Integration of tree source and sink activities.

2022 ◽  
pp. 96-113
Author(s):  
T. M. DeJong

Abstract Tree crop modeling could be instrumental in facilitating integration of numerous aspects of the development, growth and physiology of fruit tree crops and provide a valuable tool for testing concepts for understanding how fruit trees work, if it could be achieved. This chapter presents a synopsis of how modeling of fruit trees was approached. It focuses on the development of a mechanistic, compartmental model of mature peach tree carbon partitioning over a growing season. The model was termed a compartmental model because carbohydrates were only distributed to the collective compartments of fruits, leaves, stems and large branches, and the trunk according to their relative demand functions as the season progressed. Roots were only given carbohydrates when the demands of all of the other organs were fulfilled. This model demonstrated that carbohydrate partitioning in trees could be modeled without deterministic, empirically derived, partitioning coefficients and was useful for indicating periods of the growing season when calculated photosynthetic assimilation was not adequate to supply calculated carbohydrate demands of growing organs. The development of the described model is so complex that the modeling work will never be fully completed. However, to demonstrate the utility of this modeling approach, it was decided to develop an L-Almond model using the same approach.

Horticulturae ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 86
Author(s):  
Abdel-Moety Salama ◽  
Ahmed Ezzat ◽  
Hassan El-Ramady ◽  
Shamel M. Alam-Eldein ◽  
Sameh Okba ◽  
...  

Adequate chill is of great importance for successful production of deciduous fruit trees. However, temperate fruit trees grown under tropical and subtropical regions may face insufficient winter chill, which has a crucial role in dormancy and productivity. The objective of this review is to discuss the challenges for dormancy and chilling requirements of temperate fruit trees, especially in warm winter regions, under climate change conditions. After defining climate change and dormancy, the effects of climate change on various parameters of temperate fruit trees are described. Then, dormancy breaking chemicals and organic compounds, as well as some aspects of the mechanism of dormancy breaking, are demonstrated. After this, the relationships between dormancy and chilling requirements are delineated and challenging aspects of chilling requirements in climate change conditions and in warm winter environments are demonstrated. Experts have sought to develop models for estimating chilling requirements and dormancy breaking in order to improve the adaption of temperate fruit trees under tropical and subtropical environments. Some of these models and their uses are described in the final section of this review. In conclusion, global warming has led to chill deficit during winter, which may become a limiting factor in the near future for the growth of temperate fruit trees in the tropics and subtropics. With the increasing rate of climate change, improvements in some managing tools (e.g., discovering new, more effective dormancy breaking organic compounds; breeding new, climate-smart cultivars in order to solve problems associated with dormancy and chilling requirements; and improving dormancy and chilling forecasting models) have the potential to solve the challenges of dormancy and chilling requirements for temperate fruit tree production in warm winter fruit tree growing regions.


Land ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 451
Author(s):  
Van Hung Do ◽  
Nguyen La ◽  
Rachmat Mulia ◽  
Göran Bergkvist ◽  
A. Sigrun Dahlin ◽  
...  

Rapid expansion of unsustainable farming practices in upland areas of Southeast Asia threatens food security and the environment. This study assessed alternative agroforestry systems for sustainable land management and livelihood improvement in northwest Vietnam. The performance of fruit tree-based agroforestry was compared with that of sole cropping, and farmers’ perspectives on agroforestry were documented. After seven years, longan (Dimocarpus longan Lour.)-maize-forage grass and son tra (Docynia indica (Wall.) Decne)-forage grass systems had generated 2.4- and 3.5-fold higher average annual income than sole maize and sole son tra, respectively. Sole longan gave no net profit, due to high investment costs. After some years, competition developed between the crop, grass, and tree components, e.g., for nitrogen, and the farmers interviewed reported a need to adapt management practices to optimise spacing and pruning. They also reported that agroforestry enhanced ecosystem services by controlling surface runoff and erosion, increasing soil fertility and improving resilience to extreme weather. Thus, agroforestry practices with fruit trees can be more profitable than sole-crop cultivation within a few years. Integration of seasonal and fast-growing perennial plants (e.g., grass) is essential to ensure quick returns. Wider adoption needs initial incentives or loans, knowledge exchange, and market links.


