The yield of sugar orange is closely related to meteorological conditions in the flowering and fruiting period, and meteorological disasters at the flowering and early fruiting stage seriously affect its yield. To stu...The yield of sugar orange is closely related to meteorological conditions in the flowering and fruiting period, and meteorological disasters at the flowering and early fruiting stage seriously affect its yield. To study influences of meteorological disasters in the flowering and early fruiting stage on sugar orange industry in Guilin, meteorological disasters in the flowering and early fruiting stage and its defense measures were analyzed and studied. The flowering and early fruiting stage of sug- ar orange in Guilin is from March to June, and sudden change of temperature, thunderstorm, hale, hail, rainstorm and other natural disasters can cause the falling of large numbers of flowers and young fruit, damage of tree body, reduction of fruit in quantity, and decrease of its yield. Timely understanding information of disastrous weather and implementing management of water and fertilizer can effectively reduce the loss caused by meteorological disasters and ensue high quality and high yield of sugar orange.展开更多
Based on ASP.NET,a orange fruit tree fertilizer expert system software was developed.The system could simulate and decide an annual fertilization plan for young and mature trees in terms of geographical position and c...Based on ASP.NET,a orange fruit tree fertilizer expert system software was developed.The system could simulate and decide an annual fertilization plan for young and mature trees in terms of geographical position and climate.This paper introduced the design conditions,framework,production,and deployment of the system.It exhibited characters of orange specialty and was a typical online agriculture expert system.The use of the system for orange fruit management could decrease production cost,guarantee orange quality and improve economical benefit at the same time.Farmer using the system saved N input by 41-238 g/plant,P2O5 input 3-24 g/plant,and K2O input 1-36 g/plant,and got higher yield by 6-17 kg/plant.展开更多
This study aimed to provide a theoretical basis for adopting suitable cultivation measures to tackle calcium (Ca) deficiency in citrus leaves. The Newhall navel orange (Citrus sinensis Osbeck) canopy was sprayed w...This study aimed to provide a theoretical basis for adopting suitable cultivation measures to tackle calcium (Ca) deficiency in citrus leaves. The Newhall navel orange (Citrus sinensis Osbeck) canopy was sprayed with 20.0 mmol L-1 of Ca(NO3)2 during physiological fruit drop period, fruit expanding period, and fruit maturing period on 30, 90, and 210 days after full bloom (DAFB), respectively, and its effects on leaf gas exchange parameters and leaf mineral nutrition and fruit quality were analyzed. The results showed that: (1) The photosynthetic rate (ACO2) at 9:00 a.m. and 16:00 p.m. of fruit expanding period with 30 and 90 DAFB Ca(NO3)2treatments slightly or significantly improved mainly by decreasing stomatal limitation and nonstomatal limitation, respectively. (2) Compared with control (CK), the Ca concentration in leaves with 30, 90, and 240 DAFB Ca(NO3)2 treatments increased by 127.16; 97.53, and 33.33%, respectively, and the leaf magnesium concentra- tion also increased by more than 32.26%. However, Ca(NO3)2 canopy spraying on 30 DAFB significantly reduced the leaf potassium concentration, by 22.14% compared with CK. (3) Ca(NO3)2 canopy spraying on 30 DAFB decreased the second fruit drop rate by 30.55% and increased the weight per fruit by 25.04%, thus resulting in a significant increase in citrus yield. (4) Spraying Ca(NO3) on 30 DAFB mainly affected the metabolism of titratable acid (TA) to improve the maturity of citrus fruits. Whilst it improved the external quality and the coloring of citrus fruit significantly. Therefore, Ca(NO3)2 canopy spraying during physiological fruit drop period has a better influence on the tree character and fruit quality of Newhall navel orange (Citrus sinensis Osbeck).展开更多
An optimum method has been developed for extracting volatile organic compounds (VOCs) which contribute to the aroma of different species of citrus fruit (orange, lemon, lime, and mandarin). Headspace solid phase micro...An optimum method has been developed for extracting volatile organic compounds (VOCs) which contribute to the aroma of different species of citrus fruit (orange, lemon, lime, and mandarin). Headspace solid phase microextraction (HS-SPME) combined with gas chromatography (GC) coupled with flame ionization detection (FID) is used as a very simple, efficient and non-destructive extraction method. A three phase 50/30 μm PDV/DVB/CAR fibre was used for the extraction process. The optimal sealing time for volatiles reaching equilibrium from whole fruit in the headspace of the chamber was 20, 16, 8 and 16 hours for lemon, lime, mandarin, and