Monday, February 27, 2012
Application for export to Canada
Just a reminder to commercial blueberry growers in NC who ship to Canada that March 1 is the deadline for participation in the state Blueberry Certification Program. The blueberry maggot fly (Rhagoletis mendax) is a sporadically-occurring pest of blueberry in North Carolina, and shipment of blueberries to Canada is limited to fruit from fields enrolled in a state certification program administered by the NCDA&CS. For more information contact Dr. Alonso Suazo, (919) 733 6931, ext.237, or email Alonso.Suazo@ncagr.gov
Tuesday, February 21, 2012
Blueberry Irrigation Methods
On most sites, irrigation is essential for survival of newly planted bushes, and for consistent growth and yield throughout the life of the planting. The types of irrigation most often used on blueberry in North Carolina are:
1. Overhead -- impact sprinklers on 6 ft risers (12 sprinklers per acre) are used for both drought relief and for frost/freeze protection in the spring. These systems use about 68 gallons per minute per acre (4080 gallons per hour on a 60 x 60 ft spacing) and usually exceed the continuous capacity of available wells, so water is first pumped into a reservoir (pond), and the irrigation system pumps from the pond. This is the most common system used on large farms in the coastal plain, where a single pond/pump setup may cover 20-25 acres.
2. Micro-sprinklers -- Not very commonly used, these are small spray heads on stakes about 12 inches above the ground that wet a 3-ft to 5-ft circle around each bush. Coverage is better than with drip lines, but like drip, micros cannot be used for frost/freeze protection. Some growers who have tried micro-sprinklers have since replaced them with drip sytems, because micro-sprinklers are easily damaged by equipment or by farm workers stepping on them during harvest.
3. Drip line (built-in emitters) -- a heavy flexible line with built-in, pressure-compensated emitters every 18 inches. Output is usually about 0.5 gph per emitter, or 24 gallons per minute per acre (1452 gallons per hour per acre). Different emitter spacings are available, and double lines can be used to increase the wetted area. Water quality has to be good or the tiny emitters will become clogged with sand/grit or precipitated iron and carbonates. Drip irrigation is the most commonly used system in the piedmont of NC.
4. Drip line (punch-in emitters). Similar to above, except the emitters are not built into the drip line. Emitters must be inserted by hand using a special tool to punch holes in the drip line. This system can be customized by only putting emitters at the plant, or by adding more emitters at a later date.
5. Lay-flat drip tape -- lightweight drip tapes are not recommended.. Most lay-flat tapes are less durable and can only be expected to last one or two seasons. Occasionally used for temporary systems, prior to installation of the permanent drip or overhead system.
Other methods of getting water to blueberries have included flood irrigation, water table management (by holding water in ditches around the field), and (in western NC) piping or channeling water by gravity from a spring or well further uphill.
1. Overhead -- impact sprinklers on 6 ft risers (12 sprinklers per acre) are used for both drought relief and for frost/freeze protection in the spring. These systems use about 68 gallons per minute per acre (4080 gallons per hour on a 60 x 60 ft spacing) and usually exceed the continuous capacity of available wells, so water is first pumped into a reservoir (pond), and the irrigation system pumps from the pond. This is the most common system used on large farms in the coastal plain, where a single pond/pump setup may cover 20-25 acres.
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| Overhead irrigation can be used for drought relief or for freeze protection |
2. Micro-sprinklers -- Not very commonly used, these are small spray heads on stakes about 12 inches above the ground that wet a 3-ft to 5-ft circle around each bush. Coverage is better than with drip lines, but like drip, micros cannot be used for frost/freeze protection. Some growers who have tried micro-sprinklers have since replaced them with drip sytems, because micro-sprinklers are easily damaged by equipment or by farm workers stepping on them during harvest.
3. Drip line (built-in emitters) -- a heavy flexible line with built-in, pressure-compensated emitters every 18 inches. Output is usually about 0.5 gph per emitter, or 24 gallons per minute per acre (1452 gallons per hour per acre). Different emitter spacings are available, and double lines can be used to increase the wetted area. Water quality has to be good or the tiny emitters will become clogged with sand/grit or precipitated iron and carbonates. Drip irrigation is the most commonly used system in the piedmont of NC.
 |
| Drip line with built-in emitters every 18 inches |
4. Drip line (punch-in emitters). Similar to above, except the emitters are not built into the drip line. Emitters must be inserted by hand using a special tool to punch holes in the drip line. This system can be customized by only putting emitters at the plant, or by adding more emitters at a later date.
 |
| Drip line with punch-in emitters placed at every plant |
5. Lay-flat drip tape -- lightweight drip tapes are not recommended.. Most lay-flat tapes are less durable and can only be expected to last one or two seasons. Occasionally used for temporary systems, prior to installation of the permanent drip or overhead system.
