Effect of cultural practices on the manganese status of soil and citrus trees under irrigation.

1954 ◽  
Vol 5 (1) ◽  
pp. 31 ◽  
Author(s):  
J Connor

The occurrence of manganese deficiency in citrus on an experimental orchard established in light horticultural soil in the Murrumbidgee Irrigation Area is reported. There is a relationship between visual symptoms of deficiency and the amount of manganese in the leaf. When the leaf manganese falls to 20 p.p.m., 50 per cent. of the trees show visual deficiency symptoms. Trees on Sweet Orange stock had less manganese and showed more visual deficiency symptoms than trees on Rough Lemon stock. A decrease in soil pH consequent on the addition of ammonium sulphate fertilizer led to a graduated increase in exchangeable soil manganese and leaf manganese. Bringing the calcareous subsoil to the surface consequent on digging trenches for laying agricultural drains led to acute manganese deficiency. Trees on plots tilled during the summer have greater leaf manganese contents than trees on sod plots or plots not tilled but kept free of weeds by herbicidal sprays, but these cultural treatments do not affect the exchangeable soil manganese. Possible reasons for the differences are discussed.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 595c-595
Author(s):  
Ashok K. Alva

The aim of this study was to investigate soil pH and copper (Cu) interactions affecting Cu phytotoxicity to young citrus trees on different rootstocks. Hamlin oranges on either Carrizo citrange, sour orange, or rough lemon rootstocks were grown on Candler fine sand at varying soil pH (5.0, 5.5, 6.0, 6.5) without additional Cu or soil applied Cu (liquid form; 240 kg Cu/ha; nine pre- and five post-planting applications over a period of 43 months). Increasing soil pH increased tree height, canopy volume and trunk diameter of trees on all three rootstocks, regardless of Cu treatments. Tree growth response to an increase in soil pH was greater in Cu amended as compared to unamended treatments. Response to pH increase above 6.0 was marginal as compared to that for pH increase from 5.0 to 6.0. Leaf Cu concentrations showed negligible differences in response to Cu treatments; however, Cu concentrations in fibrous roots increased by 126 to 152% in Cu amended as compared to unamended treatments.


HortScience ◽  
1991 ◽  
Vol 26 (5) ◽  
pp. 576-579 ◽  
Author(s):  
George Yelenosky

One- to 4-year-old sweet orange trees, Citrus sinensis (L.) Osbeck cv. Valencia on rough lemon (C. jambhiri Lush.) rootstock, were used in a series of tests on the depth and stability of supercooling in various parts of greenhouse-grown trees held in pots during controlled freezes. Thermocouples were attached to flowers, fruit, leaves, and wood. Supercooling levels were inconsistent, ranging from – 3C to – 7C. Nucleation was spontaneous and well defined by sharp exotherms. Rapid progression of crystallization (≈ 60 cm·min–1) indicated no major obstacles to ice propagation throughout the tree above soil level. The site of initial freezing was variable, with a tendency for trees to freeze from the base of the stem toward the top. The location of tissue damage did not necessarily correspond to the location of initial freeze event. Freezing in the wood often preceded freezing of flowers.


1948 ◽  
Vol 38 (3) ◽  
pp. 315-322 ◽  
Author(s):  
J. H. Quastel ◽  
E. J. Hewitt ◽  
D. J. D. Nicholas

SUMMARY1. Pot and field experiments were made to compare the effects of thiosulphates and sulphur on the incidence of manganese deficiency in oat, beet and pea grown in two manganese-deficient soils.2. The addition of sodium or calcium thiosulphate to oat plants growing in a manganese-deficient fen soil in boxes markedly reduced symptoms of ‘grey speck’ and increased the soluble manganese content in the leaf tissues, but the effect was transient.3. The growth of beet in this soil in clay pots was improved by the addition of thiosulphates, and also by painting the exterior of the pots with bitumen paint or by covering the surface of the soil with a thin layer of sand. The thiosulphate treatments increased the manganese uptake by the plants and reduced the symptoms of manganese deficiency, particularly when applied to pots painted with bitumen paint.4. Field experiments with an old garden soil deficient in manganese showed that thiosulphate treatments increased the manganese uptake of beet. Placement treatments were more effective than broadcast treatments and greatly improved the growth of beet and reduced or eliminated manganese-deficiency symptoms, without producing any change in soil pH.


