Progress 10/01/08 to 09/30/13
Outputs
OUTPUTS: Outputs: 2008/01 To 2012/12. During these five years efforts were coordinated with our annual Poinsettia trial in December when over 100 cultivars are evaluated. The dramatic increase in heating fuel directed our attention to evaluating simple possible changes to "accepted" production methods to save energy. The simplest and most obvious of all changes was to reduce greenhouse growing temperatures, however this ""savings" often comes at the risk of increasing production time and increasing disease problems in the crop. "Cool" production practices have been enthusiastically endorsed but their value is predominately industry anecdotal evidence. We decided to evaluate one popular approach and estimate what if any savings are associated with the methodology. Each year, all cultivars in the trial were placed into two physically separate greenhouse environments, each (35 x29)1015 sq ft. Plants were grown in identical (normal) day and night temperature regimes until the last five weeks of production at which time in one section (section 3) night temperature was lowered 5-6 F below "normal" night temperatures from 65 to 59 F. The results were promising and resulted in better quality plants, no visible production delays or increase in disease incidence. The latter may have resulted from a judicious preventive use of a fungicide and careful attention to greenhouse humidity management. PARTICIPANTS: The following companies and individuals contributed significantly with materials and or effort to this project during it's duration. Nicolletta Graf, And Gail Johnson; Rutgers Floriculture Greenhouse. Dummen USA, Inc. 5544 Hilliard Rome Office Park Hilliard, OH 43026 First Class Plants 1517 Governor Bridge Road Davidson, MD 21035 Jim Willmott 120 West Centennial Drive Medford, NJ 08055 Syngenta Flowers, Inc. 6899 Winchester Circle, Suite 102 Boulder, CO 80301 Paul Ecke Ranch PO Box 230488 Encinitas, CA 92023-0488 TARGET AUDIENCES: Greenhouse growers: New temperature management strategy. Agriculture Agents: Current information on new varieties and effects of environmental modifications on production. General Public: Increased awarenes of new varieties,increased understanding of care in the home. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
We used a free software package published by the USDA/ARS to evaluate potential energy savings brought about by the 5F lowering of night temperature using the typical weather scenario for Newark NJ. Using fuel oil costs of $4.40 a gallon it was estimated by the software that $267 was saved by the "cool" temperature finishing of the crop. This is about $0.27 a square foot for that five week period or about $0.065 per sq. ft. per day. The amount may seem trivial but when considered on a per acre basis a grower can potentially save $286 per day and a large grower (10 acres for ease of example) $2,860 per day. New Jersey has many growers in excess of 12 acres. It is important to keep in mind that actual temperature, actual oil prices and the type of heating system used will greatly effect this prediction with mild weather and recent falling prices greatly reducing impact. Nonetheless, significant savings is possible under any circumstance as even at $2.00 per gallon $1,400 per acre per day can be saved, and the culture change if managed correctly results in a better quality plant which should then attract a better price in the market place. The promising results of the first two years wereconfirmed over the course of the next three seasons. These confirmatory results were witnessed by approximately 1200-1500 visitors over the years, who attended the Poinsettia Open House. We extended this information thru grower meetings several times during the five year period. We believe that the practical utilityand limits of this conservation technique have been fully explored as it relates to the type of production environment in New Jersey.
