Glozer Dr, Kitren

Grant, Joseph A

Lang, Gregory :

Optimizing Nitrogen Availability in Cherry Growth to Obtain High Yield and Fruit Quality , Annual Report 2008 Contract # Project Leaders Gregory Lang , Professor , Tree Fruit Physiol . Kitren Glozer , Associate Project Scientist Dept of Horticulture , Michigan State Univ . Dept of Plant Sciences , Univ . of California East Lansing , MI 48824 Davis , CA 95616 - 8515 ( 517 ) 355 - 5191 x . 1388 langg @ msu.edu ( 530 ) 754 - 4096 kglozer @ ucdavis.edu Joe Grant , Farm Advisor UC Coop . Extension , San Joaquin County Stockton , CA 95205 ( 209 ) 953 - 6115 jagrant @ ucdavis.edu Cooperators Steve DaValle Lawrence Sambado Grupe Operating Company Prima Frutta Packing 3255 W . March Lane P.O . Box 877 Suite 400 Lodi , CA 95241 Stockton , CA 95219 ( 209 ) - 931 - 2568 office ( 209 ) 368 - 3314 office ( 209 ) - 931 - 9424 fax ( 209 ) 333 - 6247 fax lawrences @ pf - pv.com sdavalle @ grupe.com Project Objectives This project directly addresses the research - based development of cost - effective N fertilization practices to improve N fertilizer use efficiency and minimize environment impacts in sweet cherry production . The FREP program goals aligned with this project include 1 ) nutrient uptake by tree crops , including determination of tissue nutrient thresholds , and 2 ) guidelines for orchard fertilization patterns , including foliar nutrient management and effective fertilizer timing . Specifically , for sweet cherry , the objectives include : 1 ) Quantify the seasonal pattern of N partitioning to sweet cherry tissues as influenced by soil and foliar applications , formulations , timing , and rootstock . 2 ) Determine the relationship of fruiting spur N reserves to subsequent spring spur leaf development , fruit set , and fruit growth potential . 3 ) Determine the impact of fall dormancy - inducing and late winter dormancy - breaking treatments on fruiting spur N reserves and early spring growth demand for N . 4 ) Develop recommendations to balance soil and foliar N application methods ( timing and rates ) to optimize annual fruit yields and quality while minimizing excessive vegetative growth . Abstract Three experimental orchards were selected by rootstock and location . All were planted in 1998 and all are â?? Bing â?? as the scion cultivar . Orchard 1 is on P . mahaleb seedling rootstock near Lodi with Acampo Sandy Loam soil . Orchards 2 and 3 , located near Linden , are , respectively , on 1 Gisela 6 ( P . cerasus x . P . canescens ) clonal and Mazzard ( P . avium ) seedling rootstock on Cogna Loam soil . Trees at Orchard 1 are trained to a traditional open vase ; Orchards 2 and 3 to a â?? steep leader â?? system with three primary scaffold branches . Each trial site is designed as a randomized complete block design with six single - tree replicates separated by one to three â?? â?? guard â?쳌 trees and rows separating treated trees . Baseline data on N content began in February 2008 , followed by vegetative and reproductive data as the growing season progressed . The fertilization treatments were initiated during bloom in March 2008 . By February 2009 , an entire set of treatments will have been applied . At present , samples and data collected include N content from dormant and growing spur and vegetative buds ( collected prior to and at â?? budswell â?? in February and March , respectively , and in September ) , young and mature spur and shoot leaves ( April , July and mid - September ) , and small fruits collected at 20 days after full bloom ( prior to â?? pit - hardening â?? ) . Trunk cross - sectional area ( TCSA ) at the start and end of the growing season has been measured for vegetative growth . Leaf size was measured by digital image analysis . Phenological and productivity data , including full bloom date and duration of bloom , yield per tree , yield efficiency ( yield / TCSA ) , and fruit quality ( size , firmness , maturity , Brix and fruit removal force , or â?? pull force â?? ) were collected during the 2008 season . Harvest for all orchards was a single â?? strip pick â?쳌 . Differences observed that may be attributed to N treatments to date include : â?¢ At Orchard 3 , trees that received bloom and / or post - bloom N treatments had more vegetative growth measured as increase in TCSA than trees that received only soil N in summer â?¢ A slight delay in fruit maturation in trees at Orchard 1 that received post - bloom N application â?