Sweet Orange Orchard Architecture Design, Fertilizer, and Irrigation Management Strategies under Huanglongbing-endemic Conditions in the Indian River Citrus District

The prevalence of Huanglongbing (HLB) in Florida has forced growers to search for new management strategies to optimize fruit yield in young orchards and enable earlier economic returns given the likelihood of HLB-induced yield reductions during later years. There has been considerable interest in modifying orchard architecture design and fertilizer and irrigation management practices as strategies for increasing profitability. Our objectives were to evaluate how different combinations of horticultural practices including tree density, fertilization methods, and irrigation systems affect growth, foliar nutrient content, fruit yield, and fruit quality of young ‘Valencia’ sweet orange [Citrus sinensis (L.) Osbeck] trees during the early years of production under HLB-endemic conditions. The study was conducted in Fort Pierce, FL, from 2014 to 2020 on a 1- to 7-year-old orchard and evaluated the following treatments: standard tree density (358 trees/ha) and controlled-release fertilizer with microsprinkler irrigation (STD_dry_MS), high tree density (955 trees/ha) with fertigation and microsprinkler irrigation (HDS_fert_MS), and high tree density with fertigation and double-line drip irrigation (HDS_fert_DD). Annual foliar nutrient concentrations were usually within or higher than the recommended ranges throughout the study, with a tendency for decreases in several nutrients over time regardless of treatment, suggesting all fertilization strategies adequately met the tree nutrient demand. During fruit-bearing years, canopy volume, on a per-tree basis, was higher under STD_dry_MS (6.2–7.2 m3) than HDS_fert_MS (4.3–5.3 m3) or HDS_fert_DD (4.9–5.9 m3); however, high tree density resulted in greater canopy volume on an area basis, which explained the 86% to 300% increase in fruit yield per ha that resulted in moving from standard to high tree density. Although fruit yields per ha were generally greatest under HDS_fert_MS and HDS_fert_DD, they were lower than the 10-year Florida state average (26.5 Mg·ha−1) for standard tree density orchards, possibly due to the HLB incidence and the rootstock chosen. Although tree growth parameters and foliar nutrient concentrations varied in response to treatments, management practices that included high tree density and fertigation irrespective of irrigation systems produced the highest fruit yields and highest yield of solids. Soluble solids content (SSC) and titratable acidity (TA) were lower, and the SSC-to-TA ratio was highest under STD_dry_MS in 2016–17, with no treatment effects on quality parameters detected in other years. Both drip and microsprinkler fertigation methods sufficiently met tree nutrient demand at high tree density, but additional research is needed to determine optimal fertilization rates and better rootstock cultivars in young high-density sweet orange orchards under HLB-endemic conditions in the Indian River Citrus District.

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‘Ray Ruby’ Grapefruit Affected by Huanglongbing II. Planting Density, Soil, and Foliar Nutrient Management

HortScience ◽

10.21273/hortsci15255-20 ◽

2020 ◽

Vol 55 (9) ◽

pp. 1420-1432

Author(s):

Dinesh Phuyal ◽

Thiago Assis Rodrigues Nogueira ◽

Arun D. Jani ◽

Davie M. Kadyampakeni ◽

Kelly T. Morgan ◽

...

Keyword(s):

Growth Parameters ◽

Quantitative Polymerase Chain Reaction ◽

High Density ◽

Fruit Yield ◽

Soluble Solids ◽

Planting Density ◽

Nutrient Concentrations ◽

Trunk Diameter ◽

Canopy Volume ◽

Foliar Nutrient

Since the arrival of Huanglongbing (HLB) disease in Florida, several management approaches, including modification of orchard architecture design and nutritional therapy, have been explored. High-density plantings anticipate early economic returns from HLB-affected orchards. With no cure available for HLB, balanced nutrient application through soil and foliar spraying can mitigate the disease. A 2-year study was conducted to investigate the effects of three grapefruit (Citrus paradisi) planting densities [single-row (300 and 440 trees per ha), and double-row high-density (975 trees per ha)], two controlled-release fertilizer (CRF) blends, and foliar-applied micronutrients (FAM) (a blend of B, Mn, and Zn at 0, 1.5, 3, and 6 times the recommended rates) on grapefruit growth and fruit yield, physiological parameters, and foliar nutrient concentrations in an HLB-affected orchard. All the trees tested positive for HLB based on real-time quantitative polymerase chain reaction (qPCR) test. The highest planting density resulted in the lowest trunk diameter and canopy volume. Despite lower yield per tree in 2019–20, 975 trees per ha planting induced the greatest fruit and solid yields per ha. Also, the fruit produced from 975 trees per ha planting tended to be acidic with the deposition of more soluble solids. Use of CRF with higher micronutrients increased canopy volume with the expense of reduced fruit number in 2019–20. FAM did not affect cycle threshold (Ct) value and tree growth parameters. Fruit yield, photosynthesis rate, and stomatal conductance (gS) decreased, and all leaf nutrient concentrations except B increased in 2019–20 with all FAM rates tested. In conclusion, our study showed that high-density planting optimizes yield under HLB-endemic conditions. In addition, supplemental soil and foliar micronutrient application do not enhance yield of HLB-affected trees over a 2-year timeframe, warranting further research for confirmation of results.

