Seedling Size Research Articles

Assessment of a 15-year white-tailed deer management program and woody recovery in a suburban forest preserve

Overbrowsing by highly abundant white-tailed deer (Odocoileus virginianus) negatively impacts the regeneration of the forest understory throughout the eastern United States. Deer management programs are often used by land managers to reduce deer densities and promote forest regeneration. This study examines the impact of a 15-year-long archery-based deer management program on the understory of a nature preserve in southern NY consisting of an old-growth hemlock and second-growth mixed hardwood forest. Vegetation plots were sampled every 3–5 years between 2004 and 2019, while deer density was estimated using camera trap survey data annually since 2009. Generalized mixed-effects models were used to determine the influence of deer density, forest type, canopy cover, and time on species richness, native stem density and total stem density. The most predictive models showed an increase in richness as time went on. Additionally, stem density had a negative relationship with deer density (i.e., stem density and species richness increased as deer density declined over time). For both native and total stem density, the highest-ranked model included only deer density as a predictor. Generally, woody species richness and stem density increased in the seedling (<0.3 m tall) and sapling (0.3–0.9 m tall) size classes but remained relatively constant for the transgressive (>0.9 m) size class over time and as deer density decreased. Many native species exhibited density increases in the smallest size classes, but black birch (Betula lenta), American beech (Fagus grandifolia), and mapleleaf viburnum (Viburnum acerifolium) were the only native species to increase in the transgressive (>0.9 m tall) class. Several non-native species, however, did increase in the transgressive size class since 2004. These results indicate that the forest has improved as a result of the DMP, but long-term recruitment of native species is still uncertain. The DMP has shown the potential to help restore woody regeneration but monitoring should continue to ultimately determine whether deer management can allow for true recruitment of native seedlings into the forest understory and canopy.

Pollination Biology of an Endemic Hawaiian Tree, Erythrina sandwicensis (Fabaceae: Papilionoideae), in a Novel Ecosystem1

Tropical dry forest ecosystems are among the most endangered ecosystems globally. In Hawai‘i, dry forest species are under threat due to habitat destruction, invasive species, and a loss of mutualisms including pollinators. Understanding the pollination biology of species at risk can inform conservation strategies. This study aimed to identify the breeding system and types of floral visitors to Erythrina sandwicensis (Fabaceae) or wiliwili, an iconic Hawaiian tree in decline and with little regeneration. We conducted hand-pollination trials and observed visitors in two sites: a botanical garden and a forest site. We compared fruit set, seed set, seed germination, seedling growth rate, and seedling size across four pollination treatments: open control, autogamy, geitonogamy, and xenogamy. We found that wiliwili is visited by a novel suite of non-native visitors. All treatments produced seeds, but the xenogamous (cross) treatment produced significantly more fruit and seeds than the control or other treatments. Seedlings produced from cross-pollinated treatments were also taller and had wider basal diameters after twenty-eight days of growth. These results indicate that wiliwili employs a mixed-mating system, and that trees are pollen limited. Enhancing current populations of wiliwili to promote cross-pollination could help increase population regeneration.

Analytical Comparison between the Speed of Screw and Crank-Rocker Based Pick and Place Mechanisms for Seedling Tray Seeding Machine

In this study the operational speed of screw based pick and place mechanism was compared with that of a crank-rocker based pick and place mechanism analytically for the design of a seeding machine for system of rice intensification (SRI) seedling tray. The configurations of the two types of mechanisms were generated based on their positions relative to a seedling tray conveyor and size of seeding manifold. The screw based mechanism consists of a vertical screw to which the seeding manifold was mounted and a horizontal screw to which the vertical mechanism was mounted. The vertical screw bearing the seeding manifold reciprocates down to pick seeds from seed container and back to the initial position. The horizontal screw translates horizontally to deliver the vertical screw bearing the seeding manifold to the seedling tray on the conveyor. The crank-rocker based mechanism consists of a pair of crank-rocker carrying a seeding manifold in between them. The mechanism rotates clock wise to pick seed and counter clock wise to drop the seed on the seedling tray. The time required for a complete pick and place circle was computed for both mechanisms using basic mechanics principles. Crank-rocker mechanism with a theoretical pick and place period of 1 second was found to be better than the screw based mechanism with 78.8 second per pick and place circle.

