Agrobacterium rhizogenes. [Descriptions of Fungi and Bacteria].

1965 ◽  
Author(s):  
A. C. Hayward
Keyword(s):  
Geographical Distribution ◽  
Agrobacterium Rhizogenes ◽  
Apple Trees ◽  
Untreated Soil ◽  
Pratylenchus Vulnus ◽  
Nursery Stock ◽  
Small Roots ◽  
Lesion Nematode ◽  
One Year ◽  
Fibrous Roots

Abstract A description is provided for Agrobacterium rhizogenes. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Maluspumila, Rosa spp., Rubus spp. A further 23 hosts representing 22 genera in 12 families are listed by Elliott (31: 105), p. 4. DISEASE: Hairy root of apple, pear, raspberry, and rose. Symptoms on apple consist of a very large number of small roots protruding from the stems or roots or from localized hard swellings at graft unions, or in roses at the ends of cuttings or at disbud scars (43: 487). These malformations may be fleshy at first but eventually become fibrous. Distinguished from crown gall caused by A. tumefaciens, by the production of fibrous roots on the surface of the gall. Apple trees inoculated with A. rhizogenes became stunted whilst trees infected with A. tumefaciens were not significantly smaller than controls (38: 527). Inoculation of apple trees with mixed cultures of the two species resulted in gall formations showing intergrading features characteristic of both diseases (11: 461). The two pathogens also produce distinct symptoms on rose (43: 487). GEOGRAPHICAL DISTRIBUTION: Widely distributed in apple nurseries and orchards in the U.S.A. Also recorded on rose in Calif, and Texas (43: 487; 19: 348; 16: 613). Outsize the U.S.A., there are few definite records. There are reports from Japan (Fujioka, 32: 278, p. 12), Bulgaria (13: 493), France (43: 2639), and two unconfirmed from Italy (15: 774; 25: 493). Records given by Hedgecock (Bull. Bur. Pl. Ind. U.S. Dep. Agric. 186: 12, 1910) of the occurrence of the pathogen in Canada, Germany and the Netherlands have not been confirmed and are probably incorrect (CMI Map 140). TRANSMISSION: Agrobacterium rhizogenes is exclusively a wound pathogen (13: 776), and is readily disseminated on nursery stock which may become infected from soil or by tools contaminated with the pathogen when cuttings or grafts are made. Infection is also spread in apple stocks by insects which eat the galls and other underground parts. On rose, the bacteria may penetrate roots through injuries causes by the root-lesion nematode, Pratylenchus vulnus (43, 481). Survival in steamed or untreated soil for more than one year has been demonstrated, and virulence has been maintained in culture for over 19 years (40: 513).

scholarly journals Chemical Defoliation of Apple and Pear Nursery Stock

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 665b-665
Author(s):  
D.E. Deyton ◽  
C.E. Sams ◽  
J.C. Cummins ◽  
R.E. Myers ◽  
M.A. Halcomb
Keyword(s):  
Block Design ◽  
Dry Weight ◽  
Old Field ◽  
Apple Trees ◽  
Nursery Stock ◽  
Randomized Complete Block Design ◽  
Nursery Trees ◽  
Pear Trees ◽  
One Year ◽  
Treated Apple

Hand-defoliation of field-grown `Golden Delicious' apple and `Bradford' pear nursery trees before autumn digging is a major production cost. One-year-old field-grown trees were sprayed to runoff on 18 Oct. 1994 with; 1) 1% FeEDTA, 2) 1% CuEDTA, 3) 1% ZnEDTA, 4) 100 ppm Harvade, 5) 50 ppm Dropp, 6) 500 ppm Folex, or 7) 2.5% EDTA or 8) leaves were removed by hand or 9) leaves left on trees (control). Treatments were arranged in a randomized complete-block design, with three trees/plot and four replications. Leaves on each tree were counted before treatment and 7, 14, 21, 28, and 35 days after treatment (DAT). One tree per plot was dug, stored until February and grown the following summer. Nontreated apple and pear trees had 13% and 38% defoliation, respectively, 35 DAT. CuEDTA treated apple trees had 62% and 93% defoliation 7 and 14 DAT, respectively. Pear trees treated with Cu had 18% and 100% defoliation 7 and 14 DAT, respectively. Treatment with FeEDTA resulted in 96% defoliation of pear within 7 DAT but only 57% defoliation of apple 35 DAT. ZnEDTA, Harvade, Folex, or Dropp did not significantly promote defoliation. Copper-treated apple trees had less budbreak than nontreated trees but similar budbreak as hand-defoliated trees. None of the treatments influenced budbreak of pear. None of the treatments affected the cumulative dry weight of trees at the end of the next growing season.