orange respectively. Optimum fibre exposure times for whole fruit were 2, 4, 2 and 2 hours for lemon, lime, mandarin, and orange respectively. Three chamber volumes (500, 1000 and 2000 ml) were evaluated for the collection of VOCs with the 500 ml chamber being selected. The 500ml chamber produced the highest quality peak areas and quantity of extracted volatiles. As a result of fruit respiration, the percentage of oxygen (O2) of all citrus fruit species in 500 ml chamber decreased from 21.8% to 18.8% in the 20 hours sealing time, while carbon dioxide (CO2) contents increased to 2.9% also in the 20 hours sealing time. The results of this study showed the feasibility of this technique for identifying VOCs from four of the citrus fruit species and its potential as a routine method for physiological studies on citrus fruit or on other fruit species.展开更多
The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twi...The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twice,and broken wall cooking machine processing.The particle size distribution,free polyphenols,bound polyphenols and antioxidant activity of whole fruit pulp prepared by the three kinds of pulverization methods were discussed.The results showed that the particle size distribution of the whole fruit pulp by wet superfine grinding was more concentrated compared with the broken-wall cooking machine processing,and the total phenols dissolution rate of the navel orange whole pulp was increased by 6.9%,and the total flavonoid dissolution rate was increased by 13.5%.The results also suggested that wet superfine grinding twice could improve 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging activity of polyphenols in the whole fruit pulp,wet superfine grinding once and wet superfine grinding twice also could obviously enhance the reducing power and iron reduction ability of polyphenols in the whole fruit pulp.In conclusion,wet superfine grinding could increase both the polyphenol content and antioxidant activity of navel orange whole fruit pulp,it can be used as a pretreatment processing method for preparing navel orange whole fruit pulp.展开更多
Physico-chemical composition of sweet orange (Citrus sinensis L.) cv. blood red was determined in relation to different storage conditions and micronutrients application at department of horticulture, Agricultural U...Physico-chemical composition of sweet orange (Citrus sinensis L.) cv. blood red was determined in relation to different storage conditions and micronutrients application at department of horticulture, Agricultural University Peshawar, Pakistan during 2006-2007 and 2007-2008. The post-harvest quality of sweet orange was evaluated for 60 days storage with 20 days intervals. Fruit were harvested after the foliar application of zinc and boron in two consecutive seasons. The harvested fruits were stored at an ambient temperature (ATS) of 25 + 2 ℃ and at low temperature storage (LTS) of 15 ± 2 ℃ with 60%-70% relative humidity (RH) for 60 days. Sweet oranges stored at LTS maintained better fruit quality than ATS. The foliar application of zinc and boron significantly enhanced fruit juice content, total soluble solids (TSS), ascorbic acid (AA) and non-reducing sugar (NRS) of fruit. However, fruit juice content, TSS and AA were observed significantly higher, when the fruit was treated with high zinc (1%) and low boron (0.02%). The percent of weight loss, disease incidence, TSS and reducing sugar (RS) increased with increasing the storage durations. A reduction was noted in fruit juice, AA and NRS with increasing the storage durations.展开更多
Selection of rootstock is very important for citrus production. Besides its major role on resistance, the rootstock also can affect fruit production and quality. Currently, the main concerns on selection of rootstock ...Selection of rootstock is very important for citrus production. Besides its major role on resistance, the rootstock also can affect fruit production and quality. Currently, the main concerns on selection of rootstock for citrus production are compatibility and resistance, due to less information on the impacts of rootstock to the performance of scion varieties. This study aims to provide information on performances of navel orange varieties on different rootstocks. Three late-ripening navel orange varieties(Citrus sinensis var. Powell, Chislett and Banfield) grafted on seven rootstocks(Swingle citrumelo(C. paradisi× P. trifoliata), Carrizo citrange(C. sinensis×P. trifoliata), X639(C. reticulata×P. trifoliata), MXT(C. sinensis×P. trifoliata), Hongju(C. reticulata), Ziyang Xiangcheng(C. junos) and trifoliate orange(P. trifoliata)) were used as plant materials for comprehensive comparison of the performances on tree growth, fruit yield and quality in 21 scion–stock combinations. Investigation was carried out in these combinations in field nine years after planting. Vigorous growth of all the three late-ripening navel orange varieties was observed on Carrizo