Average Trunk Diameter Research Articles

ORCHARD EVALUATION OF CHERRY VARIETY-ROOTSTOCK ASSOCIATIONS IN THE SECOND YEAR AFTER PLANTING

The cherry is a fruit tree with economic importance, due to its nutritional proprieties, technological and commercial, in Romania finding good conditions for growth and production. The study was conducted at Research Station for Fruit Growing Constanta (RSFG Constanta), in a cherry plot planted in 2020. The objective of the study was to evaluate the orchard, in the climatic conditions of the South-East Romania of some cultivar/rootstock combinations. Ten cherry cultivars, created in Romania, or newly introduced in our country were studied, grafted on two vegetative rootstocks: IPC5 and IPC7. In the two years of the study (2021-2022), observations were made on growth vigor, tree height and on the number of anticipated shoots for each combination studied cultivar/rootstock. In terms of growth vigor, the highest average trunk diameter was recorded for the Daria/IPC7 30.56 mm. The highest average length of shoots was noted in the cherry cultivars Cociuvas and Daria grafted on the rootstock IPC7, which were 129 cm and 118 cm, respectively.

Effect of Rootstock on Vineyard Establishment Using Green-Growing Benchgrafts

Demand for vine plant material has increased drastically due to the ongoing expansion of viticulture, and recent widespread replanting efforts. Nurseries and growers are turning to green-grafted vines to meet demand. Unfortunately, most vineyard establishment studies have centered around dormant benchgrafted vines. Thus, little is known regarding the specific establishment trends of green-growing benchgrafts. This study aimed to explore the role rootstock selection has in green-growing benchgraft establishment and development over the first four years post-planting. Vitis vinifera L. cv. Sauvignon blanc was grafted onto multiple rootstocks of varying parentage, including ‘101-14MGT’ (V. riparia × V. rupestris), ‘1103P’ (V. berlandieri × V. rupestris), ‘110R’ (V. berlandieri × V. rupestris), ‘420A MGT’ (V. berlandieri × V. riparia), and ‘Teleki 5C’ (V. berlandieri × V. riparia). The experimental site was organized using a completely randomized design (n = 12) with all vines managed to industry-standard cultural practices. Vines grafted onto 1103P had the largest average trunk diameter (p = 0.0012) and circumference (p < 0.0001) at 22.2 mm and 7.57 cm, respectively. Vines grafted onto 110R had the second-largest trunk circumference at 6.65 cm. Vines grafted onto 110R had the largest concentration of total non-structural carbohydrates at planting at 1.47 g/L, followed by 1103P at 1.25 g/L (p < 0.0001). Total non-structural carbohydrate concentrations in the trunk during dormancy was the highest in 110R at 16.0% total dry weight (p = 0.0008). The larger trunk size and more extensive carbohydrate reserves suggest that green-growing benchgrafts using 110R or 1103P have a higher capacity and likelihood of establishment success.

Плантационное выращивание Pinus sibirica Du Tour в среднетаежной зоне Республики Коми

In order to create a valuable gene pool of cedar pines in the conditions of the Komi Republic, rootstock crops of Siberian pine (Pinus sibirica Du Tour) were planted on the territory of laboratory training center of the Syktyvkar Forest Institute. The plants were collected from different areas of the Komi Republic and the Arkhangelsk region for adjustment to the local, northwestern climate. The paper presents the results of the variational analysis of morphological parameters and growth dynamics in P. sibirica cultures. Height, trunk diameter, and crown diameter were chosen as the morphometric criteria. The variability of the studied traits ranged from 18.8 to 93.1 %. The average height of the plants was 72.2±3.9 cm, the average trunk diameter was 2.0±0.1 cm. The most changeable characteristic was the diameter of the crown of the plants, which ranged between 11 and 148 cm with Сv of 30.6–93.1 %. The plants of Yarensk origin were the most developed according to the examined morphometric criteria. The average growth of P. sibirica plants in height within the age group of 9–11 years over three years was 13.5±0.9 cm. The lowest growth rate was registered in plants of the Sysola group (1 cm), whereas plants of Yarensk origin had the highest growth rate (38 cm). Throughout the research period, plants of all groups had a consistent rise in overall height. However, this trait variability was reduced only in the group of plants of Yarensk origin. The maximum variability in all three traits was observed in plants of Syktyvkar origin with Сv of 39.7–93.1 %. In general, high variability in the development of Siberian pines over three years across all experimental groups was detected. The investigation results can be applied for further research on the development and inheritance of economically valuable traits and decorative characteristics of P. sibirica in the conditions of the middle taiga subzone of the Komi Repub lic. For citation: Parshina E.I., Dymova O.V., Titov E.V. Plantation Cultivation of Pinus sibirica Du Tour in the Middle Taiga Subzone of the Komi Republic. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 3, pp. 195–204. (In Russ.). https://doi.org/10.37482/0536-1036-2023-3-195-204

