Yield,fruit quality,and tree health of ‘Allen Eureka’ lemon on seven rootstocks in Saudi Arabia

Since environmental conditions and cultural practices vary from one area to another, yield, fruit quality, and tree health measurements were conducted over 9 years to evaluate the long-term adaptability and performance to local conditions of ‘Allen Eureka’ lemon (Citrus limon Burm.f.) budded on seven rootstocks in the Najran area of Saudi Arabia. Trees on Citrus macrophylla (CM), Volkamer lemon (VL), and Cleopatra mandarin (Cleo) were the most productive, while trees on Amblycarpa (Amb), rough lemon (RL), Citrus taiwanica (CT), and sour orange (Citrus aurantium L.) (SO) had the lowest yield. Fruit from trees on CM and VL were also the largest in size and had the thickest rind, but were among those that had the lowest juice content and lowest total soluble solids. None of the trees on Cleo, VL, or RL died until the 14th year. However, there was a high mortality rate and severe tree decline on SO, CT, and Amb.     

Evaluation of rootstocks for the Cyprus local lemon variety ‘Lapithkiotiki’

The effect of various rootstocks on yield, yield efficiency, tree size and fruit quality of the local lemon variety ‘Lapithkiotiki’ (Citrus limon (L.) Burm. F.) was studied under Cyprus conditions. Total cumulative yield over 13 years of production was the highest on rough lemon (C. jambhiri Lush) followed by that on Volkameriana (C. volkameriana Ten. & Pasq.), Yuma Ponderosa lemon (C. limon (L.) Burm. F.), sour orange (C. aurantium L.), Citrus macrophylla Wester, Morton citrange (C. sinensis cv. Washington navel × Poncirus trifoliata (L.) Raf.), Yuma citrange, Rangpur lime (C. limonia Obs.), Palestine sweet lime (C. limettioides Tan.), C-32 citrange and Citremon 1449 (C. limon × P. trifoliata), although no statistically significant differences were found between sour orange, the commercial rootstock used in Cyprus, and the other above mentioned rootstocks. Next in order as regards to total cumulative yield was Cleopatra mandarin (C. reticulata Blanko.) followed by Carrizo citrange, with statistically significant differences compared with sour orange. Trees on Citrumelo CPB-4475 (C. paradisi Macf. × P. trifoliata) and C-35 citrange died 3–4 years after grafting. Canopy volume was the lowest for trees on Cleopatra mandarin and Carrizo citrange. Yield efficiency A, expressed as total cumulative yield per trunk cross-sectional area, was the highest on C. macrophylla and lowest on Carrizo citrange. Rootstock significantly affected fruit size and weight, rind thickness, juice content, brix, total acids and brix:acid ratio. The results of the present study reveal that the most promising rootstocks that may replace sour orange for the local lemon variety ‘Lapithkiotiki’ under Cyprus conditions are Volkameriana, Yuma Ponderosa lemon, C. macrophylla and Citremon 1449.     

不同柑橘砧木对锦橙果实品质的影响

 2006—2008年连续3年研究11种砧木对铜水72-1锦橙果实品质的影响。结果表明：不同砧木对果实颜色和内在品质均有影响,其中以卡里佐枳橙为砧的果实亮度最好,黄色度值最高,果实最大,果皮最薄;以路比枳为砧的果实红色度值和固酸比（TSS/TA）最高,果皮最厚;以沃尔卡姆为砧的亮度最差,黄色度值、单果质量和可食率最低,中心柱最小;以C35枳橙为砧的中心柱最大且维生素C含量最低;以光皮酸橙为砧的果实红色度最低而可食率最高;以里其16-6枳为砧的果实可溶性固形物（TSS）含量最高;以孙楚沙橘为砧的果实可滴定酸（TA）和维生素C含量最高,而TSS/TA最低;果实TSS和TA最低的砧木为枸头橙。品质综合评价,性状表现较好的为孙楚沙橘、卡里佐枳橙和C35枳橙,而表现较差的为兰普莱檬和沃尔卡姆柠檬。     