citrange with the largest canopy volume at 33.34 m3 and the highest yield at 29.43 kg per tree, but a low yield efficiency at 2.87 kg m–3. On the contrary, those on trifoliate orange had the smallest canopy volume at 10.79 m3 and the lowest fruit yield at 12.51 kg per tree, but the highest yield efficiency at 3.95 kg m–3. Rootstocks did not show significant effects on fruit size, fruit shape index, peel thickness and the edible rate of the fruits, but fruit quality was significantly affected by the rootstocks. Fruits from the trees grafted on trifoliate orange presented the best quality with significantly higher total soluble solids(TSS) content than those on Ziyang Xiangcheng and Hongju, and also the highest ratio of TSS/titratable acidity(TA). The TA content was observed from the fruits on X639 at 0.59 g 100 mL–1. Vitamin C(Vc) content of fruits on Hongju was the highest at 49.25 mg 100 mL–1. Growth vigor of the trees was positively correlated with fruit yield at an extremely significant level. The canopy volume was negatively correlated with yield efficiency, but positively correlated with compatibility index. Results of this study indicated that the rootstock has great impacts on the growth vigor of the tree, yield efficiency and quality of the fruit. In order to achieve good quality and yield efficiency for navel orange production, less growth vigor rootstock such as trifoliate orange is highly recommended.展开更多
Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit.So,choice of rootstock for a specific growing region is an important decision for a grower to make whe...Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit.So,choice of rootstock for a specific growing region is an important decision for a grower to make when establishing a commercial citrus orchard.This study was undertaken to assess effects of rootstock and location on quality of orange fruit.The study was conducted over two consecutive years(2017/18 and 2018/19).Scions from the Gunda Gundo orange grove were grafted on rough lemon and sour orange rootstocks and planted in Tigray and Afar,Ethiopia at four sites(Abala,Agulae,Adiha and Rama).The experiment was laid out in Randomized Complete Block Design(RCBD)with four replications.Data on different physico-chemical and bioactive compounds were collected and analyzed using R software(version 4).Compared to sour orange,rough lemon rootstock revealed higher fruit mass(151.96 g,195.38 g),fruit length(62.27 mm,68.88 mm)and fruit diameter(65.58 mm,71.3 mm),in 2017/18,2018/19,respectively.Among the four locations(Abala,Agulae,Adiha and Rama),higher juice percentage was found in Adiha(43.47%in 2017/18)and Abala(49.87%,in 2018/19).In 2017/18 higher total soluble solid(TSS,13.87%),TSS/acid ratio(19.18)and fruit rag(32.77%),were obtained at the Rama site.On the one hand,higher vitamin C(826.6 mg·kg^(-1))and total phenolic content(208 mg·kg^(-1 )GAE)were recorded at Agulae than Abala,Adiha and Rama sites from sour orange rootstock.High TSS,TSS/acid ratio and antioxidant were recorded from orange fruits at Rama site.This was expected to have resulted from hot climate conditions at the site.Besides,at a relatively cooler condition of the Agulae site,high phenolic,reduced ferric power and high vitamin C were recorded.Rough lemon rootstock improved fruit size,while rootstock did not affect the contents of TSS,TSS/acid ratio across the sites in both harvesting years.展开更多
In Egypt, oranges are the most important citrus crops for local consumption or export. It represents approximately 72.2% of the total Egyptian citrus production in 2019/2020. The main cultivated variety of orange is t...In Egypt, oranges are the most important citrus crops for local consumption or export. It represents approximately 72.2% of the total Egyptian citrus production in 2019/2020. The main cultivated variety of orange is the Washington navel orange and it is more popular because of its delicious taste, nutrition, and its seedless besides being rich in vitamin C. Washington navel orange is susceptible to fruit cracking, and it is a common physiological disorder that takes place during fruit development. This work aims to investigate the negative effect of fruit cracking in reducing the yield and quality of Washington navel orange produced in Egypt by studying major economic indicators and estimating an economical evaluation of using treatment of Washington navel orange during the period time of 2007/2008 until 2019/2020. Results showed that fruit areas and production of Washington navel orange represented about 52.9% and 53.2% of fruit areas and production of orange during the study period. However, the yield was unstable with a significant annual growth rate of about 1.1%. Also, the last mentioned treatment achieved a high price for farmers by about 5.1% and total revenue of about 3.2% during the study period. Nowadays, Egypt has become the largest exporter of oranges in the world within the last year and the achieved earnings reached $661 million in 2019/2020. In addition, results showed that evaluation of using a treatment to reduce the rate of Washington navel orange cracking was economical to be applied.展开更多