РОСТ ПОЛУСИБСОВЫХ ПОТОМСТВ СОСНЫ ОБЫКНОВЕННОЙ В ИСПЫТАТЕЛЬНЫХ КУЛЬТУРАХ СЕВЕРНОГО КАЗАХСТАНА

The article discusses the main taxation indicators of half-sibs at the age of 36 years. The total viability of all families is 51.5%, the average height is 17.04 ± 0.13 m, and average trunk diameter at a height of 1.3 m is 19.97 ± 0.21 cm. A high negative correlation (r = -0.68) was found with respect to the trunk diameter and viability indicators. It was found that the height growth of half-sibs is influenced by genotype by 30.6%, and the diameter growth - by 15.6%. A significant increase in height compared to the control was observed in 40.7% of families, while a minor increase in trunk diameter was noted in a small portion of families - 5.6%. The selective height improvement effect amounted to 8.8%, and for trunk diameter, it was 13.5%. It was determined that the offspring of plus trees obtained in the same year with free pollination in a natural plantation and a collection plot (clone of a plus tree) had both low and high overall combining ability, depending on the pollinator. Based on the results obtained, it is concluded that it is impractical to separate families from the same plus tree depending on the origin when assessing their growth.

Исследования потомства плюсовых деревьев Pinus sylvestris L. в испытательных культурах первой генерации

The article describes the characteristics of the seed progeny of plus trees Pinus sylvestris L. at the age of 37, he was born in the Akmola region of Northern Kazakhstan. The purpose of the study is to carry out a preliminary selection and genetic assessment of the plus pine trees based on the results of testing their semi-plus offspring of the first generation. The safety of test cultures is 57.5%. The research covered 73 families of half-sibs, the total sample was 5,553 trees. It was found that in terms of height, more than half of the families (56.2%) had an excess over the control. However, only 28.8% of families were significantly higher than the control, the breeding effect of which was within 6.0%. The average trunk diameter of these families exceeded the control by 3.9%. Of these families, less than a quarter (23.8%) significantly exceeded the control value by 14.9%. As a result, 5 families (1k, 13k, 42, 38, 3k) were classified as the most productive. When assessing the sanitary condition of half-siblings, 2 families (51k and 16k) were classified as weakened, and the remaining families were classified as healthy. When assessing qualitative characteristics, clustering was carried out, with the help of which the studied families were divided into 3 main groups. The weakened families were united into a separate cluster. According to the results of score assessments, the trees of these families had poor trunk quality and weak stability. The second and third clusters are formed from families with high average grades and good condition. However, the families of the third cluster, according to the results of ball scores, are the most stable, differ in greater straightness and dense bifurcation. It was found that according to the results of a comprehensive selection and genetic assessment of the offspring of P. sylvestris plus trees of the first generation, 6.9% of families (1k, 13k, 42, 38, 3k) were classified as promising.

Taxation characteristics and life state of Quercus robur l. in various forest conditions in the Tunnel beam (Dnipro city)

