Southwick, Stephen :

Grant, Joseph A

Glozer Dr, Kitren

Hansen, Randy :

Project Title : Evaluation of Mahaleb rootstock selections 2003 Project Leader : Steve Southwick , Pomologist , Pomology Department , U . C . Davis Cooperators : Joe Grant , Farm Advisor , San Joaquin County Kitren Glozer , Staff Research Associate , Pomology Department , U . C . Davis Randy Hansen , PCA , Weddle , Hansen and Associates , Inc . , Placerville , CA Summary 2003 : In March 1995 , we planted the first ( Stockton area - Site 1 ) of five rootstock trials to evaluate new mahaleb rootstocks that are thought to be resistant to Phytophthora spp . Site 2 in Lodi ( planted 1996 ) and Site 3 ( University of California , Davis ) planted in 1998 , were budded with > Bing = clone IR 83 - 2 - 5 . Site 3 had been seeded with Phytophthora spp . to insure that the disease organism was present . The site is poorly drained and prone to flooding as well . An additional planting was made in 1999 in Stockton ( Site 5 ) which has been evaluated for survival and growth . When Sites 2 and 3 are compared , mahaleb selections 155 - 1 , Small Turkish , P50 , 156 - 5 , NY 34 , 162 - 1 , and P1 Large leaf have maintained the highest survival rates at both sites . Of the controls , Standard mahaleb showed highest death rate , followed by Mazzard and Colt . Several new mahaleb selections performed better in terms of survival than any of the standard control rootstocks . At Site 5 , Small Turkish , 156 - 5 , NY 34 , Standard mahaleb and Colt have shown a 100 % survival rate . We anticipate an official release of three rootstocks to the trade in 2004 . The rootstocks currently identified for release include 155 - 1 , 156 - 5 and 159 - 5 . Problem and its significance : Prunus mahaleb is one of the leading rootstocks for sweet cherry growers in California , but is susceptible to root and crown rot fungal diseases generally known as Phytophthora spp . Growers have experience with mahaleb and , other than being susceptible to Phytophthora disease , it is suitable for California growing conditions . Mahaleb trees from seed are drought tolerant , moderately resistant to bacterial canker and hypersensitive to Western - X . Mahaleb produces few root suckers , but gophers damage trees on mahaleb . Within the population of mahaleb clones that have been tested in the field are those that reduce tree size , have degrees of resistance to Phytophthora spp . , and alter the branching and bearing habit of > Bing = . It is well known that there are many mahaleb clones , but they have not been critically examined in the field under California conditions . We believe it is important to discern whether any of these mahaleb clones propagated clonally are horticulturally better than what is currently available . From 48 mahaleb clones screened by the California cherry industry and University of California for Phytophthora susceptibility and vegetative rooting ability , approximately 20 were selected for their effect on horticultural characteristics . The field evaluation of these mahaleb clones is a natural evolution in the development of improved cherry rootstocks . Several Gisela rootstocks currently being evaluated have been shown to reduce the size of cherry trees across several orchard locations and improve early fruit production . A problem with Gisela rootstocks may be the tendency toward over production and small fruit size as trees reach 5 to 6 years - old . Management techniques can mitigate those problems , but It is likely that mahaleb will maintain a position in the California cherry industry as one of the preferred rootstocks for cherry growers . By evaluating these Phytophthora resistant mahaleb clones for their horticultural ( tree size , suckering , fruit size , yield ) effects , clear separation of mahaleb clones can be made based upon performance in the field and growers can make more informed decisions about which A mahaleb @ is best for them . Development of these superior mahaleb clones is also compatible with current and future trends in tree training and pruning of sweet