¢ A slight reduction in fruit firmness and removal force ( measures of maturity ) in bloom - treated fruit at Orchard 3 . Bloom and post - bloom N advanced maturity the most at this orchard . Nitrogen content of shoot and spur buds in February ranged from 1.3 % to 2.5 % . In March , once budbreak had occurred and prior to bloom or leaf - out , nitrogen reserves had been remobilized and the range in tissues increased to 2.2 to 3.2 % . No significant differences were found in nitrogen contents in spur or shoot buds , when comparing within the bud type and particular orchard . Fruit nitrogen was lowest at Orchard 3 ( 2.9 - 3 % ) , intermediate at Orchard 1 , ( 3.2 - 3.4 % ) and highest at Orchard 2 ( 3.8 - 4.4 % ) . Introduction Average sweet cherry yields in California ( ~ 3.4 tons / acre ) are typically less than those in the Pacific Northwest ( ~ 5.5 tons / acre ) , due partly to insufficient chilling in some years and excessive vigor that promotes vegetative growth at the expense of reproduction . It is unlikely that current standard fertilization practices â?? soil - applied N just after harvest â?? supply N in the most optimal , demand - driven timing ( i.e . , to meet reproductive needs without excessively promoting vegetative growth ) , nor is the standard practice of leaf analysis in midsummer likely to be a good indicator of N needs for subsequent season reproductive growth . Sweet cherry bears primarily on two - year and older fruiting spurs and has a short bloom - to - ripening period for fruit development . This differs from most fruit crops , which impacts the timeframe for nutrient demand from the developing fruit as well as from the spur ( vs . shoot ) leaf populations that are critical for support of fruit growth . Consequently , cherry growers know little about efficiently supplying demand - driven nutrients , of which nitrogen ( N ) is the most critical , and thus rely primarily on practices adopted from peach , almond , or apple orchard 2 management . While dwarfing rootstocks are not widely adopted in California cherry culture , increased use to reduce vegetative vigor and tree size for mechanical harvest may occur in future and the differing N requirements for standard rootstocks and dwarfing rootstocks should be determined . Those standard rootstocks which vary in vigor , and are indicated for use in different soils and growing conditions in California may also vary in their optimal N requirement for the same scion variety . Furthermore , due to the higher chilling requirements of cherry than peach or almond , dormancy - breaking treatments in winter often are applied that further impact nutrient ( particularly N ) storage in , and demand by , tissues and organs . There is some indication that fall foliar application of urea may help hasten cold acclimation and reduce the incidence of bacterial canker in sweet cherry . Thus , nutritional studies in other tree crops , such as almond , do not provide optimal benchmarks for sweet cherry . For example , differences between cherry and almond that impact nitrogen usage include potential spur lifespan ( 1 - 3 years in almond , much longer in cherry ) , extensive vegetative growth in cherry throughout the growing season , and leaf metabolism that appears to be nitrogen level - dependent in cherry and not in almond . Our project will identify the periods of N demand by key cherry tissues ( fruiting spurs vs . shoots ) as well as N stores for spring growth , and examine the potential to optimize N supply efficiency via soil vs . foliar applications and timings . It will include the interactive effects of dormancy - breaking treatments that contain N as a component , such as CAN - 17 and KNO . Observations 3 on sweet cherry and peach indicate that the type of nitrogen source used to break dormancy may have carryover effects from year - to - year in timing of bloom , fruitfulness , and the balance of reproductive to vegetative growth . This project will investigate the potential to use appropriately - timed analysis of spur N as a diagnostic measure of adequacy for subsequent reproductive growth ( vs . mid - summer leaf analysis of N as a measure of adequacy for current vegetative growth ) . Project Objectives This project directly addresses the research - based development of cost - effective N fertilization practices to improve N fertilizer use efficiency and minimize environment impacts in sweet cherry production . The FREP program goals aligned with this project include 1 ) nutrient uptake by tree crops , including determination of tissue nutrient thresholds , and 2 ) guidelines for orchard fertilization patterns , including foliar nutrient management and effective fertilizer timing . Specifically , for sweet cherry , the objectives include : 1 ) Quantify the seasonal pattern of N partitioning to sweet cherry tissues as influenced by soil and foliar applications , formulations , timing , and rootstock . 