梁平柚矮化砧木的筛选

供试柚品种为梁平柚,砧木为枳、香橙、宜昌橙和酒饼簕、以酸柚砧为对照。1983年秋嫁接,1984年秋定植。7年观察结果表明,酒饼簕、宜昌橙、枳对梁平柚有矮化作用,其中以酒饼簕最明显。枳砧梁平柚定植后第2年(1986年),有1/3的植株试花,第3年全部开花,结果最多的一株达8个;香橙、宜昌橙、酸柚砧(对照)梁平柚定植后第3年试花;酒饼簕砧梁平柚第5年试花。枳砧梁平柚树高、树冠体积、枝条电阻值、枝条节间长度等均明显低于对照。初步认为,枳是梁平柚比较理想的矮化砧木。     

Additional nitrogen fertilization affects salt tolerance of lemon trees on different rootstocks

Irrigation with saline water is one of the major problems in citrus crop in arid and semi-arid regions. Because rootstock and fertilization play an important role in citrus salt tolerance, we investigated the influence of the nitrogen fertilization and rootstock on salt tolerance of 2-year-old potted Fino 49 lemon trees. For that, trees grafted on Citrus macrophylla (M) or Sour orange (SO) rootstocks were watered for 12 weeks with complete nutrient solution containing either 0 mM NaCl (control, C), 50 mM NaCl (S), 50 mM NaCl with an additional 10 mM potassium nitrate (S + N), or 50 mM NaCl with a 1% KNO₃ (S + Nf) foliar spray application. Trees on M were more vigorous than trees on SO and saline treatments reduced leaf growth similarly in trees on both rootstocks. Trees on SO had a lower leaf Cl⁻ and Na⁺ concentration than those on M. Additional soil nitrogen (S + N) decreased leaf Cl⁻ concentration and increased leaf K⁺ concentration in salinized trees on both rootstocks. However, the salinity-induced reduction leaf growth was similar in S + N and S trees. This was due to osmotic effect, beside leaf Cl⁻ and Na⁺ toxicity, played an important role in the growth response of Fino 49 lemon to the salt stress. Additional foliar nitrogen in the S + Nf treatment also reduced leaf Cl⁻ concentration relative to the S treatment but trees from S + Nf treatment had the lowest leaf growth. Net assimilation of CO₂ (ACO₂$A_{\text{C}{\text{O}}_2}$), stomatal conductance (g_s) and plant transpiration were reduced similarly in all three salt treatments, regardless rootstock. Salinity reduced leaf water and osmotic potential such that leaf turgor was increased. Thus, the salinity-induced ACO₂$A_{\text{C}{\text{O}}_2}$ reductions were not due to loss of turgor but rather due to high salt ion accumulation in leaves.     

Growth,yield and fruit quality of ‘Van’ and ‘Stark Hardy Giant’ sweet cherry cultivars as influenced by grafting on different rootstocks

The influence of Adara, CAB 6P, Gisela 5, MaxMa 14, Saint Lucie GF 64 (SL 64), Saint Lucie GF 405 (SL 405), and Tabel rootstocks onto vegetative growth, yield and fruit quality of ‘Van’ and ‘Stark Hardy Giant’ (SHG) sweet cherry cultivars was studied during 10 years after grafting. The experiment was performed in the Ebro Valley (Zaragoza, Spain), on a heavy and calcareous soil. Significant differences in some of these parameters such as vigour, yield, fruit size, soluble solids content (SSC), titratable acidity (TA), skin colour and fruit firmness were examined among rootstocks. In general, the highest vigour, annual and cumulative yield were induced by Adara rootstock, whereas Gisela 5 induced the lowest when grafted with both cultivars. The highest yield efficiency was induced by Gisela 5 due to its low trunk cross-sectional area (TCSA), together with Adara, CAB 6P and Tabel for ‘SHG’ cultivar. Regarding fruit quality, Adara, CAB 6P and MaxMa 14 showed, in general, the highest fruit weight and the more attractive skin colour for both sweet cherry cultivars. Furthermore, the high yield shown by Adara did not significantly affect its fruit size. Cherries of trees grafted on Adara also showed high firmness, which implies a better resistance to post-harvest damage. CAB 6P showed a tendency to induce higher TA. Despite the higher firmness of fruits on Gisela 5 and its tendency to induce higher SSC and ripening index, the smaller size fruits together with the less attractive skin colour resulted in a non-interesting rootstock in terms of fruit quality for our growing conditions. Interesting correlations were found among quality parameters, such as the positive correlation showed by SSC with fruit weight and TA. The work demonstrates that the scion–rootstock combination influences some important sweet cherry attributes such as vigour, yield, fruit size, acidity, skin colour and firmness.     