cherries in California . Introduction : Mahaleb ( Prunus mahaleb ) rootstocks are commonly used rootstocks for sweet cherries in California . Since they are propagated by seed they can be highly variable in the orchard with regard to individual horticultural performance because they are grown in blocks where cross - pollination among types is common . A clonal source of mahaleb rootstocks should help to reduce performance variability . In addition , AStandard mahaleb @ is generally quite sensitive to various species of Phytophthora . We have been working over the last several years to propagate and select Phytophthora - resistant Prunus mahaleb ( mahaleb ) rootstock materials . The materials can be propagated by hardwood or softwood cuttings , ( as well as in the form of virus - free seedlings ) and have shown resistance to several strains of Phytophthora based upon stem and soil inoculation of potted and flooded greenhouse grown tree experiments . : Field evaluation of vegetatively propagated mahaleb selections for various horticultural Objectives characteristics and survival under field growing conditions with disease ( i.e . Phytophthora ) pressure . From 1992 through 2000 we have used softwood and hardwood cuttings to produce rooted rootstocks to be budded with standard > Bing = . Additionally , we started using virus - free seedlings from a different source in 1999 ( Site 5 ) . Our field trials have screened 23 mahaleb clones produced from these cuttings . Also , budwood of 70 mahaleb clones , including items that were included in the cuttings program and newly acquired selections from the USDA Plant Introduction Station , have been budded on mahaleb rootstocks to develop a new AMother Block @ for future propagation needs . All field sites have either an inoculation of Phytophthora or a history of tree death from symptoms that suggested Phytophthora . Annual counts of tree death and tree growth were augmented in 1998 with sampling for Phytophthora from symptomatic or newly dead trees ( Sites 2 and 3 ) . These samples were tested for Phytophthora spp . by Greg Browne in the Department of Plant Pathology , UCD / USDA . Although Phytophthora was detected in the samples , these trees may not necessarily have died from disease , however , the indications are fairly strong that the disease is the principal cause of tree death at these sites ( Site 3 had been intentionally inoculated with Phytophthora for research purposes ) . s : Plans and Procedure Locations and plant materials : In March 1995 , we planted a limited number of trees in the Stockton area ( Site 1 ) . The site was an orchard of adobe clay where numerous trees had died . The mahaleb clones were planted as interplants . Trees were irrigated by impact sprinkler . The conditions were rough in the orchard for establishing trees , but not unlike others in the region . These selections had previously exhibited resistance to Phytophthora spp . after stem inoculation tests . By 1999 , tree survival at this site was limited to one or two trees and we are no longer evaluating this site . On 15 February , 1996 an additional mahaleb rootstock trial was planted in the Lodi / Stockton area ( Site 2 ; cooperator Lodi Farming ) . Trees were planted at a spacing of 18 feet between rows and 13 feet between trees . The cultivar was > Bing = and the pollenizers were > Rainier = / mahaleb ( 8.3 % ) and > Black Tartarian = / Colt / Mazzard ( 8.3 % ) . Pollenizers were planted as every fourth tree in alternate rows ; replicates were planted as a randomized block design . The soil was a Wyman clay loam and the trees were irrigated by impact sprinklers . Trees were headed at planting to a height of 20 inches and current season = s shoots were headed during the summer at 18 inches . The training system was open center . Standards of mahaleb , and Mazzard were planted for controls . Additional plantings were made in a new site on 9 April ( Site 3 ; University of California , Davis ) in 1998 with trees budded in 1996 with > Bing = clone IR 83 - 2 - 5 . Site 3 is a poorly drained site that