Publications
- No publications reported this period
|
Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: 2011/01 To 2011/12. As in previous years research efforts were coordinated with our annual Poinsettia trial in December when over 100 cultivars are evaluated. The dramatic increase in heating fuel continues to direct our attention to evaluating simple changes in production methods to save energy. The simplest and most obvious way to save energy is to reduce greenhouse temperatures and, consequently, heating costs. However, this "savings" often comes at the risk of increasing production time and increasing disease problems in the crop. "Cool" production practices have been enthusiastically endorsed but their value is predominately industry anecdotal evidence. We decided to evaluate one popular approach and estimate what, if any, savings are associated with the methodology. We also extended the "cool" production to an earlier portion of the production cycle. All cultivars in the trial were placed into two physically separate greenhouse environments, each (35 x29)1015 sq ft. Because of detrimental effects observed in 2010, we did not allow greenhouse temperatures to drop in accordance with outside temperatures early in the crop. In NJ temperatures will often reach the 50's at night but there is no danger of freezing in the greenhouse. In short, we had tried to avoid heating inputs that might normally be applied to maintain a 64 deg F night temperature, but the impact on quality was such that this was deemed an unacceptable approach to energy savings. Plants were grown in identical (normal) day and night temperature regimes until the last eight weeks of production, at which time in one in both sections the night temperature was lowered 5-6 F below "normal" night temperatures from 65 to 59 F. The results confirmed previous comparative results (2008). Both sections resulted in better quality plants, no visible production delays or increase in disease incidence. Again, the latter may have resulted from a judicious preventive use of a fungicide and careful attention to greenhouse humidity management. As might be expected from plant growth modeling results for this crop some height responses were observed on some cultivars as day and night temperature differentials increased. This indicates a need to plan for late season growth regulator applications at modest levels in some cases. As this treatment is an expense of materials and labor, it may mitigate some of the benefits of "cool finishing" this crop. In the coming season we will look closely at which cultivars this may be a problem for and suggest that growers stick with those that do not respond so dramatically to the increasing day night differential and or look at the impact of lowering day temperatures to keep the differential constant throughout the crop. PARTICIPANTS: This Project receives direct industry support in gifts in kind of plant material. Cooperators include; Syngenta Plant Products, The Paul Ecke Ranch, Dumann Int.,The Ball Company. TARGET AUDIENCES: The Target audiences for this are commercial greenhouse growers in the Northeast as well as consumers and the general public. The inent is to make growers aware of the latest cultivars and their production challanges and consumers aware of new varieties and the proper way to handle this product in their home. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Within the first 2 weeks of production it became clear that failure to heat the greenhouse to 64F night temperatures early in production was a misguided conservation method. While temperatures never fell below 50 at night symptoms of leaf yellowing and poor root development were evident and the usual night temperature of 64F was quickly restored. Clearly, what is possible near the end of production is not an option when establishing this crop. In previous years we used a free software package published by the USDA/ARS to evaluate potential energy savings brought about by the 5F lowering of night temperature using the typical weather scenario for Newark NJ. Using fuel oil costs of $4.40 a gallon it was estimated by the software that $267 was saved by the "cool" temperature finishing of the crop. This is about $0.27 a square foot for that five week period or about $0.065 per sq. ft. per day. The amount may seem trivial but when considered on a per acre basis a grower can potentially save $286 per day and a large grower (10 acres for ease of example) $2,860 per day. New Jersey has many growers in excess of 12 acres. It is important to keep in mind that actual temperature, actual oil prices and the type of heating system used will greatly effect this prediction with mild weather and recent falling prices greatly reducing impact. Nonetheless, significant savings are possible under any circumstance as even at $2.00 per gallon $1,400 per acre per day can be saved, and the culture change, if managed correctly, results in a better quality plant which should then attract a better price in the market place. While prices were a bit lower this year,, results continue to be confirmatory with regard to the lowering of night temperatures to finish this crop. This technique is very detrimental if applied earlier in the crop cycle. Results were witnessed by hundreds of visitors to this year Poinsettia Open House, including the technical and sales representatives of the major Poinsettia breeding programs who donated plants. Again, we will be extending this information thru newsletter and grower meetings this spring (February, and April)of 2012. We have seen how far we can "stretch" this concept before it became culturally counter productive, which we have demonstrated is the case with early season attempts to lower night temperatures and some increased height increases caused by lowering night temperatures. Some growth regulating late season drenches may be conducted next season if day temperature adjustments are not adequate to control this late season "stretch"
Publications
- No publications reported this period
|
Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: 2010/01 To 2010/12. As in previous years research efforts were coordinated with our annual Poinsettia trial in December when over 100 cultivars are evaluated. The dramatic increase in heating fuel continues to direct our attention to evaluating simple changes in production methods to save energy. The simplest and most obvious way to save energy is to reduce greenhouse temperatures, and consequently heating costs. However, this "savings" often comes at the risk of increasing production time and increasing disease problems in the crop. "Cool" production practices have been enthusiastically endorsed but their value is predominately industry anecdotal evidence. We decided to evaluate one popular approach and estimate what if any savings are associated with the methodology. We also extended the "cool" production to an earlier portion of the production cycle. All cultivars in the trial were placed into two physically separate greenhouse environments, each (35 x29)1015 sq ft. Unlike previous years we allowed greenhouse temperatures to drop in accordance with outside temperatures early in the crop. In NJ temperatures will often reach the 50's at night but there is no danger of freezing in the greenhouse. In