柑橘果实糖积累与蔗糖代谢酶活性的研究

研究了脐橙、柠檬果实发育过程中汁胞和果皮内糖含量与糖代谢酶活性的变化。结果表明：不同柑橘品种、不同部位糖积累和相关酶活性变化不同。柑橘汁胞和果皮中还原糖含量均高于蔗糖含量。随着脐橙汁胞中糖分的积累,酸性转化酶(SAd)活性持续下降,至采收时几乎为零,说明SAd 的下降与脐橙汁胞糖分积累有很大关系。柠檬汁胞中的中性转化酶(NI)活性随着果实成熟而下降,在成熟时保持极低水平,而此时SAd 活性则较高,是其它酶活性的6倍以上,表明柠檬汁胞中糖分的利用在果实成熟前与NI活性有极大的关系,在成熟期则与高SAd 活性有关。脐橙和柠檬汁胞间糖组分的明显差异和相关酶的变化动态表明蔗糖合成酶(SS)和转化酶在柑橘汁胞糖代谢中可能起到重要作用。     

Effects of gibberellic acid and cycocel on colouring and sizing of lemon

The effects of autumn applications of GA₃ and CCC on colouring and sizing of ‘Lisbon’ lemon (Citrus limon (L.) Burm. f.) were investigated over a period of 6 years. The implications of regulating the colour and size of lemon on extending its harvest were also assessed.A combination of GA₃ at 10 p.p.m. and CCC at 1000 p.p.m. delayed colouring and arrested growth of lemons, thus extending harvest into late spring by increasing the supply of small-sized premium quality fruit. The effects on colouring could be ascribed to the inhibition of carotenogenesis and the decline in the rate of chlorophyll losses which, although primarily GA₃ effects, were enhanced by CCC. Fruit circumference was reduced and juice content was probably less in the early developmental stages.     

Rootstock influence on the incidence of rind breakdown in ‘Navelate’ sweet orange

Summary

The influence of three rootstocks, Carrizo citrange (Citrus sinensis (L.) Osb. × Poncirus trifoliata (L.) Raf.), Cleopatra mandarin (Citrus reshni Hort. ex Tanaka) and sour orange (Citrus aurantium L.) on the incidence and severity of rind breakdown in ‘Navelate’ sweet oranges was studied over seven years in four orchards. The proportion of affected fruit was greater in trees on Carrizo citrange (60% on an average) followed by Cleopatra mandarin (38%) and then on sour orange (9%). There were also significant differences in the severity of the disorder among rootstocks; more than 35% and 20% of fruit from trees on Carrizo citrange and Cleopatra mandarin, respectively, were rejected for commercialization, whereas only 4% of fruit on sour orange was rejected. Cryo-scanning electron microscopy (SEM) of fruit peduncles showed that average diameter of xylem vessel elements of peduncles of fruits on Carrizo citrange rootstock were 6% and 17% larger than those on Cleopatra mandarin and sour orange, respectively. Defoliation of fruit-bearing branches reduced water loss from fruit, maintained fruit peel water potential at a higher value than that of fruit on undefoliated branches and reduced the proportion and severity of affected fruit. It is concluded that fruit-tree water relationships are related to rind breakdown in ‘Navelate’ oranges and low fruit water content might be responsible for the disorder.     