Analytical Comparison between the Speed of Screw and Crank-Rocker BasedPick and Place Mechanisms for Seedling Tray Seeding Machine

In this study the operational speed of screw based pick and place mechanism was compared with that of a crank-rocker based pick and place mechanism analytically for the design of a seeding machine for system of rice intensification (SRI) seedling tray. The configurations of the two types of mechanisms were generated based on their positions relative to a seedling tray conveyor, seed container and size of seeding manifold. The screw based mechanism consists of a vertical screw to which the seeding manifold was mounted and a horizontal screw to which the vertical mechanism was mounted. The vertical screw bearing the seeding manifold reciprocates down to pick seeds from seed container and back to the initial position. The horizontal screw translates horizontally to deliver the vertical screw bearing the seeding manifold to the seedling tray on the conveyor. The crank-rocker based mechanism consists of a pair of crank-rocker carrying a seeding manifold in between them. The mechanism rotates clock wise to pick seed and counter clock wise to drop the seed on the seedling tray. The time required for a complete pick and place circle was computed for both mechanisms using basic mechanics principles. Crank-rocker mechanism with a theoretical pick and place period of 1 second was found to be better than the screw based mechanism with 78.8 second per pick and place circle.

Managing Cashew Rootstock Grafting Size Through Organic Fertilizers

Seed born cashew (Anacardium occidentale L) seedlings are planted directly when they are produced from polyclonal orchards. In a common scenario, cashew seedlings are grafted before transplanting. For this purpose, adjusting the size between scions and rootstock is highly important for the success of grafts and it can be achieved through a visual selection of scions. However, when working with large numbers of seedlings physical and visual selection becomes laborious and time consuming for the workers. Therefore, creating uniformity in seedlings size before grafting is crucial. We present experimental results showing the linear regression between the fertilization level and seedling stem size. Two experiments were conducted in Mozambique: One at Nassuruma cashew Research Station, Nampula province, following a Completely Randonmized Block Design (CRBD), seven treatments, ten bags per treatment and five replicates. The treatments consisted of a fertilizer organically composted from cashew nut shells and applied at rates of 0, 4, 8, 16, 32, 40 and 48% of the total amount of soil in each bag. The second experiment was carried out at Chizavane nursery, in Gaza Province, also based on CRBD, in factorial arrangement of 4 and 3 levels of Kelp and Stimu biofertilizers respectively. Two stem size variables, diameter and height, were considered and data collected at 120 days after seedlings emergence in Nampula and 45 days after emergence in Gaza Province. Polynomial or simple regression analysis model for stem diameter and plant height was performed. The stem diameter was linearly described as an increasing equation. The height was also linearly related to fertilizer but following a decreased equation. We concluded that applying appropriate dosage of fertilizer in the soil or on the leaves could adjust the stem size of the rootstock required for grafting and therefore adjust the stem to the size of scions available. The treatments with high level of Kelp, Stimu and cashew compost fertilization resulted in increase of 8,5%, 6% and 16,6% of diameter respectively. However, the treatments caused a reduction of height at rate of 14,3%, 3,2% and 25,08% respectively. The stem and scion size adjustment are highly important for increasing the grafting success rate in a cashew nursery.

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.

Grass invasion reduces the resilience of tree regeneration to fire in the Central Hardwoods Region

Non-native grass invasions are altering fuels and fire behavior in forests, with uncertain consequences for tree regeneration and forest dynamics. We examined whether invasion by Microstegium vimineum, the most widespread invasive grass in the eastern United States, interacts with prescribed fire to reduce tree regeneration and evaluated how such interactions might influence long-term regeneration dynamics in the Central Hardwoods Region. Using paired invaded and uninvaded plots subjected to fall or spring burning, we quantified differences in pre-fire juvenile tree regeneration, fire intensity, and survival and resprouting rates of naturally established juvenile trees of varying sizes and species. Field data were then used to parameterize the Forest Vegetation Simulator (FVS), a forest growth and yield simulation model. Prior to burning, seedling density was 43% lower in invaded than uninvaded plots and the seedling size-class distribution skewed toward larger individuals, suggesting grass invasion and fire previously acted as a filter on small tree regeneration or that invasion occurred in areas with larger and fewer trees. Burning resulted in similar rates of fuel consumption among treatments, with 1-h, 10-h, and 100-h fuels decreasing an average of 23%, 42%, and 18.5% respectively. However, invaded plots exhibited lower flame lengths, shorter fire residence times, and smaller burned areas than uninvaded plots, indicating lower fire intensity. Despite experiencing lower fire intensity, invaded plots had 46% higher mortality of small trees (<3 mm stem diameter) and nearly 54% lower post-fire seedling persistence overall compared to uninvaded plots. Resprouting rate was positively related to seedling size and decreased marginally with invasion. Both a structural equation model and FVS simulations demonstrated that grass invasion had large, negative effects on seedling resprouting, regardless of fire intensity effects. Post-fire sapling persistence did not differ with invasion status. These results suggest that, while grass invasion can have varying effects on fire intensity, it consistently alters forest dynamics by reducing the resilience of tree regeneration to fire. Lengthening the time between prescribed fire applications in grass-invaded forests may be necessary to allow juvenile trees to reach an adequate size to survive burning.

