Copper supply and fruit yield of young Citrus trees: fertiliser sources and application methods

Huanglongbing (HLB) is one of the most devastating diseases of citrus, which is associated with Candidatus Liberibacter asiaticus (Las) in the United States. To date, no effective antimicrobial compound is commercially available to control the disease. In this study, we investigated the effects of different antimicrobial chemicals with suitable surfactants on HLB-affected matured citrus trees with emphasis on the fruit yield and quality. Each treatment was applied three times in a 2-week interval during the spring flush period, one time in summer and three times during the autumn flushing period. We extensively examined different parameters such as pathogenic index, disease index, tree canopy, fruit yield, quality, and nutritional status. The results showed that among the treatments, penicillin (PEN) with surfactant was most effective in suppressing Las titer in infected citrus trees, followed by Fosetyl-Al (ALI), Carvacrol (CARV), and Validamycin (VA). Fruit quality analysis revealed that PEN treatment increased the soluble solids content (SSC), whereas Oxytetracycline (OXY) treatment significantly reduced titratable acidity (TA) level and increased the SSC/TA ratio compared to the control. Nutrient analysis showed increased N and Zn levels in ALI and PEN treatments, and OXY treatment increased leaf P, K, S, and Mg levels compared to untreated control. Furthermore, B, Ca, Cu, Fe, and Mn in leaves were reduced in all chemical treatments than that of the untreated control. These findings revealed that some of the chemical treatments were able to suppress Las pathogen, enhance nutritional status in leaves, and improve tree growth and fruit quality of HLB-affected trees.

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Nutrition of Florida Citrus Trees, Third Edition

EDIS ◽

10.32473/edis-ss478-2020 ◽

2020 ◽

Vol 2020 (2) ◽

Author(s):

Davie Mayeso Kadyampakeni ◽

Kelly T. Morgan

Keyword(s):

Irrigation Scheduling ◽

Soil Sampling ◽

Previous Edition ◽

Application Methods ◽

Production Practices ◽

Florida Citrus ◽

Ph Management ◽

Page Book ◽

Protective Screen ◽

Citrus Trees

This update to 2007's second edition adds information regarding nutrition of Florida citrus trees affected by huanglongbing (HLB), also known as citrus greening. Much of the guidance provided in this document on nutrients, application methods, leaf and soil sampling, and irrigation scheduling is also effective for trees affected by HLB. However, research conducted since the previous edition was published has established changes in many production practices, including nutrient rates, irrigation scheduling, soil pH management, and use of Citrus Under Protective Screen (CUPS). Changes to the second edition will appear at the beginning of chapters 2, 6, 8, 9, and 11. <a href="http://edis.ifas.ufl.edu/topic_series_nutrition_of_florida_citrus_trees">See also this topic page</a> for links to individual chapters in HTML and PDF formats. This 115-page book was edited by Kelly T. Morgan and Davie M. Kadyampakeni, and published by the UF/IFAS Department of Soil and Water Sciences.

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By-product Iron-humate Increases Tree Growth and Fruit Production of Orange and Grapefruit

HortScience ◽

10.21273/hortsci.33.1.71 ◽

1998 ◽

Vol 33 (1) ◽

pp. 71-74 ◽

Cited By ~ 9

Author(s):

A.K. Alva ◽

T.A. Obreza

Keyword(s):

