1. Please state project objectives and what work was done this quarter to address them:1. To determine how many leaf nutrient sampling per year are required to effectively capture the tree nutritional statusand adjust fertilizer accordingly.2. To establish the relationship of leaf nutrient concentration with yield, fruit drop, and canopy density3. To determine how the leaf nutrient (all 14 nutrient) levels change in the tree throughout the year.4. To evaluate how the leaf age affects the leaf nutrient status.The project started this quarter. The main goal for this quarter was to identify sites, mark trees, and collect baseline data.We surveyed 10+ sites to finalize the 4 sites for this trial, two sites are on Ridge and 2 are in southwest.. Ine ach site morethan 100 trees were manually screed for canopy density and disease index rating to identify trees as Mild and Severe. Thefinal data trees were tagged and tree health data such as canopy volume, leaf area index, leaf chlorophyll, leaf size andweight, root density been collected. Leaf samples for starch quantification and leaf, root and soil for nutrient analysis hasbeen collected are being processed. The spring flush has been tagged on the trees. 2. Please state what work is anticipated for next quarter:1. Data analysis and interpretation2. Processing samples for starch3. Tagging summer flush4. Collecting samples for nutrient analysis5. Applying fertilizer treatments based on leaf results 3. Please state budget status (underspend or overspend, and why): Currently, the project is still in the set up phase.The budget is spent as per the plan where major funds have been used for nutrient anlaysis. We have found dedicatedpersonnels to work on this project starting this quarter.
1. Please state project objectives and what work was done this quarter to address them:1. To determine how many leaf nutrient sampling per year are required to effectively capture the tree nutritional statusand adjust fertilizer accordingly.2. To establish the relationship of leaf nutrient concentration with yield, fruit drop, and canopy density3. To determine how the leaf nutrient (all 14 nutrient) levels change in the tree throughout the year.4. To evaluate how the leaf age affects the leaf nutrient status.The project started this quarter. The main goal for this quarter was to identify sites, mark trees, and collect baseline data.We surveyed 10+ sites to finalize the 4 sites for this trial, two sites are on Ridge and 2 are in southwest.. Ine ach site morethan 100 trees were manually screed for canopy density and disease index rating to identify trees as Mild and Severe. Thefinal data trees were tagged and tree health data such as canopy volume, leaf area index, leaf chlorophyll, leaf size andweight, root density been collected. Leaf samples for starch quantification and leaf, root and soil for nutrient analysis hasbeen collected are being processed. The spring flush has been tagged on the trees. 2. Please state what work is anticipated for next quarter:1. Data analysis and interpretation2. Processing samples for starch3. Tagging summer flush4. Collecting samples for nutrient analysis5. Applying fertilizer treatments based on leaf results 3. Please state budget status (underspend or overspend, and why): Currently, the project is still in the set up phase.The budget is spent as per the plan where major funds have been used for nutrient anlaysis. We have found dedicatedpersonnels to work on this project starting this quarter.
