Root Collar Diameter Research Articles

Adaptation of Cedro-Vermelha, Tarumã-Azeitona, Ingá-Doce, Branquilho-Bravo and Ocotea-Guaicá Seedlings to Shading Levels

Abstract As native tree species are often used for densification, enrichment and degraded areas recovery, a better understanding of the behavior of their seedlings in response to light exposure is needed. This study evaluates the growth and morphological behavior of five native forest species of the Brazilian Mixed Ombrophilous Forest under shading levels of 90%, 50%, and 0%. The species were measured for height to root collar diameter (RCD) ratio (H:D), leaf area (LA), Dickson’s quality index (DQI), and stem, leaf, and root biomass. The LA did not differ among the treatments for three species and did not differ among species in full sun. The results for H:D ratio, DQI, and biomass indicate better growth in treatments with greater light availability. The species are recommended to be used as follows: Cedro-vermelha in full sun; Taruma-azeitona, Inga-doce, and Ocotea-guaica in varying environmental conditions; and Branquilho-bravo in 50% shade and full sun conditions.

Growth Performance Assessment of <i>Chamaecyparis obtusa</i> Stand in Gyeongnam Province, S. Korea

Growth causes in trees to change in volume (size) and shape or form. These changes can be positive or negative and it is the result of different factors either biotic or a biotic. A stand or individual trees have characteristic growth patterns and understanding the sources of change or factors that are influencing the growth is crucial for the productivity of forests. In this study the growth performance of <i>Chamaecyparis obtusa</i> (<i>C. obtusa</i>) was studied to assess the growth condition of young stand in the Gyeongnam province since the time of plantation. Historical tree growth was measured using standard forest growth evaluation (height and root collar diameter measurement) techniques to analyze increment from individual trees at seventy two sites in eight cities and counties. The relationship between soil properties, climate, altitude and aspect with tree growth was evaluated. The results of the study showed variation of growth pattern for the same species of similar age categories at different sites and the combined effects of climate, soil properties, altitude, aspect and management are the strongest drivers of changes in the growth. It was recommended to consider the above factors for further expansion of plantation of the species and apply periodic silvicultural treatments to the stands in order to facilitate the growth and wood quality.

Growth and carbon storage of black saxaul in afforested areas of the Aralkum Desert

This study aimed to determine the growth and carbon storage of planted Haloxylon aphyllum in the Aralkum Desert in Kazakhstan. Six sites afforested in 2000, 2005, 2009, 2010, 2013, and 2017 were selected. The root collar diameter (cm) and height (m) were measured for all H. aphyllum in 30 m×44 m plots. Biomass accumulation (g m-2) and carbon storage (C g m-2) were calculated using allometric equations and the carbon concentration data of Haloxylon species. The diameters varied from 2.5 cm to 4.3 cm and the height varied from 106.2 cm to 223.7 cm. The growth of H. aphyllum was not linearly related to the afforestation year or soil properties. Tree growth might have been influenced by variations in the microclimate, such as temperature, precipitation, and dust storms. The mean total biomass accumulation was 20.57 g m-2 and ranged from 2.42 g m-2 to 64.53 g m-2. The mean carbon storage was 9.70 C g m-2 and ranged from 1.12 C g m-2 to 30.61 C g m-2. These biomass and carbon storage estimates were smaller than those reported for other Central Asian deserts, but afforestation enabled the generation of vegetative cover and consequently, carbon sequestration in the manmade Aralkum Desert.