was thought to be prone to Phytophthora disease because of the previous cropping and use history of the site . The trees are managed by micro - sprinkler irrigation and trained to a Modified Spanish Bush . They were planted in 1998 . The site was seeded with Phytophthora spp . to insure that the disease organism was present ; the presence of the disease organism was confirmed by F . Bliss and A . Almehdi in 1998 . As trees died , cause of death ( Phytophthora vs . other factors ) has been recorded . Mahaleb clones planted at this site have been screened for Phytophthora resistance , however , we believe that it is important to field test the clones under differing conditions to judge actual performance . A set of virus - free seedling clones was budded with > Bing = at Fowler Nursery and was planted at UCDavis ( Site 4 ) on 11 March , 1999 . Seedlings of standards were also planted . Pollenizers were > Van = , > Black Tartarian = and > Larian = planted within one of three clone rows , at every fourth or fifth tree . Proportion of pollenizers were : 31 , 23 , 46 , respectively . Rooted cuttings from Fowler Nursery have been used to replace trees lost in 1999 . A fifth site was established in the Stockton area by Joe Grant from Fowler propagates ( rooted cuttings ) . Survival , vegetative and reproductive evaluations : Death from Phytophthora and non - specified reasons has been evaluated and recorded annually in July to September and during the dormant season ( Sites 2 , 3 , 5 and 4 through 2003 ) . Vegetative growth has been measured by trunk circumference ( usually October - November ) and , at times , by a growth rating system . TCSA ( trunk cross - sectional area ) has been calculated from trunk circumferences ( measured at about 30 cm from the soil surface after leaf fall ) taken annually after about two years from initial planting ( Sites 2 , 3 , 5 ) . Suckers ( trunk and root ) have been counted at both Sites 2 and 3 . Site 2 started cropping in 2000 and we rated bloom abundance ( or > intensity = , defined as amount of canopy filled with flowering buds ) , crop density and fruit size . Fruit size ( weight per fruit ) was evaluated by collecting a random sample of 10 fruit from the periphery of each treatment / replicate tree . In 2001 we measured earliness of bloom , trussbud density ( number of trussbuds per cm shoot length ) , estimated fruit set and fruit size ( fruit weight from 20 fruit selected randomly from harvested fruit ; rowsize of 10 fruit subsample ) . The fruit sampled for these measurements were also evaluated for defects ( spurs , doubles and deep suture ) . Yield for each of two harvests , total yield , yield efficiency and percentage of yield harvested in the first pick were measured in 2001 . In 2002 , on 20 March , we measured earliness of bloom ( rating based on proportion of flowers open of those present ) ; in 2003 we measured bloom intensity on March 23 . Fruit evaluation for 2002 and 2003 has included size ( rowsize of 10 fruit and weight of 10 to 25 fruit ) and fruit maturity ( 25 fruit , 2003 ) . Yields have been calculated in 2002 and 2003 similarly to 2001 . Bloom occurred at Site 3 beginning in 2000 , and was evaluated in 2001 as bloom intensity , flower abundance and average full bloom date . In 2002 we measured bloom in Site 3 on 29 March and leafout on 11 April , evaluating bloom abundance ( rating density of buds expanded of those present ) and earliness of bloom , as in Site 2 . Leafout was rated as amount of vegetative bud break and filled canopy . Similar measurements were made at Site 4 in 2001 . Trees at these two sites ( adjacent to each other ) suffered extensive tree blow - over and some tree death in late spring - summer of 2001 . In 2003 we measured bloom abundance at Site 3 . n : Results , Site 2 Stockto Tree survival and growth : The clonal rootstocks were initially tested by stem inoculation and soil flooding tests against strains of Phytophthora and found to show some promise with regard to tolerance or resistance . Under field tests there is pressure from stem pitting