The dark side of nursery photoperiod reduction on summer plantation performance of a temperate conifer: High winter mortality mediated by reduced seedling carbohydrate and nitrogen storage

Planting during summer is considered as a suitable option for forest plantations in regions with a temperate monsoon climate. However, seedlings planted early in the summer are not dormant and experience active growth, which makes them vulnerable to planting stress. The artificial reduction of the photoperiod in the nursery is used to harden seedlings of boreal and alpine tree species for summer planting. Little, however, is known about the effect of artificial reduction of photoperiod with respect to summer planting in temperate monsoon climate tree species.The objective of this study was to assess the effect of length and timing of photoperiod reduction on seedling morphology and physiology attributes in the nursery and on the field performance of Pinus tabuliformis. We applied four photoperiod treatments (6 h, 8 h, 10 h, control) in the nursery on four dates in the summer (June 23, July 3, July 13, and July 23). The nursery and field site were located near Beijing, Northern China. We measured seedling morphology and non-structural carbohydrates and nitrogen concentrations in the nursery and in the field. Additionally, we measured field mortality and plant growth for three years.The reduction of the photoperiod did not have any effect on bud set, but it reduced seedling growth and non-structural carbohydrate concentration, while increasing plant N concentration. A delay in the application of photoperiod treatments increased plant size and the proportion of seedlings that developed buds, and it decreased plant non-structural carbohydrates and nitrogen concentration. High field mortality was typically observed in the winter, and the early application of photoperiod treatments increased winter mortality but enhanced field growth. Mortality during the first winter was negatively related to plant non-structural carbohydrates and nitrogen concentrations at the beginning of the cold season. In contrast, photoperiod had no effect on outplanting mortality and a minor effect on field growth. Field growth in subsequent growing seasons was directly related to the size of the plant at the beginning of the first cold season. However, field growth during the growing season immediately after planting was negatively related to seedling size, and positively related to non-structural carbohydrates and nitrogen concentrations at planting.This study demonstrates that summer planting of container seedlings is feasible for P. tabuliformis, and there is no need to reduce the photoperiod in the nursery before outplanting. Optimizing the planting date during the summer appears to be critical for good mid-term growth and low winter mortality.

Effects of smoke water on germination, seedling vigour and growth of Sceletium tortuosum

Sceletium tortuosum (L.) N. E. Br. is a South African protected species widely utilized in traditional medicine. The plants' mesembrine-type alkaloids have immense potential in modern pharmacology as treatments for numerous medical and psychological disorders. Fresh plant material is paramount for researchers and pharmaceutical companies as it is presently the only available alkaloid source. Although S. tortuosum is a conservation concern and valuable to the pharmaceutical industry, information on germination behaviours of this species is scant. This study highlights the effects of the bio-stimulant smoke water (SW) on germination, seedling vigour and growth of Sceletium tortuosum in vitro. A standardized smoke extract was diluted to concentrations of 1:500, 1:1000, 1:1500, 1:2000, 1:2500 (v/v). Seeds were pulse-treated with SW solutions for 1, 2, 8 and 24 h. The study included positive and negative control treatments. The highest mean germination percentage and germination rate were recorded for 1:1000 SW for 24 h (83 ± 1.9%) and 1:2500 SW for 24 h (6.35 seeds germinated/day). Vigour index was highest for 1:1000 SW (24 h). Smoke water only improved seedling growth when germination occurred slowly. Although mean shoot length was optimal for 1:2500 (1 h) – 4.19 ± 0.15 mm – mean root length and seedling size were highest in the negative and positive (1 h) control treatments. This investigation showed that SW effectively improved germination and seedling vigour of S. tortuosum, however, alternatives must be investigated to optimize seedling growth when this biostimulant is applied.

