Progress report for LNE20-395
Project Information
Problem and Justification: Current recommendations for fall nitrogen application and row cover management in annual strawberry plasticulture are based on tradition and calendar date. Decisions regarding both practices would be more appropriately based on the floral status of plants in production. Pre-plant N normally provided plasticulture strawberries is unnecessary: it does not improve yield. However, targeted weekly pulses of N for 3 consecutive weeks starting one week after floral initiation begins in the fall significantly enhances subsequent yield. Row covers applied to strawberries in the fall at the appropriate time increase yield the following spring by increasing the number of flowers per plant and protecting plants from excessive cold during dormancy. Growers fertilize with N and apply row covers based on tradition and calendar date without any knowledge of the floral status of their plants. Flower mapping is used to to evaluate a plants floral status. While widely used in Europe, flower mapping has not been developed for US growers and data illustrating its usefulness for North American production has not been generated. Solution and Approach: Flower mapping is not difficult and growers could easily learn the technique. Strawberry growers taught how to flower map and interpret the results would be able to make science-based decisions regarding production practices rather than relying on tradition or calendar date. Precisely timed nitrogen fertilization and row cover applications based on floral mapping would improve yields and empower growers with a new management tool. Basing decisions on self-generated knowledge rather than tradition or calendar date would reduce grower stress associated with these decisions. In addition, the chances for over-fertilization with N and the associated environmental risks would decrease. Growers supplied with flower mapping kits and taught to flower map at one of 3 regional grower meetings would then employ flower mapping on their farms, submit maps to us via e-mail and interpret their maps with our help to evaluate management choices for their specific situation. Milestones and Performance Target: Seventy-five growers will adopt strawberry flower mapping as a management tool to properly time fall N applications and efficiently manage row cover placement based on farm-specific data which will significantly increase yields on their farms. Considering even only modest yield improvements much less then that reported in the literature (350 to 500%), a conservative estimate of a 25% increase would translate into a minimum of an additional $1,000 an acre (at $1.00 per lb) due to use of flower mapping. In addition, eliminating ineffective traditional pre-plant N fertilization by substituting it with targeted N pulses would reduce N application by 20 lbs/acre, saving growers money, improving yields and reducing the chances of environmental contamination from unnecessary N fertilization.
Science-based decisions using flower mapping will replace tradition and calendar based recommendations for N fertilization and row cover management to increase grower confidence and reduce stress with enhanced yields of 1,000 lbs per acre on at least one acre per farm on seventy-five farms in the Northeast.
This project is evaluating strawberry flower mapping as a tool for nitrogen and row cover management.
Cooperators
- (Educator and Researcher)
Research
Flower mapping is a tool for strawberry growers (1) for targeting pulses of N in the fall to enhance flowering and fruiting in the annual plasticulture system and (2) for managing row cover application to optimize crown branching and floral initiation in short-day cultivars grown in the annual plasticulture system. Flower maps will remove the uncertainty regarding the effectiveness of current practices involving fall N fertilization and row cover management and replace it with farm-generated, science-based recommendations to maximize sustainable strawberry production in the northeast.
The research component of this project has two goals (1) to establish, document and demonstrate the clear relationship between floral status and productivity in strawberry and (2) to demonstrate that plant floral status can be modified with N and row cover manipulation based on floral maps. We will demonstrate the usefulness of floral mapping by demonstrating floral modification with pulsed N fertilization and appropriate row cover management.
Both goals are addressed with one large integrated field study. Weekly flower maps and associated floral goals from propagation in July through harvest the following June will be developed for 2 cultivars in the annual plasticulture system. Modification of plant floral status via controlled N-pulse treatments and row cover manipulation will be assessed from September through December.
Research will be conducted at Rutgers Fruit and Ornamental Research Center in Cream Ridge, NJ and duplicated at The Clifford E. & Melda C. Snyder Research and Extension Farm - Rutgers Center for Sustainable Agriculture in Pittstown, NJ. All plants will be propagated at Rutgers Fruit and Ornamental Research Center in Cream Ridge, NJ.
Two variations of the annual plasticulture system will be utilized for the evaluation. One variation (the short day system) is the traditional annual plasticulture system using the short-day cultivar ‘Chandler’ which is familiar to growers. The other variation (the long-day system) utilizes the long day cultivar ‘Albion’ in a fall, off-season system that is becoming increasingly popular in the northeast.
Short day system
Plug plants (total of 14,000) of ‘Chandler’ will be produced from cold-stored dormant crowns obtained from a commercial nursery. Plugs will be flower mapped weekly and their floral status evaluated. Plants will be established in the ‘flower map’ field on raised beds with trickle irrigation covered with black plastic mulch on or about September 15. Three fertilizer treatments will be evaluated: (1) standard pre-plant application, (2) no pre-plant + no elevated weekly pulses, (3) no pre-plant + elevated N once a week for 3 consecutive weeks beginning 1 week after floral initiation is detected with flower maps). The elevated N pulses will be provided via fertigation with 800 ppm N derived from calcium nitrate. Three dates of row cover application will be evaluated: (1) when nightly temperatures are below 50F for 3 consecutive nights, (2) November 15, and (4) December 15. Plants (5 per treatment combination) will be sampled from the flower map field (destructive sampling) weekly (17 sample dates) and flower mapped to establish a baseline of plant floral status over time. If 4 to 6 crowns are not present when the nightly temperature falls below 50F for 3 consecutive nights, row covers will be installed to induce further branching. Control plants will be maintained and flower mapped weekly. Plants will be mapped every three weeks from Dec 1 through harvest the following spring (8 sample dates).
The experimental design is a split-split plot with 5 replications of the main plot. The main plot is N fertilization, the sub-plot is row cover treatment and the sub-sub-plot is sampling date. The experiment will be repeated at both sites for two more years. The design will be identical at both sites each year, with separate randomizations at each site in each year to facilitate a direct comparison of location and year in the statistical analysis. (A field map / plot plan example is available as an uploaded file.)
Separate ‘production’ fields with the exact same treatments will be established adjacent to the flower map trials at both sites to evaluate production in the spring. The experimental design is a split-plot with 5 replications of the main plot. The main plot is N fertilization and the sub-plot is row cover treatment. The experiment will be repeated at both sites for two more years. The design will be identical at both sites each year, with separate randomizations at each site in each year to facilitate a direct comparison of location and year in the statistical analysis.
All data will be tested for normality, and the aligned rank transformation (Durner, 2019) utilized for non-normal variables. All data will be analyzed using an analysis of variance and means separated using Fishers Protected LSD and planned F-tests, when appropriate.
Long day system
Plug plants of ‘Albion’ will be produced from cold-stored dormant crowns obtained from a commercial nursery. Plugs will be flower mapped weekly until November 1 to evaluate their floral status over time. Plugs will be established in the field on raised beds, trickle irrigated and covered with white plastic mulch. Treatments will include controlled photoperiod flower initiation using intermittent incandescent field lighting (Durner, 2018) followed by 3 weekly nitrogen pulses beginning one week after floral initiation. To further extend the season, a high tunnel (14’ x 100’) will be erected over the field planting when the minimum nighttime temperature falls below 45F for three consecutive nights. Fall and early winter flowering and yield will be recorded. Once temperatures are too cold for production (freezing temperatures inside the tunnel at night) row covers will be placed over the beds. Spring yield will also be evaluated.
The experimental design is a split-split plot with 5 replications of the main plot. The main plot is photoperiod treatment, the sub-plot is N fertilization, and the sub-sub plot is sampling date. The experiment will be repeated at both sites for two more years. The design will be identical at both sites each year, with separate randomizations at each site in each year to facilitate a direct comparison of location and year in the statistical analysis.
