Climatic conditions have changed within the cloud forests of southern Mexico, but the effects of these changes on tree phenology are not well understood. Our study aimed to determine relationships between seasonal patterns of flowering and fruiting and the annual and long-term changes in temperature and rainfall in El Triunfo Biosphere Reserve, Mexico. Flowering and ripe fruiting intensity and fruit number were recorded for 158 trees of 21 zoochorous species during 17 months in 2019–2021. Circular statistics, synchronization calculations, and generalized linear mixed models were used to determine phenological patterns and relationships between phenophases and temperature, rainfall, and solar radiation. Flowering was most closely associated (negatively) with rainfall, whereas ripe fruiting was positively associated with solar radiation. We compared recent fruiting seasonality with phenological data collected in 1991–1993. The mean date of community fruiting in 2019–2020 was earlier (April 4) than in 1992 (May 1) and 1993 (May 13). Community fruit number in 2020–2021 decreased in comparison to 2019–2020. Our results suggest that decadal trends of increasing minimum daily temperature and an earlier and wetter wet season influenced the timing of community fruiting phenology, and fruit numbers varied greatly between years, possibly impacting resource availability for frugivores in El Triunfo.

Introduction. Diverse fruit crops with a high value reduce the risk of crop failure and offer alternatives to farmers and the market. The scope of profitable production with such quality crops along with environmental concerns make the evaluation of new species desirable. The aim of our study was to determine the most appropriate species of Physalis for small-scale commercial production in the temperate climate of western Himalayan regions. Materials and methods. Four Physalis species, viz., P. peruviana, P. ixocarpa, P. pruinosa and P. nicandroides, were field-grown during 2010–2011 in the experimental field of the Central Institute of Temperate Horticulture, Srinagar, India, to determine the most appropriate species of Physalis suitable for a temperate climate. Results and discussion. All the species tested produced vegetative growth, flowered and fruited; however, they differed significantly. The number of basal shoots was found to be maximum for P. pruinosa (6.37), whereas the maximum number of prickles per shoot was recorded as maximum for P. nicandroides (6.48). The number of points of attachment varied significantly with species, and the maximum was recorded for P. pruinosa and P. ixocarpa (7.16 for each); the maximum size of fully developed leaves (146.8 mm) and overall plant height (168.27 cm) were recorded for P. pruinosa. Physalis pruinosa and P. ixocarpa were found to exhibit vigorous growth under a temperate climate. Significant differences were recorded for fruiting, flowering and yield potential among the Physalis species. The minimum days taken for bud burst were reported for P. nicandroides (23.55) and P. ixocarpa (24.41). Similarly, the minimum days taken to reach maturity were reported for P. peruviana (64.96). The maximum number of fruits per plant (260.23), length of fruit (33.83 mm), average fruit weight (37.19 g), husk weight (0.32 g), fruit husk ratio (121.27), maximum fruit firmness (43.96 Relative Index) and yield (9.96 Relative Index) were recorded for P. pruinosa. Significant variation was recorded in quality attributes. The highest total soluble solids were found for P. nicandroides (8.46 °Brix), whereas the minimum total titrable acidity (0.35%) and maximum ascorbic content (38.41 mg·100 g–1) were recorded for P. peruviana. The ‘L’ value of fruits, showing brightness, was recorded as the highest for P. peruviana (58.97), whereas fruits of all the species showed a negative ‘a’ value, indicating that none of them produced redness; however, the ‘b’ value, indicating yellowness, was maximum for P. pruinosa (18.72).

Introduction. There has been increasing interest in the domestication potential of indigenous fruit trees. Nevertheless, our understanding of how these species’ abundance and yield of fruit is altered by ecological conditions, which is critical to foresee realistic sustainable management plans, is limited. Materials and methods. We used local ecological knowledge, presence / absence data and quantitative methods to examine the effect of ecological conditions on the distribution, abundance and yields of tamarind trees (T. indica) across three ecological regions in Benin, West Africa. Results and discussion. Rural communities’ knowledge on the species’ ecological range was congruent with scientific findings. The natural distribution of tamarind individuals was limited to the Sudanian and the Sudano-Guinean regions and their density declined with increasing moisture, being highest (2 trees·km-2) in the Sudanian region and lowest in the Guineo-Congolian region (scarce). On the other hand, fruit and pulp mass and number of seeds per fruit varied significantly, being higher in the Guineo-Congolian wetter region. However, no significant variation occurred among ecological regions for estimated overall fruit yields per tree. This might indicate that tamarind trees tend to invest in a small number of very large fruits under wetter conditions and a very large number of small fruits under dryer conditions. Conclusion. The results showed that semi-arid lands would best suit T. indica domestication. Nevertheless, its productivity could be higher under wetter conditions. Because of its affinity for gallery forests, we recommend thorough studies on its capacity to survive the increasing drought in its current ecological range.