Lipopeptide production by Bacillus atrophaeus strain B44 and its biocontrol efficacy against cotton rhizoctoniosis.

An assay was conducted to show the comparisons the effects of nine metal ions on antagonistic metabolites (lipopeptides, siderophores and gibberellins) by Bacillus atrophaeus strain B44 using well-diffusion assays, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis, chrome azurol S plus mannitol salt agar (CAS-MSA) tests, and reversed-phase high-performance liquid chromatography (RP-HPLC) analysis. This assay is also designed to demonstrate the biocontrol efficacy of B44 against cotton rhizoctoniosis using pot culture tests. Both the lipopeptide yield and the antimicrobial activity of B44 increase with the MnSO4, MgSO4, CaCO3, and CuSO4 treatments and either have no effect or decreased lipopeptide yield and antimicrobial activity with the FeSO4, K2HPO4, KCl, KH2PO4 and ZnSO4 treatments. The medium containing MgSO4 has no significant effect on either the lipopeptide yield or antimicrobial activity. MALDI-TOF-MS analysis shows a broad range of m/z peaks, indicating that strain B44 produces a complex mixture of iturin, surfactin, and fengycin lipopeptides. Gibberellin production by strain B44 varies greatly depending on the culture medium, and the siderophore production is not significantly affected by the culture medium. Pot tests show that lipopeptide production affects the disease control efficacy of strain B44. The biocontrol efficacy of B. atrophaeus strain B44 is related to the lipopeptide yield. Moreover, B. atrophaeus strain B44 significantly increases the size of cotton seedlings, which is related to the GA3 concentration.

Fertile Crescent crop progenitors gained a competitive advantage from large seedlings.

Cereal domestication during the transition to agriculture resulted in widespread food production, but why only certain species were domesticated remains unknown. We tested whether seedlings of crop progenitors share functional traits that could give them a competitive advantage within anthropogenic environments, including higher germination, greater seedling survival, faster growth rates, and greater competitive ability.Fifteen wild grass species from the Fertile Crescent were grown individually under controlled conditions to evaluate differences in growth between cereal crop progenitors and other wild species that were never domesticated. Differences in germination, seedling survival, and competitive ability were measured by growing a subset of these species as monocultures and mixtures.Crop progenitors had greater germination success, germinated more quickly and had greater aboveground biomass when grown in competition with other species. There was no evidence of a difference in seedling survival, but seed size was positively correlated with a number of traits, including net assimilation rates, greater germination success, and faster germination under competition. In mixtures, the positive effect of seed mass on germination success and speed of germination was even more beneficial for crop progenitors than for other wild species, suggesting greater fitness. Thus, selection for larger seeded individuals under competition may have been stronger in the crop progenitors.The strong competitive ability of Fertile Crescent cereal crop progenitors, linked to their larger seedling size, represents an important ecological difference between these species and other wild grasses in the region. It is consistent with the hypothesis that competition within plant communities surrounding human settlements, or under early cultivation, benefited progenitor species, favoring their success as crops.

The effect of transplant age on vegetable growth characteristic in a cylindrical paper pot system

This study aimed to estimate the seedling performance of cylindrical paper pot (CPP) seedlings and to determine the optimal transplanting age of CPP seedlings based on seedling vigor. The studied vegetables were cucumber, tomato, paprika, and two varieties of cabbage, and the younger seedlings were obtained by shortening their raising period by 10 and 20 days with CPP. At the same transplanting age, the size of CPP seedlings was smaller pre-transplant but increased to a similar level to the plug seedlings soon after transplanting. The growth curves of leaf area and dry weight of younger CPP seedlings exhibited a steeper rise trend. The seedling vigor indicators, relative growth rate (RGR), net assimilation rate (NAR), were significantly increased in younger CPP seedlings of all vegetables, which were 10 or 20 days younger than plug seedlings. The compactness (CP) and seedling health index (SHI) of cucumber, and the leaf area ratio (LAR) and specific leaf area (SLA) of cabbage were significantly increased when shortened by 10 and 20 days, while the CP and SHI of paprika were significantly decreased when shortened by 20 days. Our results suggest that CPP may prevent the seedlings from overstretching and can provide a wild range of transplanting age choices to produce vigorous seedlings. Further, the seedling vigor indicators were successfully used to determine the transplanting age of CPP seedlings. The optimal transplanting age of CPP seedlings of tomato, paprika, and cabbage was 10 days younger than plug seedlings, whereas cucumber transplanting age could be decreased by either 10 or 20 days.