Author(s):  
P. Holliday

Abstract A description is provided for Sphaeropsis tumefaciens. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Citrus aurantifolia and other species of Citrus (sweet orange, rough lemon and ortanique). DISEASES: Knot of lime (Citrus aurantifolia) and other species of Citrus including sweet orange, rough lemon and ortanique. The so-called knots are gall-like growths, rounded (1-7 cm diam.) but sometimes elongated, on the stems. These swellings begin by being covered with normal bark which changes to a whitish, rough, cork-like tissue, this extends in size, becoming fissured, with mueh enlarged woody tissue. The knots are firmly attached and may occur in large numbers over considerable lengths of stem which may be girdled and killed. The surface of the knot may become soft and crumbling, but it is hard inside, where black streaking indicates the presence of mycelium. A gall may form up to 40 shoots, from multiple bud formation, some over 1 m long and often themselves bearing knots or galls (witches' broom effect). These abnormal shoots eventually die. Knots can occur on the trunk and severe infection leads to death of the tree. GEOGRAPHICAL DISTRIBUTION: Possible confusion with other similar disease-like symptoms in citrus (and because considerable damage only seems to occur in Jamaica) makes the distribution uncertain (CMI Map 386. ed. 1, 1961). Besides Jamaica it occurs in Florida and has been described from Cameroon (27: 564) and India (40: 533); it has also been reported from Ceylon, Cuba, Egypt, Guyana, Indonesia (Java), Venezuela. Some of these records are considered to be doubtful. TRANSMISSION: Not known.


2011 ◽  
Vol 12 (1) ◽  
pp. 24 ◽  
Author(s):  
Yulu Xia ◽  
Gecheng Ouyang ◽  
Ronald A. Sequeira ◽  
Yu Takeuchi ◽  
Ignacio Baez ◽  
...  

The Asian form of huanglongbing (HLB) is caused by ‘Candidatus Liberibacter asiaticus (Las),’ a phloem-limited bacterium transmitted by the Asian citrus psyllid, Diaphorina citri Kuwayama. Nutrient management, together with other cultural practices such as pruning and irrigation, for mitigation of the disease has been practiced in China for many years. Our literature review, field survey, and interviews with Chinese scientists and growers indicate that these cultural practices were generally ineffective for the disease management. However, a nutritional approach in conjunction with other cultural practices such as irrigation can maintain grove productivity for a certain time depending on the type of citrus species/cultivars, the age of the trees, the propagation method of the plants, the Asian citrus psyllid (ACP) (Diaphorina citri Kuwayama) population, and other factors. Symptomatic mature pommelo (Citrus maxima Merr) and sweet orange (C. sinensis L. Osbeck) plants can commonly survive and maintain a certain level of productivity for an additional 4 to 5 years, even longer assuming vigorous ACP control. Accepted for publication 27 June 2011. Published 3 October 2011.


2005 ◽  
Vol 54 (4) ◽  
pp. 571-571 ◽  
Author(s):  
P. Ramachandran ◽  
J. Agarwal ◽  
A. Roy ◽  
D. K. Ghosh ◽  
D. R. Das ◽  
...  

1991 ◽  
Vol 116 (3) ◽  
pp. 351-358 ◽  
Author(s):  
P. J. Last ◽  
K. M. R. Bean

SUMMARYField experiments in 1987 and 1988 on peaty-loam, Mn-deficient soils of the Adventurers series in Cambridgeshire, UK, tested the response of sugarbeet to three forms of manganese fertilizer supplied as foliar sprays. The influence of a wetter and an adjuvant on manganese absorption and growth was also investigated.Cutonic and chelated forms of Mn, when applied at standard rates, were inefficient at increasing Mn concentrations in plants and alleviating deficiency symptoms during early summer. Mn concentrations in foliage increased rapidly after spraying with manganese sulphate, and most of the deficiency symptoms disappeared. These benefits were usually enhanced when manganese sulphate sprays were used with an adjuvant.Averaged over both years, yield without Mn was 8·83 t sugar/ha; the largest yield, 9·56 t/ha, was obtained with manganese sulphate plus adjuvant. Smaller benefits were obtained with the other forms of Mn. The adjuvant, when used with chelated Mn, appeared to depress sugar yields in both years. The likelihood of reducing the number of sprays required to control Mn deficiency on Fen soils was improved by using an adjuvant with manganous sulphate sprays.