Influence of forest conditions on the taxation characteristics and the vital state of Quercus robur L. was analyzed. The plants were planted on artificial plantations laid in a tunnel beam in the city of Dnipro in 1961. The experimental plots was located in thalweg (mesohygrophilic conditions – L3) and on the slope of the northern exposure (mesoxerophilic conditions – L1). The 301 specimen of Q. robur L. trees grow on the slope (SG1), and 357 specimen in the thalweg beam was found. The oak trees of three morphological races were planted in tunnel beam: Q. r. pectinata Schneid, Q. r. longiloba Lash, Q. r. Laciniata Schneid. The Q. r. pectinata Schneid are dominate: in the thalweg – 82.70 % (SG3), on the slope (SG1) – 78.60 %. It was found, that in talweg the plants have a larger average height and average trunk diameter. In mesohygrophilic conditions more plants are assigned to the last two classes of height (16.1–18.0 and 18.1–20.0 m), than in mesoxerophilic. The tallest trees grows in thalweg. There are 22 m heigh, and on the slope – 19.5 m. In accordance with calculations, the average height of trees in thalweg is 16 m; on the slope it is 14 m, diameter 42 cm and 32 cm, respectively. Most of the trees in the the experimental plots are in the category of vitality state: healthy tree. There are more such trees in mesohygrophilic conditions than in mesoxerophilic ones (76.40 and 63.90 %, respectively). Weakened trees on the slope of the beam are 32.70 on the slope of the beam, and in the thalweg 17.40 %. The vital status index of oak plantations on the slope is 88.0 %, and in the talwez – 91.0 %. There is no fresh dead wood and dead wood of previous years on the experimental plots. The indeх of the vitality state of the planting in mesohygrophilic conditions is higher, than in mesoxerophilic conditions. Favorable conditions of water supply conduced to the better growth of branches shoots and leaves on them. Tree pathologies are more common on the slope of the beam in mesoxerophilic growth conditions. The analysis of oak trees damage shown, that the largest part falls on the dry top of slope. There are no fungus cup and tumors on the trunks, only one tree with excrescence was found. Such trunk pathologies as inclination, curvature, multi-stemmeds and dryness of thick skeletal branches was revealed. There were much less of trunk pathologies in mesoxerophilic conditions.

Physiological mechanisms underlying extreme longevity in mountain pine trees.

Ancient trees are life history longevity winners that mostly persist in remote and environmentally harsh mountainous areas. Here, we performed a multifeature analysis in a protected mature mountain pine (Pinus uncinata) forest to identify the morphological and physiological traits that make these trees unique. We compared the physiology of meristematic and somatic tissues (apical buds and needles, respectively) from juvenile, mature young, mature old, and mature ancient trees under cold stress and nonstress conditions. We successfully identified key morphological features of extreme longevity at the organism level, as well as various growth, vigor, stress, and dormancy markers underlying extreme longevity in old and ancient trees. Results indicated that evolution has exerted selective pressure on specific physiological traits that make trees become longevity winners (<0.1% of the tree population were ancient trees, with an average trunk diameter >100 cm and an estimated age of 700 years). Traits entailing longevity not only included apical dominance loss, epicormic growth, and modular senescence, but also an extreme plasticity in both meristematic and somatic tissues (buds and needles, respectively), as shown by various physiological markers. In conclusion, ancient trees are oddities that not only possess a unique ecological value but also show divergent physiological behaviors selected during their evolution to allow them to cope with adversities and attain long life.

THE EFFECT OF ECOLOGICAL FACTORS ON GROWTH OF Sterculia foetida L. IN BUON DON AND EA SUP DISTRICTS, DAK LAK PROVINCE

Accurate and reliable assessment of site suitability for the growth of selected plant species is critical for afforestation projects and programs to improve rural livelihoods. This research examines the relationship between growth of Sterculia foetida L. and six ecological factors in Buon Don and Ea Sup districts, Dak Lak Province. The purpose of the research is to predict the growth in average height and trunk diameter of the trees using ecological factors that are easy to measure and observe. These include topography (slope) and soil characteristics (clay ratio, depth of soil layer, surface and subsurface rock concentrations, and agglomeration ratio). The ecological factors were evaluated by multivariable regression analysis of growth data from 31 experimental plots, 16 in Buon Don district and 15 in Ea Sup district. The results show that four of the six factors affect average growth in tree height and that five factors affect average trunk diameter growth. The findings are of practical value for households and agricultural extension officers to consider before planting Sterculia foetida L. in the two areas.