Natural regeneration status and soil seed bank composition in IITA Forest Reserve, Ibadan, Oyo State, Nigeria

The International Institute of Tropical Agriculture (IITA) Forest Reserve is a secondary rainforest that has been protected since 1965. It serves as a refuge for many species that were once common but have declined, due to urbanisation and population pressure. The study was conducted to assess the natural regeneration status and soil seed bank composition of the Forest Reserve. Two transects of 500 m were laid out using systematic line transect sampling technique. Ten sample plots of 25 m × 25 m (625 m2) on each line transect were used to identify tree species. Subplots of 5 m × 5 m for shrub and climber species, as well as 1 m × 1 m for herb species were demarcated at the corners and centre of the main plots for identification. Quadrats (15 × 15 cm) were laid out at the corners of the plots and at the centre for soil collection at depths of 0–5 cm, 5–10 cm and 10–15 cm. The regeneration status of species was determined based on sample size of seedlings, saplings and mature trees. Floristic compositions in the Forest Reserve included 58 tree, 26 shrub, 19 climber and 6 herb species. The natural regeneration status of the Forest Reserve was good with high numbers of seedlings (465/ha; 37.05%) and saplings (431/ha; 34.34%) compared with mature trees (359/ha; 28.61%). The families observed to be most abundant in the regeneration were Malvaceae, Moraceae and Apocynaceae. A total of 21 species was recorded using the seedling emergence technique. There were 11 herbs, six climbers, one shrub and three tree species. Similarity between standing vegetation and seed bank was low (0.067). The study revealed a poor soil seed bank composition, suggesting that regeneration of woody species from the persistent seed bank would be hampered if the standing vegetation is degraded.

Estimation of Corn Emergence Date Using UAV Imagery

HighlightsUAV imagery can be used to characterize newly-emerged corn plants.Size and shape features used in a random forest model are able to predict days after emergence within a 3-day window.Diameter and area were important size features for predicting DAE for the first, second, and third week of emergence.Abstract. Assessing corn (Zea mays L.) emergence uniformity soon after planting is important for relating to grain production and making replanting decisions. Unmanned aerial vehicle (UAV) imagery has been used for determining corn densities at vegetative growth stage 2 (V2) and later, but not as a tool for quantifying emergence date. The objective of this study was to estimate days after corn emergence (DAE) using UAV imagery and a machine learning method. A field experiment was designed with four planting depths to obtain a range of corn emergence dates. UAV imagery was collected during the first, second, and third weeks after emergence. Acquisition height was approximately 5 m above ground level, which resulted in a ground sampling distance of 1.5 mm pixel-1. Seedling size and shape features derived from UAV imagery were used for DAE classification based on a random forest machine learning model. Results showed that 1-day DAE could be distinguished based on image features within the first week after initial corn emergence with a moderate overall classification accuracy of 0.49. However, for the second week and beyond, the overall classification accuracy diminished (0.20 to 0.35). When estimating DAE within a 3-day window (-1 to +1 day), the overall 3-day classification accuracies ranged from 0.54 to 0.88. Diameter, area, and the ratio of major axis length to area were important image features to predict corn DAE. Findings demonstrated that UAV imagery can detect newly-emerged corn plants and estimate their emergence date to assist in assessing emergence uniformity. Additional studies are needed for fine-tuning the image collection procedures and image feature identification to improve accuracy. Keywords: Corn emergence, Image features, Random forest, Unmanned aerial vehicle.

Knowledge Level of Farmers and the Importance of Coffee Seedling Attributes and Accessibilities in Bandung Regency, West Java, Indonesia

Bandung Regency is one of the main Arabica coffee plant development centers in West Java, especially in Pangalengan District. The problem of Arabicacoffee farming is that the seedlings used not from recommended seed gardens, which may affect coffee productivity in the future. There are several factors thatinfluence farmers in the selection of coffee seedlings, including the knowledge of farmers on the attributes of coffee seedlings, and the importance of the attributes. The purpose of this study were 1) analyzing farmers’perception on the importance of different coffee seedlings attributes; 2) analyzing farmers’ knowledge of the seedlings attributes in each coffee variety; 3) analyzing the level of suitability and gap of the attributes of Arabica coffee seedling and the position of various categories of attributes and seedling accessibility in the concept of priority. The research method used quantitative approach from 77 coffee farmers. The data was analysed using descriptive analysis, Importance Performance Analysis and Cartesian diagrams. The results show that in general all the coffee attributes and seedlings accessibility evaluated had a positive score and very important for farmers. Furthermore, the farmers’ knowledge on the attributes and seedlings accessibility was variaed. Farmers have good knowledge on seedlings size, productive age, productivity, fertilizer use efficiency, seedling price, and ease of obtaining seedling attributes. There is an unsuitability and gap between the important and knowledge level of farmers about coffee attributes and seedlings accessibility.