2 ) Determine the relationship of fruiting spur N reserves to subsequent spring spur leaf development , fruit set , and fruit growth potential . 3 ) Determine the impact of fall dormancy - inducing and late winter dormancy - breaking treatments on fruiting spur N reserves and early spring growth demand for N . 4 ) Develop recommendations to balance soil and foliar N application methods ( timing and rates ) to optimize annual fruit yields and quality while minimizing excessive vegetative growth . 5 ) Quantify the seasonal pattern of P , K , Zn , Fe , B , Ca , S , Mg , Mn , and Cu partitioning to sweet cherry tissues as influenced by optimized N fertilization recommendations and rootstock . 3 Project / Workplan Description TASK 1 : Seasonal pattern of N partitioning to fruiting spur and shoot storage and growth . Subtask 1.1 : Assign treatments to develop baseline data â?? Three experimental orchards were selected by rootstock ( Orchards 1 - 3 ) and location ( Orchards 1 vs . 2 and 3 ; 2 and 3 in same location ) . All were planted in 1998 and all are â?? Bing â?? as the scion cultivar . Orchard 1 is on P . mahaleb seedling rootstock near Lodi on Acampo Sandy Loam soil ; trees are planted at 13 â?? x 18 â?? spacing ( 186 trees per acre ) . Orchards 2 and 3 , located near Linden , are , respectively , on dwarfing clonal rootstock Gisela 6 ( P . cerasus x P . canescens ) and Mazzard ( P . avium ) seedling rootstock . Soil at Orchards 2 and 3 , which are in adjacent blocks , is Cogna Loam . Orchard 2 is planted at 14 â?? x 17 â?? ( 183 trees per acre ) , and Orchard 3 is planted at 12 â?? x 16 â?? ( 227 trees per acre ) . Trees at Orchard 1 are trained to a traditional open vase ; Orchards 2 and 3 to a â?? steep leader â?? system with three primary scaffold branches . Ten nitrogen treatments ( Table 1 ) were assigned to each orchard with six trees per treatment in a randomized complete block design . Treatments were initiated during bloom and continued through the 2008 season . Foliar N treatments were applied by backpack mist - blower sprayer at a carrier volume ( based on tree canopy volume ) of 150 gallons / acre at Orchards 1 and 3 and 75 gallons / acre at Orchard 2By February , 2009 , an entire set of treatments will have been applied . Subtask 1.2 : Seasonal tissue sampling â?? At present , we have collected dormant and growing spur and terminal shoot buds , young ( fully - expanded , April ) and mature ( post - harvest in June , and September ) spur and shoot leaves , and small fruits collected at 20 days after full bloom , prior to â?? pit - hardening â?? ( Table 2 ) . We identified the type of buds to be collected as those most representative of high seasonal demand , thus , the spur buds were those entering into the first year of bearing on 2 - year - old wood on precocious mahaleb and Gisela 6 rootstocks and on 3 - year - old wood on Mazzard rootstock . Terminal buds from vegetative shoots were selected for tissue analysis . In each case , at least 10 buds were obtained . Shoot and spur leaves were collected from the same types of shoots , at least 10 leaves of each type . Subtask 1.3 : Seasonal growth measurements - - Phenological and productivity data , including full bloom date and duration of bloom , yield per tree , yield efficiency ( yield / TCSA ) , and fruit quality ( size , firmness , maturity , Brix and fruit removal force , or â?? pull force â?? ) were collected during the 2008 season . Trunk cross - sectional area ( TCSA ) was measured for vegetative growth , calculated from trunk circumferences taken at 6 inches above ground level in March and in October . Leaf area can be an indicative measure of vegetative growth , and indirectly reflect N status . Leaf area was measured in April using digital image analysis ( DIA ) of leaf photographs ( Bakr , 2005 ; Oâ??Neal , 2002 ) . Harvest for all orchards was a single â?? strip pick â?? on June 2 at Orchard 1 and June 6 at Orchards 2 and 3 . Samples of fruit were obtained at random from pickers â?? bins and evaluated on the day following harvest for maturity , firmness , size , stem / fruit removal force ( FRF ) and soluble solids . Maturity was measured by color , as per picking and grading guidelines ( CDFA and California Cherry Advisory Board ) . Only salable mature fruit were evaluated for quality , after a 100 - fruit random subsample from bin - collected fruit was evaluated for spread in