short we were avoiding heating inputs that might normally be applied to maintain a 64oF night temperature. Ultimately, plants were grown in identical (normal) day and night temperature regimes until the last eight weeks of production at which time in one in both sections the night temperature was lowered 5-6 F below "normal" night temperatures from 65 to 59 F. The results confirmed previous comparative results (2008). Both sections resulted in better quality plants, no visible production delays or increase in disease incidence. Again, the latter may have resulted from a judicious preventive use of a fungicide and careful attention to greenhouse humidity management. PARTICIPANTS: Nicolletta Graf, a NJAES Greenhouse Supervisor and several volunteers are instrumental in the conduct of this trial and the experiments therein. Cooperating partners providing gifts in kind support include; The Paul Ecke Ranch, The George Ball Company, Syngenta Flowers Inc. Dummen Usa, Inc. The Poinsettia Open House component provides an opportunity for industry and Extension professionals to view the latest cultivars and learn about any unique or novel aspects associated with the successful produciton of this important crop. TARGET AUDIENCES: Industry Professionals, Extension professionals, and the consuming public all have equal access to and can benefit from the results of this project. Grower meetings also provide an opportunity to those who are unable to attend the campus event. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
Within the first 2 weeks of production it became clear that failure to heat the greenhouse to 64F night temperatures early in production was a misguided conservation method. While temperatures never fell below 50 at night symptoms of leaf yellowing and poor root development were evident and the usual night temperature of 64F was quickly restored. Clearly, what is possible near the end of production is not an option when establishing this crop. In previous years we used a free software package published by the USDA/ARS to evaluate potential energy savings brought about by the 5F lowering of night temperature using the typical weather scenario for Newark NJ. Using fuel oil costs of $4.40 a gallon it was estimated by the software that $267 was saved by the "cool" temperature finishing of the crop. This is about $0.27 a square foot for that five week period or about $0.065 per sq. ft. per day. The amount may seem trivial but when considered on a per acre basis a grower can potentially save $286 per day and a large grower (10 acres for ease of example) $2,860 per day. New Jersey has many growers in excess of 12 acres. It is important to keep in mind that actual temperature, actual oil prices and the type of heating system used will greatly effect this prediction with mild weather and recent falling prices greatly reducing impact. Nonetheless, significant savings is possible under any circumstance as even at $2.00 per gallon $1,400 per acre per day can be saved, and the culture change if managed correctly results in a better quality plant which should then attract a better price in the market place. While prices were a bit lower this year results continue to be confirmatory with regard to the lowering of night temperatures to finish this crop. This technique is very detrimental if applied earlier in the crop cycle. Results were witnessed by hundreds of visitors to this year Poinsettia Open House, including the technical and sales representatives of the major Poinsettia breeding programs who donated plants. Again, we will be extending this information thru newsletter and grower meetings this spring (February 15) of 2011. We will see how far we can "stretch" this concept before it becomes culturally counter productive, which we have demonstrated is the case with early season attempts to lower night temperatures.
Publications
- No publications reported this period
|
Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Outputs: 2009/01 To 2009/12. As in previous years research efforts were coordinated with our annual Poinsettia trial in December when over 100 cultivars are evaluated. The dramatic increase in heating fuel has directed our attention to evaluating simple changes in production methods to save energy. The simplest and most obvious way to save energy is to reduce greenhouse temperatures, and consequently heating costs. However, this ""savings" often comes at the risk of increasing production time and increasing disease problems in the crop. "Cool" production practices have been enthusiastically endorsed but their value is predominately industry anecdotal evidence. We decided to evaluate one popular approach and estimate what if any savings are associated with the methodology. All cultivars in the trial were placed into two physically separate greenhouse environments, each (35 x29)1015 sq ft. Plants were grown in identical (normal) day and night temperature regimes until the last eight weeks of production at which time in one in both sections the night temperature was lowered 5-6 F below "normal" night temperatures from 65 to 59 F. The results confirmed previous comparative results (2008). Both sections resulted in better quality plants, no visible production delays or increase in disease incidence. Again, the latter may have resulted from a judicious preventive use of a fungicide and careful attention to greenhouse humidity management. PARTICIPANTS: Approximately 100 Poinsettia cultivars are provided by leading breeders/propagators such as; Fischer, Paul Ecke Ranch, and Syngenta and are on display during our annual Poinsettia open house. TARGET AUDIENCES: The target audiences are; Poinsettia propagators, growers, extension personel, and the consumer public who purchaes this important NJ crop. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Impacts: We used a free software package published by the USDA/ARS to evaluate potential energy savings brought about by the 5F lowering of night temperature using the typical weather scenario for Newark NJ. Using fuel oil costs of $4.40 a gallon it was estimated by the software that $267 was saved by the "cool" temperature finishing of the crop. This is about $0.27 a square foot for that five week period or about $0.065 per sq. ft. per day. The amount may seem trivial but when considered on a per acre basis a grower can potentially save $286 per day and a large grower (10 acres for ease of example) $2,860 per day. New Jersey has many growers in excess of 12 acres. It is important to keep in mind that actual temperature, actual oil prices and the type of heating system used will greatly effect this prediction with mild weather and recent falling prices greatly reducing impact. Nonetheless, significant savings is possible under any circumstance as even at $2.00 per gallon $1,400 per acre per day can be saved, and the culture change if managed correctly results in a better quality plant which should then attract a better price in the market place. These confirmatory results were witnessed by hundreds of visitors to this years Poinsettia Open House and we will be extending this information thru newsletter and grower meetings this spring of 2010. In the coming year we will see how far we can "stretch" this concept before it becomes culturally counter productive.