Inventory of Dryobalanops aromatica Gaertn. in Lae Kombih Forest Park Area, Subulussalam

Dryobalanops aromatica Gaertn. is a plant that grows in the tropical rain forests of western Indonesia which is categorized as a valuable timber tree. Dryobalanops aromatica Gaertn is a plant that is categorized as a valuable timber tree. Dryobalanops aromatica Gaertn also known as the camphor tree, lime or Sumatran camphor, this tree can grow to a height of 60 m with an average trunk diameter of 9 m. Camphor tree is a plant species belonging to the Dipterocarpaceae family which has several advantages because its tree trunk can produce a variety of high economic value commodities such as camphor, balsamic acid, resin, essential oil, beams, poles, roof construction and boards in residential buildings. The method used for the inventory of rare plants is done by using the method of vegetation analysis, the parameters in this study were the type, number, diameter and height of the Dryobalanops aromatica Gaertn. tree. Vegetation analysis was carried out by plotting 13 plots, each sample plot measuring 20 m x 20 m. The sample used is a total sample using a random sampling system method, the sampling chossen by exploring the area of the Tahura Lae Kombih area where the Dryobalanops aromatica Gaertn is located. The results shows that the plant species were found starting from the seedling, sapling, pole and tree levels. The most dominant species in this area is Dryobalanops aromatica Gaertn that has Important Value Indeks of seedling 163%, Sapling 270%, Pole 283% and Tree 216%.

Стокорегулирующая способность лесных полос в связи с их таксационными характеристиками

Purpose: to investigate the flow-regulating role of forest belts in connection with their taxation characteristics. Methods: artificial sprinkling of soils under the forest belts canopy. Results. Pseudoacacia robinia prevails in the forest belts in Rostov region (basin of the Kundryuchya river, ordinary chernozems). By the age of 35, this species can reach an average height of 12 m, an average diameter of 12 cm. Regression equations for the relationship of the runoff coefficients with the average height of Robinia pseudoacacia and its average diameter, wood reserves of forest belts and cross-sectional areas of trunks were obtained. These taxation characteristics determine the precipitation absorption intensity through the tree waste bulk and forest flor, root saturation, water-physical and chemical properties of the topsoil, which change with the age of plantings. When the age of 20 years is exceeded, the forest belts will completely absorb high intensity rainfall. At this age, the Robinia pseudoacacia will exceed the average height of 9.4 m, and its average trunk diameter will approach 10 cm. At the same time, the stock of raw wood in the forest belt will reach 57 m³/ha, and the cross-sectional area of the trunks – 11 m²/ha. The functional relationship between soil erosion and runoff coefficients confirms the close relationship between soil erosion and the main taxation characteristics of forest belts. The analysis of these relationships showed that storm erosion of soil under the forest canopy is completely absent when the taxation indicators reach the following values: the average Robinia height is 9 m, the average trunk diameter is 9.2 cm, the stock of wood is 46 m³/ha, the cross-sectional area of the trunks is 10.2 m²/ha. Conclusions. By the age of the forest belts 20 years, the runoff under the forest canopy will be completely regulated, and there will be no soil erosion. Forest belts older 20 years need to enhance their flow-regulating capacity by combining them along the lower edge with the simplest hydraulic structures.

Species diversity and aesthetic characteristics of the plantings of the settlement park (urban-type settlement Ilarionove)

Dendroflora of the park of the urban-type settlement Ilarionove consists of 438 exemplars of trees, mainly deciduous, which belong to 32 species. The most abundant species is Robinia pseudoacacia, the representativity of which is 25% in relation to the total number of trees in the garden and park object. Acer platanoides and Acer negundo (11.19 and 10.05%) are represented in significant quantities and Aesculus hippocastunum is represented in sufficient quantities. The families are represented mainly by 1–2 species, with the exception of Aceraceae, Salicaceae and Ulmaceae, which included 4, 4, and 3 species, respectively. The decorative trees that are blooming amount to 52,25 % of all plants in the park. The biodiversity index is 11,74, which is quite high compared to other parks in the Dnipropetrovsk region. 71.65% of all trees in the park are introduced species, whose homeland is mainly North America. Trees in the park grow mainly in rows (Acer platanoides, Aesculus hippocastunum and Gleditschia triacanthos) and some in groups as hedgerows (Spiraea vanhouttei). As to the stem diameter, the most numerous are groups with relevant indicator value of 14,1–18,0; 32,1– 38,0 and 38,1–42,0 – 12,56; 12,32 and 12,32 % relative to the number of all trees in the park. The average trunk diameter is 27 cm. The height of about half of the trees ranges from 8,1 to 12,0 m – 52.09 % of the total number of exemplars. As for the vitality, 51,37 % of park trees are without signs of damage, moderately weakened trees amount to 35,39%, no dead-standing trees have been detected. According to the requirements for productive capacity of soil, the available assortment of woody plants in the park corresponds to the soil conditions of the territory, but only partially to the moisture regime. In terms of aesthetic value, the phytocenosis of the park is classified as class II.