Efecto de la aplicación combinada de abono líquido y sólido en la producción de plantines de café (Coffea arabica) cultivado bajo condiciones de vivero en Chirinos, Cajamarca, Perú

The obtaining of vigorous plants in nursery guarantees the successful development of crops in the field. Fertilization of plants in nursery is one of the fundamental pillars in the establishment of crops that can remain for more than 15 years in the field. In this regard, the objective of this study was to determine the effect of organic fertilizers Churufer and Churubiol made in Finca Churupampas Chirinos-Cajamarca-Peru for the production of coffee seedlings (Yellow Caturra variety) from nursery. The experiment was conducted as a Randomized Complete Block Design (RCBD) with sixteen treatments, three blocks and ten plants per experimental unit. The organic fertilizers used were T1) Control without organic fertilizer, T2) Churufer (biosol), T3) Pachacushi (compost), T4) Guano Island, T5) Churubiol (biol), T6) Kapsitron (biol), T7) Huallquin-fer (biol), T8) Churufer+Churubiol, T9) Churufer+Kapsitron, T10) Churufer+Huallquin-fer, T11) Pachacushi+Churubiol, T12) Pachacushi+Kapsitron, T13) Pachacushi+Huallquin[1]fer, T14) Guano Island+Churubiol, T15) Guano Island+Kapsitron, T16) Guano Island +Huallquin-fer. After 120 days, it was verified that coffee seedlings treated with the combination of organic fertilizers Churufer+Churubiol presented the best results in Plant Height (15,64 cm), Number of Leaves (8,83), Stem Diameter (2,62 mm), Fresh Weight of Leaves (3,09 g), Fresh Weight of Stem (0,0054 g), Fresh Weight of Root (0,0100 g) and Total Fresh Weight (3,0988 g). In this way, it is concluded that the organic fertilizers elaborated in Finca Churupampas significantly improved the size and weight of coffee seedlings.

Seedling survival declines with increasing conspecific density in a common temperate tree

AbstractFeedbacks between plants and their soil microbial communities often drive negative density dependence in rare, tropical tree species, but their importance to common, temperate trees remains unclear. Additionally, whether negative density dependence is driven by natural enemies (e.g., soil pathogens) or by high densities of seedlings has rarely been assessed. Density dependence may also depend on seedling size, as smaller and/or younger seedlings may be more susceptible to mortality agents. We monitored seedlings of Quercus rubra, a common, canopy‐dominant temperate tree, to investigate how the density of neighboring adults and seedlings influenced their survival over two years. We assessed how the soil microbial community influenced seedling survival by growing seedlings in a glasshouse inoculated with soil collected from beneath conspecific and heterospecific mature trees. In the field, seedling survival was lower in areas with high densities of mature conspecifics but was unrelated to either conspecific or heterospecific seedling density. Smaller seedlings were also more sensitive than larger seedlings to neighboring adult conspecifics. In the glasshouse, seedlings grown with soil from beneath a conspecific adult had a higher mortality rate than seedlings grown with soil from beneath heterospecific adults or sterilized soil, suggesting that soil microbial communities drive the patterns of mortality in the field. These results illustrate the importance of negative density‐dependent feedbacks resulting from the soil microbial community in a common and ecologically important temperate tree species.