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(374) Fertilization of Southern Highbush Blueberries on Pine Bark Beds

HortScience ◽

10.21273/hortsci.40.4.1059b ◽

2005 ◽

Vol 40 (4) ◽

pp. 1059B-1059

Author(s):

Jeffrey G. Williamson ◽

E. Paul Miller

Keyword(s):

Block Design ◽

Irrigation Management ◽

Fruit Yield ◽

Pine Bark ◽

Growth Responses ◽

Liquid Fertilizer ◽

Canopy Volume ◽

Highbush Blueberries ◽

Southern Highbush ◽

Fertilizer Rates

Bearing `Misty' and `Star' southern highbush blueberries were grown on pine bark beds and fertilized at three rates using granular and liquid fertilizers with a 3–1–2 (1N–0.83K–0.88P) ratio. Granular fertilizer was applied 8 times per year at 4-week intervals beginning in April and continuing through October. Liquid fertilizer was applied with low volume irrigation 16 times per year at 2-week intervals during the same period. During the growing season, irrigation was applied at 2- to 3-day intervals in the absence of rain. A 2 cultivar × 2 fertilizer type × 3 fertilizer rate factorial arrangement of treatments was replicated 8 times in a randomized complete-block design. All fruits were harvested from single-plant plots at 3- to 4-day intervals. Canopy volume was not affected by fertilizer type, but fruit yield was slightly greater for granular than for liquid fertilizer treatments. In 2003, fruit yield of 2.5-year-old `Misty' and `Star' plants increased with increasing fertilizer rates up to the highest rate tested (50 g N/plant/year). Similarly, in 2004, fruit yields increased with increasing fertilizer rates up to the highest rate (81 g N/plant/year). Root distribution was limited to the 12-cm-deep layer of pine bark with very few roots penetrating into the underlying soil. The positive growth responses of blueberry plants to high fertilizer rates in pine bark beds suggests that soluble fertilizer was leached through the pine bark layer into the soil below the root zone. More frequent, lighter applications of soluble fertilizers, use of slow-release or controlled-release fertilizers, and careful irrigation management may improve fertilizer use efficiency of blueberry plantings on pine bark beds.

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Canopy health, but not Candidatus Liberibacter asiaticus Ct values, are correlated with fruit yield in Huanglongbing affected sweet orange trees

10.1101/2021.09.07.459315 ◽

2021 ◽

Author(s):

Amit Levy ◽

Taylor Livingston ◽

Chunxia Wang ◽

Diann Achor ◽

Tripti Vashisth

Keyword(s):

Sweet Orange ◽

Field Trials ◽

Fruit Yield ◽

Ct Value ◽

Independent Field ◽

Canopy Volume ◽

Candidatus Liberibacter ◽

Liberibacter Asiaticus ◽

Almost All ◽

Orange Trees

AbstractIn Florida, almost all citrus trees are infected with Huanglongbing (HLB), caused by the gram-negative, intracellular phloem limited bacteria Candidatus liberibacter asiaticus (CLas). Distinguishing between the severely and mildly sick trees is important for managing the groves and testing new HLB therapies. A mildly sick tree is one that produces higher fruit yield, compared to a severely sick tree, but measuring yields is laborious and time consuming. Here we characterized HLB affected sweet orange trees in the field in order to identify the specific traits that are correlated with the yields. We found that canopy volume, fruit detachment force (FDF) and the percentage of photosynthetically active radiation interception in the canopy (%INT) were positively correlated with fruit yields. Specifically, %INT measurements accurately distinguished between mild and severe trees in independent field trials. We could not find a difference in the Ct value between high and low producing HLB trees. Moreover, Ct values did not always agree with the number of CLas in the phloem that were visualized by transmission electron microscopy. Overall, our work identified an efficient way to distinguish between severe and mild HLB trees in Florida by measuring %INT and suggests that health of the canopy is more important for yields than the Ct value.