Other methods of getting water to blueberries have included flood irrigation, water table management (by holding water in ditches around the field), and (in western NC) piping or channeling water by gravity from a spring or well further uphill.
Saturday, February 18, 2012
Chill Hour Requirements
Most blueberries require a certain amount of cold weather during winter in order to leaf and flower normally the following spring. Generally chill hours refers to hours below 45 degrees Fahrenheit, however for blueberry chill hour calculations in North Carolina we use a model developed by Dr. Mike Mainland to account for both (i) partial chilling at moderate temperatures and (ii) the negation of chill that occurs with warm temperatures in winter.
The Mainland Model accumulates 1 point for average hourly temperatures below 45° F; 0.5 points for temperatures 45-55° F; -0.25 points from 55-65° F; -1 point for temperatures 65° F and above. The model begins each fall when there is a positive balance that is not negated by warmer weather. Once 800+ chill hours have accumulated, points are no longer subtracted for temperatures 55° and above. The model ends February 28 at midnight.
Chill requirements vary a lot by blueberry cultivar and species. Gerard Krewer and Scott NeSmith at UGA wrote a nice article summarizing chilling hour requirements for cultivars in GA, many of which are also grown in NC. For cultivars grown in the southeastern US, approximate ranges (chill hour requirements) would be something like this:
0 to 250 hours = Very low-chill southern highbush cultivars for Florida and other low-chill areas (Emerald, Snowchaser and others)
250 to 400 hours = Moderate low-chill southern highbush cultivars for southeastern NC, SC and GA (Star, Rebel and others)
350 to 800 hours = Rabbiteye cultivars for most of NC, such as Premier, Powderblue, Tifblue and others
400 to 900 hours = higher-chill southern highbush cultivars (Legacy, Reveille, O'Neal and others)
900 to 1200 hours = Most Northern highbush cultivars (Duke, Jersey, Bluecrop and others)
Some cultivars have different chill requirements for leaves compared to flowers. O'Neal flower buds break dormancy readily after 400 hours or so, but the leaf buds do not seem adequately chilled until about 700 hours are reached.
Chill hours vary tremendously depending on where you are in NC. To see current chill hour accumulation at a site near you, go to the excellent blueberry chill calculator hosted by the State Climate Office. For instance, today (18 Feb 2012) accumulated chill hours at a mountain location (Asheville) are1578 hours, compared to only 772 in the coastal plain (Elizabethtown). At these levels, blueberries in westen NC should leaf and flower normally, while in the coastal plain, higher-chill cultivars like Duke, Jersey or Reveille will experience reduced or delayed flower development.
The Mainland Model accumulates 1 point for average hourly temperatures below 45° F; 0.5 points for temperatures 45-55° F; -0.25 points from 55-65° F; -1 point for temperatures 65° F and above. The model begins each fall when there is a positive balance that is not negated by warmer weather. Once 800+ chill hours have accumulated, points are no longer subtracted for temperatures 55° and above. The model ends February 28 at midnight.
Chill requirements vary a lot by blueberry cultivar and species. Gerard Krewer and Scott NeSmith at UGA wrote a nice article summarizing chilling hour requirements for cultivars in GA, many of which are also grown in NC. For cultivars grown in the southeastern US, approximate ranges (chill hour requirements) would be something like this:
0 to 250 hours = Very low-chill southern highbush cultivars for Florida and other low-chill areas (Emerald, Snowchaser and others)
250 to 400 hours = Moderate low-chill southern highbush cultivars for southeastern NC, SC and GA (Star, Rebel and others)
350 to 800 hours = Rabbiteye cultivars for most of NC, such as Premier, Powderblue, Tifblue and others
400 to 900 hours = higher-chill southern highbush cultivars (Legacy, Reveille, O'Neal and others)
900 to 1200 hours = Most Northern highbush cultivars (Duke, Jersey, Bluecrop and others)
Some cultivars have different chill requirements for leaves compared to flowers. O'Neal flower buds break dormancy readily after 400 hours or so, but the leaf buds do not seem adequately chilled until about 700 hours are reached.
Chill hours vary tremendously depending on where you are in NC. To see current chill hour accumulation at a site near you, go to the excellent blueberry chill calculator hosted by the State Climate Office. For instance, today (18 Feb 2012) accumulated chill hours at a mountain location (Asheville) are1578 hours, compared to only 772 in the coastal plain (Elizabethtown). At these levels, blueberries in westen NC should leaf and flower normally, while in the coastal plain, higher-chill cultivars like Duke, Jersey or Reveille will experience reduced or delayed flower development.
