INCREASING CITRUS FRUIT SIZE USING AUXINS AND POTASSIUM.

1993 ◽  
pp. 112-119 ◽  
Author(s):  
Y. Erner ◽  
Y. Kaplan ◽  
B. Artzi ◽  
M. Hamou
Keyword(s):  
2019 ◽  
Vol 48 (5) ◽  
pp. 95-101
Author(s):  
Ulzii-Orshikh Dorj ◽  
Uranbaigal Dejidbal ◽  
Hongseok Chae ◽  
Lkhagvadorj Batsambuu ◽  
Altanchimeg Badarch ◽  
...  

A new computer vision algorithm for citrus fruit quality classification based on the size of a single tree fruits was developed in this study. The image properties of area, perimeter, and diameter for the citrus fruits were measured by pixels. In order to estimate citrus fruit size in a realistic manner, the ratios of diameter, perimeter and area in pixel values in relation to the actual size of one fruit were determined. The total of 1860 citrus fruits were grouped based on diameter, perimeter, and area in pixels. The results of the grouping of citrus fruits by diameter, perimeter and area were compared with the results of the survey research into citrus fruit size as conducted by the Jeju Citrus Commission. Comparative results reveal that the image of the citrus fruit diameter in pixels demonstrate a more accurate size than the other two pixel values, i.e. perimeter and area.


2016 ◽  
Vol 46 (5) ◽  
pp. 825-831 ◽  
Author(s):  
Demétrius de Araújo ◽  
Carlos Gilberto Raetano ◽  
Hamilton Humberto Ramos ◽  
Douglas Sampaio Ribeiro da Rocha ◽  
Evandro Pereira Prado ◽  
...  

ABSTRACT: Citrus black spot (CBS) caused by Guignardia citricarpa is one of the most serious Brazilian citrus diseases. This study aims to assess the interference of three application volumes in spray deposition citrus fruit, as well as fruit growth and rainfall effects on spray deposit reduction during the CBS control period. The experiment was carried out in a commercial citrus orchard, with sixteen-year-old trees of the Valencia variety, in Mogi Guaçu, São Paulo State, Brazil. The spray volumes were: 3.5 (1333L ha-1), 4.5 (1714L ha-1) and 8.5 (3238L ha-1) litres per tree, sprayed by an airblast sprayer using fungicides at recommended periods for disease control. The spray deposition quantification and residue was done by spectrophotometry using a copper oxychloride tracer. Samples were collected in three height zones of the tree (top, middle and bottom) and placed between trees on line plantation. Spray depositions were significantly smaller in the first application as a consequence of reduced fruit size. The spray losses on average for each day of rainfall ranged from 4.0 to 5.7%. There was no significant difference between application volumes regarding spray deposition on citrus fruit,which makes possible the reduction of application volumes, however, it is necessary to improve spraying techniques for the top zone of the citrus tree.


Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1305
Author(s):  
Marco Caruso ◽  
Alberto Continella ◽  
Giulia Modica ◽  
Claudia Pannitteri ◽  
Riccardo Russo ◽  
...  

Citrus fruit quality and scion productivity are influenced by the choice of rootstock. We aimed to evaluate the effect of rootstocks on yield and fruit quality of Mandared, a triploid pigmented mandarin. To do so, we established a rootstock field trial on a high pH soil (8.6) in which Mandared was grafted onto 11 rootstocks. These included some standard rootstocks, such as trifoliate orange ((Poncirus trifoliata (L.) Raf.), Troyer citrange (Citrus sinensis (L.) Osb. × P. trifoliata), Swingle citrumelo (Citrus paradisi Macf. × P. trifoliata), and C35 citrange (C. sinensis × P. trifoliata), as well as new releases from the Council for Agricultural Research and Economics (CREA, Acireale, Italy) and the University of California Riverside (UCR). The cumulative yield was measured over five consecutive years, while fruit quality was analyzed for two years. The trees on C35, C57 (Citrus sunki Hort. ex. Tan. × P. trifoliata), and C22 (C. sunki × P. trifoliata), started to set fruits one year earlier than the others. The trees on C57 provided some of the highest cumulative yields and canopy volumes. The production of Mandared grafted onto C57 was double that of Mandared grafted onto Troyer, while Mandared grafted onto C35 and C22 resulted in the best yield efficiency. The trees on Swingle and C57 significantly reduced the pre-harvest fruit drop, to which Mandared is particularly sensitive. However, grafting Mandared onto Swingle resulted in the highest variation among replicates, probably due to its high sensitivity to iron chlorosis. Most of the fruit quality parameters, such as fruit size, total soluble solids (TSS), and acidity were not significantly different among the rootstock treatments. However, fruits produced by Mandared grafted onto C22 had one of the highest rates of anthocyanin accumulation. The results indicate that C57, C35, and C22 were the most suitable rootstocks for Mandared in South-Eastern Sicily.


Author(s):  
Bilge Yilmaz ◽  
Berken Çimen ◽  
Turgut Yesiloglu ◽  
Meral Incesu ◽  
Muge Uysal Kamiloglu ◽  
...  

