Climate and species stress resistance modulate the higher survival of large seedlings in forest restorations worldwide.

Seedling planting plays a key role in active forest restoration and regeneration of managed stands. Plant attributes at outplanting can determine tree seedling survival and consequently early success of forest plantations. Although many studies show that large seedlings of the same age within a species have higher survival than small ones, others report the opposite. This may be due to differences in environmental conditions at the planting site and in the inherent functional characteristics of species. Here, we conducted a global-scale meta-analysis to evaluate the effect of seedling size on early outplanting survival. Our meta-analysis covered 86 tree species and 142 planting locations distributed worldwide. We also assessed whether planting site aridity and key plant functional traits related to abiotic and biotic stress resistance and growth capacity, namely specific leaf area and wood density, modulate this effect. Planting large seedlings within a species consistently increases survival in forest plantations worldwide. Species' functional traits modulate the magnitude of the positive seedling size-outplanting survival relationship, showing contrasting effects due to aridity and between angiosperms and gymnosperms. For angiosperms planted in arid/semiarid sites and gymnosperms in subhumid/humid sites the magnitude of the positive effect of seedling size on survival was maximized in species with low specific leaf area and high wood density, characteristics linked to high stress resistance and slow growth. By contrast, high specific leaf area and low wood density maximized the positive effect of seedling size on survival for angiosperms planted in subhumid/humid sites. Results have key implications for implementing forest plantations globally, especially for adjusting nursery cultivation to species' functional characteristics and planting site aridity. Nursery cultivation should promote large seedlings, especially for stress sensitive angiosperms planted in humid sites and for stress-resistant species planted in dry sites.

The interaction between genotype and maternal nutritional environments affects tomato seed and seedling quality.

Seed and seedling traits are affected by the conditions of the maternal environment, such as light, temperature, and nutrient availability. In this study, we have investigated whether different maternally applied nitrate and phosphate concentrations affect the seed and seedling performance of two closely related tomato species: Solanum lycopersicum cv. Money maker and Solanum pimpinellifolium accession CGN14498. We observed large differences for seed and seedling traits between the two species. Additionally, we have shown that for nitrate most of the seed and seedling traits were significantly affected by genotype-environment interactions (G×E). The effect of the maternal environment was clearly visible in the primary metabolites of the dry seeds. For example, we could show that the amount of γ-aminobutyric acid (GABA) in Money maker seeds was affected by the differences in the maternal environments and was positively correlated with seed germination under high temperature. Overall, compared with phosphate, nitrate had a larger effect on seed and seedling performance in tomato. In general, the different responses to the maternal environments of the two tomato species showed a major role for G×E in shaping seed and seedling traits.

Replacing traditional nursery soil with spent mushroom substrate improves rice seedling quality and soil substrate properties.

Currently, large quantities of spent mushroom substrate (SMS) are produced annually. Because SMS has high water retention and nutrients, it has great potential to replace traditional topsoil for raising seedlings in agricultural production. However, few studies have examined the effects of substituting SMS for paddy soil on rice seedling growth and soil nutrients. SMS was mixed with rice soil in different proportions (20%, 50%, and 80%), and chemical fertilizer, organic fertilizer, and peat substrate were added in addition to equivalent nitrogen as a traditional seedling nursery method for comparison. Compared to traditional paddy soil (CK), the seedling qualities of the three SMS ratio treatments were all higher. Adding SMS at different ratios promoted rice seedling root growth, elevated the soluble protein concentration, and amplified the superoxide dismutase (SOD) enzymatic action in rice seedlings. Total porosity and aeration porosity of the soil increased by 17.40% and 32.90%, respectively. Soil organic carbon (SOC), total nitrogen (TN), and total phosphorus (TP) increased by 21.26-118.48%, 50.44-71.68%, and 23.08-80.17%, respectively. Besides, the relative abundance of Bacillus, Bacteroidetes, and other bacteria as well as the abundance of Ascomycota were all significantly increased. Adding 50% SMS increased the abundance of Pseudomonas by 8.42 times. The seedling quality of the 50% SMS treatment was even higher than chemical fertilizer and organic fertilizer treatments, only second to the peat substrate treatment. In summary, partial substitution of paddy soil with SMS can ameliorate substrate properties, improve seedling quality, and increase microbial diversity, indicating the suitability of SMS as a replacement for rice soil in seedling substrates. The 50% SMS ratio is the best. This study provides a basis for SMS to replace traditional rice soil in seedling cultivation.