scholarly journals Control of Pratylenchus vulnus on American Boxwood

1985 ◽  
Vol 3 (1) ◽  
pp. 20-22
Author(s):  
Austin Hagan ◽  
Charles Gilliam
Keyword(s):  
Plant Growth ◽  
Nematode Control ◽  
Pratylenchus Vulnus ◽  
Lesion Nematode ◽  
One Year

Post-plant applications of Nemacur 15G, Vydate 10G, Furadan 10G, and Temik 15G controlled lesion nematode, Pratylenchus vulnus, on roots of Amencan boxwood. Combination of fall and spring nematode applications provided season long nematode control. One year after application, significant increases in shoot numbers and plant growth occurred with treated plants compared to nontreated plants.

Herbicide Effects on Weed Control and Shoot Growth of Young Apple (Malus sylvestris) and Peach (Prunus persica) Trees

1994 ◽  
Vol 8 (4) ◽  
pp. 840-848 ◽  
Author(s):  
Chester L. Foy ◽  
Susan B. Harrison ◽  
Harold L. Witt
Keyword(s):  
Shoot Growth ◽  
Field Experiments ◽  
Prunus Persica ◽  
Weed Species ◽  
Apple Trees ◽  
Herbicide Treatments ◽  
One Year ◽  
Broadleaf Species ◽  
Old Trees ◽  
Peach Trees

Field experiments were conducted at two locations in Virginia to evaluate the following herbicides: alachlor, diphenamid, diuron, metolachlor, napropamide, norflurazon, oryzalin, oxyfluorfen, paraquat, pendimethalin, and simazine. One experiment involved newly-transplanted apple trees; the others, three in apple and one in peach trees, involved one-year-old trees. Treatments were applied in the spring (mid-April to early-May). Control of annual weed species was excellent with several treatments. A broader spectrum of weeds was controlled in several instances when the preemergence herbicides were used in combinations. Perennial species, particularly broadleaf species and johnsongrass, were released when annual species were suppressed by the herbicides. A rye cover crop in nontreated plots suppressed the growth of weeds. New shoot growth of newly-transplanted apple trees was increased with 3 of 20 herbicide treatments and scion circumference was increased with 11 of 20 herbicide treatments compared to the nontreated control. Growth of one-year-old apple trees was not affected. Scion circumference of one-year-old peach trees was increased with 25 of 33 herbicide treatments.

Melampsora medusae. [Descriptions of Fungi and Bacteria].

1975 ◽  
Author(s):  
J. Walker
Keyword(s):  
New Zealand ◽  
Geographical Distribution ◽  
Northern Hemisphere ◽  
Populus Deltoides ◽  
Leaf Damage ◽  
Main Method ◽  
Melampsora Medusae ◽  
Nursery Stock ◽  
Eastern Australia ◽  
Incremental Growth