Objective 1 – Determine the effect of the ratio and concentration of Fe2+ + organic acid on hydroxyl radical production and stability. Objective complete. Objective 2 – Determine the phytotoxic levels of Fe2+ + organic acid solutions on citrus. Objective complete. Objective 3 – Determine the effect of Fe2+ + organic acid solutions on HLB titer using a rapid greenhouse, HLB-infected citron, rooted shoot bud assay. Continuing work to develop a rapid greenhouse screening system. Current systems are not yet ready for screening methods to cure or manage HLB. No CRDF funds being used for this research. Objective 4 – Requires screening system – see objective 3 discussion.Objective 5 – Requires screening system – see objective 3 discussion. Objectives 6 and 8 (Note: there is no 7) – These are the field tests for the various ferrous iron (Fe2+) and citric acid treatments on HLB status and horticultural measures for both mature (HLB symptomatic) and nonbearing (non-symptomatic) trees. Throughout this quarter (Jan 1 – Mar 31) as well as the project timeline, conventional pesticide spray applications for non-bearing grapefruit trees were applied to all the treatments in the trial and were based on scouting and were in accordance with IFAS guidelines. Similarly, irrigation events were made based on tree and field conditions as determined by soil feel and appearance, tensiometer readings, water table observation well measurements and visual assessment of tree canopy. Fertilizer applications were made via fertigation and were `spoon fed’ with frequent small applications bi-weekly. No dry fertilizer was used. All 7 experimental treatments were applied to the trial block as per the protocol. There was one cold front that impacted the trial location in Indian River County on 02/04/2021 with a low temperature documented at 35.97 . F. Only very minor leaf drop occurred 5 days after the cold weather. Rainfall over this quarter was 5.79 in. with on 0.33 in. recorded in March 2021 requiring frequent irrigation events. Visual assessments of tree condition were made on 01/14/21 using a numerical rating of 1-4 for each tree quadrant and were averaged for each tree. Other field measurements included fruit counts (01/28/2021) and trunk caliper measurements (03/31/2021). Leaf sampling for PCR analysis was performed on 01/27/2021. As in prior quarters, a ground application of herbicide was made, and plant material was removed in preparation for a 03/06/2021 UAV flight to collect aerial imagery for canopy area determinations. Aerial images were taken with a UAV equipped with a 20 MP digital camera on 3/6/2021. A set of overlapping images were taken at two altitudes – 75 and 150 feet. Images taken at 75 feet are for photo-documentation (0.27 inch/pixel) of the experiment and will be made available at the completion of the project. Images taken at 150 feet (0.53 inch/pixel) were processed by segmenting the image into trees and background using machine learning image analysis. Once the trees were segmented (identified and separated from the background), various measures were made/calculated including canopy area, density, perimeter, convex hull area and perimeter, and minimum and maximum caliper diameters. These measures, as well as the ground measures, will be correlated (statistical analysis) with the iron treatments to determine their effects.
Objective 1 – Determine the effect of the ratio and concentration of Fe2+ + organic acid on hydroxyl radical production and stability. Objective complete. Objective 2 – Determine the phytotoxic levels of Fe2+ + organic acid solutions on citrus. Objective complete. Objective 3 – Determine the effect of Fe2+ + organic acid solutions on HLB titer using a rapid greenhouse, HLB-infected citron, rooted shoot bud assay. Continuing work to develop a rapid greenhouse screening system. Current systems are not yet ready for screening methods to cure or manage HLB. No CRDF funds being used for this research. Objective 4 – Requires screening system – see objective 3 discussion.Objective 5 – Requires screening system – see objective 3 discussion. Objectives 6 and 8 (Note: there is no 7) – These are the field tests for the various ferrous iron (Fe2+) and citric acid treatments on HLB status and horticultural measures for both mature (HLB symptomatic) and nonbearing (non-symptomatic) trees. Throughout this quarter (Jan 1 – Mar 31) as well as the project timeline, conventional pesticide spray applications for non-bearing grapefruit trees were applied to all the treatments in the trial and were based on scouting and were in accordance with IFAS guidelines. Similarly, irrigation events were made based on tree and field conditions as determined by soil feel and appearance, tensiometer readings, water table observation well measurements and visual assessment of tree canopy. Fertilizer applications were made via fertigation and were `spoon fed’ with frequent small applications bi-weekly. No dry fertilizer was used. All 7 experimental treatments were applied to the trial block as per the protocol. There was one cold front that impacted the trial location in Indian River County on 02/04/2021 with a low temperature documented at 35.97 . F. Only very minor leaf drop occurred 5 days after the cold weather. Rainfall over this quarter was 5.79 in. with on 0.33 in. recorded in March 2021 requiring frequent irrigation events. Visual assessments of tree condition were made on 01/14/21 using a numerical rating of 1-4 for each tree quadrant and were averaged for each tree. Other field measurements included fruit counts (01/28/2021) and trunk caliper measurements (03/31/2021). Leaf sampling for PCR analysis was performed on 01/27/2021. As in prior quarters, a ground application of herbicide was made, and plant material was removed in preparation for a 03/06/2021 UAV flight to collect aerial imagery for canopy area determinations. Aerial images were taken with a UAV equipped with a 20 MP digital camera on 3/6/2021. A set of overlapping images were taken at two altitudes – 75 and 150 feet. Images taken at 75 feet are for photo-documentation (0.27 inch/pixel) of the experiment and will be made available at the completion of the project. Images taken at 150 feet (0.53 inch/pixel) were processed by segmenting the image into trees and background using machine learning image analysis. Once the trees were segmented (identified and separated from the background), various measures were made/calculated including canopy area, density, perimeter, convex hull area and perimeter, and minimum and maximum caliper diameters. These measures, as well as the ground measures, will be correlated (statistical analysis) with the iron treatments to determine their effects.