Effects of the seedling tray overlapping for seed emergence mode on emergence characteristics and growth of rice seedlings.

Seedling mode plays a crucial role in the rice production process, as it significantly affects the growth and development of seedlings. Among the various seedling modes, the seedling tray overlapping for seed emergence mode (STOSE mode) has been demonstrated to be effective in enhancing seedling quality. However, the impact of this mode on the germination and growth of seeds with varying plumpness remains uncertain. To investigate the effect of the STOSE mode on seedling emergence characteristics, growth uniformity, and nutrient uptake of seeds with varying plumpness levels, we conducted a study using super early rice Zhongzao 39 (ZZ39) as the test material. The seeds were categorized into three groups: plumped, mixed, and unplumped. The results indicated that the STOSE mode significantly improved the seedling rate for all types of seeds in comparison to the seedling tray nonoverlapping for seed emergence mode (TSR mode). Notably, the unplumped seeds exhibited the most pronounced enhancement effect. The soluble sugar content of the seeds increased significantly after 2 days of sowing under the STOSE mode, whereas the starch content exhibited a significant decrease. Furthermore, the STOSE mode outperformed the TSR mode in several aspects including seedling growth uniformity, aboveground dry matter mass, root traits, and nutrient uptake. Overall, the STOSE mode not only promoted the germination and growth of plumped and mixed seeds but also had a more pronounced impact on unplumped seeds.

Optimal seeding rate enhances seedling quality, mechanical transplanting quality, and yield in hybrid rice.

To determine the appropriate seeding rate for machine-transplanted hybrid rice, field experiments were conducted during 2022-2023 using the hybrid rice variety Huazhe You 210 as the material. Four seeding rate treatments were set up: 40 (T1), 60 (T2), 80 (T3) and 100 g tray-1 (T4), to investigate the effects of seeding rate on the seedling quality, transplanting quality, yield formation, and economic benefits of high-quality indica hybrid rice seedlings. The results showed that with increasing seeding rate, the seedling base stem diameter and seedling plumpness of hybrid rice seedlings decreased, but the root entwining force gradually increased, leading to a deterioration in individual seedling quality but an improvement in collective characteristics. As the seeding rate increased, the missing hill rate during mechanical planting of hybrid rice significantly decreased, while the number of seedlings per hill and the damaged seedling rate showed an upward trend. The growth volume of tillers, tillering spikelet rate, and harvest index of hybrid rice in the field showed an overall downward trend with increasing seeding rate, while the accumulation of dry matter initially increased and then decreased. The yield and economic benefits of hybrid rice grains showed an initial increase followed by a decrease with increasing seeding rate, with the highest yield and economic benefits achieved with the T2 treatment. In conclusion, the appropriate seeding rate for machine-transplanted hybrid rice is T2 (60 g tray-1), which can maintain good seedling quality and improve transplanting quality, coordinate larger collective growth and appropriate harvest index, contributing to high yield and good economic benefits.

Can Rice Growth Substrate Substitute Rapeseed Growth Substrate in Rapeseed Blanket Seedling Technology? Lesson from Reactive Oxygen Species Production and Scavenging Analysis.