Acorn size influence on the quality of pedunculate oak (Quercus robur L.) one-year old seedlings

Pedunculate oak (Quercus robur L.) is one of the most important deciduous tree species in the Serbian and European forests. Different negative factors limit natural regeneration of pedunculate oak forests, so producing of high quality seedlings becomes imperative to ensure successful forest restoration. This research was conducted with to aim to determine whether acorn size is related to seedlings quality. Acorns were collected from the natural pedunculate oak forest and divided into two groups by their size. Acorns were sown in the spring into plastic containers after five months cold storage. Size of acorns was in the standard species range, though germination was low (&lt; 20 %). Germination was more then double in group of large acorns in comparison to group of smaller acorns (19.2 %, respectively 8.6 %). Height and root collar diameter of produced seedlings were lower than seedlings produced in seedbeds in commercial nurseries in Serbia, but it was in range of container produced seedlings in some similar researches. Height to root collar diameter ratio and shoot to root ratio were considered as satisfactory for containerized seedlings. There was not strong correlation between acorn size and seedlings quality attributes.

Determination of seedling quality characteristics of stone pine (Pinus pinea L.), valonia oak (Quercus ithaburensis Decne. subsp. macrolepis (Kotschy) Hedge &amp; Yalt.) and Turkey oak (Quercus cerris L.) seedlings

Bu çalışmada, İzmir/Torbalı orman fidanlığında yetiştirilen fıstıkçamı (Pinus pinea L.), palamut meşesi (Quercus ithaburensis Decne subsp. macrolepis (Kotschy) Hedge & Yalt.) ve saçlı meşe (Quercus cerris L.) fidanlarının fidan kalite özellikleri belirlenmiştir. Bu amaçla, rastgele seçilen 2+0 yaşlı, 12x22.5 cm ebatlı polietilen torbalarda yetiştirilen fıstıkçamı, palamut meşesi ve saçlı meşe fidanları temin edilmiştir. Her bir türün, fidan boyu (cm), kök boğazı çapı (mm), gövde ve kök taze ağırlığı (g), gövde ve kök kuru ağırlığı ölçülmüştür. Ayrıca fidan boyu/kök boğazı çapı oranı, gövde/kök kuru ağırlık oranı, Dickson kalite indeksi hesaplanmıştır. Fıstıkçamının ortalama fidan boyu 21.02 (cm), kök boğazı çapı 5.4 (mm), fidan boyu/kök boğazı çapı oranı 39.11, gövde/kök kuru ağırlık oranı 1.05, Dickson kalite indeksi 0.15 bulunmuştur. Palamut meşesinin ortalama fidan boyu 20.6 (cm), kök boğazı çapı 5.8 (mm), fidan boyu/kök boğazı çapı oranı 36.84, gövde/kök kuru ağırlık oranı 0.41, Dickson kalite indeksi 015 bulunmuştur. Saçlı meşenin ortalama fidan boyu 9.85 (cm), kök boğazı çapı 4.3 (mm), fidan boyu/kök boğazı çapı oranı 23.79, gövde/kök kuru ağırlık oranı 0.19, Dickson kalite indeksi 0.2 bulunmuştur. Fidanların kalite sınıfları Türk Standartları Enstitüsü (TSE)’nün “iğne yapraklı ağaç fidanları” (TS 2265, 1988) ve “yapraklı orman ağacı fidanları” (TS 5624, 1988) standartlarına göre değerlendirilmiştir. TS 2265 iğne yapraklı ağaç fidanı standardında belirtilen fidan boyu, çap ve gövde/kök kuru ağırlık oranı kriterleri birlikte değerlendirildiğinde fıstıkçamı fidanlarının % 97.06’sı I. sınıf, % 2.94’ü II. sınıfta yer almıştır. Yapraklı orman ağacı fidan standardında belirtilen en az boy ve kök boğazı çapı nitelikleri birlikte değerlendirildiğinde; palamut meşesi fidanlarının % 97.06’sı standart altı, % 2.94’ü II. sınıf bulunmuştur. Bu standart da belirtilen en az boy ve kök boğazı çapı nitelikleri birlikte değerlendirildiğinde; saçlı meşesi fidanlarının boyları standartta belirtilen boy değerlerinin altında kaldığı için standart altı olarak değerlendirilmiştir. Ayrıca ağaç türlerinin kuraklığa karşı dayanıklılığı ve zarar durumlarının görsel tespiti yapılmıştır. Bu sınıflandırmaya göre; saçlı meşe iyi, fıstıkçamı ve palamut meşesi zayıf sınıfta yer almıştır.