maturity ( by 6 color grades ) . Fruit from Orchard 1 were separated visually into the 6 color grades of green , straw , colorbreak ( change from straw to pink ) , light red , dark red , and mahogany color categories by four trained evaluators using California Cherry Advisory Board color reference cards . Because of grading inconsistencies among evaluators , a Minolta CR - 10 colorimeter was used for grading fruit from Orchards 2 and 3 , using the same color categories on the color cards as a reference . A protocol was developed to convert CR - 10 readings to the equivalent color grades . This protocol is similar to industry standards for cling peach ( Slaughter and Crisosoto , 2006 ) and other commodity quality evaluation ( Mitcham et al . , 1996 ) . Where percentage of fruit is shown 4 for the color grades in this report , grades â?? green â?? and â?? straw â?? are combined due to very low numbers of fruit in each of these grades at harvest . Once fruit was graded thus , a subsample of 50 salable ( defect - free , light red to mahogany ) fruit were selected and used for fruit firmness , size , fruit removal force ( FRF ) and Brix determinations . Firmness and size ( BioWorks FirmTech II ) and FRF ( Imada digital force gauge ) measurements were made on individual fruits ; a single Brix value was determined using juice extracted from each 50 - fruit subsample . Subtask 1.4 : Tissue N analyses . At present , samples and data collected include N content from dormant and growing spur and vegetative buds ( collected prior to and at â?? budswell â?? in February and March , respectively , and in September ) , young and mature spur and shoot leaves ( April , July and mid - September ) , and small fruits collected at 20 days after full bloom ( prior to â?? pit - hardening â?? ) . Subtask 1.5 : Data , statistics and reporting - - All data collected to - date has been evaluated through statistical tests and is presented in the annual report . TASK 2 : Relationship of fruiting spur N reserves to subsequent spring spur leaf development , fruit set , and fruit growth potential The intent is to create different levels of total N in fruiting spurs with pre - dormant and post - dormant applications of N in different forms and amounts , then to correlate tissue N to subsequent flowering , fruit set , quality , and vegetative growth . This will lead to a recommendation for the most effective strategies to optimize N supply at the most critical times of N demand by fruit and fruiting support tissues . Subtask 2.1 : Assign treatments to develop baseline data and impose varied N Subtask 2.2 : Seasonal tissue sampling Subtask 2.3 : Seasonal growth measurements Subtask 2.4 : Tissue N analyses . Subtask 2.5 : Data , statistics and reporting TASK 3 : Determine the impact of fall dormancy - inducing and late winter dormancy - breaking treatments on fruiting spur N reserves and early spring growth demand for N Subtask 3.1 Assign treatments - - The objective of this task will be addressed primarily by the following Treatments ( Table 1 ) : ( T2 ) Soil applied N at 90 lb / acre after harvest plus ZnSO + urea applied in fall for defoliation plus 4 late - winter KNO for breaking dormancy . 3 + urea plus late winter CAN - 17 for ( T3 ) Soil applied N at 90 lb / acre after harvest plus fall ZnSO 4 breaking dormancy . + urea plus late winter CAN - 17 for ( T4 ) Soil applied N at 45 lb / acre after harvest plus fall ZnSO 4 breaking dormancy . The rationale is to develop data on tissue N levels and growth from low soil applied N plus dormancy induction / breaking treatments . Post - harvest applications as soil - applied CaNO have been made . Fall ZnSO + urea application 3 4 will be made at approximately 3 chill portion accumulation ( Dynamic Model , Erez et al . , 1990 . ) . Late winter applications will be made at timing consistent with typical commercial practice for CAN - 17 ( approximately 49 - 55 chill portion accumulation ) . Dataloggers were placed in the trial orchards in mid - October to collect chill data for timing of dormancy - inducing and dormancy - breaking treatments , as well as effects of treatments on flowering and fruiting , with respect to amount of chilling received . 