Rapeseed (Brassica napus L.) seedlings suffering from inappropriate growth substrate stress will present poor seedling quality. However, the regulatory mechanism for the production and scavenging of reactive oxygen species (ROS) caused by this type of stress remains unclear. In the current study, a split plot experiment design was implemented with two crop growth substrates-a rice growth substrate (RIS) and rapeseed growth substrate (RAS)-as the main plot and two genotypes-a hybrid and an open-pollinated variety (Zheyouza 1510 and Zheyou 51, respectively)-as the sub-plot. The seedling quality was assessed, and the ROS production/scavenging capacity was evaluated. Enzymatic and non-enzymatic systems, including ascorbic acid and glutathione metabolism, and RNA-seq data were analyzed under the two growth substrate treatments. The results revealed that rapeseed seedling quality decreased under RIS, with the plant height, maximum leaf length and width, and aboveground dry matter being reduced by 187.7%, 64.6%, 73.2%, and 63.8% on average, respectively, as compared to RAS. The main type of ROS accumulated in rapeseed plants was hydrogen peroxide, which was 47.8% and 14.1% higher under RIS than under RAS in the two genotypes, respectively. The scavenging of hydrogen peroxide in Zheyouza 1510 was the result of a combination of enzymatic systems, with significantly higher peroxidase (POD) and catalase (CAT) activity as well as glutathione metabolism, with significantly higher reduced glutathione (GSH) content, under RAS, while higher oxidized glutathione (GSSH) was observed under RIS. However, the scavenging of hydrogen peroxide in Zheyou 51 was the result of a combination of elevated oxidized ascorbic acid (DHA) under RIS and higher GSH content under RAS. The identified gene expression levels were in accordance with the observed enzyme expression levels. The results suggest that the cost of substituting RAS with RIS is a reduction in rapeseed seedling quality contributing to excessive ROS production and a reduction in ROS scavenging capacity.

Growth of tomato and cucumber seedlings under different light environments and their development after transplanting.

Selecting suitable light conditions according to the plant growth characteristics is one of the important approaches to cultivating high-quality vegetable seedlings. To determine the more favorable LED light conditions for producing high-quality tomato and cucumber seedlings in plant factories with artificial light (PFALS), the growth characteristics of tomato and cucumber seedlings under seven LED light environments (CK, B, UV-A, FR, B+UV-A, UV-A+FR, and B+FR) and the development of these seedlings after transplanting into a plastic greenhouse were investigated. The results showed that the seedling height and hypocotyl length increased in treatments with far-red light supplementation (FR, UV-A+FR, and B+FR), but decreased in the B treatment, in both varieties. The seedling index of tomato seedlings increased in the B+UV-A treatment, while that of cucumber seedlings increased in the FR treatment. After transplanting into a plastic greenhouse, tomato plants that radiated with UV-A had greater flower numbers on the 15th day after transplanting. In cucumber plants of the FR treatment, the flowering time was significantly delayed, and the female flower exhibited at a lower node position. By using a comprehensive scoring analysis of all detected indicators, light environments with UV-A and FR were more beneficial for improving the overall quality of tomato and cucumber seedlings, respectively.

Importance of controlling mesocotyl elongation in the development of rice seedlings intended for mechanical transplantation.

The mesocotyl facilities the emergence of deep-sown rice. However, the effects of mesocotyl elongation on mechanically transplanted rice seedlings remain unclear. In this study, the indica three-line hybrid rice Chuanyou 6709 (CY6709) and the indica conventional rice Guichao II (GCII) were selected as experimental materials. The seedlings were grouped based on mesocotyl lengths of 1.0 and 2.0 cm (M1 and M2, respectively), and seedlings without mesocotyl elongation were used as a control (M0). Seedling morphology, root morphology and physiology, and dynamic changes in soluble sugar and protein, malondialdehyde (MDA), and antioxidant enzyme activity in the mesocotyl were evaluated. The results showed that the elongation of mesocotyl is not conducive to improving the quality of mechanically transplanted seedlings, resulting in weak seedlings and poor root coiling force. The mesocotyl lengths of the seedlings showed a single peak with increasing seedling age, which gradually disappeared. The longer the mesocotyls, the slower their senescence. The MDA content of M2 was significantly lower than that of M1, and the activities of soluble sugar, soluble protein, and antioxidant enzymes of M2 were higher than those of M1, implying that seedlings with longer mesocotyls yielded lower-quality seedlings, reducing their suitability for mechanized transplantation. Compared with those of M0, the root-shoot ratio, stem base width, leaf age, leaf area, white root number, root coiling force, root length, root surface area, and root volume of M1 and M2 were reduced. Therefore, in the raising of rice seedlings, excessive elongation of the rice mesocotyl is not conducive to optimum root growth and development of aboveground structures for seedlings that are suitable for mechanized transplantation. Controlling the mesocotyl elongation can facilitate the cultivation of high-quality mechanically transplanted seedlings.