Influence of rootstock on orchard productivity and fruit quality in peach cv. ‘Redhaven’

Summary

We have evaluated the influence of four different peach rootstocks (Prunus pumila,‘GF 655/2’ ,‘Missour’ and ‘GF 677’ as a standard) planted in medium-heavy to heavy soil on phenological events (flowering and harvest date), growth, yield, fruit quality and mortality of peach (P. persica L.) scions of cv. ‘Redhaven’. At the end of flowering, there were no significant differences between the different rootstocks in the years 1999, 2000, 2003 and 2004. In 2001, trees grafted on P. pumila reached the end of flowering 2 d before trees grafted on the other rootstocks. ‘Redhaven’ fruits ripened on the same day on trees grafted on the different rootstocks. The differences were only between years. The results showed that significantly less vigorous trees, according to their trunk cross-sectional area (TCSA) and canopy volume, with the lowest yield, were observed on P. pumila rootstock. The rootstock P. pumila had a significant negative influence on fruit dimensions and mortality was 50%. Trees grafted on ‘GF 655/2’ rootstock produced significantly lower yields than those grafted on ‘GF 677’ or ‘Missour’ rootstocks. Only the ‘GF 655/2’ rootstock had root suckers. Trees grafted on ‘GF 677’ rootstock were significantly more vigorous than on the other rootstocks, and produced the highest yield with good fruit quality. The final canopy volumes of peach trees grafted on the different rootstocks were very different. The most vigorous trees were those grafted on ‘GF 677’ rootstock, where the final tree volume was 12.8 m³. Trees grafted on P. pumila and ‘GF 655/2’ had significantly lower TCSA values than on the other rootstocks.     

Performance of Marsh Seedless Grapefruit on Six Rootstocks in Cyprus

Yield, fruit quality, growth and the levels of 12 elements in the leaves were measured for 12-year-old Marsh Seedless grapefruit trees on six rootstocks. Trees on rough lemon and Cleopatra mandarin were larger than those on sour orange and consistently produced 67 and 23 per cent more fruit respectively than on sour orange. Trees on Palestine sweet lime, Troyer and Morton citranges were the least productive. Three-year means of total soluble solids ranged from 9·4 per cent for fruit from trees on Palestine sweet lime to 11–2 per cent on Cleopatra mandarin. Fruit size was good on all rootstocks but effects of rootstock on levels of Mg, Na, Cl and B in the leaves were statistically significant.     

不同类型柑橘中黄脉病毒衣壳蛋白基因的保守性及复制水平

为研究不同柑橘品种对柑橘黄脉病毒(Citrus yellow vein clearing virus,CYVCV)变异的影响,将CYVCV毒株CQ01嫁接接种于4类共35个柑橘品种,对不同植株中CYVCV的衣壳蛋白(CP)基因进行分析,结果发现仅有少数位点发生了变异。运用RT-qPCR技术检测不同柑橘品种中CYVCV的相对含量,发现甜橙类品种中CYVCV的相对含量最高,墨西哥来檬中CYVCV的相对含量最低。植株中CYVCV的含量与其症状不存在明显的关联。     

Influence of annual fruit shake-removal and Ethrel on citrus yield over four years

Trunk-shake harvesting did not reduce subsequent crops of orange cvs Washington and Leng Navel, Marsh grapefruit or Frost Nucellar Lisbon lemon when they were harvested about the middle of their maturity season, but it reduced subsequent yields of Valencia orange. Ethephon (as Ethrel) reduced the average annual yield of harvested fruit over the four years of the trial for all cultivars except Lisbon lemon. Thus, despite the risk of reducing subsequent cropping, trunk-shake harvesting without the use of Ethrel enables up to 80% of the crop to be removed with the remainder to be hand harvested according to market demand and price.     

琼中绿橙果实品质分析

对海南省琼中县不同地区绿橙的果实外观性状及营养成分等主要品质进行分析。结果表明,琼中绿橙果实圆形,果形指数为0.98;果皮厚度为3.05mm,果皮绿色;单果囊瓣数11.03瓣,果重为171.27g,种子数为14.31粒,种子重2.58g,出汁率56.4%;可溶性固形物为10.89%,可滴定酸为0.55%,固酸比为20.24,Vc含量为47.33mg/100g。这些分析旨在为琼中绿橙品质选育和优质栽培提供一定的参考。     

Long-term performance of ‘Ellendale’ mandarin on seven commercial rootstocks in sub-tropical Australia

