Light distribution on <i>citrus canopy</i> affects physiological parameters and fruiting pattern

Light interception by the orange tree canopy during flower bud differentiation and subsequent flowering and fruit setting has been monitored by continuous data recording from 48 silicon cells distributed in different canopy zones. Two experimental conditions have been tested: trees artificially shaded by a black nylon net cage, and non-shaded trees. Observations were made on the total radiation accumulated in the different canopy zones, and they were related to photosynthetic activity, stomatal conductance) flowering and fruiting pattern, and fruit quality. The different light distribution affected both photosyntesis and stomatal conductance: in fact, they were both drastically reduced in shaded trees, and a significant decrease was also found in both shaded and unshaded trees in relation to different canopy zones. A significant decrease of flowering and fruit setting was found from the top of the canopy to the bottom and from outside to inside, in relation to the different amount of radiant energy availability. Finally significant differences were found on fruit quality

Evaluating the impact of Hymenoscyphus fraxineus in Trentino (Alps, Northern Italy): first investigations

The spread of Hymenoscyphus fraxineus has been causing great concern regarding the survival of European ash (Fraxinus excelsior) throughout Europe since the 1990s. The disease was first recorded in Trentino (southern Alps, Italy) in 2012 and has spread throughout the mountain landscape, where ash trees are scattered in small and isolated stands in different valleys. The status of the disease was checked by monitoring the damage to natural regeneration and adult trees in 90 sites spread over the whole region. The survey confirmed the complete colonization by the pathogen of the whole investigated area, with high levels of damage to both young and adult ash trees. Regeneration (both seedlings and saplings) was observed to be affected by the fungus in 88 plots out of 90. Out of 4486 examined young European ashes, 2261 (50.4%) were affected and 789 (17.6%) were already dead. Ten of the 384 assayed flowering ashes (Fraxinus ornus) showed symptoms on branches and apical stems, similar to those observed for European ash. Isolation and molecular analysis proved the presence of the fungus on both symptomatic European and flowering ashes. The examined 386 adult trees showed different levels of damage, sometimes reaching more than 75% of the crown. Some individual trees (42) growing close to severely damaged trees appeared fully healthy, which suggests the possible existence of some resistant/tolerant individuals in the examined populations

SP513 Small Flowering Trees for Tennessee Landscapes

Small flowering trees are second only to shade trees for importance in the landscape. Flowering trees are valuable plants with colorful, showy blossoms and other unusual features that give interest and variety in the landscape. All trees flower, but large trees are valued for providing shade, even though flowers may be noticeable. Large trees establish the basic framework of the landscape and should be planted in key locations for optimal shading. Most properties need both small and large trees, which creates a more desirable landscape. Carefully select your small flowering trees to ensure they fit into the landscape. In addition to their blooms, they can screen objectionable views, provide more privacy by adding height to a fence or give interest as specimen plants. Most small residential landscapes need only a few flowering trees. They should not be scattered indiscriminately over an area, but grouped according to height and canopy forms. Avoid combining trees with extremes in canopy forms and texture. Trees are more distinctive when there is a thread of continuity between them

Karakteristik Pembungaan Dan Sistem Perkawinan Nyamplung (Calophyllum Inophyllum) Pada Hutan Tanaman Di Watusipat, Gunung Kidul

Flowering are influenced by internal factors, such as genetic and phytohormone, and environment factors, such as sunlight and nutrition intake. The flowering characteristics influence fruiting and genetic diversity seedlings through mating systems. This study aims to assess flowering and fruiting characteristics and to determine pattern of mating system of a Calophyllum inophyllum plantation at Watusipat, Gunung Kidul. Flowering and fruiting were observed at 4 locations, 3 parts of crown, and 4 main directions to know the effects of sunlight, nutrition intake and phytohormone in the flowering process. Mating system was assessed by comparing genetic diversity values between parent trees and offsprings. The values of genetic diversity were analyzed using 5 RAPD primers with 17 polymorphic loci. Analysis of variant showed that the locations, crown parts, directions and interaction between a location and direction significantly affected to differences number of flowers and fruits. Values of genetic diversity (h) of parent trees ranged between 0.1471 and 0.3056. The values increased at almost overall offsprings; it ranged between 0.2864 and 0.3750. Values of genetic distance (Da) between parent trees were high and very high (0.197 – 0.364), but the values was decreased between parent trees and their offspring, even between offspring populations. A dendrogram showed two main clusters; first cluster consisted parent trees at up edge with rare trees and second cluster consisted sub cluster parent trees at up edge; sub cluster parent trees at down middle; and sub cluster parent trees at down edge and overall offsprings. Flowering/ fruiting characteristics and pattern of mating systems of C. inophyllum were briefly discussed

Effect of paclobutrazol on growth and flowering of lychee (Litchi chinensis)

The effects of either foliar (1.00-4.00 g/L) or soil applications (0.25-1.00 g/m2 tree ground cover) of paclobutrazol, during autumn, on vegetative flushing and flowering of 3 lychee (Litchi chiriensis) cultivars (Bengal, Kwai May Pink and Tai So) were investigated over 3 years at 8 sites in subtropical southern Queensland. Cultivars at these sites varied in the level of vegetative flushing prior to panicle emergence in May-August and flowering in spring. Paclobutrazol reduced flushing and increased flowering in 5 out of 8 orchards, maintained dormancy and reduced flowering in 1 orchard, and had variable effects in 2 orchards, depending on the method of application. The maximum level of flowering in paclobutrazol treated trees occurred when the control trees bloomed moderately (40-60% of terminal branches). The responses were sometimes weak when the trees were very vigorous (<30% bloom). Paclobutrazol had no significant effect or reduced flowering of heavily blooming (70-100% bloom) trees. Paclobutrazol had only a small effect on panicle development, fruit set and fruit quality at most sites. Yield reflected the flowering response to paclobutrazol, except when yields were lowered by excessive male flowering or bird damage to the fruit