Bio-Priming of Soybean with Bradyrhizobium japonicum and Bacillus megaterium: Strategy to Improve Seed Germination and the Initial Seedling Growth.

Bio-priming is a new technique of seed treatment that improves seed germination, vigor, crop growth and yield. The objective of this study was to evaluate the effectiveness of Bradyrhizobium japonicum (commercial strains) and Bacillus megaterium (newly isolated strains) as a single inoculant and co-inoculant during seed bio-priming to improve seed germination and initial seedling growth of two soybean cultivars. The treated seeds were subjected to germination test (GT), cold test (CT) and accelerated aging test (AAT). B. megaterium significantly improved all parameters in GT and CT; final germination, shoot length, root length, root dry weight, and seedling vigor index in AAT, as compared to control. In addition, co-inoculation significantly increased all parameters except shoot dry weight in GT; all parameters in CT; germination energy, shoot length, root length, and seedling vigor index in AAT, in comparison to the control. Moreover, Br. japonicum significantly improved the germination energy, shoot length, shoot dry weight, root dry weight, and seedling vigor index in GT; all parameters in CT; shoot length, root length, and seedling vigor index in AAT, compared with non-primed seeds. Thus, B. megaterium strains could be used in soybean bio-priming as a potential single inoculant and co-inoculant, following proper field evaluation.

Rabbit manure compost as a peat substitute for compound growing media: Proportioning optimization according to physiochemical characteristics and seedling effects.

A large amount of rabbit manure is produced with the development of the rabbit industry, which will cause environmental pollution without proper treatment. Rabbit manure compost may be suitable for seedling cultivation, considering its low moisture, low heavy metal, high lignocellulose, and good fertilizer effect. In this study, a pre-proportioning test of growing media was conducted to optimize the ratio of perlite and vermiculite with peat/rabbit manure compost according to their physicochemical properties. Then, based on the results of the first proportioning optimization, the mixing ratio of rabbit manure compost and peat was further optimized using a bioassay. In this bioassay, salt-tolerant calendula (Calendula officinalis L.) and salt-intolerant cucumber (Cucumis sativus L.) were selected as test plants. The seedling effects (e.g., seedling emergence percentage, plant growth parameters, plant biomass, and nutrient effects) were evaluated. It was shown in the results that the rabbit manure compound growing media could be used for the seedlings, and suitable seedling performance was obtained with the increase of the total porosity (5.0%-61.2%), organic matter content (8.3%-39.9%), and nutrient elements from the rabbit manure compost. From the perspective of seedling emergence, there was no significant difference between rabbit manure compound media and peat treatment, in which the highest emergence percentages were >90%. At the same time, the nutrient performance of plant aboveground was significantly increased in rabbit manure compound growing media compared to peat treatment. In particular, the contents of P and Mg were increased by 31%-141.4% and 80.4%-107.8% for calendula and by 82.6%-117.4% and 35.1%-67.6% for cucumber, respectively. It was indicated in the two-step optimization that the rabbit manure compost proportion of 30%-50% (that is, 60%-100% instead of peat) was more suitable. Additionally, the greenhouse gas emission could be reduced by using rabbit manure compost replacing peat, and the greenhouse gas emission reduction potential would be 3.65 × 105-4.06 × 108 kg CO2-equivalent/year in China, which has important ecological significance.

Germination and the Initial Seedling Growth of Lettuce, Celeriac and Wheat Cultivars after Micronutrient and a Biological Application Pre-Sowing Seed Treatment.