(1) During 1978–1981, marked individuals of 107 species of treelets and shrubs in three forest types between 1300–1650 m elevation at Monteverde, Costa Rica, were monitored at monthly intervals for behaviour of leafing, flowering, and fruiting.

(2) Although there was not a pronounced seasonal pattern of leafing activity, more species produced new leaves in the dry season. Species that flush large quantities of new leaves do so more commonly in the drier months. Leaf loss was gradual and unobtrusive in species observed.

(3) Flowering activity was greatest in the late dry season and early wet season. Most species exhibited extended flowering; only 15% of the species were massively flowering. Massive flowerers showed less seasonality than extended flowerers.

(4) Of the species studied, the majority had relatively unspecialized flowers which were visited by a variety of insects; small bee-pollination was the next most common, followed by hummingbird, beetle, settling moth, sphingid, butterfly, large bee and fly pollination (the pollination system of 18 species was unknown). Hummingbird pollinated species showed little seasonality of flowering when compared with species exhibiting small moth, and beetle pollination syndromes, as well as those with unspecialized flowers.

(5) The vast majority of species studied have fleshy fruits (sarcochores). Fruiting activity was less markedly seasonal than flowering. Species with fruit are more numerous in the second half of the year (the wet season and early dry season). The second year of the study saw substantially fewer species in fruit than the first year; this is attributed to the greater than usual rainfall and inclement weather during the peak flowering season.

(6) Cloud forest shrub and treelet phenology is compared with patterns of other forests that have been studied. In general, the greater the rainfall, the less seasonality of flowering and fruiting is seen. Although Monteverde is very wet, rainfall is intermediate between that of lowland dry and lowland wet forest in Costa Rica. Seasonality of flowering and fruiting at Monteverde is more pronounced than at La Selva (wet) and less obvious than in Guanacaste (dry).

The importance of figs as keystone resources depends partly on their year-round fruiting pattern. However, most non-equatorial fig species show seasonality in reproductive phenology. If fig and other species' fruiting peaks coincide, the importance of figs as key resources during lean fruiting periods may be reduced. Fig and other forest tree phenology was studied in a deciduous and an evergreen site in the Western Ghats, southern India, from January 1991 to May 1992. In the deciduous site, most non-fig flowering and leaf flushing occurred during the two dry seasons, while most fruiting occurred during the dry and early wet seasons. In the evergreen site, all non-fig tree phenological stages – flowering, fruiting and leaf flushing – were concentrated during the two dry seasons annually (dry and post-monsoon). Individual fig trees produced crops one to three times annually, at different times of the year for different trees. Fig community fruiting peaks in the evergreen site coincided with fruiting peaks of the other forest trees, but in the deciduous site occurred slightly offset from non-fig fruiting peaks. The role of figs as key resources is likely to differ among forests, and to depend on factors such as diversity of fruiting pattern among fig species, fig tree density and territoriality of frugivores.

Fruit production by an understorey tree, Miconia centrodesma, was monitored in treefall gaps and under intact canopy in a Costa Rican lowland rain forest. Trees in gaps displayed much less seasonality in fruit production than trees of intact forest sites. For example, ripe fruits were common on gap trees for a six month period (January-June) when few or no trees under intact canopy were in fruit. The frequent and aseasonal fruiting of gap trees demonstrates that they are not constrained by phenological cueing mechanisms; the influence of such cues is overridden by habitat. Trees in gaps also produced larger crops, had more extended fruiting episodes, and fruited more frequently than shaded conspecifics. This level of intraspecific variation in fruiting behaviour suggests that treefall gaps play an important role in determining the reproductive success of M. centrodesma. A substantial proportion of an individual's lifetime seed output may be produced during the brief period it occupies a gap. In addition, the large and continuous supply of fruits produced in gaps by M. centrodesma and other understorey plants, may mean that gaps function as ‘keystone habitats’ by providing resident frugivores with fruit during periods of general fruit scarcity.