Separate ‘production’ fields with the exact same treatments will be established adjacent to the flower map trials at both sites to evaluate production in the spring. The experimental design is a split-plot with 5 replications of the main plot. The main plot is photoperiod and the sub-plot is N treatment. The experiment will be repeated at both sites for two more years. The design will be identical at both sites each year, with separate randomizations at each site in each year to facilitate a direct comparison of location and year in the statistical analysis.
All data will be tested for normality, and the aligned rank transformation (Durner, 2019) utilized for non-normal variables. All data will be analyzed using an analysis of variance and means separated using Fishers Protected LSD and planned F-tests, when appropriate.
While farmers will not have researcher directed work on their farms, they will be involved by developing their own floral maps and adjusting production practices with our help and documenting any changes in productivity they observe as a result of these adjustments.
Work initiated in 2020
Chandler Flower Mapping
Plug plants of ‘Chandler’ were purchased from a commercial nursery in New Jersey for establishing in the field at the Cream Ridge Center and Snyder Farm for flower mapping studies. Plugs were planted in the plasticulture system on 9 September 2020 at Cream Ridge and 28 August at Snyder Farm. By 23 September 2020, approximately 50% of the plants at each location had died. Samples were evaluated by Rutgers plant pathologist Dr. Andy Wyenandt. He found high levels of Rhizoctonia and what appeared to be Thielaviopsis root rots on the samples. With such plant losses, the experimental plan for ‘Chandler’ in 2020 was modified to evaluate nitrogen application based on flower maps (N0 (control, 0 ppm nitrogen), N1 (800 ppm N one week after floral initiation detected) and N2 (800 ppm N one week after floral initiation + 800 ppm N two weeks after floral initiation). The row cover portion of the study was omitted due to lack of sufficient plant material for testing. In addition, the study at Cream Ridge was reduced to 3 replicates (initially planned for 5 replicates). Samples for floral mapping were taken from each site on the dates indicated in Table 1.
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Table 1. Planting, sampling and treatment dates for floral mapping study of ‘Chandler’ strawberry established in a plasticulture system at two sites in New Jersey. |
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Location |
|
|
Date |
Cream Ridge |
Snyder Farm |
|
Planting date |
9 September 2020 |
28 August 2020 |
|
Flower mapping |
10, 15, 21, 28 September |
|
|
|
5, 14, 19, 27 October |
15, 22, 30 October |
|
|
2, 11, 19 November |
6, 13, 20 November |
|
Nitrogen treatment 1 (N1) |
10/21 |
10/22 |
|
Nitrogen treatment 2 (N2) |
10/21 + 10/27 |
10/22 + 11/4 |
|
Row cover installation |
10 December |
14 December |
On each date listed for flower mapping in Table 1, five (Snyder Farm) or six (Cream Ridge) single plant samples from each site were taken from each nitrogen treatment and flower mapped. Flower mapping consisted of evaluating the terminal meristem and determining whether it was floral or vegetative via dissection using a digital microscope. The status of the terminal meristem was assigned 0 if vegetative and 1 if floral. If the meristem was floral, the floral stage was further categorized based on which flowers of the inflorescence were discernable at dissection: primary only = stage 1, secondary = stage 2, tertiary = stage 3 and quaternary or greater as stage 4. Axillary bud status was also evaluated for all buds subtending a live leaf. Buds were categorized as vegetative (0), runner (2) or branch crown. If a branch crown was present, the floral status of its terminal meristem was evaluated and categorized using the same criteria used for evaluating the terminal meristem of the main crown.
Data for flower mapping were evaluated separately for the two sites. A non-parametric analysis of data utilizing the Wilcoxon option in PROC NPAR1WAY test of the SAS® system which utilizes the Kruskal-Wallis test was used to evaluate differences in bud status and stage among the three treatments. Evaluations were performed for each meristem position on the main crown, beginning with the terminal position and progressing basipetally along the main crown. Results are presented in the section labelled ‘Results and Discussion’.
Albion Conditioning and Flower Mapping
The ‘Albion’ experiment was performed at one site only (Cream Ridge) in 2020. Plug plants were propagated at the Cream Ridge Center using runner tips collected from mother plants established in coco coir bags on 29 June 2020 set atop raised beds covered with black plastic mulch. Mother plants were fertilized weekly with 60 ppm N obtained from Peters 20-20-20 soluble fertilizer supplied through trickle irrigation via an E-Z flo injector. Tips were harvested beginning 17 August 2020. Tips were set into 50-cell trays containing Pro Mix Organic mix. Tips were misted for 15 minutes every 60 minutes for 2 weeks until roots were established. Conditioning treatment of ‘Albion’ plugs was initiated on 9 September 2020. Conditioning consisted of a 2 x 2 factorial combination of photoperiod and nitrogen treatment. Photoperiod treatments were (1) natural daylength (SD) or (2) natural daylength supplemented with 15 minutes of incandescent radiation (C9, 7 watt bulbs (Novelty Lights, Inc., Centennial, CO) suspended 15 cm above the plant canopy) every hour from 7 pm until 7 am for two consecutive weeks (LD). Nitrogen treatment consisted of 0 or 800 ppm N during the second week of long day exposure. Plants were fertilized with Peters Soluble Fertilizer (20% available N, 20% available P2O5, 20% available K2O) diluted with water to provide 800 ppm N. Plants received enough solution to saturate the soil. The 0 ppm N treatment received no supplemental fertilization. After conditioning, plugs were established in a plasticulture field planting at Rutgers Cream Ridge Research Farm. Plants were established on raised beds (20 cm high x 90 cm wide) covered with white on black (1 mil) plastic mulch with the white side exposed. There were two staggered rows per bed with 30 cm between rows and 38 cm between plants in the row. Irrigation was provided as needed via drip tape (10 Mil Medium Weight 5/8" AquaTraxx Drip Tape, 12” spacing, flow rate 0.45, The Toro Company, Bloomington, MN) placed in the center of the bed underneath the plastic mulch. Gothic Pro high tunnels (Farmers Friend, LLC) were erected over the plasticulture field. Three tunnels were erected. Each tunnel enclosed 2 adjacent beds. Each bed was a replicate with the 4 conditioning treatments randomly arranged in 20 plant plots to provide 4 treatment plots per bed. There were a total of 6 replicates (2 per tunnel) in the experiment.
On each date listed for flower mapping in Table 2, six single plant samples from each treatment were flower mapped. One plant was sampled from each treatment in each replicate. Flower mapping consisted of evaluating the terminal meristem and determining whether it was floral or vegetative via dissection using a digital microscope. The status of the terminal meristem was assigned 0 or vegetative and 1 if floral. If the meristem was floral, the floral stage was categorized based on which flowers of the inflorescence were discernable at dissection: primary only = stage 1, secondary = stage 2, tertiary = stage 3 and quaternary or greater as stage 4. Axillary bud status was not evaluated.
To increase statistical sample size, dates were combined as follows: 28 September, 5 October and 14 October combined as ‘Early Fall’ and 19 October, 27 October and 2 November combined as ‘Late Fall’.
Data for flower mapping were evaluated using a non-parametric analysis of data utilizing the Wilcoxon option in PROC NPAR1WAY test of the SAS® system which utilizes the Kruskal-Wallis test to evaluate differences in bud status and stage among the four treatments. Results are presented in the section labelled ‘Results and Discussion’.
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Table 2. Planting, sampling and treatment dates for floral mapping study of ‘Albion’ strawberry established in a high tunnel plasticulture system at Rutgers Cream Ridge Research Center, Cream Ridge, New Jersey. |
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Activity |
Date |
|
Mother plant establishment |
29 June 2020 |
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Runner tip harvest |
17 August 2020 |
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Conditioning treatment initiated |
16 September 2020 |
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Field planting date |
5 October 2020 |
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Flower mapping |
21, 28 September |
|
|
5, 14, 19, 27 October |
|
|
2 November |
Since the ‘Albion’ planting was established too late to produce a fall crop, an early spring crop will be forced to determine if spring forcing is an option for when the fall crop cannot be achieved. In addition, forcing an early spring crop will provide evidence as to whether or not conditioning is appropriate for high tunnel forcing systems. Conditioning has been shown to be quite effective for late summer cropping of ‘Albion’.