Seed treatments with zinc, boron, biostimulant Coveron and MIX (zinc + boron + Coveron) were applied to three lettuce and three celeriac cultivars. Seeds of three wheat cultivars were treated under laboratory conditions with Trichoderma harzianum and eight Bacillus spp. Seed germination, seedling growth, and the presence of the following pathogens were determined: Fusarium sp., Alternaria sp., Penicillium sp., and Mucor sp. The Coveron treatment was the most effective on lettuce seeds tested in the germination cabinet. Seed germination was higher by 4% than in the control. Alternatively, germination of seeds treated with boron in the greenhouse was higher by 12% than in the control. The Coveron treatment had the highest effect on the shoot length, which was greater by 0.7 and 2.1 cm in the germination cabinet and the greenhouse, respectively. This treatment was also the most effective on the root length. Zn, B, and MIX treatments increased celeriac seed germination by 14% in the germination cabinet. The Zn treatment was the most efficient on seeds tested in the greenhouse. The germination was higher by 15%. A significant cultivar × treatment interaction was determined in both observed species under both conditions. The maximum effect on wheat seed germination (8%) was achieved with the T. harzianum treatment in the Salazar cultivar. A significant interdependence (p ≤ 0.01 to p ≤ 0.001) was established between seed germination and the seedling growth. The interrelationship between seed germination and pathogens of all cultivars was negative.

Effect of Rhizophagus irregularis on Growth and Quality of Cannabis sativa Seedlings.

Rhizophagus irregularis is an arbuscular mycorrhiza fungus that can enhance plant nutrition and reduce transplant shock on seedlings. The present study aims to evaluate the effects of this fungus on the quality of cannabis (Cannabis sativa L.) seedlings.A greenhouse float system experiment was conducted in a completely randomized design with three treatments. The treatments included the application of 40, 80 and 120 fungus spores per L of nutrient solution (AMF1, AMF2 and AMF3, respectively). The evaluation was performed based on the agronomic characteristics of the seedlings (root and stem length and weight, stem diameter), N and P content, survival rate, and the Dickson's quality index (DQI). Results indicated that root length and stem dry weight were significantly increased (by 34.14% and 21.4%, respectively) in the AMF3 treatment. The biomass of the seedlings' roots, the fresh weight and the N content were not affected by the AMF. On the contrary, survival rate, P content and DQI were significantly increased in AMF3 (by 5%, 24.3% and 12.4% respectively). Overall, our findings suggest that the application of high doses of Rhizophagus irregularis (AMF3) on float system-produced cannabis seedlings results in a considerable increment of their quality.

Full-scale of composting process of biogas residues from corn stover anaerobic digestion: Physical-chemical, biology parameters and maturity indexes during whole process.

Recycling of biogas residues from corn stover anaerobic digestion is crucial for the development of biogas industry. Full-scale composting process is the feasible way to convert biogas residues to fertilizer. The aim of the study was to explore the feasibility of full-scale composting process to dispose biogas residue to fertilizer, and to evaluate the quality of the compost. The results showed the biogas residues could rapidly reach the thermophilic stage and last at least 20 days, NH4+-N, TOC and C/N decreased along with the composting process, while TP, TK and NO3--N showed an opposite trend. Germination index(GI) and seedling growth index showed that raw biogas residues was toxic for plant, but the GI and seedling growth index were increased during the composting process, except for the cooling stage sample. Anaerolineaceae and Limnochordaceae were the main bacteria involved in the composting process, and Chaetomium was the most important fungus.

Co-composting of the biogas residues and spent mushroom substrate: Physicochemical properties and maturity assessment.

Recycling of BR and SMS are crucial for the development of biogas industry and commercial mushroom cultivation. The seed germination test is limited to examine the maturity of compost because of lacking the effect of insoluble part on plant growth. The aim of this study was to evaluate the maturity of compost by analysis the relationship between agronomic parameters of plant growth with physicochemical parameters of compost. The thermophilic period (over 50 °C) was lasted 52 days. TOC, C/N, AP and NH4+-N was decreased along with composting process, while TK, TP, AK and NO3--N showed an opposite trend. As for seedling quality, the raw material (T0) showed the worst plant growth but the 100% compost (T1) showed better seedling quality compared with commercial seedlings. According to the analysis of Spearman correlation, the results indicated that TOC, C/N, NH4+-N, NO3--N, AK and lignocellulose can be used to evaluate compost maturity.