1971 ◽  
Vol 11 (48) ◽  
pp. 123 ◽  
Author(s):  
CR Millikan ◽  
EN Bjarnason ◽  
BC Hanger

Five scions and ten rootstocks were tested in an eight-year trial at Irymple, near Mildura, Victoria. The scions were two old-line Lisbons, a nucellar Eureka, and two old-line Eurekas. Cumulative yields averaged for the ten rootstocks and expressed as a percentage of the best scion were : Rix Lisbon 100, Doncaster Lisbon 99, Frost Nucellar Eureka 95, Rodwell Eureka 89, and Villa Franca Eureka 73. The rootstocks, with their percentage yields in parentheses, were : Rough lemon (100), Cavanagh sweet orange (90), Symons sweet orange (84), Marsh grapefruit (73, Cox sweet orange (74), Cleopatra mandarin (72). Seville sour orange (721, Sampson tangelo (69), Emperor mandarin (69), and Carrizo citrange (30). The poor performance of Carrizo citrange is discussed in terms of virus infection and incompatibility. The incidence and importance of scion overgrowth is also reported and discussed.


1972 ◽  
Vol 12 (55) ◽  
pp. 203 ◽  
Author(s):  
LM Stafford

Two experiments with Navel orange scions (CV. Washington and Leng) on a number of rootstocks were done on three sandy Mallee soils in the Mildura irrigation district. Rootstocks included sweet orange (eight cultivars), rough lemon, mandarin (two cultivars), trifoliate orange, and citrange (two cultivars). In experiment 1 (1949 to 1963) eight sweet orange rootstocks gave similar results in terms of yield and tree size. Leng produced more but smaller fruit than Washington, but total weights were similar. In experiment 2 (1959 to 1969 and continuing) Leng trees were larger, produced more fruit, and on one soil a greater weight of fruit per tree than Washington. Sweet orange rootstocks were usually superior to other rootstocks on each soil type, although rough lemon gave results that were similar and, for a few combinations, superior. Trees on mandarin rootstocks were low producers and small in the early part of the experiment, but by the end of the period were yielding as much fruit as those on sweet orange. Trifoliate rootstocks were unsatisfactory, and citrange intermediate between sweet orange and trifoliate. No fruit quality differences ascribable to rootstock were detected.


1992 ◽  
Vol 32 (8) ◽  
pp. 1141 ◽  
Author(s):  
RA Sarooshi ◽  
RJ Hutton

Juice quality, yield performance, and cropping efficiency of 6 midseason orange varieties (Hamlin, Parramatta, Pineapple, Joppa, White Siletta, and Mediterranean Sweet), together with Seedless Valencia on 4 rootstocks [Troyer citrange, Poncirus trifoliata, rough lemon, and either Benton citrange (coastal) or sweet orange (inland)], were studied for their suitability for both processed and fresh orange juice production. Promising midseason varieties for processed orange juice were Parramatta and Hamlin on Troyer citrange, and Parramatta on P. trifoliata, when grown in coastal districts. Debittered juice of Joppa on Troyer citrange could also be used for processing by early September on the coast. Preferred inland varieties for production of processed orange juice were Mediterranean Sweet and Harnlin on Troyer citrange. Midseason oranges grown inland had higher citric acid levels than the same variety grown on the coast. This resulted in inland fruit having lower ratios of total soluble solids (TSS) to acid, and later maturities, than fruit grown on the coast. Acceptable fresh orange juice was produced from fruit of Parramatta, Hamlin, White Siletta, and Mediterranean Sweet varieties grown on Troyer citrange rootstock in coastal districts; inland, fruit of Mediterranean Sweet, Joppa, Parramatta, and White Siletta varieties on Troyer citrange rootstock produced good quality, fresh orange juice. Hamlin can also be marketed as fresh fruit. In coastal production areas, harvesting can commence from mid July for Hamlin, from mid to late August for Parramata, and from early September for White Siletta and Mediterranean Sweet. Harvest in inland districts for processed juice should commence in mid July for Hamlin and in early September for Mediterranean Sweet, whilst harvest for fresh juice and/or fruit should proceed in early September for Mediterranean Sweet, and in late September for Parramatta, White Siletta, and Joppa. Highest fruit yields and large trees were produced by Parramatta and Joppa on Troyer citrange and rough lemon rootstocks. Most quality characteristics were better for fruit produced on Troyer citrange than on rough lemon. Both Benton citrange and sweet orange performed poorly and are not recommended as rootstocks for midseason oranges. All varieties on Troyer citrange had better yield and TSS/ha than those on P. trifoliata rootstock, which produced smaller but highly cropping efficient trees.


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