The demographic history of a flower-cohort of the tropical tree Dicymbe altsonii (Caesalpiniaceae) was studied by collecting litter from flowers, fruits and seeds, and by monitoring seedling survival. Flower production was estimated at 137 to 172 m−2 in a plot of 1 ha. Four percent of the flowers yielded a pod, which contained an average of 2.0 seeds. Post-dispersal mortality over 3 mo was 39% of the initial number of dispersed seeds. Most flowers and fruits were aborted. Insect and vertebrate predation in the tree and on the ground was very low. Reproductive litter production of this species was estimated to be equal to leaf litter production. The amount of phosphorus lost in litter from fruits and flowers was much larger than in leaf litter. This implies that the impact of the biennial flowering events on the nutrient dynamics of the trees and of the ecosystem may be large. It is argued that the reproductive cycle and the pre-dispersal demography of Dicymbe seem to be determined by a scarcity of nutrient resources, and possibly by pollinator limitation.

Hong Kong is on the northern edge of the tropics and near the boundary of the Paleotropical and Holarctic floral kingdoms. The phenological states of 105 plant species in secondary shrubland were recorded weekly for three years. Community patterns of reproductive phenology are highly seasonal and vary little between years. There is a flowering maximum in May and a fruiting maximum in December/January. The winter fruiting peak coincides with diet switching by resident omnivorous birds and the arrival of partially frugivorous migrants from the Eastern Palearctic. However, wind-dispersed species also have a fruiting maximum at the same time, suggesting that fruiting in winter has other advantages.

The 71 ha Bukit Timah Nature Reserve contains the largest surviving area of primary rain forest in Singapore. The recorded vascular plant flora of the forest consists of at least 854 species: 787 angiosperms in 109 families, 65 pteridophytes and three gymnosperms. 58.6% of the species are trees or shrubs, 18.7% climbers, 12.3% terrestrial herbs, 8.8% epiphytes and hemi-epiphytes, 1.0% saprophytes and 0.6% parasites. The four families with most species -Rubiaceae, Euphorbiaceae, Orchidaceae and Moraceae - account for a quarter of the angio-sperm flora but contribute few large trees. Community reproductive phenology is charac-terized by supra-annual bursts of general flowering and fruiting, contrasting with a low back-ground level. After an exceptionally dry and sunny February, 1987, more than 150 species in 42 families flowered between late March and late May, followed by an equally well-defined fruiting peak 13 weeks later, between late June and late August.

The general flowering of lowland dipterocarp forests of South-east Asia is a unique phenomenon that occurs intermittently, sometimes many years apart, and may be widespread throughout the region or sporadic. During a general flowering a very large number of tree families, including the well-known Dipterocarpaceae, flower and fruit exceptionally heavily. The huge pulse of flowering is echoed by an apparent explosion in the number of pollinators, and this is further augmented by migration of pollinators from the forest fringes. The huge demand for pollinators seems to be solved among several dipterocarps through utilization of tiny, fast breeding, floral-feeding insects such as thrips and hoppers. Competition for pollinators is further reduced through development of sequential flowering among several groups of trees that share similar pollinators. The resulting massive general fruiting seems to contribute to a heightened level of faunal activity and numbers. This long-intervalled flowering and fruiting phenology which dominates these lowland dipterocarp forests may have partly contributed to the lowered animal biomass frequently alluded to when these forests are compared with neotropical forests.

During a 4-y study of the palm Oenocarpus bataua, 368 reproductive structures on 102 palms were monitored. A reproductive structure required nearly 2 y for successful completion, from bud to ripe fruit. We found correlations with summed rainfall and averaged relative humidity and/or solar radiation for initiation of bud appearance, flowering and fruit maturation over 0–4 mo prior to the events, and another set of correlations over longer periods up to 11–12 mo before. Climatic variables showing short-term correlations (apparently triggering an event) often differed from those showing long-term correlations (which presumably initiated developmental processes culminating in the event itself). A high degree of asynchrony occurred in production of reproductive structures both within and between individual palms even within major reproductive peaks, and there were pronounced differences between individuals in total reproductive effort. Nearly all palms passed 1–3 y with little or no reproduction despite similar environmental conditions between years. We conclude that the supra-annual cycle of this palm is not the result of inadequate environmental cues in some years. There appear to be at least two different types of supra-annual cycles in tropical plants, differing in the relative importance of extrinsic cues vs. intrinsic physiological rhythms and in intrapopulation synchrony.