Effects of some nitrogen-fixing plants on seedling growth of scotch

Nitrogen is one of the most important nutrients for plants, and some plants are involved in the conversion of atmospheric nitrogen to organic form. These plants are capable of nitrogen fixing by bacteria in their roots and are important in alleviating nitrogen deficiency and improving soil. The objective of this research is to determine the growth differences in Scotch pine (Pinus sylvestris L.) seedlings grown together with some nitrogen-fixing species. The study was conducted in The Research and Application Greenhouse at Faculty of Forestry, Karadeniz Technical University. Alnus glutinosa, Robinia pseudoacacia and Vicia sativa were selected as nitrogen-fixing species. Seeds were sown, by different sowing combinations, in special sowing crates in November. For 1-year-old scotch pine seedlings after the first growing period, seedling length, root collar diameter and sturdiness quotient were determined. The results indicated that while the average length of Pinus sylvestris seedlings sown alone was 3.36 cm, the average length of the seedlings belonging to Pinus sylvestris+Vicia sativa combination reached 6.84 cm. Similarly, mean root collar diameter was 0.47 mm greater in the Pinus sylvestris+Vicia sativa sowing combination. The use of higher quality seedlings obtained through sowing combination of Pinus sylvestris+Vicia sativa can be advantageous in areas where there is a ground cover problem or the use of quality seedlings is required because of extreme conditions in terms of altitude, climate and soil.

THE EFFECT OF DIFFERENT HARVEST DATES ON THE YIELD AND QUALITY OF THE GOLDEN THISTLE (Scolymus hispanicus L.)

The objective of this study was to determine the yield and quality characteristics of golden thistle (Scolymus hispanicus L.) harvested at different maturity stages. The trial was arranged in the Randomised Complete Block Design under the ecological conditions of Izmir, Turkey in 2017 and 2018 growing seasons and the plants were harvested from November to August at 10 monthly periods. Root lenght (cm), root yield (kg ha-1), root bark yield (kg ha-1), dry root bark yield (kg ha-1), root collar diameter (mm), root xylem diameter (mm), cortex thickness (mm), taraxasterol rate (%) taraxasterol acetate rate (%) were determined. The highest root and root cortex yields were obtained from the plants harvested in july, the average of two years as 19770.64 kg ha-1 and 6480.65 kg ha-1, respectively. The highest taraxasterol and taraxasterol acetate rates were obtained in May harvest as 0.042% and 0.015% in two years respectively.

Fire Survival of Longleaf Pine (Pinus palustris) Grass Stage Seedlings: The Role of Seedling Size, Root Collar Position, and Resprouting

Longleaf pine (Pinus palustris Mill.) forest is a well-known fire-dependent ecosystem. The historical dominance of longleaf pine in the southeast United States has been attributed to its adaptation known as the grass stage, which allows longleaf pine seedlings to survive under a frequent surface fire regime. However, factors affecting post-fire survival of grass stage seedlings are not well understood. In this study, we measured live and dead longleaf pine grass stage seedlings to quantify the role of seedling size, root collar position, and sprouting in seedling survival following a wildfire in the sandhills of South Carolina. We found that fire resulted in almost 50% mortality for longleaf pine grass stage seedlings. Fire survival rate increased with seedling size, but a size threshold for fire tolerance was not supported. Fire survival depended on the position of root collar relative to the mineral soil. Seedlings with protected root collars (i.e., buried in or at the level of mineral soil) experienced &lt;21%, while seedlings with exposed root collars (i.e., elevated above mineral soil) suffered &gt;90% post-fire mortality. Ability to resprout contributed to 45.6% of the total fire survival, with the small seedlings (root collar diameter (RCD) &lt; 7.6 mm) almost exclusively depending on resprouting. Our findings had significant implications for fire management in longleaf pine ecosystems, and the current frequency of prescribed fire in sandhills might need to be lengthened to facilitate longleaf pine natural regeneration.