Abstract A description is provided for Melampsora medusae. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Pycnia and aecia on Coniferae, especially Larix and Pseudotsuga, less commonly on Pinus and other genera (Ziller, 1965). Uredinia and telia on species of Populus, especially Populus deltoides, and its varieties and hybrids P. balsamifera, P. nigra var. italica and others. Its exact host range on species of Populus is not known due to confusion with other species of Melampsora and to uncertainty in the reported identity of some species of Populus and clones (Walker, Hartigan & Bertus, 1974). DISEASE: Leaf rust of poplars, causing severe leaf damage and early defoliation on susceptible species and clones. Continued defoliation of successive flushes of growth predisposes trees to winter injury and dieback (Peace, 1962) and can cause death of trees, especially nursery stock and trees 1-2 yr old (25, 204; 47, 241; Walker Haitigan & Bertus, 1974). Reduction in incremental growth of timber occurs with susceptible varieties. Some damage can occur to the conifer hosts. It is often severe on Pseudotsuga menziesii (45, 459; 47, 126) and in nurseries Pinus spp. and Larix spp. can be heavily attacked (Ziller, 1965). GEOGRAPHICAL DISTRIBUTION: North America (Canada, USA), Asia (Japan); Australasia and Oceania (Australia, New Zealand); Europe (France, Spain). Reports of Melampsora spp. on poplars (including P. deltoides and P. canadensis) from South America (Argentina, 21, 173), Uruguay (Lindquist & de Rosengurtt, 1967) may refer in part to M. medusae. TRANSMISSION: By air-borne urediniospores, often over long distances (suspected from eastern Australia to New Zealand). Urediniospores survive the winter in milder climates on semi-evergreen lines and on green sucker growth of deciduous trees. This is probably the main method of overwintering in the Southern Hemisphere and in warmer parts of the Northern Hemisphere. The possibility of bud carryover as occurs with M. epitea on Salix in Iceland (Jorstad, 1951) and the Canadian Arctic (Savile, 1972) should be investigated. Telia survive the winter and basidiospores formed in spring infect susceptible conifers in parts of the Northern Hemisphere (Ziller, 1965) but no conifer infection has so far been found in Australia.

Scirrhia pini. [Descriptions of Fungi and Bacteria].

1973 ◽  
Author(s):  
E. Punithalingam
Keyword(s):  
New Zealand ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Forest Floor ◽  
Republic Of Georgia ◽  
Long Distance Dispersal ◽  
Long Distance ◽  
Nursery Stock ◽  
Airborne Conidia ◽  
Infected Material

Abstract A description is provided for Scirrhia pini[Mycosphaerella pini]. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On pines including Pinus radiata and its hybrids, P. halepensis, P. canariensis, P. carbaea, P. ponderosa, P. nigra and others, Pseudotsuga menziesii (46, 2860), Larix decidua (49, 273). DISEASE: Dothistroma blight; red band. GEOGRAPHICAL DISTRIBUTION: North America (Canada, USA including Alaska), South America (Argentina, Brazil, Chile, Uruguay), Australasia and Oceania (New Zealand), Asia (Brunei, India, Japan), Africa (Ethiopia, Kenya, Malawi, Rhodesia, Swaziland, Tanzania, Uganda), Europe (Austria, France, Rumania, UK, USSR (Republic of Georgia), Yugoslavia) (CMI Map 419, ed. 2, 1970; record in CMI Herbarium). TRANSMISSION: By airborne conidia released and dispersed by a splash take-off mechanism for short distances. Long distance dispersal may be by transport of infected material, such as nursery stock and, under special conditions, clouds may carry sporal inoculum (43, 2100). Survival time of inoculum in the form of cast, infected foliage on the forest floor is limited to 2-6 months under moist conditions (50, 2003).

Peronospora hariotii. [Descriptions of Fungi and Bacteria].

1983 ◽  
Author(s):  
S. M. Francis
Keyword(s):  
Downy Mildew ◽  
Geographical Distribution ◽  
Weather Conditions ◽  
Lower Surface ◽  
Buddleja Davidii ◽  
Nursery Stock ◽  
Terminal Bud

Abstract A description is provided for Peronospora hariotii. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Buddleja davidii cv. White Profusion, B. globosa and cultivars, especially cv. Lemon Ball. DISEASE: Downy mildew of Buddleja. This is a disease of nursery stock and there are no reports of the fungus infecting mature plants. Young plants 1-2 ft. high bear conspicuous brown lesions on their leaves. These begin as a yellow area on the upper surface which soon turns brown and brittle. Leaves affected in this way usually drop off. The leading shoot and terminal bud may also die. The down, which develops on the lower surface of infected leaves, is pale to medium brown depending on age and weather conditions. GEOGRAPHICAL DISTRIBUTION: Europe (Britain, France). TRANSMISSION: Not known.