5 Subtask 3.2 : Seasonal tissue sampling Subtask 3.3 : Seasonal growth measurements Subtask 3.4 : Tissue N analyses . Subtask 3.5 : Data , statistics and reporting . Results and Discussion Nutrient analyses completed thus far showed no differences in total N content among treatments within each orchard and tissue type ( Table 3 ) , as might be expected for the early stages of treatment imposition . Analyses of mid - summer and September tissue samples have not yet been completed . In all orchards and treatments , % N in both shoot buds and spur buds increased sharply from February to March with remobilization of stored nutrients at budbreak . April leaf and fruit N concentration was highest in all treatments at Orchard 2 , which may be interpreted as being due to less tree volume ( due to dwarfing rootstock ) per unit of nitrogen applied . Orchard 1 N values were intermediate and Orchard 3 had the lowest leaf and fruit N in April . The high vegetative vigor and large tree size at Orchard 3 may account for lower unit of N per tissue volume in all tissues . Nitrogen values for fruit from all orchards tended to be similar to that found in fully - expanded leaves , ranging from 2.9 to 4.4 % N . No significant differences in N status were found within a particular organ ( shoot bud , spur bud , leaf , or fruit ) within a given orchard . Shoot leaf size ( Table 4 ) was greatest at Orchard 1 , lowest at Orchard 3 , and intermediate at Orchard 2 . Orchard 1 tree canopies are kept very open by annual removal of large and small limbs via heavy pruning , maximizing within â?? canopy light distribution . Leaf area was not different among treatments within an orchard , except at Orchard 2 , where leaf size also showed high variability among replicates . Spur leaf area and N content among the orchards showed similar patterns to shoot leaves , namely , the highest values were at Orchard 1 , lowest at Orchard 3 , and Orchard 2 intermediate . TCSA was lowest at Orchard 2 , as expected with the dwarfing and highly productive rootstock at this site ( Table 5 ) . Seasonal changes in TCSA varied greatly among trees at each site , but there were no statistically significant differences in seasonal growth due to N treatment within each orchard . Such natural variability may require the cumulative increase in TCSA over the three year period of the trial to ascertain the affects of the treatments . The duration and date of peak bloom â?? recorded as â?? baseline data â?쳌 for comparing treatment effects in future years â?? were : 12 days and March 24 at Orchard 1 , and 11 days and March 26 at Orchards 2 and 3 . At Orchard 1 , fruit was mostly dark red and mahogany at harvest ( Table 6 ) . Post - bloom N ( Treatments 8 and 10 ) slightly delayed maturity , as evidenced by a higher percentage of fruit at â?? colorbreak â?? ( changing from straw to pink fruit ) , and fewer dark red fruit . Firmness ( Table 7 ) and Brix ( Table 8 ) did not vary among treatments at this site . FRF ( Table 7 ) was slightly reduced in Treatment 8 and highest in Treatment 10 , with no clear relationship to treatment when all indices of maturity are considered . Fruit size ( Table 7 ) was significantly different by treatment ( ranging from rowsize 9.7 to 10.1 ) , but all averaged out to row size 10 , thus no practical difference in fruit size was found ; weight of 25 fruit corroborated this finding of no difference among treatments ( Table 8 ) . Yield per tree among the treatments imposed prior to harvest showed no difference , nor did yield efficiency ( Table 8 ) . At Orchard 2 , fruit maturity was not different among treatments : about half of all fruit were dark red , and most of the remaining fruit were evenly found in either light red or mahogany colors . Fruit firmness , size and soluble solids were not different by treatment ; FRF was statistically 6 different among treatments , with the highest FRF in fruit that had received no N ( Treatment 1 ) and lowest in the post - bloom treatment . However , there was overlap with results from the bloom and combination bloom , post - bloom treatments , such that a clear relationship to treatment was not apparent . There were no differences among treatments in yield or yield efficiency . At Orchard 3 , fruit maturity showed some statistical differences among treatments , with a higher percentage of fruit â?? salable â?? colors for Treatment 10 , which had received both bloom and post - bloom treatments . There was no clear - cut treatment effect in any maturity or quality measure that clearly showed a treatment difference , even where statistical differences resulted . Yield and yield efficiency were not different among treatments . Consequently , baseline data for each orchard has now been collected and it is expected that we will begin to see treatment differences as the full set of treatments is completed in the coming year . Outreach Activities Summary The project has not yet completed the first full year of treatments , nor the first year - and - a - half of data evaluation from those treatments , however , outreach efforts representing the first yearâ??s work will include : th 1 . 