[Effects of combined red, blue and white LED light on the quality of eggplant seedlings and fruit peels.] / LEDçº¢ã€è“ã€ç™½ç»„åˆå ‰å¯¹èŒ„å­å¹¼è‹—è´¨é‡å’Œæžœçš®å“è´¨çš„å½±å“.

The effects of red/blue=3/1 [R/B=3/1(9/3), as control, CK1], white light (W, as control, CK2), and combined light of red, blue and white [R/B/W=3/1/1 (9/3/3), T1; R/B/W=9/3/8, T2; R/B/W=3/1/6 (9/3/18), T3; R/B/W=3/1/16 (9/3/48), T4] on the growth, root development, quality and yield of eggplants were examined to provide theoretical and technical support for intensive and high-efficient light supplement and eggplant seedlings cultivation, using LED to accurately regulate light environment and 'Gailiangdalong' eggplant, based on the previous findings of the benefits of R/B=3/1 to the cultivation of eggplant seedlings. The results showed that R/B/W=9/3/8 treatment significantly increased plant height, stem diameter, seedling index, shoot dry weight, root dry weight, root development, anthocyanins and flavonoids content in eggplant peels and early yield. Root/shoot, total phenolic content in eggplant peels and soluble sugar content in pulps under R/B/W=3/1/1 treatment were significantly higher than those of other treatments. Total leaf area and free amino acid content in pulps were higher under R/B/W=3/1/6 treatment. The soluble protein content in pulps was higher under R/B/W=3/1/16 treatment. In summary, combined LED light of red, blue and white could improve the quality of eggplant seedlings and the yield and quality of eggplant fruits, with R/B/W=9/3/8 treatment being the best one in our study.

Combining pre-treatment strategies for broilers industry waste valorization.

aiming at expanding the possibilities for broiler slaughter wastes valorization, composting piles were submitted, at different time points (T0, T10, T20, T30 and Control) representing the treatments, to a solid-liquid fraction separation (FS), after being submerged in water (2:1, water:compost, in the fresh weight). After FS, solid material separated with a strain was again placed in piles for the final stage of composting, being evaluated the organic composts obtained after the stabilization phase (65 days) and maturation (95 days), in the different treatments. Reductions in mass (60-62%) and volume (56-64%) were greater in piles submitted to FS in comparison to control piles (52% and 54%). On the other hand, the FS induced greater losses of C (70.3-71.3%), N (55-62%), P (41.7-54.4%) and K (62.3-72.1%) in comparison to the control (65.2%, 48.0%, 28.1%, and 37.6%, respectively). We conclude that, as a way of integrating bioprocesses, FS does not have negative effects on the composting process. Moreover, compost mixtures from FS-treated piles, when used as substrate, yield better seedlings in comparison to mixtures from control.

Continuous Spectrum LEDs Promote Seedling Quality Traits and Performance of Quercus ithaburensis var. macrolepis.

Regulation of the growth, development, and quality of plants by the control of light quality has attracted extensive attention worldwide. The aim of this study was to examine the effects of continuous LED spectrum for indoor plant pre-cultivation and to investigate the morphological and physiological responses of a common broadleaved tree species in Mediterranean environment, Quercus ithaburensis var. macrolepis at seedling developmental stage. Thus, the seedlings were pre-cultivated for 28 days, under five different LED light qualities: (1) Fluorescent (FL) as control light (2) L20AP67 (high in green and moderate in far-red), (3) AP673L (high in green and red), (4) G2 (highest in red and far-red), AP67 (high in blue, red, and far-red), and (5) NS1 (highest in blue and green and lowest in far-red) LEDs. Further examination was held at the nursery for 1 year, on several seedling quality traits. Indeed, AP67 and AP673L triggered higher leaf formation, while L20AP67 positively affected seedling shoot development. NS1 and AP67 LED pre-cultivated seedlings showed significantly higher root fibrosity than those of FL light. Furthermore, NS1 and AP673L LEDs induced fourfold increase on seedling root dry weight than FL light. Hence, evaluating the seedling nursery performance attributes, most of those photomorphogenetic responses previously obtained were still detectable. Even more so, LED pre-cultivated seedlings showed higher survival and faster growth indicating better adaptation even under natural light conditions, a fact further reinforced by the significantly higher Dickson's quality index acquired. In conclusion, the goal of each nursery management program is the production of high quality seedlings with those desirable traits, which in turn satisfy the specific needs for a particular reforestation site. Thus, the enhanced oak seedling quality traits formed under continuous LEDs spectrum especially of NS1 and AP673L pre-cultivation may potentially fulfill this goal.