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Effect of nitrogen, phosphorus and potassium fertiliser rates on fruit yield, leaf mineral concentration and growth of young orange trees in the Sunraysia district

Australian Journal of Experimental Agriculture ◽

10.1071/ea9910263 ◽

1991 ◽

Vol 31 (2) ◽

pp. 263 ◽

Cited By ~ 1

Author(s):

R Sarooshi ◽

RG Weir ◽

BG Coote

Keyword(s):

Sweet Orange ◽

Maximum Yield ◽

Soil Management ◽

Bare Soil ◽

Fruit Yield ◽

Nutrient Concentrations ◽

Mineral Concentration ◽

Orange Trees ◽

Phosphorus Application ◽

Leaf P

Fruit yield, leaf nutrient concentrations and growth response of young Valencia orange trees to 4 rates of nitrogen (N, 75-450 kg/ha), phosphorus (P, 0-180 kg/ha) and potassium (K, 0-360 kg/ha) were studied using 2 soil management systems (sod-sown and bare ground) and 2 rootstocks (Troyer Citrange and Sweet Orange). Eight-year-old Sweet Orange produced maximum yield at the higher rates of applied N and P and medium level of K, but at 12 years of age, highest yields occurred at the lowest rate of applied N, medium P and nil K. High N without P at year 12 strongly depressed yield especially on bare soil. Phosphorus application at high rates of N greatly increased yield but had no effect at lower rates of N. The effect of nutrients on yield was smaller on Troyer than on Sweet Orange rootstock. Leaf N concentration increased with amount of N applied and slightly increased with K applications but not with applied P. Leaf P concentrations increased with higher rates of applied P, especially in year 12 and at the lowest rate of applied N. Both rootstock and management affected leaf P concentration. Leaf K increased with amount of applied K. Highest concentrations of leaf K were from Troyer trees under bare soil management but this trend declined with time. The effects of fertilisers on tree size were small and varied with rootstock and management.

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Subsoiling and Planting Method on the Initial Growth of ‘Pera’ Sweet Orange (Citrus sinensis (L.) Osbeck)

Journal of Agricultural Science ◽

10.5539/jas.v11n9p1 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1

Author(s):

Thaís N. Meneses ◽

Mauricio A. Coelho Filho ◽

Hermes P. Santos Filho ◽

Luana L. A. Santos ◽

Abelmon S. Gesteira ◽

...

Keyword(s):

Soil Profile ◽

Root Length ◽

Management Practices ◽

Sweet Orange ◽

Root Length Density ◽

Early Stage ◽

Initial Growth ◽

Stage Of Development ◽

Canopy Volume ◽

Diameter Classes

The objective of this work was to evaluate the vegetative vigor and root architecture of ‘Pera CNPMF D-6’ sweet orange grafted on Rangpur lime at early stage of development, submitted to different planting methods (planting of nursery trees produced in a protected environment-PNT and planting of seeds at the definitive place-PS) and soil preparation with and without subsoiling. The experiment was carried out at the Lagoa do Coco Farm, Rio Real, Bahia, Brazil. Biometric evaluations were performed to estimate the variables: canopy volume (CV), vegetative vigor index (VVI) and canopy cover rates in the planting row (CCR-R) and interrow (CCR-I). Root samples were also collected up to a depth of 1.45 m at five points in the planting row. The roots were digitized and processed to obtain total root length (TRL), root length density (RLD), average root diameter (RD) and root length for the diameter classes. Plants produced in protected environment exhibit greater shoot vegetative and root development compared to those produced by sowing at the definitive place, at least for the young orchard and under rainfed conditions. Subsoiling did not affect root system distribution and PNT favored the increase in TRL along the soil profile compared to PS, for all diameter classes evaluated, contributing to the increase in vegetative vigor observed in the plants. Regardless of the management practices adopted, roots were concentrated in the first 0.35 m of the vertical soil profile, due to physical impediment caused by the presence of cohesive horizons.

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Less Is More: A Hard Way to Get Potential Dwarfing Hybrid Rootstocks for Valencia Sweet Orange

Agriculture ◽

10.3390/agriculture11040354 ◽

2021 ◽

Vol 11 (4) ◽

pp. 354

Author(s):

Danilo Pereira Costa ◽

Eduardo Sanches Stuchi ◽

Eduardo Augusto Girardi ◽

Alécio Souza Moreira ◽

Abelmon da Silva Gesteira ◽

...