1. Please state project objectives and what work was done this quarter to address them: Objective 1: Determine effects of lowered soil pH on CLas populations and root physiology including internal root apoplast and vascular tissue pH.We are preparing plant material for CLas inoculation to initiate these experiments Objective 2: Field test multiple acidification materials including organic acids for tree response CLas suppression, nutrient uptake, and root and vascular pH changes We have identified multiple candidate field sites and are currently working on assessing soil characteristics to make sure they fit within the desired starting conditions, especially pH, for the trial. 2. Please state what work is anticipated for next quarter: In the next quarter we anticipate inoculating greenhouse trees with CLas for objective 1. In the next quarter we anticipate finalizing field site selection, layout of plots, preliminary plot data collection, and initiation of treatments for objective 2 3. Please state budget status (underspend or overspend, and why): The budget is in underspend because we need final field site selection before determining the injection equipment and amount of chemical for application based on row length.
1. Please state project objectives and what work was done this quarter to address them: Objective 1: Determine effects of lowered soil pH on CLas populations and root physiology including internal root apoplast and vascular tissue pH.We are preparing plant material for CLas inoculation to initiate these experiments Objective 2: Field test multiple acidification materials including organic acids for tree response CLas suppression, nutrient uptake, and root and vascular pH changes We have identified multiple candidate field sites and are currently working on assessing soil characteristics to make sure they fit within the desired starting conditions, especially pH, for the trial. 2. Please state what work is anticipated for next quarter: In the next quarter we anticipate inoculating greenhouse trees with CLas for objective 1. In the next quarter we anticipate finalizing field site selection, layout of plots, preliminary plot data collection, and initiation of treatments for objective 2 3. Please state budget status (underspend or overspend, and why): The budget is in underspend because we need final field site selection before determining the injection equipment and amount of chemical for application based on row length.
The purpose of this project is to assess nitrogen (N) fertilization rates for high-density plantings of different scion and rootstock combinations in four commercial citrus growers. The overall approach is to 1) determine the appropriate N rates needed to support tree growth and productivity, 2) compare data obtained with existing UF/IFAS N recommendations, and 3) revise best management practices (BMPs) for N application in young trees planted in high-density plantings affected by Huanglongbing (HLB).
The PhD student and Research Assistant for the project were hired with a short delay due to covid-19, but already started working on the project.
We contacted the grower collaborators participating: IMG Citrus (Brian Randolph), Peace River Citrus (Larry Black Jr.), Agromillora Florida/ Lost Lake Groves (Clay Pedersen), Graves Brothers (David Howard), and scheduled/performed site visits to all locations. The planting densities and variety/scion combinations were chosen, maps generated, experimental units identified with permanent signs, and the current information regarding N fertilization requested to proceed with the treatment applications. We anticiapate ordering the fertilizer by the end of this month to proceed with the May/June fertilization as scheduled. The first tree size data collection will happen in the next quarter. We contacted AgerPoint to potentially collect tree size data using Lidar sensors but cost was prohibitive. The project is on schedule.
The purpose of this project is to assess nitrogen (N) fertilization rates for high-density plantings of different scion and rootstock combinations in four commercial citrus growers. The overall approach is to 1) determine the appropriate N rates needed to support tree growth and productivity, 2) compare data obtained with existing UF/IFAS N recommendations, and 3) revise best management practices (BMPs) for N application in young trees planted in high-density plantings affected by Huanglongbing (HLB).