and Phytophthora sp . , as well as unknown mortality . Survival in 2003 was highest ( 100 % ) with mahaleb clones 155 - 1 , Small Turkish , and P50 ( Table 1 ) . Survival rates were next highest in Standard Mazzard ( 93 % ) , 156 - 5 ( 92 % ) , 162 - 1 ( 87 % ) , NY 34 ( 85 % ) , and P1 Large Leaf ( 80 % ) . Other mahaleb selections under test ranged from 87 to 25 % survival and Standard mahaleb had 55 % survival . For the last 3 years the degree of pruning has increased . Pruning has a dwarfing effect so we believe the most accurate measure of tree growth precedes 2001 measurements . On November 26 , 2002 , the most vigorous rootstock was 299 - 3 ( Table 2 ) . Among the least vigorous were 159 - 5 , 163 - 1 , 141 - 1 , and 136 - 2 . Other rootstocks were intermediate in vigor between the most and least vigorous rootstocks aforementioned , including Standard mahaleb and Mazzard . Flowering , fruit size and maturity , yields : We found in 2003 that many of the mahaleb selections had comparable bloom timing ( Table 3 ) . Standard Mazzard and P50 had bloom delay compared to many other selections . The most advanced bloom was noted in selections 294 - 3 , P2 small leaf , 297 - 2 , and 163 - 1 and Standard mahaleb was similar to those . We found in 2002 that there was variation in the amount of flowers open at a single moment in time based upon rootstock and that some selections had more flowers fully open in advance of other selections . Among the selections with the greatest advancement in flowering were 159 - 5 , 294 - 3 , 295 - 3 , and 297 - 2 . Among the selections having the most delay in flower opening were mazzard , P50 , 759 - 2 , and 251617 . Standard mahaleb was similar to many other selections and was grouped in the middle . Larger fruit were noted with selections 136 - 2 , 162 - 1 , and 294 - 3 ( Table 3 ) . Although there were significant differences among rootstocks with regard to fruit size ( both row size and weight per fruit ) , fruit size was not noticeably different based upon rootstock when crop load was considered ( data not shown ) . Moreover , the fruit size differences were numerically small when rootstock effects were compared ( data not shown ) . Therefore , in these experiments neither rootstock nor cropping dramatically affected fruit size , although pruning most likely influenced both of these factors . Fruit defects were negligible among all clones evaluated in 2003 ( data not shown ) . Highest yield per tree was noted in rootstock selection 156 - 5 ( Table 4 ) , statistically higher than the yield found with Standard mahaleb . Standard Mazzard was among the lowest yielding . Selections with high yield per tree , but equivalent statistically , included 156 - 5 , 295 - 3 , and 294 - 3 . Selections with lower yield that were equivalent statistically included P50 , 299 - 3 , 136 - 2 , Standard Mazzard , dwarf mahaleb , P1 large leaf and 159 - 5 . Other rootstocks were intermediate . Highest 3 year cumulative yield per tree were noted with selections 156 - 5 and 294 - 3 . Selections that had high cumulative yields over the life of this experiment and were statistically equivalent included selections 156 - 5 , Small Turkish , NY 34 , 294 - 3 , and 295 - 3 . The lowest cumulative 3 year yields per tree were noted with P50 and Standard Mazzard . Other rootstocks were intermediate with regard to the 3 year cumulative yield per tree . 2 with selection 759 - 2 and the lowest Yield efficiencies varied slightly in 2003 from a high of 0.14 kg / cm 2 ( Table 4 ) . Many rootstocks had similar values yield efficiency found with selection P50 at 0.2 kg / cm including Standard mahaleb and Mazzard . The greatest percentage of dark mahogany fruit were measured on rootstock selection 297 - 2 ( Table 5 ) . Most other rootstocks were equivalent and intermediate . Fruit color was delayed with Standard Mazzard rootstock . Suckering per tree : All selections produced at least some suckers either at the crown or from the rootstock ( data not shown ; see 2002 report ) . Rootstocks under test at this site continue to produce very