Variation in seed and seedling traits of &lt;i&gt;Faidherbia albida&lt;/i&gt; (DEL.) A. Chev populations in the Sudano-Sahelian zone of Cameroon

The once sustainable agroforestry system in the Sudano-Sahelian zone of Cameroon has been abandoned and trees overexploited. A study on the variability in seed and seedling traits of Faidherbia albida (DEL.) A. Chev populations from different climatic zones was carried out. Six populations were selected from Sudanian (Poli, Garoua III, and Figuil) and Sahelian (Yagoua, Moulvoudaye and Maroua I) climatic zones and harvested seeds were transported to the experimental farm of IRAD Yagoua for pretreatment and growth experiment. Four pretreatments (98% sulfuric acid, hot water, scarification and soaking in water for 24 hours) were used to initiate the germination. After one month, the rate of germination (%) was recorded and seedlings were transplanted in three substrates for seedling growth evaluation. Growth traits (Survival, plant height, root collar diameter, number of leaves, root length, plant fresh weight and plant dry weight) were measured after three months. The experimental design was a single tree plot randomized complete block design with 30 blocks. Results indicated there was significant difference (p = 0.002) among pre-treatments for the germination. The highest rate of germination was recorded with seedlings from scarified seeds (78.33%), followed by those from seeds treated with sulfuric acid (76.67%). Seeds and seedling traits were significant among populations with Yagoua recording the highest in most of the traits measured. Scarification can assist in seed germination and movement of seeds between populations and climatic zones should be considered during conservation programs.© 2019 International Formulae Group. All rights reserved.Keywords: Faidherbia albida, agroforestry parklands, seed pretreatments, seedling traits, conservation, Sudano-Sahelian, Cameroon

The use of nitrogen fertilisation for suppressing Mycosphaerella in Eucalyptus dunnii

Mycosphaerella leaf disease (MLD) is a pathogen of eucalypt plantations causing leaf spots and defoliation, and affecting growth. In this study, two different dosages of nitrogen fertilisation together with a control treatment currently used for two clones being affected by MLD (C18 and C25) of Eucalyptus dunnii were tested. We measured root collar diameter (D) and height (H), and assessed disease severity in the apical, middle and basal portions of the crown at planting, three months after planting and five months after planting, and determined the Area Under Disease Curve Progress at the end of the study, for the following fertilisation treatments: reduced dosage 22.0 kg ha−1 of NH4NO3; control dosage 44.0 kg ha−1 of NH4NO3; and increased dosage 66.0 kg ha−1 of NH4NO3. We added 133.4 kg ha−1 of P2O5 and 28.0 kg ha−1 of KCl to each treatment. MLD severity was higher in the basal portion of the crown. Only for C18 did the control dosage and the increased dosage promote growth in root collar diameter and reduce MLD severity, respectively. For C25 there were no differences for the variables across the fertilisation treatments. For C18 correlation analysis indicated that increased nitrogen dosage reduced MLD severity (r = 0.83; p < 0.01). In conclusion, improved nitrogen fertilisation proved to be effective to reduce severity, but differences were observed between clones and fertilisation.

Polímero hidrorretentor e fertilização mineral na implantação de híbrido de &lt;i&gt;Eucalyptus urophylla&lt;/i&gt; x &lt;i&gt;Eucalyptus grandis&lt;/i&gt;