Duodichogamy and androdioecy in the Chinese Phyllanthaceae Bridelia tomentosa

Flowering plants commonly separate male and female function in time, but rarely are the two stages synchronized within and among individuals. One such temporal mating system is duodichogamy in which each plant produces two batches of male flowers that are temporally separated by a batch of female flowers, with within-individual synchrony and among-individual asynchrony to ensure mating partners. Duodichogamy is known only from a few species in four genera in unrelated families. We report on duodichogamy in the Chinese tree species Bridelia tomentosa (Phyllanthaceae), a common colonizer of disturbed habitats. In three populations monitored over 2 yr, most trees flowered in the order male → female → male, and resting periods between flowering bouts precluded selfing almost completely. Individuals flowered for several weeks, with the onset of flowering slightly asynchronous among trees. Pollination was by flies, and experimental pollen supplementation of a subset of a tree’s flowers did not increase fruit set, suggesting high levels of insect visitation and possible resource limitation. Nineteen percent of the 166 trees monitored skipped the first male phase, and another 13% skipped the female phase, remaining male in both years (and also a third year). The regular presence of pure males, if genetically fixed, would make B. tomentosa androdioecious in addition to duodichogamous. Comparison of duodichogamous taxa known so far shows that all have few ovules, fitting with the hypothesis that duodichogamy may result from male competition for access to a small supply of ovules

Breeding system and spatial isolation from congeners strongly constrain seed set in an insect-pollinated apomictic tree: Sorbus subcuneata (Rosaceae)

The article associated with this dataset is in ORE at: http://hdl.handle.net/10871/26965The datasets are the results of 1) pollen grain accumulation on stigmas. 2) Flowering phenology of individual trees as % of opened buds, with 50 percentile values of the cumulative flowering curve. 3) Location data for all trees of both species of flowering size (see article text) plus connectivity measures of maternal seed trees to all S. admonitor trees. X and y coordinates are GB OS National Grid. This data is related to the Scientific Reports paper of the same title.Whitley Wildlife Conservation Trust, Paignton Zoo Environmental ParkNER

Spatial isolation impacts pollinator visitation and reproductive success of a threatened self-incompatible Mediterranean tree

Pollination service is crucial to achieve successful plant sexual reproduction and long-term population persistence. This pollination service can be affected by plant conspecific density and also by intrinsic features of individuals related to their flowering phenology and floral display. However, studies examining intrinsic and extrinsic traits on pollinator visitation and reproductive success of Mediterranean trees with limited reproduction are still scarce. We analyzed the effects of plant isolation, flowering phenology, flower weight and tree size on flower visitation probability, flowering patch visitation probability, fruit set and crop size. To this end, we intensively monitored pollinator visitation and fruit production of 67 (in 2019) and 73 (in 2020) Pyrus bourgaeana Decne trees within a threatened Mediterranean population. Our results revealed that isolated individuals received more pollinators than those on conspecific aggregations, suggesting intraspecific competition for pollinators in dense flowering neighborhoods. However, fruit set was higher in trees close to flowering conspecifics despite having fewer visits from pollinators, suggesting pollen limitation but not pollinator limitation in spatially isolated trees. Interestingly, we found increased crop sizes in spatially isolated trees which could be related to reduced intraspecific competition for resources in low-density neighborhoods (water, nutrients) and/or to higher reproductive investment (i.e. higher flower production). Overall, our results indicated pollen but not pollinator limitation in spatially isolated trees. Under this scenario of sexual reproduction mediated by pollinators, our findings stress the relevance of individuals’ spatial distribution for self-incompatible trees exhibiting low individuals’ densitiesinfo:eu-repo/semantics/publishedVersio

Variation in Spatial Flowering Phase and Cross Pollination in the Sonoran Desert Rock Fig

The reproduction of plant species to produce seeds begins with pollination. The timing (phenology) of flowering is influenced by local environmental conditions such that neighboring plants are more likely to flower at the same time and cross-pollinate than are plants located further apart. In contrast to other flowering plants, which produce pollen and ovules simultaneously within the same flowers, wild figs (genus Ficus) produce separate male and female flowers that develop several weeks to months apart. For neighboring fig trees to cross-pollinate, they need to have flowering times that are out of phase with each other, with one tree bearing male flowers while another bears female flowers. As a result, if local environmental conditions synchronize flower production, neighboring fig trees will be less likely to cross-pollinate than trees located farther apart. We tested this prediction in the Sonoran Desert rock fig, Ficus petiolaris. Using information on flowering phenology collected from nine sites over four seasons, we calculated the probability of cross-pollination between trees as a function of the distance between them in the field. In contrast to predictions, we found significant but highly variable spatial patterns of flowering and opportunity for cross-pollination both within and across sites and seasons. An important consequence of this variation is that fig pollinators must traverse highly unpredictable distances to successfully cross-pollinate fig trees