Introduction. Le karité a une fructification aléatoire. L’objectif de notre étude a été de tester la technique d’incision annulaire comme outil de contrôle de cette fructification irrégulière. Matériel et méthodes. En août 2003, une incision annulaire portant sur les trois quarts du pourtour d’une branche a été effectuée, jusqu’à l’aubier, sur 29 karités du terroir de Bondoukuy (Burkina Faso) ; une branche de chacun de ces mêmes arbres a servi de témoin. En 2004, un essai factoriel d’incision a été entrepris ; il a porté sur deux sites de ce même terroir, deux périodes de traitement (fin août et fin novembre), trois ampleurs d’incisions (50 %, 75 % et 100 %) et cinq karités utilisés par traitement. Ce sont donc 60 karités multicaules qui ont été étudiés, un des troncs de chacun d’eux servant de témoin. La proportion de rameaux florifères (%rFl) et le nombre de fleurs (nFl) et de fruits (nFr) formés par rameaux traités et témoins ont été comptabilisés puis analysés. Résultats. Par rapport aux branches témoins, l’incision annulaire a accru de 17 % le (%rFl), 54 % le (nFl) et 100 % le (nFr) par rameau. Les périodes et ampleurs d’incision testées n’ont pas montré de différences entre elles, mais elles ont permis aux branches traitées d’obtenir un (%rFl) supérieur à celle des branches témoins. Quelle que soit la variable considérée, il est apparu une différence de performances de reproduction entre les karités des sites testés ; l’efficacité de l’incision annulaire serait donc liée aux conditions édaphiques de développement de l’arbre. Discussion et conclusion. La technique d’’incision annulaire peut donc être utilisée pour contrôler l’irrégularité de la fructification du karité. Néanmoins, des études complémentaires se révèlent indispensables pour déterminer l’effet de la période de l’incision sur le grossissement et la composition chimique des fruits.

Intraspecific synchrony in the phenology of tropical forest trees has implications for satiation of browsers and seed predators, pollination, dispersal and interpreting plant responses to environmental cues and stresses. Community phenological studies have been constrained in their consideration of these issues by the lack of concise quantitative measures of intraspecific synchrony. We propose a novel application of Colwell's predictability indices to overcome this deficiency. Its application is demonstrated by evaluating the leaf and reproductive phenologies of 8–16 individuals of each of 20 monsoon forest tree species from northern Australia monthly for 30 mo. The indices yielded substantial additional information over that provided by summaries averaged amongst conspecifics. Marked intraspecific asynchronies in leaf flush or flowering occurred in five evergreen species and two deciduous fig species, and were associated with prolonged individual commitments to these states. Five partly deciduous species exhibited marked intraspecific variation in the seasonal extent of leaf loss. We interpret the observed variation in intraspecific synchrony in terms of contrasting water-use and pollination strategies. The synchronicity indices are concise and robust to small and variable sample sizes, and may thus enhance studies of species-rich assemblages.

Within the last decade the study of phenology has taken on new importance because of its contribution to climate-change research. However, phenology data sets spanning many years are rare in the tropics, making it difficult to evaluate possible responses of tropical communities to climate change. Here we use two data sets (1970–1983 and 1990–2002) to describe the fruiting patterns of the tropical tree community in Kibale National Park, Uganda. To address variation in spatial patterns, we describe fruiting over 2–3 y among four sites each separated by 12–15 km. Presently, the Kibale region is receiving c. 300 mm more rain than it did at the start of the century, droughts are less frequent, the onset of the rainy season is earlier, and the average maximum monthly temperature is 3.5 °C hotter than it was 25 y ago. The 1990–2002 phenology data illustrated high temporal variability in the proportion of the populations fruiting. Interannual variation in community-wide fruit availability was also high; however, the proportion of trees that fruited has increased over the past 12+y. At the species level a variety of patterns were exhibited; however, a number of the most common species currently rarely fruit, and when they do, typically <4% of the individuals take part in fruiting events. Combining the data set from 1990 to 2002 with that from 1970 to 1983 for specific species again reveals an increase in the proportion of trees fruiting between 1990 and 2002; however, the proportion of the populations fruiting decreased during the earlier period. When one examines particular species over this whole period a variety of patterns are evident. For example, Pouteria altissima exhibited a relatively regular pattern of fruiting during the 1970s; however, it rarely fruited in the 1990s. Contrasting phenological patterns at four sites revealed that at the community level the fruiting patterns of only one of the six pair-wise site combinations were correlated. Relationships between rainfall and fruiting were variable among sites. Contrasting changes in fruiting patterns over the 30 y with differences among the four sites varying in rainfall, suggests that the changes observed in fruiting may be due to climate change. Responses to this climate change are likely complex and will vary among species. However, for some species, current conditions appear unsuitable for fruiting.