Tree Growth ◽

Fruit Production ◽

Fruit Yield ◽

Tree Canopy ◽

Fe Deficiency ◽

Concentration Addition ◽

Citrus Paradisi ◽

Alkaline Soils ◽

High Ph ◽

Citrus Trees

Citrus trees planted in alkaline soils typically show iron (Fe) deficiency chlorosis. Currently, Fe-EDDHA (ethylenediiminobis-2-hydroxyphenyl acetic acid) chelate is the most effective source of Fe for high pH soils. Iron humate (FeH), a by-product of the drinking water decolorization process, was compared with Fe-EDDHA for Fe deficiency correction on nonbearing `Ambersweet' orange and `Ruby Red' grapefruit Citrus paradisi Macf., and bearing `Hamlin' orange Citrus sinensis and `Flame' grapefruit trees, all on Swingle citrumelo rootstock, planted on high pH (>7.6) soils. Iron humate was applied under the tree canopy in spring at rates from 2 to 200 g Fe (nonbearing trees), or 22 to 352 g Fe (bearing trees) per tree per year. Application of FeH to nonbearing trees decreased twig dieback rating and increased flush growth, flush color rating, tree size, and leaf Fe concentration. Addition of urea or ammonium nitrate to FeH did not increase Fe availability. Iron amendments (22 g Fe per tree per year) increased fruit yield after the 1st year of application. Further increases in the rate of Fe, from 22 to 352 g Fe per tree per year as FeH, did not significantly increase tree growth, fruit yield, or fruit quality. This study demonstrated that FeH was an effective Fe source for citrus trees planted on alkaline soils.

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Nutrition of Florida Citrus Trees, 3rd Edition: Chapter 8. Recommended Fertilizer Rates and Timing

EDIS ◽

10.32473/edis-ss675-2020 ◽

2020 ◽

Vol 2020 (2) ◽

Author(s):

Thomas A. Obreza ◽

Kelly T. Morgan ◽

L. Gene Albrigo ◽

Brian J. Boman ◽

Davie Kadyampakeni ◽

...

Keyword(s):

Irrigation Scheduling ◽

Soil Sampling ◽

Application Methods ◽

Production Practices ◽

Florida Citrus ◽

Ph Management ◽

Fertilizer Rates ◽

Protective Screen ◽

Production Conditions ◽

Citrus Trees

The information provided in the 2008 2nd edition is still sound for healthy citrus trees under Florida production conditions. Much of the information provided in this document on nutrients, application methods, leaf and soil sampling and irrigation scheduling are also effective for huanglongbing (HLB) affected citrus trees. However, research conducted since HLB was detected in Florida in 2005 has established changes in many production practices, including nutrient rates, irrigation scheduling, soil pH management, and use of Citrus Under Protective Screen (CUPS). Changes to the 2nd edition of SL253 will appear in boxes similar to this one at the beginnings of chapters 2, 6, 8, 9, and 11.

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Nutrition of Florida Citrus Trees, 3rd Edition: Chapter 9. Irrigation Management to Improve Nutrient Uptake

EDIS ◽

10.32473/edis-ss676-2020 ◽

2020 ◽

Vol 2020 (2) ◽

Author(s):

Kelly T. Morgan ◽

Thomas A. Obreza ◽

Davie Kadyampakeni ◽

Said Hamido ◽

Rhuanito Soranz Ferrarezi ◽

...

Keyword(s):

Irrigation Management ◽

Irrigation Scheduling ◽

Soil Sampling ◽

Application Methods ◽

Production Practices ◽

Florida Citrus ◽

Ph Management ◽

Protective Screen ◽

Production Conditions ◽

Citrus Trees

The information provided in the 2008 2nd edition is still sound for healthy citrus trees under Florida production conditions. Much of the information provided in this document on nutrients, application methods, leaf and soil sampling and irrigation scheduling are also effective for huanglongbing (HLB) affected citrus trees. However, research conducted since HLB was detected in Florida in 2005 has established changes in many production practices, including nutrient rates, irrigation scheduling, soil pH management, and use of Citrus Under Protective Screen (CUPS). Changes to the 2nd edition of SL253 will appear in boxes similar to this one at the beginnings of chapters 2, 6, 8, 9, and 11.

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Nutrition of Florida Citrus Trees, 3rd Edition: Chapter 3. General Soil Fertility and Citrus Tree Nutrition

EDIS ◽

10.32473/edis-ss670-2020 ◽

2020 ◽

Vol 2020 (2) ◽

Author(s):

Thomas A. Obreza ◽

Mongi Zekri ◽

Stephen H. Futch

Keyword(s):

Irrigation Scheduling ◽

Soil Sampling ◽

Citrus Tree ◽

Application Methods ◽

Production Practices ◽

Florida Citrus ◽

Ph Management ◽

Protective Screen ◽

Production Conditions ◽

Citrus Trees

The information provided in the 2008 2nd edition is still sound for healthy citrus trees under Florida production conditions. Much of the information provided in this document on nutrients, application methods, leaf and soil sampling and irrigation scheduling are also effective for huanglongbing (HLB) affected citrus trees. However, research conducted since HLB was detected in Florida in 2005 has established changes in many production practices, including nutrient rates, irrigation scheduling, soil pH management, and use of Citrus Under Protective Screen (CUPS). Changes to the 2nd edition of SL253 will appear in boxes similar to this one at the beginnings of chapters 2, 6, 8, 9, and 11.