Keyword(s):

Production Efficiency ◽

Sweet Orange ◽

Fruit Yield ◽

Tree Size ◽

Soluble Solids ◽

Planting Density ◽

Rangpur Lime ◽

Less Is More ◽

Canopy Volume ◽

Dwarfing Rootstocks

As in several fruit crops, citrus trees with decreased size allow for a higher planting density, which may lead to higher productivity and facilitate operations such as harvesting and spraying. The use of dwarfing rootstocks is one of the most feasible methods for tree size control, but few commercial varieties are available to date. In this work, the long-term performance of Valencia sweet orange grafted onto 51 hybrid citrus rootstocks was evaluated in rainfed cultivation at 6.0 m × 2.5 m tree spacing in Northern São Paulo State, Brazil. About a third of the evaluated hybrids were classified as dwarfing and semi-dwarfing rootstocks, that is, respectively inducing a relative canopy volume of <40% and 40–60% compared withthe standard rootstock, the Rangpur limeSanta Cruz selection. The production efficiency and soluble solids concentration were conversely related to the canopy volume. Three citrandarins of Sunki mandarin (TSKC) × Flying Dragon trifoliate orange (TRFD) were grouped within the most productive dwarfing rootstocks. Other hybrids that expressively decreased tree size were mainly sensitive to drought; therefore, the mean fruit yield was low, indicating the need for irrigation, albeit fruit quality was high. Estimated productivity on the selected TSKC × TRFD rootstocks would double to an average of 40 t·ha−1·year−1 if tree spacing wasadjusted to the smaller tree size. Although the HTR-208 citrandarin and the LCR × CTSW-009 citrumelimonia were as vigorous as the Santa Cruz Rangpur lime, they induced an outstanding fruit yield due to their highertolerance to drought and, hence, can be considered for rainfed cultivation at wider tree spacing.

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Managing Landscape Irrigation to Avoid Soil and Nutrient Losses

EDIS ◽

10.32473/edis-ss586-2013 ◽

2013 ◽

Vol 2013 (11) ◽

Author(s):

George Hochmuth ◽

Laurie Trenholm ◽

Don Rainey ◽

Esen Momol ◽

Claire Lewis ◽

...

Keyword(s):

Natural Environment ◽

Management Practices ◽

Root Zone ◽

Irrigation Management ◽

Critical Factor ◽

Nutrient Losses ◽

County Agents ◽

The Right ◽

Soil And Water

Proper irrigation management is critical to conserve and protect water resources and to properly manage nutrients in the home landscape. How lawns and landscapes are irrigated directly impacts the natural environment, so landscape maintenance professionals and homeowners must adopt environmentally-friendly approaches to irrigation management. After selecting the right plant for the right place, water is the next critical factor to establish and maintain a healthy lawn and landscape. Fertilization is another important component of lawn and landscape maintenance, and irrigation must be applied correctly, especially following fertilization, to minimize potential nutrient losses. This publication supplements other UF/IFAS Extension publications that also include information on the role of soil and the root zone in irrigation management. This publication is designed to help UF/IFAS Extension county agents prepare materials to directly address nutrient losses from lawns and landscapes caused by inadequate irrigation management practices. This 6-page fact sheet was written by George Hochmuth, Laurie Trenholm, Don Rainey, Esen Momol, Claire Lewis, and Brian Niemann, and published by the UF Department of Soil and Water Science, October 2013. http://edis.ifas.ufl.edu/ss586

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Land-Use Impact on Stand Structure and Fruit Yield of Tamarindus indica L. in the Drylands of Southeastern Ethiopia

Life ◽

10.3390/life11050408 ◽

2021 ◽

Vol 11 (5) ◽

pp. 408

Author(s):

Gizachew Zeleke ◽

Tatek Dejene ◽

Wubalem Tadesse ◽

Pablo Martín-Pinto

Keyword(s):

Land Use ◽

Stand Structure ◽

Fruit Production ◽

Tree Density ◽

Fruit Yield ◽

Tamarindus Indica ◽

Land Use Types ◽

Significant Difference ◽

Management Plans ◽

Baseline Information

In this study, we evaluated stand status, dendrometric variables, and fruit production of Tamarind (Tamarindus indica L.) trees growing in bushland and farmland-use types in dryland areas of Ethiopia. The vegetation survey was conducted using the point-centered quarter method. The fruit yield of 54 trees was also evaluated. Tree density and fruit production in ha were estimated. There was a significant difference in Tamarind tree density between the two land-use types (p = 0.01). The mean fruit yield of farmland trees was significantly higher than that of bushland trees. However, Tamarind has unsustainable structure on farmlands. Differences in the dendrometric characteristics of trees were also observed between the two land-use types. Predictive models were selected for Tamarind fruit yield estimations in both land-use types. Although the majority of farmland trees produced <5000 fruit year−1, the selection of Tamarind germplasm in its natural ranges could improve production. Thus, the development of management plans to establish stands that have a more balanced diameter structure and thereby ensure continuity of the population and fruit yields is required in this area, particularly in the farmlands. This baseline information could assist elsewhere in areas that are facing similar challenges for the species due to land-use change.