O uso de polímeros hidrorretentores surge como uma alternativa para disponibilizar água de forma adequada na fase de implantação de povoamentos florestais, além de reter nutrientes necessários para o estabelecimento e desenvolvimento destes. No presente trabalho, objetivou-se avaliar o efeito do polímero hidrorretentor e a influência de diferentes doses de fertilização mineral no crescimento, teor e acúmulo de nutrientes do híbrido clonal de Eucalyptus urophylla x Eucalyptus grandis, na fase de implantação. O experimento foi realizado em delineamento de blocos casualizados completos, em esquema fatorial 2 x 5, sendo duas doses do polímero (0 e 1 g planta-1) e cinco combinações de fertilização mineral (N0P0K0, N0P1K0, N1P0K1, N1P1K1 e N2P2K2, correspondendo à dose de N (N0 = 0, N1 = 62 e N2 = 124 g do fertilizante por planta), P (P0 = 0, P1 = 75 e P2 = 150 g do fertilizante por planta) e K (K0 = 0, K1 = 62 e K2 = 124 g do fertilizante planta)), em três repetições com cinco plantas por parcela. As avaliações foram realizadas aos 30, 60, 120 e 150 dias pós-plantio, quando foram mensurados a altura total e o diâmetro do colo, além da análise química nutricional, aos 150 dias. A partir dos dados obtidos, observou-se que não houve interação entre o efeito do polímero e doses de fertilização mineral. Para o diâmetro do colo, o uso do polímero proporcionou maior crescimento às mudas somente nos 30 primeiros dias de avaliação, e para altura houve maior crescimento nas avaliações aos 30, 60 e 120 dias de plantio. Os tratamentos contendo fósforo (18% de P2O5) obtiveram maior incremento em diâmetro em relação aos demais nos primeiros 60 dias pós-plantio. Nas outras avaliações, a maior dose de fertilizante (N2P2K2) foi responsável pelo maior crescimento em diâmetro e altura. A maior dose de fertilização mineral promoveu maior acúmulo de NPK na parte aérea das plantas (caule, ramos e folhas). Portanto, o polímero proporcionou maior crescimento às mudas na fase inicial de desenvolvimento, e o fósforo se mostrou essencial para o crescimento em diâmetro e altura na fase de implantação do híbrido utilizado.

Growth Tendency of Quercus robur L. Provenances in Bosnia and Herzegovina Provenance Test with Relation to Fixation Index

Aim of study: Specific genetic structure of the remaining populations of pedunculate oak (Quercus robur L.) in Bosnia and Herzegovina makes them significant for the preservation of the diversity of this species in Bosnia and Herzegovina and Europe. For this reason, we established provenance test in 2009. The aim of the study is to determine the correlation between provenance growth and fixation index. The ultimate goal is the reintroduction of the species in suitable areas. Material and method: The research included measuring the height and the root collar diameter of four-, six- and eight-year-old plants in the provenance test and molecular analyses using isoenzymes. Main results: Variance analysis showed statistically significant differences between populations in all tested characteristics, which was confirmed by the Duncan test. Provenances of Miljevina Foča, Stojčevac, and Visoko Muhašinovići are at the bottom of the list with the lowest growth of four-, six-, and eight-year-old plants. Provenances of Drvar, Mutnica Cazin, Kaćuni, and Jelah showed the best growth. Highlights: Eight provenances showed positive fixation index values, particularly Miljevina Foča, Bosanska Dubica, and Drvar. Positive fixation index value of Miljevina provenance matches its low growth, while this is not the case in Drvar and Bosanska Dubica provenances.

Phytohormone effect on seedling quality in Hungarian oak

Aim of study: to find out the effects of four phytohormones, including Indole Butyric Acid (IBA), Indole Acetic Acid (IAA), and Gibberellic acids (GA3, GA4) on seedling growth of Hungarian oak which has a natural distribution in the northwestern of Turkey.Area of Study: Mature acorns of Hungarian oak were collected from a natural stand in Zonguldak-Ereğli at northwestern region of Turkey.Material and Methods: Collected acorns of the species were pretreated with 300 ppm of each phytohormone for 24 hours and sown in Yenihan State Forest Nursery of Bartin, Turkey. Two years old bare-root seedlings were used for the measurements of seedling height, root collar diameter, stem, root and seedling fresh weights, and stem, root and seedling dry weights of two bare-root seedlings for each phytohormone treatment.Main results: Best performance of all studied seedling traits with the exception of root collar diameter was revealed in seedlings with IBA. In contrast, treatment of seeds with GA3 reduced all seedling traits apart from seedling height and root collar diameter. According to Dickson quality index, IBA was displayed to be the most beneficial phytohormone application for generating Hungarian oak seedlings with better mechanical resistance during transplanting.Research Highlights: IBA should be adopted in planting the seedlings of Hungarian oak for plantation activities.Keywords: Field performance; Morphology; Phytohormone, Quality; Quercus frainetto.Abbreviations used: Dickson quality index (DQI), gibberellic acid (GA), indole acetic acid (IAA), indole butyric acid (IBA), root collar diameter (RCD), root dry weight (RDW), root fresh weigh (RFW), seedling dry weight (SEDW), seedling fresh weight (SEFW), seedling height (SH), Statistical Package for the Social Sciences (SPSS), stem dry weight (STDW), stem fresh weight (STFW).