Performance of Different Apple Cultivars in a Young High Density Orchard

Abstract The aim of the study was to evaluate the suitability of rootstock and cultivar combinations for high density orchards in northern climate conditions like in Latvia. In 2009, a trial was established with rootstocks M.9 and B.396 in combination with seven cultivars. The density of trees reached 2500 trees per 1 ha. The yields and the observed yield efficiency of all cultivars during the first four production years were larger on rootstock B.396. Also, average trunk diameter was slightly larger on this rootstock. On both rootstocks cultivars, ‘Gita’ and ‘Ligol’ had larger part of total yield formed on previous year shoots. These cultivars had more vigorous trunks as well. In the orchard at the given density, on both rootstocks thinner trunks and smaller yields were observed for cultivars with poor branching, like ‘White Transparent’ and ‘Konfetnoye’. ‘Rubin’ (Kazakh cv.) had low yield, this cultivar produces very large fruits on the ends of shoots. Lower average yields were also obtained for cultivars that produce fruits on spurs of older branch sections, like ‘Antei’ and ‘Kovalenkovskoye’. Summer cultivar ‘Konfetnoye’ had relatively smaller fruits. Rootstock B.396 and scab resistant cultivar ‘Gita’ showed best performance in the high density orchard.

Sample size for estimating average trunk diameter and plant height in eucalyptus hybrids

ABSTRACT: In eucalyptus crops, it is important to determine the number of plants that need to be evaluated for a reliable inference of growth. The aim of this study was to determine the sample size needed to estimate average trunk diameter at breast height and plant height of inter-specific eucalyptus hybrids. In 6,694 plants of twelve inter-specific hybrids it was evaluated trunk diameter at breast height at three (DBH3) and seven years (DBH7) and tree height at seven years (H7) of age. The statistics: minimum, maximum, mean, variance, standard deviation, standard error, and coefficient of variation were calculated. The hypothesis of variance homogeneity was tested. The sample size was determined by re sampling with replacement of 10,000 re samples. There was an increase in the sample size from DBH3 to H7 and DBH7. A sample size of 16, 59 and 31 plants is adequate to estimate DBH3, DBH7 and H7 means, respectively, of inter-specific hybrids of eucalyptus, with amplitude of confidence interval of 95% equal to 20% of the estimated mean.

Modeling the Multifrequency Emission of Broadleaf Forests and Their Components

This paper shows a model study about the emissivity of forests. Model outputs are compared with multifrequency airborne measurements carried out over five broadleaf forests in Italy. Two flights took place, in summer 1999 and winter 2002. Available ground truth included important variables, such as biomass, tree density, and average trunk diameter. This data set, in conjunction with allometric equations and information taken from the literature, is used to give inputs to the model. A general agreement between simulated and measured data is observed at L-, C-, and X-bands. The same model is used to investigate the sensitivity of forest emissivity to soil moisture, woody volume, and average diameter. As expected, a moderate effect of soil moisture is observed only at L-band and for forests with a lower woody volume. At L-band, the model predicts a general increase of emissivity with woody volume but indicates that also the trunk diameter exerts an important influence, since it is a variable which controls several geometrical properties. These results allow us to single out the influence of soil moisture, woody volume, and geometrical properties at L-band. The increase of emissivity with frequency, observed in experimental data, is interpreted by means of electromagnetic considerations about branch scattering.