[Objective] The aim was to explore fertilizers with different proportions of N, P and K on citrus fruit cracking and to seek best treatment in preventing fruit cracking. [Method] Compound fertilizers with different pr...[Objective] The aim was to explore fertilizers with different proportions of N, P and K on citrus fruit cracking and to seek best treatment in preventing fruit cracking. [Method] Compound fertilizers with different proportions of N, P and K were prepared, supplemented by leaf fertilizers with varying mineral elements. [Result] It is proved the treatment II containing spring fertilizers (N:P2O5:K2O=20:10:10), summer fertilizers (N:P2O5:K2O=16:8:16), and leaf fertilizers with calcium nitrate solu- tion (0.5%) achieved the best prevention effects of fruit cracking. In the meantime, N-to-K ratio and N-to-Ca ratio were proved of positive correlation with cracked fruits, and the higher the ratios, the higher the proportion of cracked fruits, vice versa. On other hand, Ca-to-K ratio was of negative correlation with cracked fruits, and the higher the ratio, the lower the proportion of cracked fruits. [Conclusion] In practical production, fertilization should be conducted as per soil moisture content, tree growth, and seasons, in a balanced and comprehensive way.展开更多
Timely detection of Mediterranean fruit fly (Medfly) is very important so that eradication action can be taken on time. The larvae stage of this insect is the most dangerous stage as it is within the pulp of the fruit...Timely detection of Mediterranean fruit fly (Medfly) is very important so that eradication action can be taken on time. The larvae stage of this insect is the most dangerous stage as it is within the pulp of the fruit, making it hard to detect by visual inspection. In most countries at ports of entry the inspector check a small sample of fruit by visual inspection or by cutting the produce and searching for fungus and pests. This paper will investigate a quick, reliable and sensitive method to determine the presence of fruit flies. Our research focuses on developing the technology for detecting hidden infestations by using the Head Space-Soild Phase Micro Extraction (HS-SPME) method coupled with Gas Chromatography-Mass Spectrocopy (GC-MS) technique. Five different types of fruit were infested with an early stage of Medfly Ceratitis capitata Wiedemann (Diptera: Tephidae). We investigated to detect the differences in volatile organic compounds (VOC’s) between infested and non- infested fruits by using HS-SPME with (GC-MS). The results indicated that for few chemicals no significant differences between infested and non-infested fruit can be seen, especially in the fruits with first instar. However, in case of third instar larvae infested fruits significant differences in the chemicals can be seen as compare to non infested fruits and other instar infestations. These chemicals include ethyl (Z)-2 butenoate, 2-heptanone, anisole, β-cis-ocimene, 1,3,7-nonatriene,4,8-dimethy-,ethyl octyate, isoamyl caproate and 1β,4βh,10βh- guaia-5,11-diene, in apple. Ethyl (Z)-2-butenoate, (+)-2-bornanone, (-)-trans- isopiperitenol, methyl caprate, caryophyllene and farnesene in orange. Butanoic acid, 3-methyl-,2-methylbutul acetate, sabinene, β-myrcene, octanoic acid, methyl ester, dihydrocarvone, (-)-trans-isopiperitenol and ethyl laurate in mandarin. Butyl 2-methylbutanoate, terpinen-4-ol, P-menth-8-en-2-one, E-,(3E,7E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene and dodecanoic acid, ethyl ester in lemon. Decane, 3-methyl-, p-menth-1,4(8)-diene, 1-undecene and α-cubebene in avocado. Thus, the VOC’s method could provide a possible tool for detecting tephritid larvae and this method could be adopted by industries importing and exporting fruit.展开更多
文摘The yield of sugar orange is closely related to meteorological conditions in the flowering and fruiting period, and meteorological disasters at the flowering and early fruiting stage seriously affect its yield. To study influences of meteorological disasters in the flowering and early fruiting stage on sugar orange industry in Guilin, meteorological disasters in the flowering and early fruiting stage and its defense measures were analyzed and studied. The flowering and early fruiting stage of sug- ar orange in Guilin is from March to June, and sudden change of temperature, thunderstorm, hale, hail, rainstorm and other natural disasters can cause the falling of large numbers of flowers and young fruit, damage of tree body, reduction of fruit in quantity, and decrease of its yield. Timely understanding information of disastrous weather and implementing management of water and fertilizer can effectively reduce the loss caused by meteorological disasters and ensue high quality and high yield of sugar orange.