Potential Workshop Participant Mailing List
Contact information for potential workshop participants was compiled from internet searches.
Digital Microscope Evaluation
Digital microscopes were evaluated for workshop use. Scopes were evaluated for image quality, ease of use, cost. The scopes evaluated included:
Kmoon 1000X Magnification USB Digital Microscope with OTG Function 8-LED Light Magnifying Glass Magnifier with Stand
Koolertron Wireless WiFi Digital USB Microscope,Portable Handheld Endoscope Camera Magnifier with 50X-1000x Zoom Magnification 1080P 2MP 8 LED Light for iPhone, iPad, Android Phone, Windows, Mac
Elikliv 4.3 inch LCD Digital USB Microscope Endoscope Record 1000X Magnification Zoom, 8 Adjustable LED Light, Micro-SD Storage, Camera Video Recorder for Repair Soldering
Andonstar Digital USB Microscope for Kids, Students Science, Children's Gift, 200X 5'' HD 2MP CMOS Magnification Zoom, Video Camera Microscope with Built-in Rechargeable Battery, LCD Screen Scope
WiFi Wireless LCD Digital USB Microscope with Stand,Koolertron 4.3 Inch 1080P 1000X Magnification Camera 2400x1584 Photo Capture,1920x1080 Video Recorder Compatible with iPhone Andoird, iPad Mac Window
LCD Digital Microscope, Kmoon G600 Portable LCD Digital Microscope with High Brightness 8 LEDs and Built-in Lithium Battery
Koolertron, 7 inch LCD Digital USB Microscope with 16G TF Card,Koolertron 12MP 1-1200X Magnification Handheld Camera Video Recorder,8 LED Light,Rechargeable Battery
Plugable USB 2.0 Digital Microscope with Flexible Arm Observation Stand Compatible with Windows, Mac, Linux (2MP, 250x Magnification)
Work initiated in 2021
'Chandler'
Evaluation of plant architecture was performed in spring 2021 to evaluate effects of fall applied nitrogen on ‘Chandler’ growth and yield. Five plants per treatment were sampled from Snyder farm plots and fifteen plants per treatment from Cream Ridge plots and plant architecture assessed via dissection. Crown, leaf, inflorescence, flower and runner numbers per plant were determined. In addition, leaf, inflorescence, flower and runner production per crown were also evaluated. Fruit were harvested biweekly from 30 plants per treatment, total yield per plant determined then evaluated for nitrogen effects on productivity.
Data from each site were evaluated separately using a non-parametric analysis utilizing the Wilcoxon option in PROC NPAR1WAY test of the SAS® system which utilizes the Kruskal-Wallis test to evaluate differences in plant architectural features among the three treatments. Results are presented in the section labelled ‘Results and Discussion’.
Fall 2021 Flower Mapping and Nitrogen Treatments
Plug plants of ‘Chandler’ were propagated from runner tips purchased from a commercial nursery in New Jersey for establishing in field plantings at Cream Ridge and Snyder Farm for flower mapping studies. Plugs were planted in the plasticulture system on 20 September 2021 at Cream Ridge and 9 September at Snyder Farm.
The experimental plan for ‘Chandler’ in 2021 included four treatments: (1) Control (0 lbs N/acre), (2) 30 lbs N/acre one week after planting, (3) 60 lbs N/acre one week after planting and (4) 60 lbs N one week after flower initiation was observed.
Planting, flower mapping, row cover installation and treatment dates are presented for both locations in Table 3.
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Table 3. Planting, sampling and treatment dates for floral mapping study of ‘Chandler’ strawberry established in a plasticulture system at two sites in New Jersey. |
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Location |
|
|
Date |
Cream Ridge |
Snyder Farm |
|
Planting date |
20 September 2021 |
9 September 2021 |
|
Flower mapping |
8, 21, 28 September |
8, 21 September |
|
|
7, 14, 20, 28 October |
14, 25 October |
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Nitrogen treatment 1 (30) |
9/28 |
9/16 |
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Nitrogen treatment 2 (60) |
9/28 |
9/16 |
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Nitrogen treatment 3 (Floral 60) |
10/28 |
10/21 |
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Row cover installation |
12/2 |
11/18 |
On each date listed for flower mapping in Table 3, five (Snyder Farm) or six (Cream Ridge) single plant samples from each site were taken from each nitrogen treatment and flower mapped. Flower mapping consisted of evaluating the terminal meristem and determining the floral or vegetative status via dissection using a digital microscope. The status of the terminal meristem was assigned 0 if vegetative and 1 to 4 if floral, depending on which flowers of the inflorescence were discernable at dissection: primary only = 1, secondary = 2, tertiary = 3 and quaternary or greater = 4.
Data for flower mapping were evaluated separately for the two sites. A non-parametric analysis of data utilizing the Wilcoxon option in PROC NPAR1WAY test of the SAS® system which utilizes the Kruskal-Wallis test was used to evaluate differences in bud status among the three treatments. Results are presented in the section labelled ‘Results and Discussion’.
Albion Conditioning and Flower Mapping
Evaluation of Fall 2020 conditioning effects on Spring 2021 Yield
This study was conducted only at Cream Ridge. Yield was evaluated in the spring of 2021 for plants conditioned in the fall of 2020. Results are presented in the section labelled 'Results and Discussion'.
Fall 2021 Conditioning for Spring Production
This study was conducted only at Cream Ridge. Due to delayed shipment of runner tips from Canada for plug production, propagation and conditioning of 'Albion' was such that a fall crop was not feasible in 2021. In order to produce a fall crop, plants should be established in high tunnels during June and July. Runner tips were not available from Canada for propagating (due to trucking issues generated by COVID) until August 17, 2021. Three to four weeks are required for plug propagation and 3 weeks are required for conditioning. Thus 'Albion' was planted in high tunnels on 30 September following propagation and conditioning.
Conditioning treatment consisted of a 2 x 2 factorial combination of photoperiod and nitrogen treatment. Photoperiod treatments were (1) natural daylength (SD) or (2) natural daylength supplemented with 15 minutes of incandescent radiation (C9, 7 watt bulbs (Novelty Lights, Inc., Centennial, CO) suspended 15 cm above the plant canopy) every hour from 7 pm until 7 am for two consecutive weeks (LD). Nitrogen treatment consisted of 0 or 800 ppm N during the second week of long day exposure. Plants were fertilized with Peters Soluble Fertilizer (20% available N, 20% available P2O5, 20% available K2O) diluted with water to provide 800 ppm N. Plants received enough solution to saturate the soil. The 0 ppm N treatment received no supplemental fertilization. After conditioning, plugs were established in a plasticulture field planting at Rutgers Cream Ridge Research Farm. Plants were established on raised beds (20 cm high x 90 cm wide) covered with white on black (1 mil) plastic mulch with the white side exposed. There were two staggered rows per bed with 30 cm between rows and 38 cm between plants in the row. Irrigation was provided as needed via drip tape (10 Mil Medium Weight 5/8" AquaTraxx Drip Tape, 12” spacing, flow rate 0.45, The Toro Company, Bloomington, MN) placed in the center of the bed underneath the plastic mulch. Gothic Pro high tunnels (Farmers Friend, LLC) were erected over the plasticulture field. Five tunnels were erected. Each tunnel enclosed 2 adjacent beds. Each bed was a replicate with the 4 conditioning treatments randomly arranged in 20 plant plots to provide 4 treatment plots per bed. There were a total of 10 replicates (2 per tunnel) in the experiment.