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EFFICACY OF DRIP-DELIVERED HERBICIDES FOR WEED CONTROL IN TOMATO IN PUERTO RICO

HortScience ◽

10.21273/hortsci.40.3.889d ◽

2005 ◽

Vol 40 (3) ◽

pp. 889d-889

Author(s):

Bielinski M. Santos ◽

James P. Gilreath ◽

Maria de L. Lugo ◽

Luis E. Rivera

Keyword(s):

Puerto Rico ◽

Field Study ◽

Weed Control ◽

Tomato Fruit ◽

Fruit Yield ◽

Viable Alternative ◽

Delivery Methods ◽

Significant Difference ◽

Herbicide Treatments ◽

Application Methods

A field study was conducted in Gurabo, P.R., to examine the potential of drip-applied herbicides for weed control in polyethylene-mulched tomato. The herbicide treatments were a) metolachlor at a rate of 1.1 kg a.i./ha; b) napropamide at 2.2 kg a.i./ha; c) pebulate at 4.5 kg a.i./ha; and d) trifluralin at 0.8 kg a.i./ha. A nontreated control was added. Each herbicide plot was split in two application methods: preemergence application and through the drip lines with 100 m3 water. In both cases, herbicides were delivered three weeks before tomato transplanting. There was no significant difference between the two delivery methods. Metolachlor showed the best control of broadleaf weeds (>80%) and highest tomato fruit yield. Applying herbicides through the drip lines is a viable alternative in mulched tomato.

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Ecological Mowing: An Option for Sustainable Weed Management in Young Citrus Orchards

Weed Technology ◽

10.1017/wet.2017.3 ◽

2017 ◽

Vol 31 (2) ◽

pp. 260-268 ◽

Cited By ~ 4

Author(s):

Rodrigo Martinelli ◽

Patrícia A. Monquero ◽

Anastácia Fontanetti ◽

Patrícia M. Conceição ◽

Fernando A. Azevedo

Keyword(s):

Cover Crops ◽

Weed Management ◽

Cover Crop ◽

Conservation Agriculture ◽

Fruit Yield ◽

Weed Density ◽

Canopy Volume ◽

Acid Lime ◽

Signal Grass ◽

Citrus Trees

The citrus yield in Brazil is not ranked among the best in the world, potentially due to inadequate management by citrus growers. The low adoption of conservation agriculture (CA) techniques and the improper application of herbicides are also well-known problems. Thus, this study evaluated the use of CA techniques, and twoUrochloaspecies (ruzi grass and signal grass) were used as cover crops. Two different types of mowers (ecological, EM; conventional, CM) launched the mowed biomass into different positions within a young Tahiti acid lime orchard (up to four years old). In addition, the integration of glyphosate into this management system was evaluated, with (GLY) and without (NO GLY) glyphosate application. This experiment was conducted across three growing seasons (2011-2014), in Mogi Mirim, São Paulo State, Brazil. The cover crop biomass yields and the effects of the mowing treatments, weed density, vegetative growth and fruit yields of the Tahiti acid lime trees were evaluated. In terms of major results, signal grass produced higher biomass yield values (up to 64%) than ruzi grass; EM promoted higher mowed biomass values in the intra-row (up to 5.1 ton ha−1, 9.0 times higher than CM), and a higher canopy volume (up to 33% than CM). These results were enhanced when ruzi grass was associated with the EM (56% lower weed density; 126% higher fruit yield than CM) and with GLY (52% higher fruit yield than NO GLY); and EM with GLY (43% lesser weed density and 107% higher fruit yield than NO GLY). Overall, ruzi grass was a good cover crop because it provided less competition for the citrus trees, EM provided a mulch layer in the intra-row of the citrus trees, and associated with GLY, these approaches could provide options for an integrated and more sustainable weed management, primarily for young Tahiti acid lime orchards.

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