Evaluation of rootstocks for Eureka and Lisbon lemons in replant ground in New South Wales

1992 ◽  
Vol 32 (2) ◽  
pp. 205
Author(s):  
RA Sarooshi ◽  
P Broadbent

The yield, growth, fruit quality, and graft compatibility of 2 lemon cultivars Eureka and Lisbon [Citrus limon (L.) Bum. f.], budded onto several new rootstocks, were studied in replant ground.Promising rootstocks for Eureka lemon were 2 new hybrids bred at Gosford, New South Wales, 3798 (Scarlet mandarin x Poncirus trifoliata) and 4017 (Smooth Seville x P. trifoliata), and also Benton citrange and Nelspruit hybrid 639. Trees on the sour orange group of rootstocks including Xingshan, Dai Dai and Baggan yielded 44-63% less than trees on rough lemon rootstocks; but their fruit quality, as evidenced by juice per cent, OBrix, and citric acid (kg/t), was better. The performance of Lisbon lemon was tested on 10 selections of F'. trifoliata, and although trees on Flying Dragon were smaller and yielded about 50% less than on Swingle, Christiansen, Large Flower, and selection 22, results were not significantly (P<0.05) different.

1989 ◽  
Vol 29 (2) ◽  
pp. 273 ◽  
Author(s):  
GAC Beattie ◽  
EA Roberts ◽  
LE Rippon ◽  
CL Vanhoff

The phytotoxicity of petroleum oil sprays to Vakncia orange (Citrus sinensis (L.) Osbeck) on Poncirus trifoliata (L.) Raf. rootstocks was investigated at Kulnura and at Griffith, New South Wales. Four narrow-range petroleum oils, designated as 206, 212, 214 and 238 oils, were applied as high volume sprays in 3 consecutive years. Annual sprays were applied during the spring, summer and autumn months of November, February and April. Some treatments were sprayed once each year, others twice. The single spray per year treatments involved concentrations of 1.2 or 2% of each oil in February or 2% of the 212, 214 and 238 oils in November or in April. A total concentration of 3.2% oil per year of the 2 12,2 14 and 238 oils was applied in February (2%) and in November of the previous year (1.2%) or in April (1.2%) to the double spray treatments. The effect of the sprays on yield variables, percentage juice, �Brix (w/w sucrose), anhydrous citric acid, rind colour and oil content was studied. Rind colour was not affected by any treatment at either location. Significant (P< 0.05), though inconsistent, effects on other characteristics of fruit quality were found. Increase in 50% distillation temperature and rate of application of oils tended to decrease �Brix. The oils did not significantly affect yield at Kulnura. At Griffith, 2% sprays of 238 oil significantly reduced yield by reducing the number of fruit. At both locations, trees sprayed with 2% oil in April tended to have lower yields than those sprayed in November or February at the same rate. The effect of sprays with total concentrations of 3.2% was variable. The 238 oil was the only oil considered to be potentially phytotoxic. This type of oil should not be used at concentrations > 2% from March to November or in consecutive years at any time. They can be used from late spring to early autumn in consecutive years at 1.2%. Variation in the phytotoxicity of oils between locations in south-eastern Australia appears to be related to variation in night temperatures in summer and early autumn which affect flower initiation.


2012 ◽  
Vol 48 (4) ◽  
pp. 563-572 ◽  
Author(s):  
AYDIN UZUN ◽  
UBEYIT SEDAY ◽  
ERCAN CANIHOS ◽  
OSMAN GULSEN

SUMMARYCitrus trees are often exposed to severe infectious diseases. Mal secco caused by Phoma tracheiphila (Petri) Kantschaveli and Gikashvili is one of the most destructive fungal diseases of lemons (Citrus limon Burm. F.). In the present study, antioxidant enzyme activity in different mal secco-resistant and susceptible citrus rootstocks including Cleopatra mandarin (C. reshni Tan.), sour orange (C. aurantium L.), rough lemon (C. jambhiri Lush.), Volkameriana (C. volkameriana Tan. and Pasq.), Carrizo citrange (Poncirus trifoliata L. Raf. X C. sinensis L. Osbeck) and trifoliate orange (P. trifoliata) was investigated. Possible differences in constitutive levels of these antioxidant enzymes and correlations between enzyme levels and mal secco caused by P. tracheiphila were examined. Among the rootstocks, Cleopatra mandarin was found to be resistant to mal secco, whereas rough lemon, sour orange and trifoliate orange were highly susceptible. Total peroxidase (TPX; EC: 1.11.1.7) activity increased in all infected rootstocks. Ascorbate peroxidase (APX; EC: 1.11.1.11) activity increased in most of the rootstocks and no correlation was found between catalase (CAT; EC: 1.11.1.6) activity and mal secco resistance. This study indicates that overall TPX activity is upregulated and APX activity is up- and down-regulated depending on the type of rootstock in response to P. tracheiphila infection.


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