Publications
- No publications reported this period
|
Progress 01/01/08 to 12/31/08
Outputs
OUTPUTS: 2008/01 To 2008/12. As in previous years research efforts were coordinated with our annual Poinsettia trial in December when over 100 cultivars are evaluated. The dramatic increase in heating fuel has directed our attention to evaluating simple production methods to save energy. The simplest and most obvious of all is to reduce greenhouse temperatures, however this ""savings" often comes at the risk of increasing production time and increasing disease problems in the crop. "Cool" production practices have been enthusiastically endorsed but their value is predominately industry anecdotal evidence. We decided to evaluate one popular approach and estimate what if any savings are associated with the methodology. All cultivars in the trial were placed into two physically separate greenhouse environments, each (35 x29)1015 sq ft. Plants were grown in identical (normal) day and night temperature regimes until the last eight weeks of production at which time in one section (section 3) night temperature was lowered 5-6 F below "normal" night temperatures from 65 to 59 F. The results were promising and resulted in better quality plants, no visible production delays or increase in disease incidence. The latter may have resulted from a judicious preventive use of a fungicide and careful attention to greenhouse humidity management. PARTICIPANTS: Plant material valued at $2000 was provided freely from the four largest Poinsettia breeding programs; Ecke, Syngenta Flowers, Dummen, and Selecta-First Class plants. Valuable technical and cultural assistance was provided by the greenhouse staff; Gail Johnson and Nicollette Graf. TARGET AUDIENCES: While the primary audience is commercial producers of Poinsettia in NJ the Poinsettia Open House is also open to the consuming public. Over the course of the three day event several hundred people attend and many are from out of state. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
We used a free software package (Virtual Grower Ver. 2.01) published by the USDA/ARS to evaluate potential energy savings brought about by the 5F lowering of night temperature using the typical weather scenario for Newark NJ. Using fuel oil costs of $4.40 a gallon it was estimated by the software that $267 was saved by the "cool" temperature finishing of the crop. This is about $0.27 a square foot for that five week period or about $0.065 per sq. ft. per day. The amount may seem trivial but when considered on a per acre basis a grower can potentially save $286 per day and a large grower (10 acres for ease of example) $2,860 per day. New Jersey has many growers in excess of 12 acres. It is important to keep in mind that actual temperature, actual oil prices and the type of heating system used will greatly effect this prediction with mild weather and recent falling prices greatly reducing impact. Nonetheless, significant savings is possible under any circumstance as even at $2.00 per gallon $1,400 per acre per day can be saved, and the culture change if managed correctly results in a better quality plant which should then attract a better price in the market place. While we did not have our results in time for this years Poinsettia Open House we will be extending this information thru newsletter and grower meetings this spring of 2009. In the coming year we will see how far we can "stretch" this concept before it becomes culturally counter productive.
Publications
- No publications reported this period
|
Progress 01/01/07 to 12/31/07
Outputs
OUTPUTS: 2007/01 TO 2007/12 As in the previous year, several Poinsettia cultivars were grown in an open roof greenhouse, equiped with an "ebb and flood" floor irrigation system and floor heating. The system is capable of maintaining two independent floor/pot temperatures and one air temperature. The night air temperature was set at 50F (-15F from normal setting)and the floor/pot temperatures of the independent zones were set at 60F and 65F respectively. Again mild fall and early winter weather in NJ minimized the potential effects of the floor temperature regimes with little or no differences among the plants resulting between treatments. No increrase in disease or delay in productin was observed but, the ariel environment seldom reached the desired settings during the production period making the potential impact upon plant habit and potential savings this season, negligible. We will be looking at potential crops during colder times of the year in future.