low numbers of suckers . Only mahaleb selection 299 - 3 produced significantly higher numbers of root suckers than the other selections tested . Mahaleb selection 251617 had the highest number of trunk suckers compared with other evaluated rootstocks in 2002 . Results Site 3 Davis : Survival , flowering and leafing : Tree survival through 2003 was 40 % with Colt , 50 % with Standard mahaleb and 20 % with Mazzard ( Table 6 ) . Mahaleb selection 155 - 1 had 100 % survival . Mahaleb selections Small Turkish and P1 large leaf had higher survival percentages than the abovementioned standards . Mahaleb selection Medium Turkish had the most advanced flowering , while Standard Mazzard was least advanced ( Table 7 ) . Standard mahaleb had an overlapping bloom abundance rating compared with many of the mahaleb selections being evaluated . The 2002 season was a relatively low chill year . Chilling was especially low until January , after which chilling accumulation appeared more normal . Bloom abundance was measured by rating the overall appearance of each tree with regard to presence of flowers . Higher numbers indicated more flowers and would seem to be indicative of trees that could be more adapted to lower chill conditions . Colt had one of the lowest rating values and Dwarf mahaleb one of the highest . None of the mahaleb selections being evaluated was different statistically from Standard mahaleb or mazzard with regard to bloom abundance . Earliness of bloom was rated based on the percentage of flowers open of the population of flowers present on the tree , with 80 % considered full bloom . The clones that showed the greatest bloom advancement included 136 - 2 and 11 - 4 , with several other clones statistically equivalent , as were Colt and Standard mahaleb . 155 - 1 was the least advanced , however , 62 % of the other mahaleb clones were statistically equivalent . These findings should be interpreted with caution , not only because they are a single year = s representation , but also because there is a high degree of variation within most clone = s population . We also evaluated leafout to evaluate the adaptation of each rootstock to the apparent low chill condition in this season . However , we could not identify an effect of rootstock with regard to the characteristics that we rated , although individual trees clearly had very poor leafing and flowering characteristics . Results Site 5 Stockton : Survival and growth : Survival was high for all trees planted ( Table 8 ) . A single tree of each of two selections ( mahaleb selection P1 Large leaf and 163 - 1 ) died to date . NY 34 was the most vigorous of the rootstocks as of November , 2002 . Standard mahaleb was the next most vigorous . The other rootstocks had statistically similar tree growth among the intermediate group , but selection 156 - 5 was considerably reduced in vegetative growth than any other selection and was significantly smaller than Standard mahaleb . Summary : Site 2 , Stockton : ! Survival highest in mahaleb 155 - 1 , P50 , Small Turkish and 156 - 5 ; other clones ranged from 25 - 87 % survival and Standard mahaleb had 55 % . ! Most clonal rootstocks were equivalent in vigor , with 299 - 3 representative of the most vigorous . Among the least vigorous were 159 - 5 , 163 - 1 , 141 - 1 , and 136 - 2 . ! Earliness of bloom : " Most advanced = 297 - 2 and 294 - 3 ( 2002 and 2003 ) , 156 - 5 , P2 small leaf and Standard mahaleb . " Most delayed = Standard Mazzard , Colt and P50 . ! Fruit size was statistically and numerically similar among rootstocks , and could to be due more to crop load , assuming pruning to be similar ! Highest 2003 yield per tree was found with selection 156 - 5 ; this yield was statistically higher than that of Standard mahaleb . Standard Mazzard was among the lowest yielding . Many selections evaluated in 2003 had statistically equivalent yields . Highest cumulative yield per tree over 3 seasons were noted with selections 156 - 5 and 294 - 3 . The lowest cumulative 3 year yields per tree were noted with P50 and Standard Mazzard . Other rootstocks were intermediate with regard to the 3 year cumulative yield per tree . ! Yield efficiency was similar among clonal selections in 2003 . ! Fruit maturity was advanced for selection 297 - 2 , but mostly fruit maturity was similar among evaluated rootstocks . ! Root and trunk suckers were found on all selections in 2002 , but prevalent on none ; 299 - 3 produced the greatest number of root suckers and 251617 the greatest number of trunk suckers Site 3 , UCDavis : ! Colt , Standard mahaleb and Standard Mazzard had survival of 40 , 50 , and 20 % , respectively . 