Since the ‘Albion’ planting was established too late to produce a fall crop, an early spring crop will be forced in 2022 to determine if spring forcing is an option for when the fall crop cannot be achieved. In addition, forcing an early spring crop will provide evidence as to whether or not conditioning is appropriate for high tunnel forcing systems. Conditioning has been shown to be quite effective for late summer field cropping of ‘Albion’.
Digital Microscope Selection
A digital microscope was selected for distribution to growers participating in the flower mapping workshop. The scope selected was the Plugable USB 2.0 Digital Microscope with Flexible Arm Observation Stand. It was selected for its ease of software installation and use for dissection.
Virtual Flower Mapping Workshop
Due to the limitations for in-person interactions imposed by COVID, digital microscopes were shipped to 20 growers in 2021. Three videos were provided online for growers to view to introduce themselves to flower mapping. The first video provided a discussion of strawberry flowering physiology, the second video demonstrated microscope use and software installation and the third video demonstrated flower mapping.
Growers were encouraged to view the videos and practice flower mapping on their own until such time as they are able to attend one of the in person sessions scheduled for spring of 2022 at the Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA and the NJ Agricultural Convention in Atlantic City, NJ.
Work initiated in 2022
'Chandler'
Evaluation of plant architecture was performed in spring 2022 to evaluate effects of fall applied nitrogen on ‘Chandler’ growth and yield. Five plants per treatment were sampled from Snyder farm plots and fifteen plants per treatment from Cream Ridge plots and plant architecture assessed via dissection. Crown, linflorescence and flower numbers per plant were determined. In addition, leaf, inflorescence, flower and runner production per crown were also evaluated.
Data from each site were evaluated separately using a non-parametric analysis utilizing the Wilcoxon option in PROC NPAR1WAY test of the SAS® system which utilizes the Kruskal-Wallis test to evaluate differences in plant architectural features among the three treatments. Results are presented in the section labelled ‘Results and Discussion’.
Fall 2022 Flower Mapping and Nitrogen Treatments
Plug plants of ‘Chandler’ were propagated from runner tips purchased from a commercial nursery in New Jersey for establishing in field plantings at Cream Ridge and Snyder Farm for flower mapping studies. Plugs were planted in the plasticulture system on 12 September 2022 at Cream Ridge and 26 August at Snyder Farm.
The experimental plan for ‘Chandler’ in 2022 included three treatments: (1) Control (0 lbs N/acre), (2) 60 lbs N/acre one week after planting, and (3) 60 lbs N/acre one week after flower initiation was observed.
Planting, flower mapping, row cover installation and treatment dates are presented for both locations in Table 4.
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Table 4. Planting, sampling and treatment dates for floral mapping study of ‘Chandler’ strawberry established in a plasticulture system at two sites in New Jersey. |
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Location |
|
|
Date |
Cream Ridge |
Snyder Farm |
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Planting date |
12 September | 26 August |
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Flower mapping |
13, 19, 28 September | 28 Sptember |
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|
6 October | 12, 28 October |
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|
1 November | |
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Nitrogen treatment 1 (60 at planting) |
19 September | 15 September |
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Nitrogen treatment 2 (60 when floral) |
14 October | 2 November |
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Row cover installation |
29 November | 21 November |
On each date listed for flower mapping in Table 4, five (Snyder Farm) or six (Cream Ridge) single plant samples from each site were taken from each nitrogen treatment and flower mapped. Flower mapping consisted of evaluating the terminal meristem and determining the floral or vegetative status via dissection using a digital microscope. The status of the terminal meristem was assigned 0 if vegetative and 1 to 4 if floral, depending on which flowers of the inflorescence were discernable at dissection: primary only = 1, secondary = 2, tertiary = 3 and quaternary or greater = 4.
Data for flower mapping were evaluated separately for the two sites. A non-parametric analysis of data utilizing the Wilcoxon option in PROC NPAR1WAY test of the SAS® system which utilizes the Kruskal-Wallis test was used to evaluate differences in bud status among the three treatments. Results are presented in the section labelled ‘Results and Discussion’.
Results 2020
Chandler Flower Mapping
Cream Ridge Location
No nitrogen fertilization effects on terminal bud status was detected. Floral initiation was first observed on 14 October. By 27 October, all terminal meristems were floral.
Nitrogen fertilization enhanced floral stage of terminal meristems. On 2 November two applications of nitrogen significantly enhanced floral development compared to one nitrogen application which significantly advanced floral development compared to controls (Table 5). On 11 November, both nitrogen treatments significantly enhanced floral development compared to controls. By 19 November, all terminal meristems had fully developed floral meristems (stage 4).
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Table 5. Average status and floral stage of terminal meristems of ‘Chandler’ strawberry in a plasticulture system (Cream Ridge). Nitrogen treatments were administered as indicated. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
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Terminal Mersitem Status |
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Treament |
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Date |
N0 |
N1 |
N2 |
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9 September |
Planting |
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10 September |
0.0 |
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15 September |
0.0 |
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21 September |
0.0 |
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28 September |
0.0 |
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5 October |
0.0 |
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14 October |
0.55 |
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19 October |
0.78 |
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N1 Treatment |
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27 October |
1.00 |
1.00 |
1.00 |
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N2 Treatment |
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2 November |
1.00 |
1.00 |
1.00 |
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11 November |
1.00 |
1.00 |
1.00 |
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19 November |
1.00 |
1.00 |
1.00 |
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Terminal Mersitem Stage |
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Treament |
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Date |
N0 |
N1 |
N2 |
|
9 September |
Planting |
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10 September |
0.0 |
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15 September |
0.0 |
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21 September |
0.0 |
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28 September |
0.0 |
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5 October |
0.0 |
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14 October |
0.78 |
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19 October |
1.22 |
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N1 Treatment |
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27 October |
1.67 |
2.67 |
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N2 Treatment |
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2 November |
1.83 c |
2.67 b |
3.67 a |
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11 November |
3.00 b |
3.80 a |
3.83 a |
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19 November |
4.0 |
4.0 |
4.0 |
Axillary meristem development
No effects of nitrogen application on axillary bud development were detected via dissection on any of the dates sampled (Table 6). Additional samples will be dissected in the spring to determine if there were any effects of nitrogen on development after 19 November.
Some interesting observations regarding floral and branch crown development were made during evaluation of dissection data. By 27 October, all terminal meristems were floral and nearly all axillary meristems were vegetative, particularly those in positions 1 through 6 (96% vegetative). Runners were detected in positions 7 and 8 on 27 October. Axillary buds were 99% vegetative on 2 November (only positions 1 through 6 were dissected on this date). Between 2 and 11 November, considerable branch crown formation occurred and 98% of the branch crowns observed were vegetative. Considerable floral initiation occurred in branched crown terminal meristems between 11 and 19 November.