PARTICIPANTS: Dr. A.J. Both participated in consultation and Mr. Jeff Akers provided some labor and technical assistance.
TARGET AUDIENCES: Commercial greenhouse growers.
Impacts
IMPACT: 2007/01 TO 2007/12 Applying heat directly to the root zone is less expensive than heating the entire greenhouse volume. The warmed floor can act as an energy flywheel which creates a stable warm root environment and warms air near the plant canopy even when the temperature of the much larger volume above is allowed to drop by 10F. Growers using recirculating irrigation sytems (flooded floor) must have the floor heated as part of the system design. We had hoped to demonstrate that contemporary Poinsettia cultivars could be grown on a heated floor at night air temperatures 10F cooler than normal without increases in root disease incidence or delays in production time. We were able to demonstrate this to a certain extent but the expected reductions in fuel costs from 10-30 percent depending upon the efficiency of the heating system and the structural condition of the greenhous were mitigated by mild weather. Lowering night air temperature 10F and using his floor
heating system to maintain a pot temperature of 60-65F has the potential under favorable conditions to save 20%. For the many growers who have this technology today this simple adjusment in "use" could save thousands of dollars per grower in fuel costs. At our annual "Poinsettia Openhouse" and at several grower meetings we have extended information on the issues surrounding lowering greenhouse temperatures to save energy.
Publications
- No publications reported this period
|
Progress 01/01/06 to 12/31/06
Outputs
Several Poinsettia cultivars were grown in an open roof greenhouse, equiped with an "ebb and flood" floor irrigation system and floor heating. The sytem is capabple of maintaining two independent floor/pot temperatures and one air temperature. The night air temperature was set at 50F (-15F from normal setting)and the floor/pot temperatures of the independent zones were set at 60F and 65F respectively. Unfortunately the extremely mild fall and early winter weather in NJ minimized the potential effects of the floor temperature regimes with little or no differences among the plants resulting between treatments. This would be good, accept, that the weather prevented the greenhouse environment from reaching the desired settings during a significant portion of the production period making the potential impact upon plant habit and potential savings this season, negligible.
Impacts
Applying heat directly to the root zone is less expensive than heating the entire greenhouse volume. The warmed floor can act as an energy flywheel which creates a stable warm root environment and warms air near the plant canopy even when the temperature of the much larger volume above is allowed to drop by 10F. Growers using recirculating irrigation sytems (flooded floor) must have the floor heated as part of the system design. Being able to grow contemporary Poinsettia cultivars at night air temperatures 10F cooler than normal without increases in root disease incidence or delays in production time could reasonably be expected to reduce fuel costs from 10-30 percent depending upon the efficiency of the heating system and the structural condition of the greenhouse. Conservatively then, a grower who spends $25,000 on fuel for the Poinsettia cropping period could save $2,500 by lowering his night air temperature 10F and using his floor heating system to maintain a pot
temperature of 60-65F. For the many growers who have this technology today this simple adjusment in "use" could save thousands of dollars per grower in fuel costs.
Publications
- E. Reiss, D.R.Mears, T.O. Manning, G.J. Wulster and A.J.Both 2006. Numerical Modeling of Greenhouse Floor Heating ASABE Journal. Accepted 10-2006.
|
Progress 01/01/05 to 12/31/05
Outputs
Increasing energy costs are beginning to seriously impact the economics of greenhouse crop production. To reduce energy costs growers are reducing night air temperatures sometimes with deliterious effects on production time and crop quality. Wulster (1984), and many others showed that rootzone heating technology can minimize the deliterious effects of lower night air temperatures for crops that prefer warmer production temperatures, particularly Poinsettia. Greenhouses with recirculating subirrigation systems are designed with floor/root zone heating as part of the system. In the intervening years Poinsettia cultivars have changed dramatically in both numbers and physiological response to the environment. In fall of 2005 several contemporary cultivars where grown at a reduced air temperature with two different root zone temperatures. 200 plants each of the Poinsettia cultivars, Flirt, Prestige and Freedom Red were grown at root zone temperatures of either 60F or 65F.