2017 ◽  
Vol 30 (4) ◽  
pp. 1040-1049 ◽  
Author(s):  
CAROLINA DELLA GIUSTINA ◽  
ROBERTA APARECIDA CARNEVALLI ◽  
MARCELO RIBEIRO ROMANO ◽  
DIEGO BARBOSA ALVES ANTONIO ◽  
CAMILA ECKSTEIN

ABSTRACT The benefits of integrating agricultural components into silvopastoral systems are widely known, but the limited knowledge about ecological processes in the establishment phase impedes the use of this technology. The objective of this study was to evaluate interactions between fruit tree species and the sward layer under canopies of trees in the establishment phase of silvopastoral systems in Mato Grosso, Brazil. The experiment was implemented in October 2013, with an evaluation period from January to July 2015. The systems were composed of eight fruit trees intercropped with Tifton 85 grass. A completely randomized block design was adopted, with two replications per area per treatment. We evaluated the agronomic performance of the fruit trees, the categories of the light environment, and the plant accumulation under the canopies. The acerola fruit trees of the variety Roxinha had higher Leaf area index (LAI) and Light interception (LI) values, showing a denser canopy with small porosity and the lowest light quality available to the plants beneath the canopy (lower red/far-red ratio), thereby decreasing plant accumulation under trees. The guava fruit trees showed higher growth rates than the other fruit trees, but lower LAI and LI values and a higher red/far-red ratio, allowing higher plant growth under the canopy. Cajá trees showed a similar behavior; however, this species is deciduous, which limits its potential use in integrated systems. Banana and coconut trees were highly dependent on irrigation during the dry season. The remaining species showed an adequate growth and potential to control plant species growth under their canopies.


2000 ◽  
Vol 6 (1) ◽  
Author(s):  
P. Benedek ◽  
J. Nyéki ◽  
I. Amtmann ◽  
F. Bakcsa ◽  
J. Iváncsics ◽  
...  

Fruit tree species suffered very strong spring frosts in 1997 in Hungary. This caused partial or total damages at buds and flowers depending on site and time of blooming. It was demonstrated at a number of experiments that frost and cold weather also strongly affected the nectar production of surviving flowers. No or very little amount of nectar was measured in flowers first of all of early blooming fruit tree species (apricot) but also of pear and apple in some places. In spite of this fact intensive honeybee visitation was detected in the flowers of fruit trees that suffered partial frost damage only at those sites where honeybee colonies were placed in or at the experimental plantations and the lack of sufficient amount of nectar did not affected bee behaviour seriously on fruit flowers. This means that bad nectar production failed to affect bee visitation of fruit trees definitely. The reason for this was the fact that not only fruit trees but another early bee plants (wild plants, too) suffered frost damage. Accordingly, in lack of forage bees intensively searched for food at blooming fruit trees with some living flowers. Consequently, there was an acceptable yield at those plantations where bud and flower damage was not complete. Accordingly, intensive bee visitation (that is moving additional bee colonies to overpopulate fruit orchards with honeybees) can be an effective tool to decrease or eliminate the detrimental effect of spring frost on the yield of fruit trees where bud or fruit damage is not too high.  


2013 ◽  
Vol 39 (1) ◽  
pp. 83-94
Author(s):  
SK. Ahiul Islam ◽  
Md. Abdul Quddus Miah ◽  
Md. Ahsan Habib

In a study conducted in three southern districts (Bhola, Borguna and Patuakhali) of Bangladesh, a total of 69 tree species was recorded from the homegardens, of which 32 were fruit tree and 37 were timber tree species. Among the fruit tree species, coconut, betel nut, mango, jackfruit, guava, velvety apple were found in more than 80% households. The stocking of fruit trees per homestead was found highest for betel nut (265) followed by velvety apple (212), mango (38) coconut (25), jackfruit (20) and guava (9). Among the timber tree species, rain tree, mehogoni, raj koroi were most prevalent and found in more than 65% homesteads. The stocking of timber trees/ homestead was found highest for mehogoni (79) and then for rain tree (57), raj koroi (29) and katbadam (6). J. Asiat. Soc. Bangladesh, Sci. 39(1): 83-94, June 2013 DOI: http://dx.doi.org/10.3329/jasbs.v39i1.16037