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Table 6. Axillary meristem development of ‘Chandler’ strawberry in a plasticulture system (Cream Ridge). Axillary meristems are labeled from apex to basal beginning with 1 as the meristem closest to the apex. Nitrogen treatments were administered as N1 (10/21) and N2 (10/21 + 10/27). Values are % of axillary meristems at that location exhibiting the listed characteristic. Values are based on 18 dissections per date. No nitrogen treatment effects were detected via dissections. |
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Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
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27 October |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
100 |
0 |
0 |
0 |
|
|
3 |
100 |
0 |
0 |
0 |
|
|
4 |
78 |
0 |
0 |
22 |
|
|
5 |
100 |
0 |
0 |
0 |
|
|
6 |
100 |
0 |
0 |
0 |
|
|
7 |
89 |
11 |
0 |
0 |
|
|
8 |
43 |
57 |
0 |
0 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
2 November |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
100 |
0 |
0 |
0 |
|
|
3 |
100 |
0 |
0 |
0 |
|
|
4 |
100 |
0 |
0 |
0 |
|
|
5 |
100 |
0 |
0 |
0 |
|
|
6z |
94 |
0 |
0 |
6 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
11 November |
1 |
94 |
0 |
0 |
6 |
|
|
2 |
78 |
0 |
17 |
6 |
|
|
3 |
56 |
0 |
44 |
0 |
|
|
4 |
33 |
0 |
67 |
0 |
|
|
5 |
56 |
0 |
44 |
0 |
|
|
6 |
71 |
0 |
29 |
0 |
|
|
7 |
69 |
13 |
19 |
0 |
|
|
8 |
58 |
17 |
25 |
0 |
|
|
9 |
75 |
25 |
0 |
0 |
|
|
10 |
25 |
75 |
0 |
0 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
19 November |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
100 |
0 |
0 |
0 |
|
|
3 |
33 |
0 |
28 |
39 |
|
|
4 |
28 |
0 |
22 |
50 |
|
|
5 |
28 |
0 |
11 |
61 |
|
|
6 |
22 |
0 |
17 |
61 |
|
|
7 |
39 |
6 |
0 |
56 |
|
|
8 |
19 |
25 |
6 |
50 |
|
|
9 |
28 |
45 |
0 |
27 |
|
|
10 |
0 |
100 |
0 |
0 |
|
zOnly 6 axillary buds per plant dissected on this date. |
|||||
Additional samples will be dissected in the spring to evaluate nitrogen effect (if any) on overwintering floral and branch crown development.
Snyder Farm Location
No nitrogen effects on floral development were detected in samples from Snyder Farm (Table 7). Nearly all terminal meristems were floral on the first sampling date, which appeared to be too late to catch the transition from vegetative to floral. In 2021, samples will be taken earlier to observe the transition and any effects of nitrogen on it.
|
Table 7. Average status and floral stage of terminal meristems of ‘Chandler’ strawberry in a plasticulture system (Snyder Farm). Nitrogen treatments were administered as indicated. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
|||
|
|
Terminal Mersitem Status |
||
|
|
Treament |
||
|
Date |
N0 |
N1 |
N2 |
|
28 August |
Planting |
||
|
15 October |
0.8 |
||
|
22 October |
1.0 |
||
|
N1 Treatment |
|||
|
30 October |
1.0 |
1.0 |
|
|
N2 Treatment |
|||
|
6 November |
1.0 |
1.0 |
1.0 |
|
13 November |
1.0 |
1.0 |
1.0 |
|
20 November |
1.0 |
1.0 |
1.0 |
|
|
Terminal Mersitem Stage |
||
|
|
Treament |
||
|
Date |
N0 |
N1 |
N2 |
|
28 August |
Planting |
||
|
15 October |
1.4 |
||
|
22 October |
2.1 |
||
|
N1 Treatment |
|||
|
30 October |
3.4 |
3.7 |
|
|
N2 Treatment |
|||
|
6 November |
4.0 |
4.0 |
3.6 |
|
13 November |
3.8 |
3.8 |
4.0 |
|
20 November |
3.4 |
4.0 |
4.0 |
The status of axillary meristems varied considerably across sample dates. The percentage of branch crowns which were floral rose from 13, 2 and 17% over the first three dates (22 and 30 October, 6 November) to 52 and 46% on the last two dates (13 and 20 November) (Table 8).
No effects of nitrogen on bud development were detected through 20 November. Additional samples will be taken in the spring of 2021 to evaluate nitrogen effect, if any, on bud development over the winter.
|
Table 8. Axillary meristem development of ‘Chandler’ strawberry in a plasticulture system (Snyder Farm). Axillary meristems are labeled from apex to basal beginning with 1 as the meristem closest to the apex. Nitrogen treatments were administered as N1 (10/22) and N2 (10/22 + 11/04). Values are % of axillary meristems at that location exhibiting the listed characteristic. Values are based on 15 dissections per date. No nitrogen treatment effects were detected via dissections. |
|||||
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
22 October |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
100 |
0 |
0 |
0 |
|
|
3 |
40 |
0 |
50 |
10 |
|
|
4 |
10 |
0 |
80 |
10 |
|
|
5 |
0 |
10 |
40 |
50 |
|
|
6 |
0 |
20 |
70 |
10 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
30 October |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
100 |
0 |
0 |
0 |
|
|
3 |
40 |
0 |
50 |
10 |
|
|
4 |
11 |
0 |
89 |
0 |
|
|
5 |
0 |
17 |
67 |
17 |
|
|
6 |
0 |
22 |
78 |
0 |
|
|
7 |
0 |
40 |
60 |
0 |
|
|
8 |
0 |
100 |
0 |
0 |
|
|
9 |
0 |
100 |
0 |
0 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
6 November |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
67 |
0 |
33 |
0 |
|
|
3 |
40 |
0 |
60 |
0 |
|
|
4 |
40 |
0 |
60 |
0 |
|
|
5 |
13 |
0 |
60 |
27 |
|
|
6 |
36 |
0 |
21 |
43 |
|
|
7 |
13 |
13 |
27 |
47 |
|
|
8 |
42 |
8 |
17 |
33 |
|
|
9 |
17 |
67 |
17 |
0 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
13 November |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
47 |
0 |
20 |
33 |
|
|
3 |
33 |
0 |
20 |
47 |
|
|
4 |
0 |
0 |
33 |
67 |
|
|
5 |
7 |
0 |
20 |
73 |
|
|
6 |
17 |
8 |
8 |
67 |
|
|
7 |
18 |
0 |
0 |
82 |
|
|
8 |
10 |
20 |
10 |
60 |
|
|
9 |
10 |
40 |
0 |
50 |
|
|
10 |
0 |
60 |
0 |
40 |
|
|
|
|
|
|
|
|
Date |
Axil |
Veg |
Runner |
Branch, veg |
Branch, floral |
|
20 November |
1 |
100 |
0 |
0 |
0 |
|
|
2 |
79 |
0 |
7 |
14 |
|
|
3 |
47 |
0 |
7 |
47 |
|
|
4 |
13 |
0 |
20 |
67 |
|
|
5 |
20 |
0 |
33 |
47 |
|
|
6 |
14 |
0 |
14 |
72 |
|
|
7 |
31 |
8 |
8 |
54 |
|
|
8 |
18 |
9 |
9 |
64 |
|
|
9 |
20 |
30 |
0 |
50 |
|
|
|||||
Albion Conditioning and Flower Mapping
Conditioning of ‘Albion’ plugs was effective in enhancing floral initiation as determined by flower mapping (Table 9). In plants dissected in early fall, long days with a boost of nitrogen enhanced both terminal meristem status and floral stage (Table 9). By late fall, the effect of conditioning with long days or nitrogen were quite visible in dissections: long days or elevated nitrogen significantly induced a shift towards floral terminal meristems compared to natural daylength controls. Stage of terminal meristem development was significantly enhanced by combining long days with elevated nitrogen. While the singular effect of elevated nitrogen under natural daylength was not observed in early fall dissections, the effect of elevated nitrogen was clear in meristems dissected later in the fall. This is important for growers who want to enhance floral development but do not wish to use supplemental lighting strategies. The elevated nitrogen treatment is very easy to implement. Conditioning start date for plants in this study was not based on dissection data as initially planned. ‘Albion’ plants dissected from late summer through early fall showed no signs of floral initiation which was an unexpected anomaly. In previous years, ‘Albion’ initiates flowers from mid-August through the fall under natural field conditions. Plants used in this study were conditioned when in a vegetative state to try to induce flower formation. The original plan was to provide extra nitrogen after floral initiation was first observed in an attempt to enhance floral development, not to induce it. Nevertheless, our results this season suggest that the use of dissections to determine appropriate timing of conditioning for long day cultivars may not be needed. The results confirm the benefits to floral development due to conditioning with daylength or nitrogen.
|
Table 9. Average status and floral stage of terminal meristems of ‘Albion’ strawberry conditioned with photoperiod and elevated nitrogen. Conditioning occurred from 16 – 30 September. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
|||
|
|
|
Photoperiod |
|
|
Date |
Nitrogen |
Short day |
Long day |
|
Early Fall |
|
Terminal meristem status |
|
|
|
0 |
0.17 b |
0.28 ab |
|
|
800 |
0.01 b |
0.44 a |
|
|
|
Terminal meristem floral stage |
|
|
|
0 |
0.28 b |
0.28 b |
|
|
800 |
0.06 b |
0.89 a |
|
Late Fall |
|
Terminal meristem status |
|
|
|
0 |
0.22 b |
0.71 a |
|
|
800 |
0.71 a |
0.88 a |
|
|
|
Terminal meristem floral stage |
|
|
|
0 |
0.44 c |
1.12 bc |
|
|
800 |
1.35 b |
2.16 a |
|
|
|||
It will be interesting to see whether or not the fall conditioning treatments influence flowering and fruiting in a forced early season spring crop. In a previous study with a long day cultivar ‘Elan’, nitrogen treatment in the fall significantly enhanced the response to spring applied nitrogen with respect to increased flowering.