基金fund by the Major Science and Technology Program (2009ZX07102-004),Chinathe IPNI (International Plant Nutrition Institute) Program,Canada (2009ZX07102-004)
文摘Based on ASP.NET,a orange fruit tree fertilizer expert system software was developed.The system could simulate and decide an annual fertilization plan for young and mature trees in terms of geographical position and climate.This paper introduced the design conditions,framework,production,and deployment of the system.It exhibited characters of orange specialty and was a typical online agriculture expert system.The use of the system for orange fruit management could decrease production cost,guarantee orange quality and improve economical benefit at the same time.Farmer using the system saved N input by 41-238 g/plant,P2O5 input 3-24 g/plant,and K2O input 1-36 g/plant,and got higher yield by 6-17 kg/plant.
基金supported by a grant from the National Natural Science Foundation of China(NSFC,31470408)the Science and Technology Support Project of Chongqing,China(cstc2014fazktjcsf 80031)+1 种基金the Fundamental Research Funds for the Central Universities,China(XDJK2016 A012XDJK2013 A002)
文摘This study aimed to provide a theoretical basis for adopting suitable cultivation measures to tackle calcium (Ca) deficiency in citrus leaves. The Newhall navel orange (Citrus sinensis Osbeck) canopy was sprayed with 20.0 mmol L-1 of Ca(NO3)2 during physiological fruit drop period, fruit expanding period, and fruit maturing period on 30, 90, and 210 days after full bloom (DAFB), respectively, and its effects on leaf gas exchange parameters and leaf mineral nutrition and fruit quality were analyzed. The results showed that: (1) The photosynthetic rate (ACO2) at 9:00 a.m. and 16:00 p.m. of fruit expanding period with 30 and 90 DAFB Ca(NO3)2treatments slightly or significantly improved mainly by decreasing stomatal limitation and nonstomatal limitation, respectively. (2) Compared with control (CK), the Ca concentration in leaves with 30, 90, and 240 DAFB Ca(NO3)2 treatments increased by 127.16; 97.53, and 33.33%, respectively, and the leaf magnesium concentra- tion also increased by more than 32.26%. However, Ca(NO3)2 canopy spraying on 30 DAFB significantly reduced the leaf potassium concentration, by 22.14% compared with CK. (3) Ca(NO3)2 canopy spraying on 30 DAFB decreased the second fruit drop rate by 30.55% and increased the weight per fruit by 25.04%, thus resulting in a significant increase in citrus yield. (4) Spraying Ca(NO3) on 30 DAFB mainly affected the metabolism of titratable acid (TA) to improve the maturity of citrus fruits. Whilst it improved the external quality and the coloring of citrus fruit significantly. Therefore, Ca(NO3)2 canopy spraying during physiological fruit drop period has a better influence on the tree character and fruit quality of Newhall navel orange (Citrus sinensis Osbeck).