Lanthanum Affects Bell Pepper Seedling Quality Depending on the Genotype and Time of Exposure by Differentially Modifying Plant Height, Stem Diameter and Concentrations of Chlorophylls, Sugars, Amino Acids, and Proteins.

Lanthanum (La) is considered a beneficial element, capable of inducing hormesis. Hormesis is a dose-response relationship phenomenon characterized by low-dose stimulation and high-dose inhibition. Herein we tested the effect of 0 and 10 µM La on growth and biomolecule concentrations of seedlings of four sweet bell pepper (Capsicum annuum L.) varieties, namely Sven, Sympathy, Yolo Wonder, and Zidenka. Seedling evaluations were performed 15 and 30 days after treatment applications (dat) under hydroponic greenhouse conditions. Seedling height was significantly increased by La, growing 20% taller in Yolo Wonder plants, in comparison to the control. Similarly, La significantly enhanced shoot diameter, with increases of 9 and 9.8% in measurements performed 15 and 30 dat, respectively, as compared to the control. Likewise, La-treated seedlings had a higher number of flower buds than the control. An increase in the number of leaves because of La application was observed in Yolo Wonder seedlings, both 15 and 30 dat, while leaf area was augmented in this variety only 30 dat. Nevertheless, La did not affect dry biomass accumulation. La effects on biomolecule concentration were differential over time. In all varieties, La stimulated the biosynthesis of chlorophyll a, b and total 15 dat, though 30 dat only the varieties Sympathy and Yolo Wonder showed enhanced concentrations of these molecules because of La. Total soluble sugars increased in La-treated seedlings 30 dat. Interestingly, while most varieties exposed to La showed a reduction in amino acid concentration 15 dat, the opposite trend was observed 30 dat. Importantly, in all varieties evaluated, La stimulated soluble protein concentration 30 dat. It is important to note that while chlorophyll concentrations increased in all varieties exposed to La, both 15 and 30 dat, those of soluble sugars and proteins consistently increased only 30 dat, but not 15 dat. Our results confirm that La may improve seedling quality by enhancing some growth parameters and biomolecule concentrations, depending on the genotype, and time of exposure.

Comparison between cattle manure, organic compost, and vermicompost in the production of Eucalyptus urograndis seedlings / Comparação entre esterco bovino, composto orgânico e vermicomposto na produção de mudas de Eucalyptus urograndis

ABSTRACT: Composting and vermicomposting before addition to the soil is a viable alternative to the disposal of cattle manure. However, this residue has been used in the untreated form for seedling production. This study evaluated the use of cattle manure in natura, and the organic composted or vermicomposted variants of cattle manure on substrates used in the production of Eucalyptus urograndis seedlings. The treatments consisted of substrates formulated by mixing the organic fertilizers with washed sand in 20, 40, 60, 80 or 100 (v/v) percentages, compared to a commercial substrate. The E. urograndis seedlings were grown in tubes in a greenhouse and evaluated after 120 days for shoot and root dry weights, plant height, stem diameter, shoot/root ratio, and Dickson quality index. The substrate formulated from a mixture of 80% (v/v) of cattle manure in natura and washed sand allows for better development in Eucalyptus seedlings. Substrate containing 100% bovine manure vermicompost or organic compost produced seedlings with lower quality than in natura bovine manure but superior to the commercial substrate. Due to the health risks associated with use of untreated bovine manure, organic compost and vermicompost are good alternatives for the production of E. urograndis seedlings.