16 Annual Fertilizer Research and Education Conference & Western Health Plant Association Central Valley Regional Nutrient Seminar , Modesto , November 12 and 13 , presenting the first annual report entitled : Optimizing Nitrogen Availability in Cherry Growth to Obtain High Yield and Fruit Quality 2 . California Cherry Advisory Board Annual Research Review , January 29 , 2009 in Lodi , California The same annual report as above , will be presented to the attendant cherry growers , PCAs , farm advisors , University researchers and industry representatives from agribusiness ( this is an open , public meeting ) , which typically number approximately 200 - 250 persons . The written report will be included in the proceedings from that meeting , distributed at the meeting . 3 . This report and the Protocol for Leaf Image Analysis will be posted and downloadable as PDF files from the UCDavis Department of Plant Sciences , Pomology Fruit and Nut Center website ( http : / / groups.ucanr.org / treecrop / ) by the end of 2008 and will be available without restriction . Similar protocols for the FirmTech II and color grading by colorimeter will be developed and posted sometime in 2009 . 4 . The Protocol for measuring FRF by digital force gauge was developed and posted as a downloadable PDF file from the UCDavis Department of Plant Sciences , Pomology Fruit and Nut Center website ( http : / / groups.ucanr.org / treecrop / ) . References Bakr , E.M . 2005 . A new software for measuring leaf area , and area damaged by Tetranychus uritcae Koch . JEN 129 ( 3 ) : 173 - 175 . Erez , A . , Fishman , S . , Linsley - Noakes , G.C . and Allan , P . 1990 . The dynamic model for rest completion in peach buds . Acta Hort . ( ISHS ) 276 : 165 - 174 . 7 Mitcham , B . , M . Cantwell and A . Kader . 1996 . Methods for Determining Quality of Fresh Commodities . Perishables Handling Newsletter Issue No . 85 : 1 - 5 . http : / / postharvest.ucdavis.edu / pubs / PHQ_85_Methods_for.pdf Oâ??Neal , M.E . , D.A . Landis , and R . Isaacs . 2002 . An inexpensive , accurate method for measuring leaf area and defoliation through digital image analysis . J . Econ . Entomol . 95 ( 6 ) : 1190 - 1194 . Slaughter , D . and C . Crisosto . 2006 . Objective Determination of Color and Firmness in Cling Peach Inspection . California Cling Peach Board Report 2006 . http : / / www.calclingpeach.com / html / Industry / E . 1 . Slaughter - Firmness % 20and % 20Color - 06 . doc 8 9 post - location 2008 , x 17 foliar bloom foliar 2.3 2.3 2.3 Apr Foliar in 2 physiologically - timed shown ; by Orchard orchards vary full Orchards acre fall at three 20 gal / A ; 10 - 30 % ( PHG + N ) bloom / petal per or 1.12 1.12 1.12 at 18 N N ) . 150 at cherry Mar pounds Foliar with ammoniacal = ( Linden / Mazzard ) sweet supplemented Actual release ) avium ) v / v v / v KNO3 w / v avium ) ] . Feb compounds . 15 % 25 % 25 % 6 % Jan - early rootstock . or ( Prunus ( PHG + N , ( dormancy CAN - 17 , CAN - 17 , application KNO3 , CAN17 3 P . Orchard ( both â?? Bing â?? nitrogenous dwarfing N soil â?? Mazzard â?? Plus and to Nov pre ( dormancy reduced applied ( Lodi ) Grow each each each on 4 induction ) by Oct - early ZnSO or trees PacificHort induction / alleviation 20 # / acre 20 # / acre 20 # / acre 6 â?? 1 treatments with Orchard leaf - fall + smaller â?? Gisela Foliar 15.5 % N ) Late mahaleb , at or for fertilization N ) trees 3 gal / A ( CaNO 27 ( 46 % pre leaf - fall 20 20 20 20 standard dormancy + [ P . 75 Foliar 20 + + + + urea ( N ) application 25 25 25 25 = Oct rootstock volume low - biuret nitrogen for of volume post impacts carrier soil and harvest 23 Experimental 90 45 45 45 45 45 45 90 90 45 June CA , are N standard carrier Soil 6 ) , plus Linden , N of ( Linden / Gisela applications , applications Calculated y Treatment comparing 1 . or Timing ( Lodi Table T10 T1 T6 T8 T5 T7 T9 T2 T3 T4 x Table 2 . Sampling of â?? Bing â?? ( Prunus avium ) sweet cherry tissues at three orchards in 2008 comparing standard soil application ( CaNO 15.5 % N ) with reduced soil application 3 supplemented with physiologically - timed foliar applications , plus impacts of dormancy induction / alleviation by nitrogenous compounds . Fruiting Shoot terminal x Fruiting spur leaf Shoot leaf Fruit Timing spur bud bud Feb 28 - Mar 1 X X Mar 14 - 18 X X Apr 11 X X X July 17 X X Sept 16 X X X X Nov ( late ) â?? Dec ( early ) X X x Samples from Feb - March , 2008 were from all