‘Ellendale’ mandarin (Citrus reticulata Blanco) on seven commercially important rootstocks was assessed over a 26-year period on a site not previously planted to citrus. Tree yield data collected each season from 1969 to 1991 showed that yields were highest on ‘Lockyer’ rough lemon (C. jambhiri Lush) and lowest on ‘Emperor’ mandarin. Yields for the two citranges (C. sinensis (L.) Osbeck × Poncirus trifoliata (L.) Raf.), ‘Troyer’ and ‘Carrizo’, were intermediate, and somewhat higher than those for two selections of sweet orange (C. sinensis (L.) Osbeck), ‘Parramatta’ and ‘Joppa’. Linear regression was used to examine changes in yielding pattern across the 23 seasons of fruit production. This revealed that ‘Troyer’ was comparable with the rough lemon selections throughout most of the experiment and significantly higher than ‘Carrizo’ during certain periods in the middle of the experiment. Similarly, while ‘Joppa’ and ‘Parramatta’ produced near-identical results during most of the experiment, ‘Joppa’ out-performed ‘Parramatta’ toward the end of the experiment. ‘Emperor’ showed a low yield trend throughout the experiment, often more than 50 kg per tree per year less than the rough lemon and citrange selections. Detailed assessment of biennial bearing showed a significant pattern commencing when trees were approximately 15 years old and intensifying until the end of the experiment. However, rootstock had no effect on the biennial bearing behaviour of ‘Ellendale’ mandarin. Correlations of cumulative yields at each harvest date with the final cumulative yield (for 23 seasons of cropping) showed instability up until approximately the eighth year of cropping after which it increased steadily, suggesting that in similar experiments there may be only marginal value in assessing yields beyond about the 10th season. Fruit quality assessments made in two consecutive seasons showed expected trends, with rough lemon (both ‘Lockyer’ and ‘Mazoe’) producing the largest and heaviest fruit, with thicker rinds, lower juice content, and lower Brix. The citrange selections (‘Troyer’ and ‘Carrizo’) resulted in fruit quality comparable to the sweet oranges (‘Parramatta’ and ‘Joppa’), with ‘Troyer’ producing significantly higher Brix levels than any other rootstock. All rootstocks produced leaf nutrient levels close to the desirable range, with significant differences for the elements P, Mg, Ca, Mn, and B. These differences separated the seven rootstocks into categories consistent with their genetic relatedness.     

Orange varieties as interstocks increase the salt tolerance of lemon trees

Summary

We investigated the ability of interstocks to increase salt tolerance in lemon trees. We compared 2-year-old ‘Verna’ lemon trees [Citrus limon (L.) Burm.; VL] grafted on Sour Orange (C. aurantium L.; SO) rootstock either without an interstock (VL/SO), or interstocked with ‘Valencia’ orange (C. sinensis Osbeck; VL/V/SO), or with ‘Castellano’ orange (C. sinensis Osbeck; VL/C/SO). Trees were grown under greenhouse conditions and supplied with nutrient solutions containing 0, 30, or 60 mM NaCl. Reductions in leaf growth caused by salt treatment were greatest in non-interstocked (VL/SO) trees, followed by VL/C/SO trees, and were the least in VL/V/SO trees. Although the levels of Cl^? and Na⁺ ions in the roots and stems were not affected by either interstock, leaf concentrations of Cl^? and Na⁺ were higher in VL/SO trees than in VL/C/SO or VL/V/SO trees, suggesting that an interstock in Citrus trees could limit the uptake and transport of such ions to the shoots. Saline-treated VL/SO trees also tended to have the lowest shoot:root (S:R) ratios; so, overall, there was a negative relationship between S:R ratio and leaf Cl- ion concentration. Leaf transpiration (E_leaf) may also be involved in the reduction in leaf Cl^? concentration, as interstocked trees had lower E_leaf values at mid-day than non-interstocked trees. Salinity increased leaf concentrations of Ca²⁺ in VL/C/SO trees and increased both leaf K⁺ and N concentrations in all trees, regardless of interstock. Salinity reduced leaf water potentials and osmotic potentials, such that leaf turgor was increased in all trees.     