Potential Workshop Participant Mailing List
Contact information for potential workshop participants was compiled from internet searches resulting in a list of 2452 names, farm affiliation and contact information.
Digital Microscope Evaluation
The two best scopes evaluated were:
- Koolertron, 7 inch LCD Digital USB Microscope with 16G TF Card,Koolertron 12MP 1-1200X Magnification Handheld Camera Video Recorder,8 LED Light,Rechargeable Battery $115.00
- Plugable USB 2.0 Digital Microscope with Flexible Arm Observation Stand Compatible with Windows, Mac, Linux (2MP, 250x Magnification) $40.00
The Koolertron scope came with its own built in 7 inch viewing screen which did not require access to a computer or phone to use. Images were exceptionally clear and easy to save either via still photos or videos. Its major drawback was price.
The Plugable scope was easy to set up, produced acceptable images and was reasonably priced. It did require a computer or phone to use.
Results 2021
Evaluation of Fall 2020 'Chandler' nitrogen treatment on Spring 2021 Flower Maps and Yield
|
Table 10. Average plant status and yield of ‘Chandler’ strawberry in a plasticulture system at two sites in New Jersey (Cream Ridge Farm and Snyder Farm). Nitrogen treatments were administered in fall 2020. No treatment effects were detected, thus mean values over all treatments are presented. |
|||
|
Location and Date |
Attribute |
Mean value |
|
|
Cream Ridge 20 April 2021 |
Crowns·plant-1 |
4.8 |
|
|
|
Leaves·plant-1 |
17.3 |
|
|
|
Inflorescences·plant-1 |
4.8 |
|
|
|
Flowers·plant-1 |
38.2 |
|
|
|
Runners·plant-1 |
0.4 |
|
|
|
Leaves·crown-1 |
3.7 |
|
|
|
Flowers·crown-1 |
8.0 |
|
|
|
Runners·crown-1 |
0.1 |
|
|
|
Yield·plant-1(g) |
516 |
|
|
Snyder Farm 4 May 2021 |
Crowns·plant-1 |
8.1 |
|
|
|
Leaves·plant-1 |
24.8 |
|
|
|
Inflorescences·plant-1 |
8.1 |
|
|
|
Flowers·plant-1 |
62.7 |
|
|
|
Runners·plant-1 |
0.5 |
|
|
|
Leaves·crown-1 |
3.1 |
|
|
|
Flowers·crown-1 |
No Fall Nitrogen |
6.8 b |
|
|
|
Fall Nitrogen |
8.2 az |
|
|
Runners·crown-1 |
0.1 |
|
|
|
Yield·plant-1 |
574 |
|
|
zMean separation at α = 0.05 via planned F-test. |
|||
Cream Ridge
No nitrogen effect on crown, leaf, inflorescence, flower or runner number per plant or leaf, flower or runner number per crown assessed via dissection in April 2021 was detected (Table 10). Average yield per plant was 516 g and was not affected by nitrogen treatment.
Snyder Farm
No nitrogen effect on crown, leaf, inflorescence, flower or runner number per plant or leaf or runner number per crown assessed via dissection in May 2021 was detected. Plants receiving fall nitrogen produced 1.4 additional flowers per crown compared to plants not receiving fall nitrogen (Table 10). Average yield per plant was 574 g and was not affected by nitrogen treatment, thus the additional flower per crown was not sufficient to enhance overall yield.
Evaluation of Fall 2020 'Albion' conditioning effects on Spring 2021 Yield
Conditioning with long-days enhanced the number of fruit produced in the spring per plant: Non-conditioned plants produced an average of 12 fruit per plant while conditioned plants produced and average of 14 fruit per plant. Weight of fruit produced was not influenced by conditioning: plants produced an average of 240 g from April through early June.
Digital Microscope Selection
A digital microscope was selected for distribution to growers participating in the flower mapping workshop. The scope selected was the Plugable USB 2.0 Digital Microscope with Flexible Arm Observation Stand. It was selected for its ease of software installation and use for dissection.
Virtual Flower Mapping Workshop
Due to the limitations for in-person interactions imposed by COVID, digital microscopes were shipped to 20 growers in 2021. Thirty-one growers requested registration forms, however only 20 returned them to provide a shipping address. The multiple e-mails sent to the growers who did not respond to encourage participation were ineffective.
Three videos were provided online for growers to view to introduce themselves to flower mapping:
Video One - Strawberry Flowering Physiology (~ 15 minutes)
https://drive.google.com/file/d/1eQqmSeR-3pDBIC4hLP9h7PXgQZHqkPxY/view?usp=sharing
Video Two - Setting up and installing your Plugable Digital Microscope
https://drive.google.com/file/d/1u1DXH6m9fx_9fhFbTbodMgN2w-y5GMt1/view?usp=sharing
Video Three - Flower Mapping A Strawberry Plug Plant (~ 15 minutes)
https://drive.google.com/file/d/1QbjJl9wXm0tA5OI8ebPBitXHpTwhJMiT/view?usp=sharing
The first video provides a discussion of strawberry flowering physiology, the second video demonstrates microscope use and software installation and the third video demonstrates flower mapping.
Growers were encouraged to view the videos and practice flower mapping on their own until such time as they are able to attend one of the in person sessions scheduled for spring of 2022 at the Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA and the NJ Agricultural Convention and Trade Show in Atlantic City, NJ.
Chandler Flower Mapping Fall 2021
Cream Ridge Location
Floral initiation was observed on 21 October in samples from Cream Ridge (Table 11).
|
Table 11. Average status and floral stage of terminal meristems of ‘Chandler’ strawberry in a plasticulture system (Cream Ridge). Nitrogen treatments were administered as indicated. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
|||||||
|
|
Terminal Mersitem Status |
||||||
|
|
Treatment |
||||||
|
Date |
N0 |
N30 |
N60 |
NFloral60 |
|||
|
8 September |
0.0 |
||||||
|
21 September |
0.0 |
||||||
|
28 September |
0.0 |
||||||
|
28 September |
N30 and N60 treatment application |
||||||
|
7 October |
0.0 |
0.0 |
0.0 |
-- |
|||
|
14 October |
0.1 |
0.0 |
0.0 |
-- |
|||
|
21 October |
1.4 |
2.6 |
2.0 |
2.0 |
|||
|
28 October |
NFloral 60 treatment application |
||||||
|
28 October |
2.6 |
1.8 |
2.6 |
2.2 |
|||
Snyder Farm Location
Floral initiation was observed on 14 October in samples from Snyder Farm (Table 12).