Dibotryon morbosum. [Descriptions of Fungi and Bacteria].

1970 ◽  
Author(s):  
B. C. Sutton
Keyword(s):  
North America ◽  
Geographical Distribution ◽  
Low Temperatures ◽  
Late Summer ◽  
Host Tissue ◽  
Prunus Serotina ◽  
Black Cherry ◽  
Trichothecium Roseum ◽  
Nursery Stock ◽  
Normal Diameter

Abstract A description is provided for Dibotryon morbosum. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: On Prunus americana, P. armeniaca, P. avium, P. besseyi, P. cerasus, P. domestica, P. maritima, P. melanocarpa, P. pennsylvanica, P. pumila, P. serotina, P. virginiana and other species of Prunus. DISEASE: Black knot of plum, damson, cherry, peach, apricot and other species of Prunus. The pathogen causes the formation of elongated black hypertrophied host tissue on the current year's branches or on trunks. These are generally confined to one side and are several times the normal diameter of the stem. The knots are olive-green and corky at first, later turning black and becoming hard and brittle. In late summer some may appear pink or white due to parasitism by Trichothecium roseum. On black cherry, P. serotina, large cankerous swellings 0.6 m or more long may be formed which render the tree worthless for timber. Attacked trees become stunted and dwarfed. GEOGRAPHICAL DISTRIBUTION: Confined to North America (Canada and U.S.A.) (CMI Map 48). TRANSMISSION: By ascospores which have a peak production in May (45, 3263h). Storage of knots from Prunus serotina at -20°C for 6 months had little effect on ascospore viability (44, 2699j). Conidia also tolerate low temperatures, surviving 192 days at -20°C but only 25 days at 21°C (47, 573). In addition to some conidia overwintering in a viable condition on plum and cherry, others develop from overwintering chlamydospores on plum buds and bark (14: 43). Prunings containing excised knots which are left lying in orchards can continue to produce viable spores for several weeks after being removed (9: 116; 24: 375). The pathogen may also be introduced to new areas on infected nursery stock (McClintock, 1945).

Response of newly planted peach and apple trees to superphosphate

1975 ◽  
Vol 26 (3) ◽  
pp. 521 ◽  
Author(s):  
BK Taylor
Keyword(s):  
Tree Growth ◽  
Phosphate Fertilizer ◽  
Fruit Trees ◽  
Yield Response ◽  
Apple Trees ◽  
Leaf Analysis ◽  
Major Interest ◽  
Marked Decline ◽  
One Year ◽  
Peach Trees

The response of peach and apple trees to added superphosphate was recorded both in the nursery and later in the orchard after transplanting. The peach and apple trees responded positively to phosphate applications in both the nursery and the orchard despite the initial presence of medium to high phosphate levels in the soils. Of major interest, too, was the absence of a consistent interaction between the phosphate treatments applied in the separate years. This suggested that the trees could not accumulate enough phosphorus in any one year to influence their response to further phosphate. Leaf analysis showed two important effects in relation to the phosphate treatments. Firstly, since high rates of application of fertilizer led to only small increases in the levels of phosphorus in the leaves, tree growth rate and phosphate absorption rate are apparently closely coupled. Secondly, the deliberate withholding of phosphate fertilizer from all trees in the fourth season led to a marked decline in the levels of phosphorus in the leaves of both peach and apple, which suggested that phosphate fertilizer should be applied annually to young fruit trees. With apple, but not peach, increasing the rate of phosphate applied in the third season stimulated the number of flower buds initiated, but this effect was not simply the result of increased vegetative growth. On the other hand, phosphate application to the peach trees in the orchard resulted in a positive fruit set and yield response in the absence of any tree growth response.

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