High frequency direct plant regeneration from leaf, internode, and root segments of Eastern Cottonwood (Populus deltoides)

Simple, reproducible, high frequency, improved plant regeneration protocol in Eastern Cottonwood (Populus deltoides) clones, WIMCO199 and L34, has been reported. Initially, aseptic cultures established from axillary buds of nodal segments from mature plus trees on MS liquid medium supplemented with 0.25 mg l−1 KIN and 0.25 mg l−1 IAA. Nodal and internodal segments were found to be extra-prolific over shoot apices during course of aseptic culture establishment, while 0.25 mg l−1 KIN concentration played a stimulatory role in high frequency plant regeneration. Diverse explants, such as various leaf segments, internodes, and roots from in vitro raised cultures, were employed. Direct plant regeneration was at high frequency of 92% in internodes, 88% in leaf segments, and 43% in root segments. This led to the formation of multiple shoot clusters on established culture media with rapid proliferation rates. Many-fold enhanced shoot elongation and growth of the clusters could be achieved on liquid MS medium supplemented with borosilicate glass beads, which offer physical support for proliferating shoots leading to faster growth in comparison to semi-solid agar or direct liquid medium. SEM examination of initial cultures confirmed direct plant regeneration events without intervening calli. In vitro regenerated plants induced roots on half-strength MS medium with 0.15 mg l−1 IAA. Rooted 5- to 6-week-old in vitro regenerated plants were transferred into a transgenic greenhouse in pots containing 1:1 mixture of vermicompost and soil at 27 ± 2°C for hardening and acclimatization. 14- to 15-week-old well-established hardened plants were transplanted to the field and grown to maturity. The mature in vitro raised poplar trees exhibited a high survival rate of 85%; 4-year-old healthy trees attained an average height of 8 m and an average trunk diameter of 25 cm and have performed well under field conditions. The regeneration protocol presented here will be very useful for undertaking genetic manipulation, providing a value addition to Eastern Cottonwood propagation in future.

Evaluation of Poplar Trees Irrigated with Livestock Lagoon Wastewater

Research conducted at Kansas State University evaluated the growth and nutrient utilization characteristics of poplar trees irrigated with livestock lagoon wastewater from May 2004 through June 2006. Poplar trees (eastern cottonwood; Populus deltoides Bartr. Ex Marsh.) were planted as dormant rooted cuttings on 19 May 2004 in a system of twelve lysimeter cells with three trees per cell. Irrigation treatments included lagoon water (LG), a blend of 50% lagoon and 50% freshwater (BL), and freshwater (FR). The lysimeters contained a silty loam soil with very low nutrient content at the start of the study, and the only nutrient applications the trees received was through the wastewater. Beginning in July 2004, weekly irrigation applications of 25 mm of the appropriate water treatment were applied to each lysimeter cell using a drip irrigation system. In order to accommodate different tree growth and water requirements in the second and third growing seasons, irrigation applications were scheduled using tensiometers at various depths. In 2005, trees showed signs of decline due to soil salinity build up in the BL and LG treatments. Freshwater leaching events and limited lagoon water applications were then scheduled for those treatments for the remainder of the study. The poplar trees showed a positive growth response to lagoon water applications. At the end of the study (June 2006), the LG treatment trees had an average height of 362 cm and trunk diameter of 65 mm, while the FR trees were significantly smaller with an average height of 281 cm and an average trunk diameter of 34 mm. Furthermore, the lagoon treatments (BL and LG) resulted in three to five times as much leaf biomass and three to four times as much woody biomass as the FR treatment. In general, soil levels of NO3-N, NH4-N, P2O5, and EC were elevated in the lagoon water treatments. Leaf tissue %N was also higher from trees that received lagoon water. Trees receiving lagoon water irrigation also required more irrigation water than the trees receiving only freshwater irrigation.

Mapping QTLs for Resistance to Frosty Pod and Black Pod Diseases and Horticultural Traits in Theobroma cacao L.

A heterozygous F1 mapping population of cacao (Theobroma cacao L.) was created and evaluated for resistance to frosty pod [caused by Moniliophthora roreri (Cif. and Par.) Evans et al.], and black pod [caused by Phytophthora palmivora (Butl.) Butl.] and for five horticultural traits at CATIE in Turrialba, Costa Rica. The population consisted of 256 F1 progeny from the cross ‘Pound 7’ × ‘UF 273’. Progeny were used to form a linkage map using 180 markers. The linkage map contained 10 linkage groups (LGs), numbered as the LG in the cacao reference map, and was used to locate putative quantitative trait loci (QTL) for resistance to the aforementioned diseases and five horticultural traits. Resistance to frosty pod was measured by internal and external pod resistance. Five QTLs for frosty pod resistance were found on three LGs, 2, 7, and 8, with UF 273 appearing to be the source of resistance. These alleles are being used for scoring progeny in ongoing cooperative marker‐assisted selection projects, and constitute the first QTLs identified for frosty pod resistance. Three QTLs for black pod resistance were found on LG 4, 8, and 10, with the most favorable alleles coming from Pound 7. One QTL was found on LG 4 for average trunk growth rate, and two QTLs for height of first jorquette were identified on LGs 4 and 6. One QTL each for average trunk diameter growth and pod color was found on LG 4.