155 - 1 had 100 % survival . Several other mahaleb clones had higher survival rates than the standards ! In the low chill year of 2002 , bloom abundance was statistically equal among clones , Standard mahaleb and mazzard ; Dwarf mahaleb was among the highest and Colt was one of the lowest . ! There was a fair degree of variation in earliness of bloom in 2003 . " 136 - 2 and 11 - 4 had early bloom in 2002 and 2003 . Medium Turkish was most early , but not statistically different compared with other selections . Colt and Standard Mazzard had most delay in bloom and Standard mahaleb was intermediate and statistically equivalent with many other selections . Site 5 , Stockton : ! Survival was high for all trees ; single trees of P1 Large leaf and 163 - 1 died . ! 156 - 5 was the least vigorous of all rootstocks tested in 2003 . NY 34 was the most vigorous of the rootstocks and Standard mahaleb was the next most vigorous . Colt was less vigorous than Standard mahaleb , but more vigorous than selection 156 - 5 . The other rootstocks had statistically similar tree growth among the intermediate group . Conclusions : Tree evaluation may continue for additional years to validate initial results . Currently we have selected three rootstocks for commercial release . The 3 rootstocks are listed below with their most important features . Features of MH 155 - 1 : $ Uniformity of plant material compared with seed - propagated mahaleb $ 100 % survival at all test sites ( higher than Standard mahaleb ) that had histories of Phytophthora and stem pitting $ Low root and trunk sucker production $ Full size tree comparable to standard seed - produced mahaleb , vigorous $ Fruit size , yield comparable or greater than standard Features of MH 156 - 5 : $ Uniformity of plant material compared with seed - propagated mahaleb $ Survival is high at all test sites to date ( higher than Standard mahaleb ) , slightly below MH 155 - 1 $ Low root and trunk sucker production $ Precocious , early high yields with > Bing = $ Tree size reduction about 5 to 10 % compared with standards ( significantly less at one site after 3 years ) ; increased yield efficiency $ Fruit size , yield comparable or greater than standard $ Has advanced bloom in some seasons with > Bing = Features of MH 159 - 5 : $ Uniformity of plant material compared with seed - propagated mahaleb $ Survival comparable to Standard mahaleb $ Tree size reduction by approximately 15 to 20 % compared with standards $ Suitable for higher density planting , increased yield efficiency $ Low root and trunk sucker production $ Precocious fruit flowering and fruit production $ Fruit size , yield comparable to or greater than standard $ Low doubling , spurring and deep suture production even with smaller tree $ Has advanced bloom in some seasons with > Bing = Table 1 . Survival of > Bing = / mahaleb selections , Site 2 Stockton ( Lodi Farming ) . % Survival Stem pitting Phytophthora 2001 sp . found 1998 Selection 7 / 9 / 99 10 / 25 / 00 3 / 19 / 01 11 / 26 / 02 6 / 9 / 03 251617 33 33 33 33 33 no P1 LL 80 80 80 80 80 no 295 - 3 44 44 44 44 25 no possible 159 - 5 67 67 60 50 40 no yes Std mahaleb 78 78 66 66 55 no possible Dwarf mahaleb 100 75 50 50 50 yes 10 - 4 59 59 59 59 59 yes 294 - 3 77 69 62 62 62 no yes 155 - 1 100 100 100 100 100 yes Std Mazzard 100 100 100 100 93 no P2 Small 80 31 31 31 31 no 759 - 2 60 60 60 60 60 yes 163 - 1 82 82 73 73 64 no 141 - 1 53 53 53 53 44 no possible NY 34 85 85 85 85 85 no 297 - 2 92 73 42 42 33 yes 162 - 1 87 87 87 87 87 yes 136 - 2 78 67 56 56 56 yes Small Turkish 100 100 100 100 100 yes 299 - 3 43 43 43 43 43 yes 156 - 5 100 92 92 92 92 no P50 100 100 100 100 100 no Table 2 . > Bing = / mahaleb selections planted 15 Feb 1996 , Site 2 Stockton ( Lodi Farming ) ; size after 6 years . 