Evaluation of a Novel Shallow Aggregate Ebb-and-flood Culture System and Transplant Size Effects on Hydroponic Basil Yield

Ornamental bedding plant operations transitioning to leafy greens and herb production must decide whether to invest in new hydroponic equipment or modify existing culture systems for edible crops. In addition, common practices used to increase space-use and production efficiencies during bedding plant production may be modified for hydroponic leafy greens and herbs, such as purchasing large seedlings for transplant. The objective of the first experiment was to evaluate plant growth in a modified and novel shallow aggregate ebb-and-flood (SAEF) system intended for bedding plant growers with an emphasis on comparing yield across four basil (Ocimum basilicum) cultivars grown in the SAEF system to those grown using the traditional nutrient film technique (NFT) and deep water culture (DWC) hydroponic systems. The second experiment objective was to evaluate basil seedling size and the time of transplant to NFT hydroponic systems to determine effects on the final yield. ‘Genovese’ basil seedlings were grown in trays with cell counts of 32, 50, 72, 105, and 162 cells with corresponding root volumes per plant of 98.1, 50.2, 38.5, 19.6, and 16.3 cm3, respectively. Seedlings were transplanted to NFT systems at 14, 21, and 28 days after sowing and were harvested at 35 days. In the first experiment, overall basil shoot fresh and dry weights per plant were intermediate in the SAEF system (90.4 and 8.3 g) compared with the DWC (102.6 and 9.1 g) and NFT (75.8 and 6.6 g) hydroponic systems. In the second experiment, final shoot fresh and dry weight per plant increased as seedling root volume increased from 16.3 cm3 [72.8 and 5.5 g (162-cell tray)] to 98.1 cm3 [148.5 and 12.2 g (32-cell tray)]. Transplanting seedlings at later dates decreased yield across tray size and root volume treatments. Differences in yield between culture systems may have resulted from differences in nutrient supply and availability for plant uptake. Transplant of large seedling plugs to hydroponic culture was not shown to increase space-use efficiency after transplant without compromising yield, likely because root zone factors limited growth during seedling production. Further investigation into maximizing plant growth during seedling production and evaluating the effects of seedling size and transplant practices are needed to determine the potential for increasing space-use and production efficiencies.

How Does the Engineering Species Affect Forest Ecosystems? Changes in Germination and Development Rate of Non-Forest Species Under the Nests of Ardea cinerea L.

Abstract An ecosystem engineer is a species that indirectly changes the availability of resources for other organisms via physical modification of the habitat. A good example of such species is Ardea cinerea L. – a big waterbird that forms colonies up to a few hundreds of nests during the breeding season. The colonies modify the habitat in the close vicinity of the nests mainly through heavy input of organic matter (feces, dropped or regurgitated food leftovers, eggshells, dead birds, etc.), which in turn affects vegetation. In our previous study, we observed that the probability of occurrence of non-forest species under the nests was 29.5 times higher in control plots in two types of forest vegetation (oligotrophic pine forest and riparian mixed forest). Adaptation for long-distance dispersal turned out to be insignificant for the probability of species occurrence, which suggested that the diaspores of those species must have been present in the forest soil before the establishment of the grey heron colony. In the present study, we used the seedling emergence method to compare the structure of the soil seed bank in breeding sites and control plots in two forest ecosystems mentioned above. We also tested whether the increased amount of nitrates in soil had a positive effect on the rate of germination and growth of seedlings. The results have shown that some reservoir of ruderal species was indeed present in the control plots, although their amount was higher under the heronries. We have proved that the number of germinating seeds of ruderal species depends on the concentration of nitrate in the soil of the pine forest. Comparison of the dry weight of 30- and 60-day-old seedlings of Rumex acetosella (pine forest) and Betula pendula (riparian forest) from the control and breeding sites showed an increased size of seedlings coming from the breeding sites of both forest communities.

Augmenting size models forPinus strobiformisseedlings using dimensional estimates from unmanned aircraft systems

In forestry, common garden experiments traditionally require manual measurements and visual inspections. Unmanned aircraft systems (UAS) are a newer method of monitoring plants that is potentially more efficient than traditional techniques. This study had two objectives: to assess the size and mortality of Pinus strobiformis Engelm. seedlings using UAS and to predict the second-year seedling size using manual measurements from the first year and from UAS size estimates. Raised boxes containing 150 seedlings were surveyed twice, one year apart, using multispectral UAS. Seedling heights and diameters at root collar (DRC) were measured manually in both years. We found that size estimates made using a vegetation mask were suitable predictors for size, while spectral indices were not. Furthermore, we provided evidence that inclusion of UAS size estimates as predictors improves the fit of the models. Our study suggests that common variables used in forest monitoring are not necessarily best suited for seedlings. Therefore, we created a new variable, called the longitudinal area (height × DRC), which proved to be a significant predictor for both height and DRC. Finally, we demonstrate that seedling mortality can be effectively measured from remotely sensed data, which is useful for common garden and regeneration studies.