文摘An optimum method has been developed for extracting volatile organic compounds (VOCs) which contribute to the aroma of different species of citrus fruit (orange, lemon, lime, and mandarin). Headspace solid phase microextraction (HS-SPME) combined with gas chromatography (GC) coupled with flame ionization detection (FID) is used as a very simple, efficient and non-destructive extraction method. A three phase 50/30 μm PDV/DVB/CAR fibre was used for the extraction process. The optimal sealing time for volatiles reaching equilibrium from whole fruit in the headspace of the chamber was 20, 16, 8 and 16 hours for lemon, lime, mandarin, and orange respectively. Optimum fibre exposure times for whole fruit were 2, 4, 2 and 2 hours for lemon, lime, mandarin, and orange respectively. Three chamber volumes (500, 1000 and 2000 ml) were evaluated for the collection of VOCs with the 500 ml chamber being selected. The 500ml chamber produced the highest quality peak areas and quantity of extracted volatiles. As a result of fruit respiration, the percentage of oxygen (O2) of all citrus fruit species in 500 ml chamber decreased from 21.8% to 18.8% in the 20 hours sealing time, while carbon dioxide (CO2) contents increased to 2.9% also in the 20 hours sealing time. The results of this study showed the feasibility of this technique for identifying VOCs from four of the citrus fruit species and its potential as a routine method for physiological studies on citrus fruit or on other fruit species.
基金Supported by National Key R&D Program(2017YFD0400701)~~
文摘The navel orange were cleaned and pulverized by a wet superfine grinding and a broken wall cooking machine,then the navel orange whole fruit pulp were obtained by wet superfine grinding once,wet superfine grinding twice,and broken wall cooking machine processing.The particle size distribution,free polyphenols,bound polyphenols and antioxidant activity of whole fruit pulp prepared by the three kinds of pulverization methods were discussed.The results showed that the particle size distribution of the whole fruit pulp by wet superfine grinding was more concentrated compared with the broken-wall cooking machine processing,and the total phenols dissolution rate of the navel orange whole pulp was increased by 6.9%,and the total flavonoid dissolution rate was increased by 13.5%.The results also suggested that wet superfine grinding twice could improve 1,1-diphenyl-2-picrylhydrazyl(DPPH)free radical scavenging activity of polyphenols in the whole fruit pulp,wet superfine grinding once and wet superfine grinding twice also could obviously enhance the reducing power and iron reduction ability of polyphenols in the whole fruit pulp.In conclusion,wet superfine grinding could increase both the polyphenol content and antioxidant activity of navel orange whole fruit pulp,it can be used as a pretreatment processing method for preparing navel orange whole fruit pulp.
文摘Physico-chemical composition of sweet orange (Citrus sinensis L.) cv. blood red was determined in relation to different storage conditions and micronutrients application at department of horticulture, Agricultural University Peshawar, Pakistan during 2006-2007 and 2007-2008. The post-harvest quality of sweet orange was evaluated for 60 days storage with 20 days intervals. Fruit were harvested after the foliar application of zinc and boron in two consecutive seasons. The harvested fruits were stored at an ambient temperature (ATS) of 25 + 2 ℃ and at low temperature storage (LTS) of 15 ± 2 ℃ with 60%-70% relative humidity (RH) for 60 days. Sweet oranges stored at LTS maintained better fruit quality than ATS. The foliar application of zinc and boron significantly enhanced fruit juice content, total soluble solids (TSS), ascorbic acid (AA) and non-reducing sugar (NRS) of fruit. However, fruit juice content, TSS and AA were observed significantly higher, when the fruit was treated with high zinc (1%) and low boron (0.02%). The percent of weight loss, disease incidence, TSS and reducing sugar (RS) increased with increasing the storage durations. A reduction was noted in fruit juice, AA and NRS with increasing the storage durations.
