volumes of nonnative blue honeysuckles were an average of 20 times those of their native counterparts. The bloom periods of native and nonnative blue honeysuckles overlapped considerably. However, only seven of the 22 living native plants produced fruits in 2021, with an average of three fruits per plant among them. In contrast, nearly all plants of the nonnative cultivars produced fruits, with an average of 616 fruits per plant. In comparison, the red-fruited invasives had an average of 9739 fruits per plant. Native blue honeysuckles produced very few seeds, whereas nonnative cultivars had an average of 13,918 seeds per plant, which was approximately one-fourth the number produced by invasive red-fruited honeysuckles. We concluded that native and nonnative genotypes of blue honeysuckle differ strikingly in survival, growth, and production of fruits and seeds. However, invasive red-fruited honeysuckles grew faster with higher fecundity than nonnative blue honeysuckles in our full-sun landscape. Because bloom times overlapped substantially between native and nonnative blue honeysuckles, the potential for gene flow to occur from planted cultivars into native populations merits consideration. Several possible explanations of differences in performance among blue honeysuckles include hybrid vigor of cultivars or shallow rooting or poor adaptability of native genotypes to the environment of the common-garden trial. Our results, which demonstrated that nonnative blue honeysuckles are likely to be distinct from their native relatives in terms of competitiveness and fecundity, suggest that caution is warranted during the introduction and cultivation of agricultural genotypes.

In an effort to mitigate the environmental impact of chemical fertilizers, plant growth-promoting rhizobacteria (PGPR) have emerged as a more sustainable alternative. Streptomyces saraceticus 31 (‘SS31’), a new strain of biocontrol bacteria, was inoculated into rhizosphere soils of ‘Benifuji’ grape to evaluate its impact on grape roots and berries. The results indicated significant improvements in soil fertility, with higher levels of organic matter, phosphorus, potassium, and nitrate nitrogen compared with those of the controls. Moreover, ‘SS31’ application elicited a notable reduction in soil pH levels, along with a substantial augmentation in the enzymatic activities of both phosphatase and invertase. The grapes treated with ‘SS31’ exhibited a notable increase in the number, length, surface area, and volume of fine roots in both 0- to 10-cm and 10- to 20-cm soil profiles. The application of ‘SS31’ resulted in the observation of greater diameter, lower density, and larger lumen area, along with increased specific hydraulic conductivity in the vessels of roots with 1- to 2-mm diameters. Despite a slight reduction in berry weight compared with that of the controls, ‘Benifuji’ grape berries displayed higher total soluble solids and lower total titratable acidity after ‘SS31’ application. Furthermore, ‘SS31’ treatment elevated the levels of volatile compounds in berries, especially fatty acid-derived compounds. A network analysis revealed a robust positive correlation between the observed improvements in grape berry quality and the morphology as well as the hydraulic conductivity of the grape fine roots. In conclusion, these findings suggest that ‘SS31’ has the potential to enhance grape root function by expanding the root absorption area and facilitating water transportation. This, in turn, may improve the flavor and aroma of ‘Benifuji’ grape berries.

The excessive use of chemical fertilizers in agriculture not only causes a decrease in soil fertility but also has negative effects on the environment, natural resources, and human health. Therefore, environmentally friendly practices, such as the use of organic fertilizers (OFs) and plant biostimulants that increase yield and fruit quality can be effective in solving these problems. In the present research study, we investigated the impact of using an OF alone and in combination with as a biostimulant different doses of humic acid (HA) on plant growth parameters, yield, fruit characteristics, and leaf mineral nutrient concentrations in plants of the Monterey and Albion strawberry varieties. As a result of this study, we determined that the combined application of the OF and HA increased the yield, fruit quality, plant growth, and nutritional elements in the crop compared with using the OF alone. In addition, the Monterey variety plants treated with OF and HA (5.0 L·ha⁻¹) in T₃ offered the best results among the different treatment groups and varieties. With this treatment, we obtained the highest total yield (262.42 g/plant), fruit weight, total soluble solids (TSS), and TSS/acid ratio, as well as increased growth parameters, and mineral nutrient concentrations in leaves. These results are hopeful for enhancing organic strawberry production.