РОЛЬ КАЧЕСТВА ЛЕСНОГО РЕПРОДУКТИВНОГО МАТЕРИАЛА ПРИ ЛЕСОВОССТАНОВЛЕНИИ

More than two billion hectares worldwide offer opportunities for restoration. The need to accelerate reforestation programmesis caused by global climate change and human impacts. There is no consensus in the scientific community as to what goals to pursue in the implementation of programs and what methods to use to achieve the goals. Confusing terminology in the field of world reforestation, conflicting research makes it necessary to establish the basic quality criteria. The impact of the quality of forest reproductive material on reforestation cannot be underestimated. Definition of forest reproduction material (FRM) quality should be project specific, because seed and seedling quality attributes targeted and desirable for one site, could be unsuitable for others. Seed size and germinability have the strongest effect on plant performance, both in nursery and on the field. Root collar diameter is the single most useful seedling morphological attribute. The most important quality attributes of seed and seedling can be improved by simple techniques and practices. In a long term, the genetic aspect of FRM quality have a decisive role and any restoration program should be based on proper seed source to site matching, with maintaining the wide genetic diversity. In any restoration program, imperative should be the use of FRM with targeted quality attributes: physical, morphological, physiological, and genetic. Meeting demands for huge quantities of FRM, should not be at the cost of quality.

Early growth performance of mycorrhizae inoculated Taurus Cedar (Cedrus libani A. Rich.) seedlings in a nursery experiment conducted in inland part of Turkey

Survival rate of seedlings planted in arid and semi-arid land parts of Turkey is low. New methods and techniques are needed to increase survival rate and growth performance of seedlings used in afforestation practices in the region. The aim of this study is to evaluate the growth performance of Taurus cedar (Cedrus libani A. Rich) seedlings receiving different mycorrhizae inoculation treatments. The experiment was conducted in the western part of Central Anatolia. Two commercial mycorrhizal cocktails were used for treatments in a completely randomized design experiment. Both ecto- and arbuscular mycorrhizal fungi were observed in the same root system of the seedlings after the mycorrhizal inoculation. But the relationship between ecto- and arbuscular mycorrhiza was antagonistic. Analysis of the data indicated that mycorrhizal colonization was effective on seedlings' morphological characteristics. The significant differences were detected for root collar diameter, shoot height, root length, specific needle area, shoot dry weight, root dry weight, shoot fresh weight, root fresh weight, shoot to root dry weight ratio, and Dickson quality index of seedling received different treatments. Mycorrhizae positively affected plant nutrition by increasing uptake of nutrients.