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Inoculation with Mycorrhizal Fungi and Irrigation Management Shape the Bacterial and Fungal Communities and Networks in Vineyard Soils

Microorganisms ◽

10.3390/microorganisms9061273 ◽

2021 ◽

Vol 9 (6) ◽

pp. 1273

Author(s):

Nazareth Torres ◽

Runze Yu ◽

S. Kaan Kurtural

Keyword(s):

Mycorrhizal Fungi ◽

Time Course ◽

Management Practices ◽

Irrigation Management ◽

Fungal Communities ◽

Soil Microbiome ◽

Wine Quality ◽

Network Analyses ◽

Vineyard Soil ◽

Vineyard Soils

Vineyard-living microbiota affect grapevine health and adaptation to changing environments and determine the biological quality of soils that strongly influence wine quality. However, their abundance and interactions may be affected by vineyard management. The present study was conducted to assess whether the vineyard soil microbiome was altered by the use of biostimulants (arbuscular mycorrhizal fungi (AMF) inoculation vs. non-inoculated) and/or irrigation management (fully irrigated vs. half irrigated). Bacterial and fungal communities in vineyard soils were shaped by both time course and soil management (i.e., the use of biostimulants and irrigation). Regarding alpha diversity, fungal communities were more responsive to treatments, whereas changes in beta diversity were mainly recorded in the bacterial communities. Edaphic factors rarely influence bacterial and fungal communities. Microbial network analyses suggested that the bacterial associations were weaker than the fungal ones under half irrigation and that the inoculation with AMF led to the increase in positive associations between vineyard-soil-living microbes. Altogether, the results highlight the need for more studies on the effect of management practices, especially the addition of AMF on cropping systems, to fully understand the factors that drive their variability, strengthen beneficial microbial networks, and achieve better soil quality, which will improve crop performance.

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Global Satellite-Based ET Products for the Local Level Irrigation Management: An Application of Irrigation Performance Assessment in the Sugarbelt of Swaziland

Remote Sensing ◽

10.3390/rs11060705 ◽

2019 ◽

Vol 11 (6) ◽

pp. 705 ◽

Cited By ~ 6

Author(s):

Poolad Karimi ◽

Bhembe Bongani ◽

Megan Blatchford ◽

Charlotte de Fraiture

Keyword(s):

Remote Sensing ◽

Performance Assessment ◽

Management Practices ◽

Local Level ◽

Water Productivity ◽

Irrigation Management ◽

Irrigation Performance ◽

Crop Water ◽

Management Regime ◽

Crop Water Productivity

Remote sensing techniques have been shown, in several studies, to be an extremely effective tool for assessing the performance of irrigated areas at various scales and diverse climatic regions across the world. Open access, ready-made, global ET products were utilized in this first-ever-countrywide irrigation performance assessment study. The study aimed at identifying ‘bright spots’, the highest performing sugarcane growers, and ‘hot spots’, or low performing sugarcane growers. Four remote sensing-derived irrigation performance indicators were applied to over 302 sugarcane growers; equity, adequacy, reliability and crop water productivity. The growers were segmented according to: (i) land holding size or grower scale (ii) management regime, (iii) location of the irrigation schemes and (iv) irrigation method. Five growing seasons, from June 2005 to October 2009, were investigated. The results show while the equity of water distribution is high across all management regimes and locations, adequacy and reliability of water needs improvement in several locations. Given the fact that, in general, water supply was not constrained during the study period, the observed issues with adequacy and reliability of irrigation in some of the schemes were mostly due to poor scheme and farm level water management practices. Sugarcane crop water productivity showed the highest variation among all the indicators, with Estate managed schemes having the highest CWP at 1.57 kg/m3 and the individual growers recording the lowest CWP at 1.14 kg/m3, nearly 30% less. Similarly center pivot systems showed to have the highest CWP at 1.63 kg/m3, which was 30% higher than the CWP in furrow systems. This study showcases the applicability of publicly available global remote sensing products for assessing performance of the irrigated crops at the local level in several aspects.

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