A comparison of conventional and alternative understory management practices for apple production: multi-trophic effects

Modification of the soil for agricultural production is commonly studied as it relates to plant health and productivity, but the implications at other trophic levels are often over-looked. This study addressed the effects of orchard understory management at several trophic levels to understand potential impacts on the whole system. The soil in a newly planted Golden Delicious apple ( Malus domestica Bork.) orchard was modified with four treatments: (1) mulch layer of composted poultry manure, (2) mulch layer of synthetic fiber, (3) conventional herbicide, and (4) hand-weeded control. These treatments were evaluated for their impact on edaphic and arboreal arthropods, substrate microclimate and weed growth, and apple tree vigor during the first year of growth (1998). Understory treatment affected edaphic arthropods at three trophic levels: detritivore, herbivore, and predator. Compost mulch significantly increased both edaphic detritivores and predators. Edaphic herbivores were less abundant in plots treated with synthetic mulch. No effect was found for arboreal herbivores, but aphidophagous Aphidoletes aphidimyza (Cecidomyiidae) larvae were more abundant on trees in compost-treated plots. Host-plant growth and leaf quality (% N) were also affected by soil management, with a higher average trunk diameter and lower average leaf nitrogen (%) in compost-treated plots, despite equivalent N-input in all four treatments. Both mulches (compost and synthetic) resulted in lower soil temperatures and higher soil moistures and suppressed weed growth 10-fold better than either conventional herbicide or hand weeding. The results indicate that soil modification affects organisms at several trophic levels, and therefore, could hold important implications for the orchard ecosystem as a whole. Overall, mulching with composted manure benefited the whole orchard system the most and was superior to conventional herbicide as an understory management practice.

Apple, Evaluation on Ntn-33893 as a Trunk Application, 1993

Abstract Experimental sprays were applied to single-tree plots in a randomized block design consisting of 10 replicates. Test trees were 2 years old and spaced 3.7 × 5.5 m apart on M.26 EMLA rootstock. The average trunk diameter of trees 46 cm above the ground was 3 cm. Treatments for all plots were applied with a paint brush to the trunk in a 20-40 cm band beginning below the main scaffold limbs on 14 Apr. All plots received a regular fungicide maintenance schedule of captan 50WP and Nova 40WP, The effect of treatments on WALH was evaluated by counting nymphs/25 injured leaves/tree for the first generation and nymphs/50 randomly selected leaves for the second generation. Effectiveness on SA was evaluated by counting aphid-infested leaves/5 growing shoots, and aphids/most infested leaf. Effectiveness of the test chemicals on ERM, AF and ZM was evaluated by counting these mites during the season on samples of 25 random leaves/ tree, 250 leaves/treatment. STLM were counted at the end of both 1st and 2nd generation by examining 4 one year old shoots and determining the number of tissue feeding mines per leaf.

Growth Rings, Age and Taxonomy of Dacrydium (Podocarpaceae) in Fiji

The anatomy of growth rings in Dacrydium (Podocarpaceae) from Fiji is described. Fungal staining may mask the heartwood growth rings and generally prevents observation of rings on either roughly cut logs or sanded sections with the naked eye. Earlywood is formed during the wet season and coincides with a peak of leaf and shoot growth. Radiocarbon dating of three trees indicates that growth rings have an approximately annual frequency. The average trunk diameter growth rate is estimated as 2.6 mm year-1. Life expectancy of established trees is estimated as 49 year. It is suggested that the endemic species D. nausoriense de Laub. may be an ecotype of D. nidulum de Laub. adapted to the drier climate of north-west Viti Levu.