Evaluasi Kesintasan dan Pertumbuhan Beberapa Jenis Pohon Lokal di Area Restorasi Cagar Biosfer Cibodas

One of the threats faced with Cibodas Biosphere Reserve area is the changes of forest area into plantation. Various efforts were made by Gunung Gede Pangrango National Park (TNGP) management to restore the area to its original function. One of the efforts is planting trees in the ex-plantation area that has been abandoned by the farmers. In 2016, Cibodas Botanics Garden was collaborated with TNGP to plant native trees species that had potency of high carbon sequestration. Six hundreds seedlings from 12 native trees species were planted ie, Altingia excelsa Noronha , Castanopsis argentea (Blume) A.DC ., Castanopsis javanica (Blume) A.DC. , Castanopsis tunggurut (Blume) A.DC , Dacrycarpus imbricatus (Blume) de Laub. , Euonymus indicus B. Heyne ex Wall ., Lithocarpus indutus (Blume) Rehder , Magnolia blumei Prantl, Persea rimosa Zoll. ex Meisn ., Syzygium acuminatissimum (Blume) DC., Sloanea sigun (Blume) K. Schum ., and Schima wallichii Choisy . The observations of evaluation done by January, February and July 2016. Parameters were observed are plant height, root collar diameter and crown width. Then, the data were analyzed by RGR (Relative Growth Rate) and RPI (Relative Performance Index). The results of observation during six months after planting shown that the average survival rate was 60.56%, with the largest survival rates were Altingia excelsa and Castanopsis javanica (80%). Castanopsis tunggurut was the lowest survival rate than the other plants (33,33%). The best growth rate is shown by Schima wallichii. In this case, obstructed plant growth is caused by the high density of weeds and shrubs so that seedlings are less exposed to sunlight and nutritional deficiencies, and also the damage that caused by humans, especially for Castanopsis tunggurut and Sloanea sigun.

Soil Solarization and Calcium Cyanamide Affect Plant Vigor, Yield, Nutritional Traits, and Nutraceutical Compounds of Strawberry Grown in a Protected Cultivation System

Soil solarization is a hydrothermal procedure of disinfesting soil of soilborne diseases and pests. Solarization can be combined with many other chemical or non-chemical alternatives to afford integrated pest and diseases management or improve plant yield. Calcium cyanamide (CaCN2) is a fertilizer used in agriculture sector and is also effective in suppressing soilborne pathogens. The present study assessed the influences of different pre-plant CaCN2 dosages on strawberry grown on solarized or non-solarized soil. Soil solarization and 500 kg ha−1 CaCN2 significantly increased early marketable yield by 105.3%, total marketable yield by 53.0% and firmness by 3.0%, respectively compared with the control (no solarization × 0 kg ha−1 of CaCN2). Exposing solarized plots to CaCN2 at 1000 kg ha−1 significantly increased fruit ascorbic acid content by 77.5% and phenolic content by 13.3% compared with fruits from control plants. Overall, plants grown on solarized soil performed better than those cultivated on no-solarized plots. Plants grown on soil treated with a dosage of 500 or 1000 kg ha−1 CaCN2 increased plant height, number of shoots plant−1, number of leaves plant−1, root collar diameter, plant visual quality, anthocyanins, and antioxidant capacity compared to control plants. Fruits from plants grown on soil exposed to CaCN2 with a dosage of 500 and 1000 kg ha−1 showed a lower N fruit content (5.4 and 19.5%, respectively) than control plants (non-treated control).

Growth and quality of Brazilian pine tree seedlings as affected by container type and volume

Abstract Araucaria angustifolia (Bert.) O. Kuntze (Araucariaceae), commonly known as araucaria and Brazilian pine tree, can be grown for their edible pine nuts (pinhões), medicinal properties, and ornamental purposes. The aim was to assess the shoot and root growth and the overall quality of A. angustifolia seedlings grown in containers with different sizes, shapes and composition. Seeds were sowed in five containers: I – 126cm3 polypropylene cone-tainers (small cone-tainers); II – 290cm3 cone-tainers (large cone-tainers); III – 879cm3 polyethylene black bags; IV- 275 cm3 nonwoven fabric (TNT) containers (small TNT container) and; 493 cm3 nonwoven fabric (TNT) containers (large TNT container). Seedlings were evaluated 210 days after sowing, regarding the following variables: aboveground height (cm), root collar diameter (mm), shoot dry mass (g), roots dry mass (g), total dry mass (g), leaf area (cm2), roots area (cm2), roots volume (cm3), sturdiness quotient, root-shoot ratio and Dickson quality index. Height was superior for seedlings grown in the plastic bags (27.6 cm) and the large TNT containers (27.02 cm) when compared to the small and large cone-tainers (21.75 and 21.78 cm, respectively). Plastic bags also presented greater values of root-collar diameter, shoots, roots and total biomass and Dickson Quality index. Small and large TNT containers promoted lower root area and volume when compared to large polyethylene cone-tainers, but allowed for the same or better aboveground growth. Taking all results analyzed together, the polyethylene black bag promoted better growth and quality of Brazilian pine tree seedlings in comparison to the other containers.