trees / treatments ; for harvest data only treatments imposed during and after bloom , through harvest were sampled , as no other subsequent treatments had been imposed until after harvest . Table 3 . Nitrogen content of â?? Bing â?? ( Prunus avium ) sweet cherry tissues at three orchards in 2008 comparing standard soil application with reduced soil application supplemented with physiologically - timed foliar applications , plus impacts of dormancy induction / alleviation by nitrogenous compounds . % N , Feb % N , Mar % N , Apr Buds Leaves Orchard / rootstock Fruit Shoot Spur Shoot Spur Shoot Spur Orchard 1 ( mahaleb 1.6 - 1.7 1.6 - 1.7 2.2 - 2.5 2.9 - 3.2 2.9 - 3.0 3.0 - 3.2 3.2 - 3.4 rootstock ) Orchard 2 ( Gisela 6 2.2 - 2.5 2.2 - 2.3 2.6 - 3.0 2.9 - 3.2 3.6 - 4.0 3.8 - 4.0 3.8 - 4.4 rootstock ) Orchard 3 ( Mazzard 1.3 - 1.4 1.3 - 1.5 2.4 - 2.5 2.4 - 2.6 2.6 - 2.8 2.8 - 2.9 2.9 - 3.0 rootstock ) 10 2 Table 4 . Leaf area ( mm ) of â?? Bing â?? ( Prunus avium ) sweet cherry at three orchards in 2008 comparing standard soil application with reduced soil application supplemented with physiologically - timed foliar applications . Fully - expanded leaves collected on April 11 from actively growing vegetative shoots or spurs in first year of bearing . Leaf digital images analyzed by ImageJ ( vers . 1.41b , http : / / rsbweb.nih.gov / ij / ) . Orchard / rootstock and treatments Shoot Spur Shoot + spur Orchard 1 : Lodi / mahaleb x Treatment 1 ( 90 # N , soil - applied June 23 ) 677 a 516 a 597 a Treatment 6 ( 1.12 # N bloom , 45 # N , June ) 672 a 489 ab 580 ab Treatment 8 ( 2.3 # N post - bloom , 45 # N , June ) 661 a 491 ab 576 ab Treatment 10 ( 1.12 # N bloom , 2.3 # N post - bloom , 45 # 658 a 484 b 571 b N , June ) Orchard 2 : Linden / Gisela 6 Treatment 1 483 ab 369 a 426 a Treatment 6 458 b 366 a 412 ab Treatment 8 476 ab 318 b 397 b Treatment 10 501 a 312 b 406 ab Orchard 3 : Linden / Mazzard Treatment 1 181 a 159 a 170 a Treatment 6 152 a 156 a 154 a Treatment 8 158 a 154 a 156 a Treatment 10 163 a 151 a 157 a x Means in the same column and orchard with different letters differ by Duncanâ??s multiple range test at P < 0.05 . y Treatments evaluated represented only those differing in nitrogen application through harvest period : Treatment 1 = no N preharvest , Treatment 6 = foliar N at bloom and petal fall as Pacific Hort Grow Plus N , Treatment 8 = foliar urea applied ~ 1 month postbloom , Treatment 10 = bloom + petal fall + postbloom applications 11 2 Table 5 . Vegetative growth as increase in trunk cross - sectional area ( TCSA , in mm ) in â?? Bing â?? ( Prunus avium ) sweet cherry at three orchards in 2008 , comparing standard soil application ( CaNO 15.5 % N ) 3 x with reduced soil application supplemented with physiologically - timed foliar applications , plus impacts of dormancy induction / alleviation by nitrogenous compounds . Actual pounds N per acre shown ; foliar applications of N are low - biuret urea ( 46 % N ) or PacificHort Grow Plus N ( PHG + N , 15 % ammoniacal N ) . Orchards vary by location ( Lodi or Linden , CA , and rootstock [ P . mahaleb , â?? Gisela 6 â?? or â?? Mazzard â?? ( both P . avium ) ] . Orchard / rootstock Linden Lodi / mahaleb y Treatment Gisela 6 Mazzard x T1 CaNO soil June 23 ( 90 # ) 55.0 a 32.2 a 42.2 ab 3 CaNO soil ( 90 # ) , 20 # each urea + zinc 3 T2 59.5 a 35.6 a 35.1 ab sulfate early Nov , KNO 6 % w / v dormant 3 CaNO soil ( 90 # ) , 20 # each urea + 3 T3 50.3 a 42.3 a 28.9 b zinc sulfate , 25 % CAN - 17 CaNO soil ( 45 # ) , 20 # each urea + 3 T4 61.7 a 25.9 a 44.9 ab zinc sulfate , 25 % CAN - 17 CaNO soil ( 45 # ) , 25 + 20 # urea Oct 20 3 57.0 a 56.7 a 52.5 ab T5 + 27 CaNO soil ( 45 # ) , bloom + petal fall foliar 3 T6 37.7 a 25.1 a 70.1 ab ( 1.12 # ) CaNO soil ( 45 # ) , 25 + 20 # urea Oct 20 3 T7 61.6 a 40.6 a 72.3 ab + 27 , bloom + petal fall foliar ( 1.12 # ) T8 CaNO soil ( 45 # ) , foliar postbloom ( 2.3 # ) 58.3 a 32.5 a 53.3 ab 3 soil ( 45 # ) , foliar postbloom CaNO 3 49.5 a 29.8 a 47.1 ab T9 ( 2.3 # ) , 25 + 20 # urea Oct 20 + 27 CaNO soil ( 45 # ) , bloom + petal fall foliar 3 T10 ( 1.12 # ) , foliar postbloom ( 2.3 # ) 25 + 20 # , 68.1 a 55.4 a 76.2 a urea Oct 20 + 27 x Mean separation within columns by Duncanâ??s multiple range test , P > 0.05 . Y Calculated carrier volume for standard trees at Lodi / mahaleb and Linden / Mazzard orchards = 150 gal / A ; at Linden / Gisela 6 orchard , carrier volume = 75 gal / A for smaller trees on dwarfing rootstock . Nitrogen shown as actual lb / acre in parentheses . 