Effects of copper, zinc and urea on defoliation and nitrogen reserves in nursery plants of almond

Bi, Guoan; Cheng, Lailiang; Fuchigami, Leslie H.

doi:10.1080/14620316.2005.11512009

Cited by 9 publications

(17 citation statements)

References 18 publications

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“…Spraying apple trees with CuEDTA can cause >80% defoliation within 6 d of application and results in low N recovery from leaves compared with natural defoliation (Guak et al, 2001). Spraying almond and apple trees with CuEDTA in October has been shown to decrease stem N concentrations (Bi et al, 2005;Guak et al, 2001). Similar effects of CuEDTA on defoliation and loss of N have been reported for almond nursery trees (Bi et al, 2005).…”

Section: Discussionmentioning

confidence: 66%

“…Chemical-induced defoliation of deciduous trees decreases the amount of N mobilized from leaves to stems and roots in the autumn; thus, it can reduce N reserves required for growth the following spring (Bi et al, 2003;Guak et al, 2001). The combination of foliar sprays with urea and CuEDTA can be used to obtain efficient early defoliation and promote N storage without reducing plant growth performance the following year (Bi et al, 2005;Guak et al, 2001). Early defoliation before terminal buds set can also inhibit the development of dormancy and cold hardiness (Fuchigami, 1970).…”

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confidence: 99%

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Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

Laywisadkul

Fuchigami

Linderman

2010

hortte

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Recent field observations by growers suggest that increased nitrogen (N) content in nursery trees resulting from foliar sprays with urea in the autumn increases tree susceptibility to infection by Phytophthora syringae. We investigated the effects of soil N availability and spraying pear (Pyrus communis ‘OHF 97’) trees with combinations of urea, chelated copper ethylenediaminetetraacetic acid (CuEDTA), and phosphonate-containing fungicides on stem N concentration and susceptibility to infection by P. syringae. Increasing soil N availability increased susceptibility to P. syringae and increased N and amino acid concentration in stems. Spraying trees with urea in the autumn increased concentrations of N and amino acids in stems and had no significant effect on tree susceptibility when stems were inoculated with P. syringae before or after urea sprays. Spraying trees with CuEDTA decreased stem N concentrations and had no significant influence on tree susceptibility to P. syringae when stems were inoculated before or after CuEDTA sprays. These results suggest the relationship between tree susceptibility to P. syringae and tree N concentration may be specific to the form of N, delivery method, or timing of N applications. Trees had higher N concentrations in stems in November than in October and were more susceptible to P. syringae when inoculated in November, suggesting that environmental factors and increasing tree dormancy may be responsible for changes in susceptibility to the pathogen. Spraying trees with fungicides containing fosetyl-aluminum in October or November decreased tree susceptibility to P. syringae. The effects of fungicides containing fosetyl-aluminum on susceptibility were similar regardless of whether trees were sprayed or not with urea or CuEDTA, suggesting that these fungicides can be used in combination with urea or CuEDTA sprays for reducing disease severity caused by P. syringae without impacting growers' objective of increasing tree N content with urea or enhancing early defoliation with CuEDTA.

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Section: Discussionmentioning

confidence: 66%

mentioning

confidence: 99%

Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

Laywisadkul

Fuchigami

Linderman

2010

hortte

Self Cite

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“…Adding urea into sprays containing CuEDTA may have decreased the efficiency of defoliation; however, our results suggest the effects of urea mitigated some of the negative effects of CuEDTA, mentioned previously, on plant quality during forcing. This type of compensatory response of adding urea to CuEDTA sprays is similar to the effects of combing urea and CuEDTA in sprays to defoliate bareroot apple and almond nursery trees (Bi et al, 2005;Guak et al, 2001). If cost or availability issues cause growers to choose CuEDTA over Def 6 as a defoliant for use with florists' hydrangeas, then adding urea to CuEDTA sprays may decrease the adverse effect of CuEDTA on plant quality during forcing.…”