The PhD student and Research Assistant for the project were hired with a short delay due to covid-19, but already started working on the project.
We contacted the grower collaborators participating: IMG Citrus (Brian Randolph), Peace River Citrus (Larry Black Jr.), Agromillora Florida/ Lost Lake Groves (Clay Pedersen), Graves Brothers (David Howard), and scheduled/performed site visits to all locations. The planting densities and variety/scion combinations were chosen, maps generated, experimental units identified with permanent signs, and the current information regarding N fertilization requested to proceed with the treatment applications. We anticiapate ordering the fertilizer by the end of this month to proceed with the May/June fertilization as scheduled. The first tree size data collection will happen in the next quarter. We contacted AgerPoint to potentially collect tree size data using Lidar sensors but cost was prohibitive. The project is on schedule.
The contract executed between CRAFT and CRDF was effective March 18, 2021, however work began on Cycle II projects beginning in July 2020 and deliverables executed during that period will be reported herein. CRAFT PARTICIPATION APPLICATION PROCESS: The CRAFT Technical Working Group, USDA/ARS and CRAFT staff were all involved with preparing the CRAFT application content for the Cycle II online application experience. The application period was open to Florida citrus growers from July 20-September 4, 2020. CRAFT received 86 applications representing 4,411 acres, including 3,014 acres for solid set plantings and 1,397 acres for reset plantings. The geographic distribution represented 11 counties and all citrus-producing regions in Florida. PROJECT SELECTION & DEVELOPMENT:After review of all projects submitted, it was determined by the Technical Working Group based on fulfillment of minimum requirements and scientific merit that 63 of the projects would be recommended for further development of experimental designs while the remaining 23 would be placed on a waitlist for future consideration dependent on funding availability. Based upon the projects presented, grower participants were organized within subgroups of similar projects (for purposes of replication) and assigned a group leader to help develop the project design. The groups are as follows:1. Rootstock/Scion2. Soil/Tree Fertility3. Pest Management4. Biostimulants5. ResetsAll of the applications approved for grower contract finalization during the reporting period are available upon request. Pre-audits of each project are used to confirm the planting of trees and compliance with contract to date. The project designs for each contract are also available upon request. As of March 31, 2020, 50 applications representing 2,062 acres have been approved by the CRAFT Board of Directors and are finalizing contracts and planting. Following completion of planting, growers are expected to report production data in real time or at least quarterly in to the USDA-CRAFT Data Portal. The data portal will include a separate entry point for data/ measurements from third party partners such as FDACS/DPI and Aerobotics. Data entered by participants and third parties for each project will be visible initially by the growers for their individual projects. Data with actual production inputs by growers is expected for the first five projects prior to the next quarterly report.In addition to execution of contracts and commencement of projects, CRAFT staff continued communications and outreach efforts including, articles in multiple industry and general publications; updating of the CRAFT website (craftfdn.org); public meetings of the Technical Working Group and Board of Directors; and more. A full list of communications efforts is available upon request.