基金financially supported by the National Key R&D Program of China (2018YFD1000101 and2018YFD0201503)the earmarked fund for China Agriculture Research System (CARS-26)+3 种基金the Fundamental Research Funds for the Central Universities,China(XDJK2016B024)the National Citrus Engineering Research Center,China (NCERC)the earmarked fund for Chongqing Special&Economic Agriculture Research System on Late Maturation Citrus,Chinathe Basic Research and Frontier Exploration Projects in Chongqing,China(cstc2018jcyjAX0400)。
文摘Selection of rootstock is very important for citrus production. Besides its major role on resistance, the rootstock also can affect fruit production and quality. Currently, the main concerns on selection of rootstock for citrus production are compatibility and resistance, due to less information on the impacts of rootstock to the performance of scion varieties. This study aims to provide information on performances of navel orange varieties on different rootstocks. Three late-ripening navel orange varieties(Citrus sinensis var. Powell, Chislett and Banfield) grafted on seven rootstocks(Swingle citrumelo(C. paradisi× P. trifoliata), Carrizo citrange(C. sinensis×P. trifoliata), X639(C. reticulata×P. trifoliata), MXT(C. sinensis×P. trifoliata), Hongju(C. reticulata), Ziyang Xiangcheng(C. junos) and trifoliate orange(P. trifoliata)) were used as plant materials for comprehensive comparison of the performances on tree growth, fruit yield and quality in 21 scion–stock combinations. Investigation was carried out in these combinations in field nine years after planting. Vigorous growth of all the three late-ripening navel orange varieties was observed on Carrizo citrange with the largest canopy volume at 33.34 m3 and the highest yield at 29.43 kg per tree, but a low yield efficiency at 2.87 kg m–3. On the contrary, those on trifoliate orange had the smallest canopy volume at 10.79 m3 and the lowest fruit yield at 12.51 kg per tree, but the highest yield efficiency at 3.95 kg m–3. Rootstocks did not show significant effects on fruit size, fruit shape index, peel thickness and the edible rate of the fruits, but fruit quality was significantly affected by the rootstocks. Fruits from the trees grafted on trifoliate orange presented the best quality with significantly higher total soluble solids(TSS) content than those on Ziyang Xiangcheng and Hongju, and also the highest ratio of TSS/titratable acidity(TA). The TA content was observed from the fruits on X639 at 0.59 g 100 mL–1. Vitamin C(Vc) content of fruits on Hongju was the highest at 49.25 mg 100 mL–1. Growth vigor of the trees was positively correlated with fruit yield at an extremely significant level. The canopy volume was negatively correlated with yield efficiency, but positively correlated with compatibility index. Results of this study indicated that the rootstock has great impacts on the growth vigor of the tree, yield efficiency and quality of the fruit. In order to achieve good quality and yield efficiency for navel orange production, less growth vigor rootstock such as trifoliate orange is highly recommended.
基金supported by the Open Society Foundation-Africa Climate Change Adaptation Initiative(OSF-ACCAI Grant No.OR2014-18350)。
文摘Rootstocks have a significant influence on adaptation to biotic and abiotic stress conditions and quality of fruit.So,choice of rootstock for a specific growing region is an important decision for a grower to make when establishing a commercial citrus orchard.This study was undertaken to assess effects of rootstock and location on quality of orange fruit.The study was conducted over two consecutive years(2017/18 and 2018/19).Scions from the Gunda Gundo orange grove were grafted on rough lemon and sour orange rootstocks and planted in Tigray and Afar,Ethiopia at four sites(Abala,Agulae,Adiha and Rama).The experiment was laid out in Randomized Complete Block Design(RCBD)with four replications.Data on different physico-chemical and bioactive compounds were collected and analyzed using R software(version 4).Compared to sour orange,rough lemon rootstock revealed higher fruit mass(151.96 g,195.38 g),fruit length(62.27 mm,68.88 mm)and fruit diameter(65.58 mm,71.3 mm),in 2017/18,2018/19,respectively.Among the four locations(Abala,Agulae,Adiha and Rama),higher juice percentage was found in Adiha(43.47%in 2017/18)and Abala(49.87%,in 2018/19).In 2017/18 higher total soluble solid(TSS,13.87%),TSS/acid ratio(19.18)and fruit rag(32.77%),were obtained at the Rama site.On the one hand,higher vitamin C(826.6 mg·kg^(-1))and total phenolic content(208 mg·kg^(-1 )GAE)were recorded at Agulae than Abala,Adiha and Rama sites from sour orange rootstock.High TSS,TSS/acid ratio and antioxidant were recorded from orange fruits at Rama site.This was expected to have resulted from hot climate conditions at the site.Besides,at a relatively cooler condition of the Agulae site,high phenolic,reduced ferric power and high vitamin C were recorded.Rough lemon rootstock improved fruit size,while rootstock did not affect the contents of TSS,TSS/acid ratio across the sites in both harvesting years.