Section: Resultsmentioning

confidence: 85%

“…Our results indicate copper-EDTA (CuEDTA) can also promote early defoliation of florists' hydrangeas (control versus copper; Table 2) and 1.0% CuEDTA is more effective than 0.5% CuEDTA on promoting early defoliation (Table 2); however, at the concentrations tested (0.5% and 1.0%), we observed some necrosis on leaves and buds after spraying (data not shown) and 1.0% CuEDTA had a negative effect on plant quality during forcing (Table 2). CuEDTA has been used as a defoliant for nursery plants (Bi et al, 2005;Guak et al, 2001;Knight, 1983;Larsen and Fritts, 1986). Using apple and cherry rootstocks, substantial defoliation was achieved by spraying trees with 2.1% CuEDTA with little or no damage to plants (Knight, 1983).…”

Section: Resultsmentioning

confidence: 99%

“…Foliar sprays of urea in the fall after terminal bud set can increase reserve N in deciduous plants without stimulating new growth late in the season Sanchez et al, 1990;Tagliavini et al, 1998). Increased N from urea sprays can compensate for the N lost from early defoliation and improve plant growth and development during the next growing season (Bi et al, 2005;Guak et al, 2001). Spraying florists' hydrangea with urea before manual defoliation has the potential to improve growth and increase the number of flowers and flower size during forcing (Bi et al, 2008).…”

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Effects of Fall Applications of Chemical Defoliants, Urea, and Gibberellic Acid on Defoliation in the Fall and Performance of Hydrangeas During Forcing

Bi¹

2009

horts

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In two separate experiments, Hydrangea macrophylla (Thunb.) Ser. ‘Merritt's Supreme’ plants were used to study the effects of foliar sprays of Def 6 (tributyl phosphorotrithioate, 2500, 5000, 7500, and 10,000 mg·L−1), gibberellic acid (GA, 50 mg·L−1), copper–EDTA (CuEDTA, 0.5% and 1.0%), Florel (2000 mg·L−1), and urea (3%) on defoliation in the fall and growth and flowering performance during forcing. Compared with controls (plants sprayed with water only), spraying plants with urea or GA alone had no influence on defoliation or plant performance during forcing, and spraying plants with Florel alone had no influence on defoliation but decreased total flower dry weight during forcing. Combining urea with Florel sprays decreased the adverse effects of Florel on plant quality and combining GA with Florel improved defoliation. Increasing concentrations of Def 6 and CuEDTA increased defoliation. Compared with controls, plants sprayed with CuEDTA exhibited more defoliation, showed bud and leaf necrosis, and produced lower flower dry weight during forcing. Combining urea with CuEDTA sprays decreased the adverse effects of CuEDTA on plant quality. Compared with controls, spraying plants with Def 6 increased defoliation, caused no visible damage to plants, and had no adverse effects on plant quality during forcing. Adding urea to sprays containing Def 6 decreased or had no influence on the efficiency of defoliation and increased total flower dry weight during forcing compared with Def 6 alone. Adding GA to sprays containing lower concentrations of Def 6 (2500 and 5000 mg·L−1) increased the efficiency of defoliation without adversely influencing plant quality.

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Organic Pollutants in Groundwater Resource

Singh

et al. 2021

Groundwater Geochemistry

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Effects of copper, zinc and urea on defoliation and nitrogen reserves in nursery plants of almond

Cited by 9 publications

References 18 publications

Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

Spraying Leaves of Pear Nursery Trees with Urea and Copper Ethylenediaminetetraacetic Acid Alters Tree Nitrogen Concentration without Influencing Tree Susceptibility to Phytophthora syringae

Effects of Fall Applications of Chemical Defoliants, Urea, and Gibberellic Acid on Defoliation in the Fall and Performance of Hydrangeas During Forcing

Organic Pollutants in Groundwater Resource

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