|
Table 12. Average status and floral stage of terminal meristems of ‘Chandler’ strawberry in a plasticulture system (Snyder Farm). Nitrogen treatments were administered as indicated. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
|||||||
|
|
Terminal Mersitem Status |
||||||
|
|
Treatment |
||||||
|
Date |
N0 |
N30 |
N60 |
NFloral60 |
|||
|
8 September |
0.0 |
||||||
|
16 September |
N30 and N60 treatment application |
||||||
|
14 October |
0.5 |
0.8 |
0.8 |
-- |
|||
|
21 October |
NFloral 60 treatment application |
||||||
|
25 October |
2.8 |
2.0 |
2.4 |
2.8 |
|||
Results 2022
Evaluation of Fall 2021 'Chandler' nitrogen treatment on Spring 2022 Flower Maps and Yield
Plant samples from each treatment and each location were dissected on 4/26 (Cream Ridge) or 5/10 (Snyder Farm). Crown, inflorescence and flower production as well as yield for Snyder Farm are presented below (Table 13). The number of inflorescences per plant at Cream Ridge was enhanced with 60 lbs N/Acre at planting compared to 30 lbs N/Acre at planting (5.3 vs 3.8 inflorescences per plant for 30 and 60 lbs N/Acre, respectively). No other significanttreatment effects were detected at Cream Ridge or Snyder Farm. Consecutive freezes on 17 and 18 April 2021 resulted in a complete crop failure at Cream Ridge.
|
Table 13. Average plant status and yield of ‘Chandler’ strawberry in a plasticulture system at two sites in New Jersey (Cream Ridge Farm and Snyder Farm). Nitrogen treatments were administered in fall 2021. No treatment effects were detected, thus mean values over all treatments are presented. |
|||
|
Location and Date |
Attribute |
Mean value |
|
|
Cream Ridge 26 April 2021 |
Crowns·plant-1 |
4.7 | |
|
|
Inflorescences·plant-1 |
4.5 | |
|
|
Flowers·plant-1 |
32.4 | |
|
|
Inflorescences·crown-1 |
0.9 | |
|
|
Flowers·inflorescence-1 |
5.8 | |
|
|
Yield·plant-1(g) |
0 | |
|
Snyder Farm 4 May 2021 |
Crowns·plant-1 |
4.8 | |
|
|
Inflorescences·plant-1 |
5.2 | |
|
|
Flowers·plant-1 |
33.7 | |
|
|
Inflorescences·crown-1 |
1.1 | |
|
|
Flowers·inflorescence-1 |
6.5 | |
|
Yield·plant-1(g) |
316 | ||
Evaluation of Fall 2021 'Albion' conditioning effects on Spring 2022 Yield
No effect of fall conditioning on yield of 'Albion' in Spring 2022 was detected. Average yield per plant from April through June was 160 g.
Flower Mapping Presentations
Presentations were made at multiple growers meetings.
Durner, E.F. 2022. Strawberry Flower Mapping. Canadian Greenhouse Growers Convention, Ontario, Canada, October 6, 2022.
Durner, E.F. 2022. Understand Strawberry Flower Physiology to Improve Production. Strawberry Café, Ohio State University, Columbus, Ohio, April 28, 2022, (Virtual).
Durner, E.F. 2022. Understand Strawberry Flower Physiology to Improve Production. Ontario Fruit and Vegetable Convention, Ontario, Canada, February 23, 2022.
Durner, E.F. 2022. Do-it-Yourself Conditioning of 'Albion' Strawberry with Photoperiod and Nitrogen to Enhance Yield. Ontario Fruit and Vegetable Convention, Ontario, Canada, February 23, 2022.
Durner, E.F. 2022. An introduction to Strawberry Flower Mapping. 2022 New Jersey Agricultural Convention and Trade Show (NJ ACTS) and New Jersey Vegetable Growers Meeting, Atlantic City, New Jersey, February 9, 2022.
Durner, E.F. 2022. Strawberry Flower Mapping: The Nitty-Gritty of Predicting Your Yields. 2022 Mid-Atlantic Fruit and Vegetable Convention, Hershey, PA. February 3, 2022.
Durner, E.F. 2022. Effects of Temperature and Daylength on Plant Growth and Development. Southeast Regional Fruit and Vegetable Conference. Savannah, Georgia, January 7, 2022. Virtual presentation.
Durner, E.F. 2022. Understanding Flower Mapping. Southeast Regional Fruit and Vegetable Conference. Savannah, Georgia, January 7, 2022. Virtual presentation.
Growers were encouraged to view the online flower mapping videos:
Video One - Strawberry Flowering Physiology (~ 15 minutes)
https://drive.google.com/file/d/1eQqmSeR-3pDBIC4hLP9h7PXgQZHqkPxY/view?usp=sharing
Video Two - Setting up and installing your Plugable Digital Microscope
https://drive.google.com/file/d/1u1DXH6m9fx_9fhFbTbodMgN2w-y5GMt1/view?usp=sharing
Video Three - Flower Mapping A Strawberry Plug Plant (~ 15 minutes)
https://drive.google.com/file/d/1QbjJl9wXm0tA5OI8ebPBitXHpTwhJMiT/view?usp=sharing
The first video provides a discussion of strawberry flowering physiology, the second video demonstrates microscope use and software installation and the third video demonstrates flower mapping.
Chandler Flower Mapping Fall 2022
Cream Ridge Location
Floral initiation was observed between 28 September and 6 October in samples from Cream Ridge (Table 14). There was no significant effect of nitrogen treatments on status or stage of floral development.
|
Table 14. Average status and floral stage of termina l meristems of ‘Chandler’ strawberry in a plasticulture system (Cream Ridge). Nitrogen treatments were administered as indicated. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
|||||||
|
|
Terminal Mersitem Status |
||||||
|
|
Treatment |
||||||
|
Date |
N0 |
|
N60 |
|
NFloral60 |
||
|
13 September |
0.0 |
||||||
|
19 September |
0.0 |
||||||
|
19 September |
N60 treatment application |
||||||
|
28 September |
0.0 |
0.0 |
- |
||||
|
6 October |
90% floral, Stage = 2.0 | 100% floral, Stage = 1.6 | - | ||||
|
14 Ocotober |
NFloral 60 treatment application | ||||||
|
1 November |
3.6 | 3.6 | 3.2 | ||||
Snyder Farm Location
Floral initiation was observed just after 12 October in samples from Snyder Farm (Table 15). While the N1 treatment had apices at a slightly more advanced stage in dissections compared to N0 and N2 on 28 October, the difference was not statistically significant.
|
Table 15. Average status and floral stage of terminal meristems of ‘Chandler’ strawberry in a plasticulture system (Snyder Farm). Nitrogen treatments were administered as indicated. Status 0 = vegetative, 1 = floral; Stage 0 = vegetative, 1 = primary visible, 2 = secondary visible, 3 = tertiary visible, 4 = quaternary visible. |
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Terminal Mersitem Status |
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|
Treatment |
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Date |
N0 |
N60 |
NFloral60 |
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2 September |
N60 treatment application |
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28 September |
0.0 | 0.0 | - | ||||
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12 October |
0.0 | 0.0 | - | ||||
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19 October |
NFloral 60 treatment application |
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28 October |
2.3 | 2.8 | 2.3 | ||||
Education
A list of 2452 potential workshop participants was compiled from various sources including already established grower contact lists from our SARE Goldenberry Project LNE18-362 as well as extensive internet searches.
An e-mail inviting them to participate in our educational program scheduled for later this year and next was sent to all members of the list on 1/11/2021.
The following invitation was sent:
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Strawberry Flower Mapping for Nitrogen and Row Cover Management Workshop
January 11, 2021
Hello,
We hope that you and your loved ones are safe and well.
We would like to invite you to participate in our newly funded Northeast Region SARE Project LNE20-395-34268, ‘Empowering Northeastern Strawberry Growers with Flower Mapping’.
If you are interested in participating, just respond YES to this e-mail, and we’ll be in touch.
This project will study flowering and fruiting in strawberry in relation to fall nitrogen and row cover management. We will be conducting flowering research at two Rutgers research farms and holding workshops or virtual demonstrations to teach growers how to flower map in conjunction with regional grower meetings. Flower mapping will help you with your nitrogen and row cover management decisions.