Effect of Different Moisture Harvesting Techniques on Seedling Survivals and Growth of Trees in Degraded Lands of Southern Tigray

Tree planting on degraded lands play a key role in forest rehabilitation processes through afforestation and/or reforestation. Moisture harvesting structures (MHSs) has significant impact on seedling survivals at degraded lands. The objectives of this study were to investigate the impact of water harvesting techniques on seedling survival and growth performance of trees. Field experiments were conducted for two rainy seasons in southern Tigray, Atsela watershed. The experimental design followed was the split plot design. The MHSs as main plot used were eye-brow basins (EBs), micro trench (MTs), improved pit (IPs) and as control normal pit (NPs). The tree species grown as subplots were Eucalyptus camaldulensis, Grevillea robusta, Olea europaea and Cupressus lusitanica. The four tree species were planted by using seedlings. The tree survival rate, height, crown width (CW) and root collar diameter (RCD) of the four tree species were measured every six months after transplanting. The result shows that MHSs were significant in tree seedling height, CW and RCD but not in tree survival rate. Tree seedling height and CW grown in EBs were significantly higher than those grown in MTs, IPs and NP (P≤0.05). RCD of tree seedling was higher when grown in EBs than NP (control) (P≤0.05). The interaction of tree species seedlings and MHSs shows that those seedlings grown on MHSs were significantly thicker, taller and more survived than those grown on the NPs (control) (P≤0.05). So based on the experiments, it is concluded that MHSs particularly the eyebrow basin was considered as the most appropriate planting pit. Therefore, further demonstration of eyebrow basin tree planting should be carried out.

Use of Time-of-Flight Ultrasound to Measure Wave Speed in Poplar Seedlings

In this study, 145 poplar (Populus × euramericana cv.’74/76’) seedlings, a common plantation tree species in China, were selected and their ultrasonic velocities were measured at four timepoints during the first growth year. After that, 60 poplar seedlings were randomly selected and cut down to determine their acoustic velocity, using the acoustic resonance method. The effects of influencing factors such as wood green density, microfibril angle, growth days, and root-collar diameter on acoustic speed in seedlings and the relationship between ultrasonic speed and acoustic resonance speed were investigated and analyzed in this work. The number of specimens used for investigating growth days and root-collar diameter was 145 in both cases, while 60 and two specimens were used for investigating wood density and the microfibril angle, respectively. The results of this study showed that the ultrasonic speed of poplar seedlings significantly and linearly increased with growth days, within 209 growing days. The ultrasonic velocity of poplar seedlings has a high and positive correlation with growth days, and the correlation was 0.99. However, no significant relationship was found between the ultrasonic velocity and root-collar diameter of poplar seedlings. Furthermore, a low and negative relationship was found between wood density and ultrasonic speed (R2 = 0.26). However, ultrasonic velocity significantly decreased with increasing microfibril angle (MFA) in two seedlings, and thus MFA may have an impact on ultrasonic speed in poplar seedlings. In addition, ultrasonic velocity was found to have a strong correlation with acoustic resonance velocity (R2 = 0.81) and a good correlation, R2 = 0.75, was also found between the dynamic moduli of elasticity from ultrasonic and acoustic resonance tests. The results of this study indicate that the ultrasonic technique can possibly be used to measure the ultrasound speed of young seedlings, and thus early screen seedlings for their stiffness properties in the future.