The greenhouse night air temperature was lowered 10F from the usual 62-65F to 52-55F. Plant height and flowering date were compared between the two treatments and with the same cultivars grown in a greenhouse with standard benches and typical night air temperatures of 62-65F. No differences in final plant height or bract size where evident on the last measurement date 12/3/2005. Visually plant quality was better at the lower air temperature with either of the root zone temperatures employed. No increases in root disease commonly associated with growing Poinsettia at cool night temperatures was observed among the treatments.
Impacts
Applying heat directly to the root zone is less expensive than heating the entire greenhouse volume. The warmed floor can act as an energy flywheel which creates a stable warm root environment and warms air near the plant canopy even when the temperature of th much larger volume above is allowed to drop by 10F. Being able to grow contemporary Poinsettia cultivars at night air temperatures 10F cooler than normal without increases in root disease incidence or delays in production time could reasonably be expected to reduce fuel costs from 10-30 percent depending upon the efficiency of the heating system and the structural condition of the greenhouse. Conservatively then, a grower who spends $25,000 on fuel for the Poinsettia cropping period could save $2,500 by lowering his night air temperature 10F and using his floor heating system to maintain a pot temperature of 60-65F. For the many growers who have this technology today this simple adjusment in "use" could save
thousands of dollars per grower in fuel costs.
Publications
- No publications reported this period
|
Progress 01/01/04 to 12/31/04
Outputs
An experiment was conducted to evaluate the efficacy of delivering low levels of plant growth retardants (PGR) for late season height control to a poinsettia crop being irrigated with and ebb and flood irrigation system in a contemporary open roof greenhouse environment. The facility has two independently floodable floor sections with their own nutrient solution reservoirs. The design allows for the complete recapture and reuse of the irrigation nutrient solution. This type of system is being used with increasing frequency in contemporary greenhouse construction and offers both advantages and challenges in terms of its management as part of a commercial greenhouse production system. The advantages are; efficient water and nutrient utilization, more uniform application of the irrigation solution, and reduced labor costs associated with irrigation of the crop. The system's challenges include the fact that, any added materials including PGR's continue to be recirculated
and, the rate of removal of specific nutrients is not well researched. Materials and Methods: Four cultivars of Poinsettia (Euphorbia pulcherrima) were grown using generally accepted cultural practices in an open roof greenhouse employing an ebb and flood irrigation system. The cultivars were Freedom Red, Peterstar Red, Red Velvet, and Plum pudding. The cultivars were equally divided between the two separate irrigation areas. On 10/28 Paclobutrazol (Bonzi) was added to the nutrient solution reservoir of one of the irrigation sections to achieve a concentration of 0.5 ppm Paclobutrazol in the irrigation solution. No PGR was added to the other irrigation section's nutrient solution, which, served as a control. The final plant height and the bract diameter of the plants were measured on 12/17. While 200 plants of each cultivar were grown 10 were randomly selected for measurement. Results: The response amongst the cultivars was not uniform, but in all cases final height and bract display
size were reduced. Reductions in bract diameter that effect display are considered undesirable side effects of height control treatments. Freedom Red and Peterstar Red were reduced in height by the treatment 12% and 4.5% respectively while the size of their bract displays were reduced 28% and 32% respectively. Red Velvet and Plum Pudding were reduced in height by 4.5% and 8% respectively while their bract display was reduced by 17% and 13% respectively. The introduction of a PGR into the irrigation solution at a low rate for late season height control impacts the Poinsettia's bract display to a greater extent than the height when employed at the times and rates described in this experiment. The response varies dramatically by cultivar.
Impacts
PGR's are expensive and have the potential to reduce crop quality when used at inappropriate rates or applied improperly or at the wrong stage of crop development. This work indicates that, at least for Poinsettia, the use of these materials in recirculating systems for late season height control is problematic. The reasons for this include the differential effects of the material on bract size and plant height and the observation that varietal differences in response should be expected. Over 100 cultivars of Poinsettia are in commerce and in commercial ebb and flood systems several if not all would receive solution from the same reservoir. This work suggests that recommendations to apply such materials to a commercial Poinsettia crop in late season may be ill advised and have the potential to seriously reduce crop value. The actual impact of this information is hard to quantify but given the fact that the Poinsettia is the largest greenhouse container crop in NJ and
the US information that helps avoid practices that may reduce the crops quality especially, late in the season could easily save growers tens of thousands of dollars.
Publications
- No publications reported this period
|
|