Star Ruby is the main grapefruit (Citrus paradisi) variety grown in Turkey; however, small fruit size is a common problem in ‘Star Ruby’ grapefruit. Fruit size is a decisive external quality parameter in citrus at the marketing of fresh citrus fruits. Fruit size can be enhanced by several techniques such as girdling and thinning. Various plant growth regulators are known to affect the growth and size of citrus fruit. The objective of the present study was to observe the effects of 2,4 dichlorophenoxypropionic acid-p (2,4-DP-P) on the fruit size, yield and quality of Star Ruby from 20-year-old trees budded on sour orange rootstock in Adana, Turkey in 2007. Four concentrations (50, 100, 150 and 300 ppm) of 2,4-DP-P were applied 8 weeks after anthesis during physiological fruit drop when the mean fruit diameter was 13-15 mm. The results indicated that the application of 2,4-DP-P increased the fruit size of Star Ruby grapefruit without reducing yield. The application had a significant effect on fruit yield except for trees treated with 50 ppm 2,4-DP-P. Compared with the control trees, applications of 2,4-DP-P increased the number of large, commercially valuable Star Ruby (>93 mm, 89-93 mm and 84-89 mm). No effects were determined on fruit internal quality parameters. Thus, the results of the present study revealed that 2,4-DP-P can be used to improve the fruit size of Star Ruby fruitlets during the June drop.


HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 550E-551
Author(s):  
Eliezer E. Goldschmidt

Carbohydrates fulfill several roles in plants; as building stones, as a source of energy, and also, as recently demonstrated, as modulators of gene expression. Primary, photosynthetic production of carbohydrates (as well as their release from tree reserves) is linked with the carbohydrate-consuming processes through complex feedback and feedforward regulatory loops. With horticultural productivity as the goal, maximum resources must be diverted toward reproductive processes. Persistence of viable vegetative structures must be secured, however, to enable the function of tree systems and ensure the tree's potential for future years. Thus, in the carbohydrate resource allocation of fruit trees, a delicate balance must be maintained between the vegetative and reproductive needs. Flowering, fruit set, and fruit enlargement have been identified as three distinct, critical stages within the annual course of yield formation in citrus. While each of these stages has its own, salient developmental features, all require considerable amounts of energy and their occurrence is dependent, at least to some extent, on the availability of carbohydrates. Whereas flower bud differentiation may require only a threshold level of carbohydrates, floral development and anthesis consume large amounts of carbohydrates due to the very large number of flowers per tree and their high rates of respiration. Fruit set is more closely linked to carbohydrate levels. Fruitlet abscission acts as a self-thinning, feedback mechanism to adjust the tree's fruit population to the carbohydrate supply. This mechanism does not operate properly in certain mandarin cultivars, resulting in alternate bearing. The acquisition of fruit size appears to be most directly correlated with the availability of photosynthate. Elimination of alternative sinks by extreme thinning and girdling brings about tremendous increases in fruit size. The fruit's vascular system also expands in response to the increase in photosynthate availability. A dynamic model has been constructed to provide a quantitative analysis of citrus trees' carbon balance during the annual productivity cycle.


Author(s):  
Abouzar Abouzari ◽  
Nafiseh Mahdi Nezhad

Citrus is the most economically important fruit crop in the world. In citrus, the concept of fruit quality comprises several other aspects intimately related to human health apart from physical attributes and diet components. Citrus is an excellent model to study fruit quality because of its peculiar fruiting, singular biochemistry and economical relevance. A citrus breeding programme starts with the selection of suitable parents and the planning of controlled crosses. Information on the breeding value of available parents and the heritability of specific characters is important in a plant breeding programme to aid the breeder in parent selection and the planning of controlled crosses. Major goals of variety breeding in citrus are mostly related to fruit quality, productivity and harvesting period. In a broad sense, citrus fruit quality includes many physical attributes like fruit color, fruit size, easy of peeling and seedlessness. These traits have become paramount in commercial citrus types and new cultivar being developed through plant breeding and selection of new sports. This paper focus on four main citrus characteristics that responsible for fruit quality and are the basis for judging the product acceptability by consumers. We also discuss the variety strategy for citrus quality improvement.


2020 ◽  
Vol 30 (6) ◽  
pp. 745-750
Author(s):  
Coral Ortiz ◽  
Antonio Torregrosa ◽  
Enrique Ortí ◽  
Sebastià Balasch

Thinning is the process of removing some flowers or fruit to increase fruit size at harvest. In the Valencia region of Spain, the thinning operation for citrus fruit (Citreae) is performed for some mandarin varieties. This is always performed manually; however, this method is very expensive. The goal of this research study was to assess the mechanical thinning of mandarin (Citrus reticulata) using a hand-held branch shaker. Different thinning treatments were conducted over a 3-year period. The gasoline-powered branch shaker was capable of detaching fruit four- to five-times faster than manual thinning. Final fruit size was significantly higher using manual and mechanical thinning compared with a no thinning treatment. Similar final fruit size was obtained with manual and mechanical thinning. However, no significant differences were found in final fruit yield by weight among no thinning, mechanical thinning, and manual thinning treatments. The use of a branch shaker could be recommended for thinning operations to increase efficiency, reduce labor costs, and obtain larger and higher-quality fruit.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
Y Kobayashi ◽  
H Takemoto ◽  
Z Fu ◽  
E Shimizu ◽  
Y Kinjo

2018 ◽  
Vol 1 (2) ◽  
pp. 17-23
Author(s):  
Takialddin Al Smadi

This survey outlines the use of computer vision in Image and video processing in multidisciplinary applications; either in academia or industry, which are active in this field.The scope of this paper covers the theoretical and practical aspects in image and video processing in addition of computer vision, from essential research to evolution of application.In this paper a various subjects of image processing and computer vision will be demonstrated ,these subjects are spanned from the evolution of mobile augmented reality (MAR) applications, to augmented reality under 3D modeling and real time depth imaging, video processing algorithms will be discussed to get higher depth video compression, beside that in the field of mobile platform an automatic computer vision system for citrus fruit has been implemented ,where the Bayesian classification with Boundary Growing to detect the text in the video scene. Also the paper illustrates the usability of the handed interactive method to the portable projector based on augmented reality.   © 2018 JASET, International Scholars and Researchers Association


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