RESUMO: Uma alternativa para destinar corretamente o esterco bovino é realizar a compostagem e/ou vermicompostagem e depois adicioná-lo ao solo como fonte de nutrientes às plantas. Porém, este resíduo tem sido utilizado na produção de mudas sem tratamento. O estudo teve por objetivo avaliar o uso de esterco bovino in natura, de composto orgânico e de vermicomposto, produzidos a partir do esterco bovino, em substratos para a produção de mudas de Eucalyptus urograndis. Os tratamentos constituíram-se dos substratos formulados pela mistura dos fertilizantes orgânicos com areia lavada nas porcentagens de 20, 40, 60, 80 e 100 (v/v), em comparação com um substrato comercial (SC). As mudas de Eucalyptus urograndis foram cultivadas em tubetes, em casa de vegetação, e avaliadas aos 120 dias quanto a massa seca da parte aérea e raiz, altura da planta, diâmetro do caule, relação parte aérea/raiz e índice de qualidade de Dickson. O substrato formulado pela mistura de 80% (v/v) de esterco bovino in natura com areia lavada proporcionou o melhor desenvolvimento das mudas de eucalipto. O substrato contendo 100% de vermicomposto de esterco bovino ou composto orgânico produziu mudas com qualidade inferior ao esterco bovino in natura, mas superior ao substrato comercial. Devido aos riscos à saúde associados ao uso de esterco bovino não tratado, o composto orgânico e o vermicomposto são boas alternativas para a produção de mudas de E. urograndis.

Produção de mudas de manjericão (Ocimum basilicum L. ) em diferentes substratos e luminosidades / Sweet basil (Ocimum basilicum L. ) seedling production in different substrates and luminosities

Apesar de vários usos na cultura popular, poucos trabalhos vêm sendo desenvolvidos em relação ao cultivo do manjericão, sendo a maior parte dos estudos relacionada à identificação dos compostos químicos e à farmacologia. Este trabalho foi realizado com o objetivo de avaliar o efeito de diferentes luminosidades e substratos na emergência, crescimento inicial e qualidade de mudas de manjericão. Utilizaram-se três substratos (substrato comercial Plantmax®, mistura de terra + areia + cama de frango (1:1:1) e terra + areia + Plantmax® (1:1:1) e dois níveis de luminosidade (Pleno Sol e 50 por cento). O delineamento experimental foi de blocos casualizados em esquema fatorial 2 (Luz) x 3 (Substratos), com quatro repetições. Avaliou-se diariamente o percentual e o índice de velocidade de emergência, e aos 60 dias após a semeadura, o crescimento e a qualidade da muda. Os substratos e níveis de luz não alteraram a porcentagem de emergência das plântulas, entretanto a velocidade de emergência foi maior em Plantmax quando em pleno sol e não diferiu entre os substratos em 50 por cento de sombreamento. No substrato terra + areia + cama-de-frango e a pleno sol as mudas apresentaram maior crescimento e qualidade. Recomenda-se a semeadura direta do manjericão em terra + areia + cama de frango pois evita-se o transplante minimizando as perdas e a necessidade de mão de obra.

Although sweet basil has been frequently used in popular culture, few studies have been developed concerning its cultivation, and most of them are related to the identification of its chemical compounds and pharmacology. The aim of this study was to assess the effect of different luminosities and substrates on the emergence, initial growth and quality of sweet basil seedlings. Three substrates (Plantmax® commercial substrate, a mixture of soil + sand + chicken manure (1:1:1), and soil + sand + Plantmax® (1:1:1) were used, together with two light levels (Full sun and 50 percent). The experimental design was in randomized blocks, in 2 (Light) x 3 (Substrates) factorial arrangement with four replicates. The emergence percentage and velocity index were daily evaluated, and at 60 days after sowing seedling growth and quality were also evaluated. The substrates and light levels did not alter the percentage of seedling emergence; however, the emergence velocity was higher in Plantmax and full sun but did not differ among substrates under 50 percent shading. In the substrate soil + sand + chicken manure and full sun, seedlings had higher growth and quality. It is recommended thus that sweet basil be directly sown in soil + sand + chicken manure since it prevents transplanting, minimizing losses and the need of labor.