Author(s):  
Shenglian lu ◽  
Guo Li ◽  
Jian Wang

Tree skeleton could be useful to agronomy researchers because the skeleton describes the shape and topological structure of a tree. The phenomenon of organs’ mutual occlusion in fruit tree canopy is usually very serious, this should result in a large amount of data missing in directed laser scanning 3D point clouds from a fruit tree. However, traditional approaches can be ineffective and problematic in extracting the tree skeleton correctly when the tree point clouds contain occlusions and missing points. To overcome this limitation, we present a method for accurate and fast extracting the skeleton of fruit tree from laser scanner measured 3D point clouds. The proposed method selects the start point and endpoint of a branch from the point clouds by user’s manual interaction, then a backward searching is used to find a path from the 3D point cloud with a radius parameter as a restriction. The experimental results in several kinds of fruit trees demonstrate that our method can extract the skeleton of a leafy fruit tree with highly accuracy.


Author(s):  
Alka TURALIJA ◽  
Anica PERKOVIC ◽  
Jasenka VIZENTANER ◽  
Jasna AVDIC ◽  
Vladimir JUKIC ◽  
...  

A fruit tree has always been a determinant of an ornamental garden shaping in Croatia. From the 13th century onward an organized planting of fruit trees has been recorded. A total of 100 gardens in Istria have been analyzed , 50 of which were examined in the Istria interior, and 50 in the coastal area. Due to the shape and architectural style, 8 different types of gardens were determined and classified, by the location,  into three climatic-relief areas A, B and C. There were 7 types of ornamental gardens with a  fruit tree as a primary determinant of the garden, except one without it. Out of the 23 recorded fruit species, cherry, figs, grapes and olives have been mostly common  in the Istria interior whereas olives, Nespoli, figs and grapes have been known in the Istria coast.


2007 ◽  
Vol 97 (3) ◽  
pp. 359-365 ◽  
Author(s):  
V. Rossi ◽  
L. Languasco

Environment-controlled studies were carried out to determine the growth of Taphrina deformans under different conditions of temperature, humidity, and nutrient availability similar to those found on plant surfaces during the peach-growing season. Both ascospores and blastospores were able to bud at all temperatures tested (5 to 37°C), with the optimum at 14 and 21°C, respectively. Temperature <20°C favored ascospore production and release, with the optimum at 10°C. Budding was approximately two-and-a-half times higher in a film of water than on a dry substrate, with 100% relative humidity and blastospores also maintained a certain budding ability at lower humidity levels (minimum tested = 47%). Both spore types did not bud after ≈50 to 55 h in the absence of external nutrients. In the presence of a periodically renewed carbon source, such as simple sugars, at concentrations that typically are present on peach plant surfaces, the fungus maintained its budding capability over time. Results showed that T. deformans is able to bud profusely under a wide range of environmental conditions that occur on peach tree surfaces. This work supports the hypothesis that T. deformans is a part of the normal epiphytic mycoflora of peach trees throughout the entire growing season.


2014 ◽  
Vol 543-547 ◽  
pp. 4161-4164
Author(s):  
Hong Juan Li ◽  
Shu Mei Zhang

Information technology includes neural networks, ontology technology, expert system, and so on, and the growth model can predict and manage growth conditions of fruit trees. The traditional expert system has shortcomings of poor self-learning ability, so the improved expert system is used to perform diagnosis of diseases and insects of fruit tree. Firstly the ontology is used to collect related symptoms of diseases and insects of fruit trees, the expert system and neural network are combined to build the prediction model of diseases and insects of fruit tree, then the conclusions of the diagnostic process are regarded as the input neurons and output neurons of neural networks, and are diagnosed by expert, so the prediction models of disease diagnosis of fruit trees are made. The models can implement the function of expert diagnosis and prediction, and provide technical support and management decision for the growth management of fruit tree, greatly improving the diagnosis efficiency of diseases and insects of fruit tree.


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