The contract executed between CRAFT and CRDF was effective March 18, 2021, however work began on Cycle II projects beginning in July 2020 and deliverables executed during that period will be reported herein. CRAFT PARTICIPATION APPLICATION PROCESS: The CRAFT Technical Working Group, USDA/ARS and CRAFT staff were all involved with preparing the CRAFT application content for the Cycle II online application experience. The application period was open to Florida citrus growers from July 20-September 4, 2020. CRAFT received 86 applications representing 4,411 acres, including 3,014 acres for solid set plantings and 1,397 acres for reset plantings. The geographic distribution represented 11 counties and all citrus-producing regions in Florida. PROJECT SELECTION & DEVELOPMENT:After review of all projects submitted, it was determined by the Technical Working Group based on fulfillment of minimum requirements and scientific merit that 63 of the projects would be recommended for further development of experimental designs while the remaining 23 would be placed on a waitlist for future consideration dependent on funding availability. Based upon the projects presented, grower participants were organized within subgroups of similar projects (for purposes of replication) and assigned a group leader to help develop the project design. The groups are as follows:1. Rootstock/Scion2. Soil/Tree Fertility3. Pest Management4. Biostimulants5. ResetsAll of the applications approved for grower contract finalization during the reporting period are available upon request. Pre-audits of each project are used to confirm the planting of trees and compliance with contract to date. The project designs for each contract are also available upon request. As of March 31, 2020, 50 applications representing 2,062 acres have been approved by the CRAFT Board of Directors and are finalizing contracts and planting. Following completion of planting, growers are expected to report production data in real time or at least quarterly in to the USDA-CRAFT Data Portal. The data portal will include a separate entry point for data/ measurements from third party partners such as FDACS/DPI and Aerobotics. Data entered by participants and third parties for each project will be visible initially by the growers for their individual projects. Data with actual production inputs by growers is expected for the first five projects prior to the next quarterly report.In addition to execution of contracts and commencement of projects, CRAFT staff continued communications and outreach efforts including, articles in multiple industry and general publications; updating of the CRAFT website (craftfdn.org); public meetings of the Technical Working Group and Board of Directors; and more. A full list of communications efforts is available upon request.
The objectives of this study are to identify optimal pH range for root function and minimize root turnover on HLB-affected rootstocks and how uneven pH levels in the root zone (e.g. irrigated vs. row middle portions of root system) affect the overall health of the tree. This is being done in a split root system in the greenhouse where pH of different parts of the root system can be controlled an maintained. The following progress reported is based on a October 31st report date. The breakdown of the 2nd experiment testing different irrigation pH’s on each half of the split root system (to mimic irrigated and non-irrigated root zones) is complete. Data is being analyzed and samples for RNAseq are being prepared. The 2nd repetition of the 1st experiment is underway to confirm the results that US942 becomes highly sensitive to low pH (5.5) when infected with HLB (root damage and excessive root leakage causing irrigation leachate pH to increase. We also expect to partially confirm this finding in the ongoing data analysis of the 2nd experiment.
Propagation of experimental trees proved more difficult than anticipated. We have transplanted the trees for the first repitition into split root rhizotrons and are preparing for HLB inoculation and sampling. The postdocs in Drs. Johnson and Wang’s labs have coordinated and done test runs of sampling procedures for RNA and metabolite samples, which will begin 2 weeks after inoculations. While we had very high success rate for Valencia on Swingle, all other combinations that included either Sugarbelle or UFR-4 had lower than expected success rates and the trees continue to underperform compared to the Val/Swingle. Although we thought we had enough plant material for both experiments vigorously growing, we have had some of the combinations struggle recently. We are contacting nurseries to see if they can provide us with grafted trees for the 2nd rep by next spring.
HLB is known to make citrus roots more susceptible to Phytophthora root rot. It also reduces the efficacy of chemical management of Phytophthora root rot, creating a difficult management scenario. Current Phytophthora management recommendations are based on pre-HLB work done in the 1980s. These three conditions raise the question of whether yield improvement from Phytophthora management is enough to pay for the management costs themselves. The goal of this project is to develop new soil propagule density managment thresholds and recommendations for chemical management of Phytophthora root rot based on ecomonic analysis of yield responses in different soil conditions. Yield has been collected from Hamlin sites and the Valencia harvest is being planned currently. Phytophthora samples have been taken and this years treatments will begin in April. We have built plot by plot microjet irrigation systems that connect to our trailer mounted handgun sprayer to mimic irrigation injection of materials for ease of application. We are currently adding the split plot factor to our plot design to begin foliar brown rot sprays in midsummer through October. We are preparing to inoculate seedlings with HLB for an additional greenhouse experiment to determine if the newly labeled chemistries have the same limitation on HLB-affected plants as fosetyl-Al and mefanoxam have shown. Many of the new chemistries are directly effective against Phytophthora in the soil rather than acting after uptake by the roots, so this is likely to reduce the limitations of Phytophthora management in HLB-affected groves and test the hypothesis. We are waiting for enough CLas+ budwood for graft inoculations or a large enough field population of psyllids after the spring flush to do a psyllid inoculation, whichever comes first.