文摘In Egypt, oranges are the most important citrus crops for local consumption or export. It represents approximately 72.2% of the total Egyptian citrus production in 2019/2020. The main cultivated variety of orange is the Washington navel orange and it is more popular because of its delicious taste, nutrition, and its seedless besides being rich in vitamin C. Washington navel orange is susceptible to fruit cracking, and it is a common physiological disorder that takes place during fruit development. This work aims to investigate the negative effect of fruit cracking in reducing the yield and quality of Washington navel orange produced in Egypt by studying major economic indicators and estimating an economical evaluation of using treatment of Washington navel orange during the period time of 2007/2008 until 2019/2020. Results showed that fruit areas and production of Washington navel orange represented about 52.9% and 53.2% of fruit areas and production of orange during the study period. However, the yield was unstable with a significant annual growth rate of about 1.1%. Also, the last mentioned treatment achieved a high price for farmers by about 5.1% and total revenue of about 3.2% during the study period. Nowadays, Egypt has become the largest exporter of oranges in the world within the last year and the achieved earnings reached $661 million in 2019/2020. In addition, results showed that evaluation of using a treatment to reduce the rate of Washington navel orange cracking was economical to be applied.
文摘[Objective] The aim was to explore fertilizers with different proportions of N, P and K on citrus fruit cracking and to seek best treatment in preventing fruit cracking. [Method] Compound fertilizers with different proportions of N, P and K were prepared, supplemented by leaf fertilizers with varying mineral elements. [Result] It is proved the treatment II containing spring fertilizers (N:P2O5:K2O=20:10:10), summer fertilizers (N:P2O5:K2O=16:8:16), and leaf fertilizers with calcium nitrate solu- tion (0.5%) achieved the best prevention effects of fruit cracking. In the meantime, N-to-K ratio and N-to-Ca ratio were proved of positive correlation with cracked fruits, and the higher the ratios, the higher the proportion of cracked fruits, vice versa. On other hand, Ca-to-K ratio was of negative correlation with cracked fruits, and the higher the ratio, the lower the proportion of cracked fruits. [Conclusion] In practical production, fertilization should be conducted as per soil moisture content, tree growth, and seasons, in a balanced and comprehensive way.
文摘Timely detection of Mediterranean fruit fly (Medfly) is very important so that eradication action can be taken on time. The larvae stage of this insect is the most dangerous stage as it is within the pulp of the fruit, making it hard to detect by visual inspection. In most countries at ports of entry the inspector check a small sample of fruit by visual inspection or by cutting the produce and searching for fungus and pests. This paper will investigate a quick, reliable and sensitive method to determine the presence of fruit flies. Our research focuses on developing the technology for detecting hidden infestations by using the Head Space-Soild Phase Micro Extraction (HS-SPME) method coupled with Gas Chromatography-Mass Spectrocopy (GC-MS) technique. Five different types of fruit were infested with an early stage of Medfly Ceratitis capitata Wiedemann (Diptera: Tephidae). We investigated to detect the differences in volatile organic compounds (VOC’s) between infested and non- infested fruits by using HS-SPME with (GC-MS). The results indicated that for few chemicals no significant differences between infested and non-infested fruit can be seen, especially in the fruits with first instar. However, in case of third instar larvae infested fruits significant differences in the chemicals can be seen as compare to non infested fruits and other instar infestations. These chemicals include ethyl (Z)-2 butenoate, 2-heptanone, anisole, β-cis-ocimene, 1,3,7-nonatriene,4,8-dimethy-,ethyl octyate, isoamyl caproate and 1β,4βh,10βh- guaia-5,11-diene, in apple. Ethyl (Z)-2-butenoate, (+)-2-bornanone, (-)-trans- isopiperitenol, methyl caprate, caryophyllene and farnesene in orange. Butanoic acid, 3-methyl-,2-methylbutul acetate, sabinene, β-myrcene, octanoic acid, methyl ester, dihydrocarvone, (-)-trans-isopiperitenol and ethyl laurate in mandarin. Butyl 2-methylbutanoate, terpinen-4-ol, P-menth-8-en-2-one, E-,(3E,7E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene and dodecanoic acid, ethyl ester in lemon. Decane, 3-methyl-, p-menth-1,4(8)-diene, 1-undecene and α-cubebene in avocado. Thus, the VOC’s method could provide a possible tool for detecting tephritid larvae and this method could be adopted by industries importing and exporting fruit.