Introduction. Vegetative and fruit growth in fruit trees are differentially sensitive to water deficit during the season depending on the stage of fruit growth. Attempts have been made to evaluate the possibilities of using regulated deficit irrigation to control vegetative growth and save water in the fruit industry. Materials and methods. Effects of water stress (WS) and crop load (CL) on fruit growth and carbon assimilation rates were evaluated in a 7-year-old ‘Elegant Lady’ peach orchard. A completely randomized block design with 2 × 3 factors [irrigation with two levels (control and WS) and CL with three levels (light, commercial and heavy)] was used. Results and discussion. Both WS and CL affected fruit growth during the last stages but not early on. CL did not affect trunk water potential which was, however, significantly reduced by WS throughout the day and the season. Trunk water potential of water-stressed trees was lower than that of control trees throughout the day and the season regardless of CL. The magnitude of WS increased as the season progressed. Stomatal conductance, transpiration rate and CO2 assimilation rate were not affected by CL but were reduced by WS. The trees responded (acclimated) to stress by progressively reducing their transpiration rate as the severity of stress increased. For each irrigation regime, assimilation rates were similar for all three crop levels. This indicated the existence of alternate sinks for assimilates when CL was low, which compensate for the reduction of fruit sink activity resulting from fruit thinning. Conclusion. Water deficit reduced trunk water potential, stomatal conductance, transpiration and photosynthesis in ‘Elegant Lady’ peach trees. However, CL had a limited effect on these functions. There were good correlations between trunk water potential and either stomatal conductance or assimilation rate in water-stressed trees but not in control trees. This indicates a poor coordination between leaf functions in peach trees under optimal conditions. However, these relationships were stronger under WS conditions. Thus, water use efficiency appeared to increase under water deficit conditions.

Introduction. En Tunisie, bien que des problèmes liés à la floraison et à la fructification se posent chez le grenadier (Punica granatum L.), aucune étude n'avait encore été menée sur cette espèce. Nos travaux ont donc cherché à étudier ces importantes étapes du cycle de reproduction de la plante chez certaines variétés locales de P. granatum exploitées dans les conditions tunisiennes. Matériel et méthodes. La dynamique de la floraison a été étudiée par le comptage régulier des fleurs formées sur branches des trois cultivars locaux : Gabsi, Kalaii et Garoussi. La chute des boutons floraux, des fleurs épanouies ou des jeunes fruits récemment noués a été comptabilisée pour l'arbre entier. Un suivi de la fertilité des fleurs et des essais d'autopollinisation par ensachage de rameaux de différentes longueurs ont été conduits sur le seul cultivar Gabsi. Résultats et discussion. La durée de la floraison a été de 8 semaines environ pour Gabsi et de 10 semaines pour Garoussi et Kalaii. Le maximum des fleurs a été obtenu entre la troisième et la cinquième semaine après le début de floraison. La majeure partie des fleurs est apparue sur du bois âgé d'un an ou plus. Le taux de rétention le plus élevé (8,4 %) a été enregistré chez le cultivar Gabsi. Les fruits ont surtout été obtenus à partir des fleurs hermaphrodites. Le calibre des fruits à la récolte a diminué au fur et à mesure que la date d'apparition des fleurs dont ils provenaient avait été tardive. Les rameaux courts ensachés n'ont pas retenu de fruits ; ceux de longueur moyenne ont permis un taux de nouaison de 2,3 % par rapport à la totalité des fleurs du rameau ; les rameaux de plus grande taille ont présenté un taux de 4,8 %. Conclusions. La floraison du grenadier est très échelonnée. Les cultivars étudiés ont différé en fonction de la date du début de floraison, de sa durée et de son intensité. Le régime de reproduction s'est révélé être l'allogamie préférentielle. L'étalement de la floraison et les particularités morpho-physiologiques des fleurs favoriseraient plutôt la pollinisation croisée.