1. Please state project objectives and what work was done this quarter to address them:Project objectives:Objective 1: Determine the effect of systemic acquired resistance (SAR) in enhanced tolerance to HLB Objective 2: Monitor tree health and HLB levels Objective 3: Conduct Juice analysis and evaluate quality parameters from selected Parson Brown trees. We have identified and collected leaf samples in the spring from 8 Parson Brown groves. Groves are spread all around the major citrus growing regions. We sampled from 3 groves in polk county, 2 groves in Highlands county, 1 grove in St. Lucie county, 1 grove in glades county and 1 grove in Collier county. Samples were collected for both RNA and DNA extractions. Most of the trees are from the PB 56-2 clone but some groves had trees of the older PB 1-2-3 clone. All growers reported lower to no fruit drop on the parson brown irrespective of rootstock used. This is in comparison with Hamlin which had severe fruit drop this year. Hamlin leaf samples from the same block or neighboring blocks were also collected for analysis. 2. Please state what work is anticipated for next quarter:In the next quarter, we will again sample the same groves and collect similar leaf samples. HLB levels will be evaluated using qPCR and we will evaluate the genetic differences between the samples. 3. Please state budget status (underspend or overspend, and why):We are on target with the spending for this project.
Objective 1 – Determine the effect of the ratio and concentration of Fe2+ + organic acid on hydroxyl radical production and stability. Objective complete. Objective 2 – Determine the phytotoxic levels of Fe2+ + organic acid solutions on citrus. Objective complete. Objective 3 – Determine the effect of Fe2+ + organic acid solutions on HLB titer using a rapid greenhouse, HLB-infected citron, rooted shoot bud assay. Continuing work to develop a rapid greenhouse screening system. Current systems are not yet ready for screening methods to cure or manage HLB. No CRDF funds being used for this research. Objective 4 – Requires screening system – see objective 3 discussion.Objective 5 – Requires screening system – see objective 3 discussion. Objectives 6 and 8 (Note: there is no 7) – These are the field tests for the various ferrous iron (Fe2+) and citric acid treatments on HLB status and horticultural measures for both mature (HLB symptomatic) and nonbearing (non-symptomatic) trees. Throughout this quarter (Oct. 1 – Dec. 31) as well as the project timeline, conventional pesticide spray applications were applied to all the treatments in the trial and were based on scouting and were in accordance with IFAS guidelines. Similarly, irrigation events were made based on tree and field conditions as determined by soil feel and appearance, tensiometer readings, water table observation well measurements and visual assessment of tree canopy. Fertilizer applications were made via fertigation and were `spoon fed’ with frequent small applications bi-weekly. No dry fertilizer was used. All 7 experimental treatments were applied to the trial block as per the protocol. There were three cold fronts that impacted the trial location in Indian River County during late Nov. through Dec. that were documented to be below 40. F. Significant leaf drop occurred 5-7 days after the cold weather but there was no treatment effect observed based on visual assessment of extent of abscission. Also, HLB leaf symptoms were prominent throughout the trial in late Dec. and will be visually assessed next quarter. A ground application of herbicide was made, and plant material was removed in preparation for a UAV flight for aerial imagery data collection. Aerial images were taken with a UAV equipped with a 20 MP digital camera on 12/31/2020. A set of overlapping images were taken at two altitudes – 100 and 150 feet. Images taken at 100 feet are for photo-documentation (0.36 inch/pixel) of the experiment and will be made available at the completion of the project. Images taken at 150 feet (0.53 inch/pixel) were processed by segmenting the image into trees and background using machine learning image analysis. Once the trees were segmented (identified and separated from the background), various measures were made/calculated including canopy area, density, perimeter, convex hull area and perimeter, and minimum and maximum caliper diameters. These measures, as well as the ground measures, will be correlated (statistical analysis) with the iron treatments to determine their effects. One additional set of images, including a photo-documentation set, will be collected at the end of the project.
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