This project is open to all strawberry growers in the northeast region however workshops will be limited in size. Participants will be taught simple flower mapping and asked to implement the technique on their farms. Project participants will be provided a dissecting kit and dissecting scope which can be connected to a laptop or your phone (IOS or Android). The scope is capable of taking pictures, thus you can email photos to us for help in interpretation and production suggestions based on your flower maps. The dissecting equipment and scope will be provided at no cost to participants and can be kept when the project is complete.
Participation will require an hour or so per week from August through December (after your training session) for flower mapping and consultation. Participants will be expected to submit yield data and to evaluate effectiveness of the technique and provide feedback regarding the project.
By the end of the project, participants will be able to flower map strawberry plants on their farms and base management decisions on how their plants are growing rather than by relying on generalized, traditional and calendar based recommendations.
If you are interested in becoming a project participant please contact Ed Durner (durner@sebs.rutgers.edu) and you will be e-mailed an application and brief questionnaire (10 minutes to complete). Each workshop is limited to 25 participants so the sooner you get your application in, the better. If you have any questions, please feel free to contact us (e-mail is best). Also, feel free to pass this invitation along to anyone you might think is interested.
Thanks for your consideration,
Ed & Pete
Edward Durner Peter Nitzsche
Associate Research Professor County Agent I / Professor
Department of Plant Biology Department of Agriculture and Natural Resources
School of Environmental and Biological Sciences Cooperative Extension of Morris County
Rutgers, The State University of New Jersey P.O. Box 900
59 Dudley Rd., New Brunswick, NJ 08901-8520 Morristown, NJ 07963-0900
durner@sebs.rutgers.edu nitzsche@njaes.rutgers.edu
This material is based upon work supported by the National
Institute of Food and Agriculture, U.S. Department of Agriculture,
through the Northeast Sustainable Agriculture Research and
Education program under sub award number LNE20-395-34268.
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Our education plan for this project consists of: (1) holding workshops at regional fruit meetings to teach strawberry growers simple flower mapping techniques, (2) providing growers the equipment to perform on-farm flower mapping and (3) providing post-workshop assistance in map interpretation as well as management recommendations based on grower-generated maps.
Whether or not we will be able to hold in-person workshops remains to be seen given the current state of the COVID pandemic. If in-person workshops are not feasible, we will hold virtual workshops as well as post videos of flower mapping techniques for growers.
By providing instruction, equipment and post-workshop support, we will build grower confidence and encourage adoption of this simple management tool to enhance strawberry production in the northeast.
The meetings still targeted for our workshops include: New England Vegetable and Fruit Conference in 2021, The Mid Atlantic Fruit and Vegetable Growers Association Annual Meeting in Hershey, PA in 2022 and 2023, and The New Jersey Agricultural Convention, Atlantic City, NJ in 2022 and 2023.
Growers will be provided a Flower Mapping Kit consisting of a digital microscope, a dissecting kit and a Flower Mapping Manual. The Flower Mapping Kits will be purchased with funds from this grant.
Two of nine digital scopes evaluated for use in this project were selected for further evaluation. We are trying to find the best quality scope at the lowest price in order to provide as many growers as possible with dissecting kits.
Since neither the Hershey nor Atlantic City workshops are being held in-person this year (2021), we are asking small fruit session moderators at both meetings to briefly explain and advertise this project. Participants for the New England meeting will be recruited via e-mail through our contact list.
Milestones
Fruit and vegetable growers in the Northeast receiving an e-mail describing this project are invited to participate in a flower mapping workshop to be held at grower meetings as described above.
An e-mail inviting growers to participate in this project was sent to 2452 growers on 1/11/2021. The delay was due to increased efforts to create a larger potential participant list.
This milestone was completed 1 March 2021.
Virtual presentations explaining this project and flower mapping were made to growers at the 2021 New Jersey Agricultural Convention and Trade Show, (February 24, 2021), the Mid-Atlantic Strawberry Programs (MASP). Webinar (March 2021) and the Southeastern Plasticulture Strawberry School, Part Three: Fruiting – Flower Mapping. Webinar (April 20, 2021).
Three webinars were presented to encourage growers to participate in this study to learn flower mapping. Twenty eight growers expressed interest in participating.
The first flower mapping workshop is held virtually in 2021 (due to COVID) and growers learn simple flower mapping.
Due to the limitations for in-person interactions imposed by COVID, digital microscopes were shipped to 20 growers in 2021. Thirty-one growers requested registration forms, however only 20 returned them to provide a shipping address. The multiple e-mails sent to the growers who did not respond to encourage participation were ineffective.
Three videos were provided online for growers to view to introduce themselves to flower mapping:
Video One - Strawberry Flowering Physiology (~ 15 minutes)
https://drive.google.com/file/d/1eQqmSeR-3pDBIC4hLP9h7PXgQZHqkPxY/view?usp=sharing
Video Two - Setting up and installing your Plugable Digital Microscope
https://drive.google.com/file/d/1u1DXH6m9fx_9fhFbTbodMgN2w-y5GMt1/view?usp=sharing
Video Three - Flower Mapping A Strawberry Plug Plant (~ 15 minutes)
https://drive.google.com/file/d/1QbjJl9wXm0tA5OI8ebPBitXHpTwhJMiT/view?usp=sharing
The first video provides a discussion of strawberry flowering physiology, the second video demonstrates microscope use and software installation and the third video demonstrates flower mapping.
Growers were encouraged to view the videos and practice flower mapping on their own until such time as they are able to attend one of the in person sessions scheduled for spring of 2022 at the Mid-Atlantic Fruit and Vegetable Convention in Hershey, PA and the NJ Agricultural Convention and Trade Show in Atlantic City, NJ.
The second flower mapping workshop is held at The Mid Atlantic Fruit and Vegetable Growers Association Annual Meeting in Hershey, PA January 2022 and growers learn simple flower mapping.
The second flower mapping workshop is held at The Mid Atlantic Fruit and Vegetable Growers Association Annual Meeting in Hershey, PA February 2022 and growers learned simple flower mapping from a video presentation.
The third flower mapping workshop is held at The New Jersey Agricultural Convention, Atlantic City, NJ, February 2022 and growers learn simple flower mapping.
The third flower mapping workshop is held at The New Jersey Agricultural Convention, Atlantic City, NJ, February 2022 and growers were provided an introduction to simple flower mapping.
Growers try flower mapping on their farms, submit maps to us via e-mail and we help them interpret their maps and evaluate management choices for their specific situation.
While nearly 40 dissecting kits were distributed to growers for flower mapping, only 2 have reported that they have tried and used flower mapping on their farms. A number of growers expressed frustration with the tedious nature of flower mapping.
Flower Mapping workshops are held at Hershey and Atlantic City a second time for growers who did not participate the first year and growers learn simple flower mapping.
Additional growers try flower mapping on their farms, submit maps to us via e-mail and we help them interpret their maps and evaluate management choices for their specific situation.
A flower mapping workshop is held at the New England Vegetable and Fruit Conference in 2023 for growers who did not participate in 2021.
This workshop was not held due to COVID restrictions. Growers were given the opportunity to participate via online instruction.
All growers try/continue flower mapping on their farms, submit maps to us via e-mail and we help them interpret their maps and evaluate management choices for their specific situation.
All growers who participated in the workshops and this project are surveyed regarding the project, the quality of the workshops, the usefulness of flower mapping on their farm, and whether or not they routinely use flower mapping as a management tool.
Milestone Activities and Participation Summary
Educational activities:
Participation Summary:
Performance Target Outcomes
Target #1
Growers will adopt flower mapping to generate on-farm, science-based knowledge to make production management choices.
75 farms
Increase in production of at least 1,000 lbs fruit on at least 1 acre per farm.