Introduction. L'insuffisance en froid hivernal dans les zones de plaine au Maroc constitue un facteur limitant de la production du pommier. Nous avons évalué les effets du cyanamide hydrogène (Dormex), seul ou additionné d'huile minérale, et de l'acide gibbérellique sur le débourrement de pommiers, dans les conditions climatiques de plaines au sud du Maroc. Matériel et méthodes. Les expérimentations ont porté sur la variété `Dorsett Golden' connue pour ses faibles besoins en froid. Un dispositif en bloc aléatoire complet avec quatre répétitions a été utilisé. Les produits testés ont été le Dormex appliqué soit seul à (1,5, 2,5 et 4) % du produit formulé, soit à 0,5 % en association avec de l'huile minérale à (2 ou 4) %, et l'acide gibbérellique à 460 mg $\cdot$ L-1. Les arbres témoins ont été traités à l'eau. L'évaluation a porté sur le débourrement, la floraison, la nouaison, la croissance végétative et la production. Résultats. Les substances chimiques ont avancé la date de débourrement et en ont amélioré le taux de même que celui de floraison, et ils ont favorisé la croissance végétative. Le rendement et le calibre des fruits ont également été améliorés de manière significative. Conclusion. Le Dormex, seul ou combiné à de l'huile minérale, et l'acide gibbérellique ont avancé et regroupé le débourrement tout en améliorant le calibre et la production en fruits du pommier `Dorsett Golden'. L'efficacité du mélange [ Dormex + huile minérale]associée à son moindre coût conduisent à recommander ce produit pour pallier le manque en froid hivernal dans les zones de plaine du Maroc caractérisées par un hiver doux.

Habitat fragmentation affects the ecology of tropical rain forests in many ways, such as reducing species diversity of many taxa (Laurance et al. 2002, Lovejoy et al. 1986) and increasing rates of tree mortality and canopy-gap formation near forest edges (Laurance et al. 1997, 1998, 2001). Such obvious alterations have been documented in many fragmented forests, but more subtle changes, such as those affecting plant phenology (the timing and frequency of flower, fruit and leaf production), have received far less attention. Adler & Kiepinski (2000) showed that different populations of the successional tree Spondias mombin on small man-made islands in Panama had highly synchronous flowering and fruiting. In montane forests in Colombia, Restrepo et al. (1999) demonstrated that under-storey fruit abundance was consistently increased over time near forest edges relative to forest interiors. Beyond these and a few other studies (Ackerly et al. 1990, Nason & Hamrick 1997), however, the effects of fragmentation on plant phenology have been inadequately assessed, especially in the tropics.

Introduction. The production of `Tahiti' limes in southern Brazil has increased in the last 20 years and has become a good alternative for citrus growers in regions where Citrus Variegated Chlorosis has affected sweet orange groves. One of the main goals to insure success in growing `Tahiti' limes is to apply the right techniques to induce out-of-season flowering and winter fruit harvest when the fruit prices are the highest. This experiment evaluated the effects of gibberellic acid application on fruit set of `Tahiti' lime trees related to out-of-season flowering and accumulated degree days. Materials and methods. Eight-year-old plants were treated with five concentrations of gibberellic acid [ (0, 10, 25, 50 and 100) mg$\cdot$L-1] applied during anthesis of out-of-season bloom. Accumulation of degree days for fruit set and fruit development in the conditions of São Paulo State, Brazil, were calculated. The percentage of fruit set determined by weekly counts of the number of flowers from anthesis to the maturation of the fruits were determined on each previously marked branch. Data were submitted to regression analysis. Results and discussion. In regard to fruit set, it was observed that 10 mg gibberellic acid$\cdot$L-1 was enough to retain more than 10% of fruits in relation to the number of formed flowers. Starting from anthesis, (837.7 and 1 115.2) accumulated degree days were necessary for the stabilization of the fruit set and fruit maturation, respectively.