12 z Table 6 . Effect of N fertilizer treatments on fruit maturity ( % fruit in given color ) in â?? Bing â?? sweet cherry , y 2008 . Salable fruit are defect - free , light red , dark red and mahogany as defined by Minolta CR - 10 colorimeter and California Cherry Advisory Board color card . y Orchard / rootstock and treatments Green Color Light Dark Mahogany Salable Straw break red red Orchard 1 : Lodi / mahaleb x Treatment 1 ( 90 # N , soil - applied June 23 ) 1 a 9 a 46 a 39 a 6 a 90 a Treatment 6 ( 1.12 # N bloom , 45 # N , June ) 1 a 4 a 45 a 46 a 4 a 95 a Treatment 8 ( 2.3 # N post - bloom , 45 # N , 4 a 28 a 47 a 8 b 12 a 68 a June ) Treatment 10 ( 1.12 # N bloom , 2.3 # N post - 6 a 15 a 45 a 30 ab 4 a 80 a bloom , 45 # N , June ) Orchard 2 : Linden / Gisela 6 Treatment 1 0 a 22 a 47 a 31 a 0 78 a Treatment 6 0 a 25 a 49 a 26 a 0 75 a Treatment 8 0 a 18 a 50 a 32 a 0 82 a Treatment 10 2 a 33 a 41 a 24 a 0 65 a Orchard 3 : Linden / Mazzard Treatment 1 2 a 50 a 35 b 13 a 0 48 b Treatment 6 7 a 37 ab 45 ab 11 a 0 56 ab Treatment 8 1 a 45 ab 45 ab 9 a 0 54 ab Treatment 10 0 a 25 b 65 a 10 a 0 75 a x Means in the same column and orchard with different letters differ by Duncanâ??s multiple range test at P < 0.05 . z Treatments evaluated represented only those differing in nitrogen application through harvest period . 13 z y Table 7 . Effect of N fertilizer treatments on fruit quality ( size , firmness , and fruit removal force [ FRF , stem â?? pull force â?? ] ) in â?? Bing â?? sweet cherry , 2008 . Only salable fruit were tested ( salable = defect - free , light red , dark red and mahogany by colorimeter and California Cherry Advisory Board color card ) . 2 2 Orchard / rootstock and treatments Firmness ( g / cm ) Rowsize FRF ( g / cm ) Orchard 1 : Lodi / mahaleb x Treatment 1 ( 90 # N , soil - applied June 23 ) 280 a 9.7 a 626 ab Treatment 6 ( 1.12 # N bloom , 45 # N , June ) 281 a 10.0 b 606 ab Treatment 8 ( 2.3 # N post - bloom , 45 # N , June ) 285 a 10.0 b 580 b Treatment 10 ( 1.12 # N bloom , 2.3 # N post - bloom , 278 a 10.2 c 641 a 45 # N , June ) Orchard 2 : Linden / Gisela 6 Treatment 1 359 a 9.8 a 638 a Treatment 6 361 a 9.8 a 579 bc Treatment 8 339 a 10.0 a 541 c Treatment 10 367 a 9.8 a 615 ab Orchard 3 : Linden / Mazzard Treatment 1 310 ab 9.4 b 388 a Treatment 6 286 c 9.3 a 347 b Treatment 8 318 a 9.5 b 399 a Treatment 10 304 b 9.6 c 381 ab x Means in the same column and orchard with different letters differ by Duncanâ??s multiple range test at P < 0.05 . y A â?? 10 row â?? cherry has a diameter of ~ 1 â?쳌 and a â?? 9 row â?? cherry has a diameter of ~ 1.2 â?쳌 , thus larger number for rowsize = smaller diameter fruit . Firmness measured by FirmTechII ( BioWorks , Wamego , Kansas ) . FRF measured by Imada DS2 digital force gauge . z Treatments evaluated represented only those differing in nitrogen application through harvest period : Treatment 1 = no N preharvest , Treatment 6 = foliar N at bloom and petal fall as Pacific Hort Grow Plus N , Treatment 8 = foliar urea applied ~ 1 month postbloom , Treatment 10 = bloom + petal fall + postbloom applications . 14 15 at efficiency measured a a a a a a a a a a a a 0.084 0.093 0.109 0.084 0.107 0.100 0.094 0.068 0.073 0.085 0.071 0.134 Yield circumference 0.05 . ( kg ) < Yield / tree P a a a a a a a a a a a a period . at 13 16 22 16 50 27 30 60 31 27 48 57 trunk test area ) / yield ) . 2008 ; harvest range cherry , multiple cross - sectional through a a a a a a a a a a a a Brix 23 24 24 20 25 21 21 23 22 19 17 20 sweet Duncanâ??s application â?? Bing â?? fruit x ab a a a a a b a b a a ( trunk a by 246 224 235 235 243 260 239 238 224 228 241 248 in g / 25 differ nitrogen quality ( TCSA letters fruit N , in efficiency differing different 45 # and post - bloom , yields June ) those yield with on June ) 23 ) calculate orchard N , only y treatments June 45 # N N , represented 2.3 # treatments post - bloom , 45 # and soil - applied to bloom , bloom , used fertilizer column Linden / Mazzard 6 Linden / Gisela Lodi / mahaleb season evaluated and N N N , ( 1.12 # same N ( 1.12 # N Orchard / rootstock ( 2.3 # of ( 90 # growing Effect the 10 10 10 6 Treatments 1 6 8 8 1 8 1 6 Treatment 2 : 1 : 3 : Treatment Treatment Treatment Treatment Treatment Treatment Treatment Treatment Treatment Treatment Treatment in 8 . Orchard Orchard Orchard Means of June ) Table start x y 16 Figure 1 . Tree architecture and spacing at three experimental orchards ; location and rootstock shown . Orchard 1 Lodi / mahaleb Orchard 2 Orchard 3 Linden / Gisela 6 Linden / Mazzard Figure 2 . Experimental unit of â?? first - bearing â?? spur buds on 2 year - old wood , DaValle / mahaleb orchard . 17