Saturday, January 21, 2012
Small Fruit Viruses
Dr. Ioannis Tzanetakis with the University of Arkansas has written an excellent article illustrating the status and implications of emerging small fruit virus diseases in the US. This APSnet post is one among many fascinating on-line articles published by the American Phytopathological Society (APS).
Friday, December 2, 2011
Summary -- 2011 NC Blueberry Season
The 2011 North Carolina blueberry crop was of excellent quality due to the combination of a dry harvest season and good labor availability, which allowed growers to harvest top-quality fruit in a timely fashion. Most growers began harvesting around 16 May, with the bulk of the crop a few days early overall. Total volume was slightly reduced compared to the previous year, due to weather. The primary weather-related causes of loss were poor pollination in late March/early April, and drought during June and July.
In southeastern NC, cool, wet weather for an eight-day period (25 Mar to 1 Apr) decreased bee activity and thus pollination success of flowers that were blooming during that time, and reduced the volume of fruit on ‘Croatan’ and other cultivars in the same flowering period. In late April, small, unexpanded berries that had not been adequately pollinated were falling off the bushes at many locations. Not all fields were affected to the same degree, because bloom times vary by location and cultivar.
A drought from late May through July resulted in some shriveled fruit and loss of berry size, which accounts in part for the slight reduction in overall yield for the state. The drought was a real challenge -- most growers have irrigation, and with near-constant watering were able to keep fields from getting too dry; however fields without irrigation were severely affected and some bushes were lost.
Price and volume data were obtained from eight major shippers in the 2011 season. The first price reported for flats of 12-1 pint cups with lids was on May 17. Prices ranged mostly $20.50-$22.00. The last f.o.b. price report was issued on July 08 at $16.00. Approximately 29 million pounds, an equivalent of 3.2 million 12 1-pint flats, were shipped for fresh market. There was also an additional 7.7 million pounds processed (frozen). This total (fresh + processed) of 36.7 million pounds represents a record volume of berries harvested for fresh sales, a reduced volume of processed berries (frozen), and a slight reduction in overall pounds for the state.
Price and volume data provided by Karrie Gonzalez, NC Market News
In southeastern NC, cool, wet weather for an eight-day period (25 Mar to 1 Apr) decreased bee activity and thus pollination success of flowers that were blooming during that time, and reduced the volume of fruit on ‘Croatan’ and other cultivars in the same flowering period. In late April, small, unexpanded berries that had not been adequately pollinated were falling off the bushes at many locations. Not all fields were affected to the same degree, because bloom times vary by location and cultivar.
A drought from late May through July resulted in some shriveled fruit and loss of berry size, which accounts in part for the slight reduction in overall yield for the state. The drought was a real challenge -- most growers have irrigation, and with near-constant watering were able to keep fields from getting too dry; however fields without irrigation were severely affected and some bushes were lost.
Price and volume data were obtained from eight major shippers in the 2011 season. The first price reported for flats of 12-1 pint cups with lids was on May 17. Prices ranged mostly $20.50-$22.00. The last f.o.b. price report was issued on July 08 at $16.00. Approximately 29 million pounds, an equivalent of 3.2 million 12 1-pint flats, were shipped for fresh market. There was also an additional 7.7 million pounds processed (frozen). This total (fresh + processed) of 36.7 million pounds represents a record volume of berries harvested for fresh sales, a reduced volume of processed berries (frozen), and a slight reduction in overall pounds for the state.
Price and volume data provided by Karrie Gonzalez, NC Market News
Wednesday, November 30, 2011
10th International Vaccinium Symposium
On behalf of the Vaccinium Species Working Group, Vine and Berry Fruits Section of the International Society for Horticultural Science (ISHS), the conveners and organizing committee invite you to attend the10th International Vaccinium Symposium, to be held June 17-22, 2012 in Maastricht, Province of Limburg, The Netherlands. The meeting is being held in conjunction with the Floriade 2012 World Horticultural Expo: http://www.floriade.nl/
For more information or to contact the conveners, please visit the symposium website: http://www.vaccinium2012.com/
I look forward to seeing you in Maastricht!
Bill Cline, Chair
ISHS Vaccinium Working Group
For more information or to contact the conveners, please visit the symposium website: http://www.vaccinium2012.com/
I look forward to seeing you in Maastricht!
Bill Cline, Chair
ISHS Vaccinium Working Group
2012 Blueberry Open House and Trade Show
The 46th Annual Open House of the North Carolina Blueberry Council is coming up on January 10th and 11th, 2012. The meeting will be held at the Sampson Agri-Exposition Center in Clinton, NC at 414 Warsaw Road near the intersection of Hwy 24 and Hwy 701 business. For more information or to preregister, Contact Julie Woodcock at (910) 471-3193, or email ncblueberry@bellsouth.net
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