Chemical Analysis and Taste Panel Evaluation of the Fruit Quality of Valencia Late Oranges on Two Rootstocks

Samples of fruit from Valencia orange trees, grafted on either Volkameriana or sour orange rootstocks were examined after standard commercial shipment and handling. Tests demonstrated differences in physical properties and chemical composition due to the rootstocks, and in acceptability as judged by a large taste panel. Fruit from trees grafted on Volkameriana was inferior in a number of respects, notably ease of peeling and flavour; juiciness and ascorbic acid content were also lower.     

Rootstocks influence fruit oleocellosis in ‘Hamlin’ sweet orange (Citrus sinensis L. Osbeck)

Oil spotting or oleocellosis, is a major problem in citrus crops. As the rootstock and fertilization play important roles in citrus growth and fruit development, we investigated the influence of different rootstocks on the growth, mineral nutrition metabolism, water relations, and fruit oleocellosis of eight-year-old field ‘Hamlin’ sweet orange trees. Trees grafted onto Lichi16-6 trifoliata (Poncircus trifoliate) had the greatest rate of oleocellosis (RO), and trees grafted onto Goutou orange (Citrus aurantium) had the greatest degree of oleocellosis (DO). In contrast, trees grafted onto Rangpur lime (Citrus limonia Osbeck) had the lowest RO and DO. Trees were the most vigorous on Rangpur lime rootstocks, followed by Lichi16-6 trifoliata, and then Goutou orange. In addition, because the scion/stock girth ratio showed significant correlations with the RO and DO, oleocellosis parameters can be a good indicator of scion/stock affinity. The total N, total P, Ca²⁺, and Mg²⁺ in leaves from trees on Rangpur lime were significantly lower than in leaves from trees on Goutou orange or Lichi16-6 trifoliata. In addition, the RO showed a significant correlation with the leaf Ca²⁺ and S concentrations and with the peel Mg²⁺ concentration. The DO was significantly correlated with the total peel N and S concentrations. In addition, the RO showed a significant correlation with the net assimilation of CO₂ (ACO₂), stomatal conductance (GS), transpiration rate (ET), and water-use efficiency (WUE). However, the DO showed a significant correlation with the GS, ACO₂, and WUE. Taken together, these results indicate that rootstocks affect the development of oleocellosis in ‘Hamlin’ sweet orange due to their effects on the mineral nutrition balance and water relations.     

纽荷尔和清家脐橙果实大量矿质营养元素含量与累积变化

在重庆北碚,以30年生枳砧清家脐橙和纽荷尔脐橙为材料,分析果实生长发育过程中N、P、K、Ca、Mg和S等6种大量营养元素含量和累积量变化。结果表明,果实生长发育过程中,纽荷尔和清家果实中N、P、Mg和S含量4月最高,Ca在10月最高,纽荷尔和清家K含量分别在9月和7月最高;Ca的主要累积时期,纽荷尔脐橙果实为6—7月和9—10月,清家脐橙果实为6月、8月和10月;除Ca外的其他大量矿质营养元素累积量较大的时期,纽荷尔和清家脐橙果实的总体上均为6—9月和11月,但清家脐橙累积最高峰一致出现在6月,纽荷尔脐橙累积最高峰至少推迟1个月左右。     

海红果冻藏品质分析

以海红果特优品种"晋海1号"及内蒙古清水河县的2个实生品种为试材,通过测定可溶性固形物含量、可滴定酸含量、固酸比、出汁率以及果实硬度,研究了不同解冻方式、冻藏时间以及冻藏过程中的解冻次数对海红果品质的影响,以期为海红果冻果加工工艺的提升提供参考依据。结果表明:2种实生海红果的可溶性固形物含量高于"晋海1号",出汁率低于"晋海1号";随着冻藏时间延长,3种海红果的出汁率均逐渐升高;经水浴解冻海红果的可溶性固形物含量低于微波解冻和空气解冻;可溶性固形物含量随着解冻次数增加逐渐降低;与未经解冻海红果相比,经解冻海红果的出汁率显著提高。