2 TCSA ( trunk cross - sectional area ; cm ) Selection 10 / 24 / 97 11 / 12 / 98 11 / 15 / 99 10 / 25 / 00 3 / 19 / 01 11 / 26 / 02 X 251617 47.9 e - g 83.0 d 173.6 a - f 253.2 a - e 338.2 a 424.7 b P1 LL 61.0 a - d 138.4 ab 224.7 a - d 273.8 a - e 284.0 abc 392.8 bc 295 - 3 46.8 efg 99.8 bcd 166.0 c - f 217.6 def 268.8 abc 409.8 b 159 - 5 43.2 g 89.2 cd 147.8 ef 181.2 f 232.3 bc 334.9 c Standard mahaleb 44.8 fg 106.7 a - d 141.8 f 223.6 b - f 293.7 abc 477.6 ab Dwarf mahaleb 50.8 c - g 123.8 a - d 198.1 a - f 268.8 a - e 318.6 ab 407.1 b 10 - 4 61.2 a - d 131.2 abc 227.6 abc 283.8 abc 306.6 ab 455.4 ab 294 - 3 65.4 ab 120.8 a - d 213.3 a - d 283.6 abc 321.0 ab 396.9 bc 155 - 1 56.6 a - g 125.1 abc 203.1 a - f 271.4 a - e 320.4 ab 384.2 bc Standard Mazzard 45.0 fg 102.6 bcd 169.1 b - f 227.6 b - f 299.3 abc 417.5 b P2 Small 54.5 b - g 138.8 ab 173.5 a - f 274.2 a - e 319.6 ab 433.1 b 759 - 2 52.1 b - g 125.7 abc 206.9 a - e 265.7 a - e 295.1 abc 417.1 b 163 - 1 52.8 b - g 107.6 a - d 188.1 a - f 220.7 c - f 261.7 abc 341.7 c 141 - 1 64.7 b 140.0 ab 220.0 a - d 279.2 a - d 300.7 abc 349.7 c NY 34 58.5 a - e 122.7 a - d 216.6 a - d 281.7 abc 306.9 ab 464.1 ab 297 - 2 65.2 ab 142.6 ab 221.8 a - d 303.5 a 329.4 ab 378.3 bc 162 - 1 64.5 ab 138.0 ab 235.6 a 314.8 a 337.0 a 438.7 b 136 - 2 57.9 a - f 125.7 abc 209.9 a - e 263.5 a - e 323.2 ab 345.3 c Small Turkish 62.6 abc 127.3 abc 213.6 a - d 286.8 ab 329.5 ab 391.1 bc 299 - 3 68.0 a 148.1 a 233.3 ab 279.1 a - d 307.2 ab 566.3 a 156 - 5 48.5 d - g 100.5cd 162.9 def 214.2 ef 250.2 c 425.7 b P50 56.4 a - g 146.2 a 230.7 ab 293.8 a 321.0 ab 376.1 bc X Mean separation within columns by Duncan = s multiple range test , P = 0.05 . Table 3 . Mahaleb clones at Site 2 , Stockton ; fruit size bloom in 2002 and 2003 and fruit size in 2002 . y Earliness of bloom Rowsize Fruit wt ( g ) Clone 3 / 20 / 02 3 / 23 / 03 2002 2003 2002 2003 x 251617 1.0 h 2.0 cde 11.1 a - e 10.25 def 7.8 bcd 10.1 a 159 - 5 2.6 a - d 2.4 bcd 11.2 a 10.51 abc 7.7 cd 8.5 c 155 - 1 1.7 e - h 2.7 a - d 11.1 a - e 10.34 b - f 7.7 bcd 9.0 bc 156 - 5 1.6 e - h 3.0 abc 11.1 a - e 10.59 a 8.1 bcd 8.6 c 162 - 1 1.9 c - h 2.9 abc 11.1 a - e 10.23 def 8.2 bcd 9.4 ab 136 - 2 1.8 c - h 2.7 a - d 10.8 fgh 10.15 ef 8.4 bc 9.7 ab 141 - 1 1.8 c - h 2.4 bcd 11.1 a - d 10.54 ab 8.1 bcd 8.6 c 163 - 1 2.3 a - e 3.2 ab 10.8 gh 10.19 ef 8.5 bc 9.3 bc 294 - 3 2.6 a - c 3.7 a 10.9 efg 10.24 def 8.5 bc 9.4 ab 295 - 3 2.7 ab 2.8 a - d 11.1 ab 10.52 abc 7.9 bcd 9.0 bc 297 - 2 2.9 a 3.1 ab 11.0 b - g 10.33 b - f 8.4 bc 9.1 bc 299 - 3 1.3 fgh 2.0 cde 11.2 a 10.30 c - f 7.7 cd 8.6 c 759 - 2 1.1 gh 2.4 bcd 11.0 a - f 10.36 a - f 8.1 bcd 9.0 bc 10 - 4 1.8 d - h 2.6 bcd 10.9 c - g 10.37 a - f 8.5 bc 9.2 bc NY 34 1.9 c - h 2.8 a - d 11.1 abc 10.47 a - d 7.8 bcd 8.9 bc P1LL 1.3 fgh 1.7 de 11.1 a - e 10.39 a - e 8.0 bcd 9.0 bc Dwarf Mhb 1.7 e - h 2.0 cde 11.0 a - e 10.13 f 8.1 bcd 9.0 bc Small Turk 1.6 e - h 2,4 bcd 11.0 a - g 10.28 c - f 8.1 bcd 9.3 b P2 Small leaf 2.2 a - e 3.2 ab 11.0 a - e 10.38 a - f 7.8 bcd 8.7 c P50 1.0 h 1.0 e 10.7 h 10.16 ef 8.4 bc 9.3 b Std Mahaleb 2.0 b - f 3.0 abc 10.9 d - g 10.26 def 8.6 b 8.9 bc Std Mazzard 1.2 fgh 1.2 e 11.1 a - d 10.31 c - f 7.4 d 9.0 bc x Mean separation within columns by Duncan = s multiple range test , P = 0.05 ; ns = non significant . y Earliness of bloom measured by rating the entire tree canopy ; 2002 , 0 = no bloom , 1 = 0 - 40 % open flowers , 2 = 40 - 80 % , 3 = 80 - 100 % , of the flowers that were present ; 2003 , 0 = no bloom , 1 = 0 - 20 % open flowers , 2 = 21 - 40 % . . . 5 = 81 - 100 % . Table 4 . > Bing = / mahaleb selections planted 15 Feb 1996 , Site 2 Stockton ( Lodi Farming ) ; yield , yield efficiency and fruit defects , in 2001 , 2002 and 2003 . Y 2 Yield ( kg ) Cumulative yield Yield efficiency ( kg / TCSA cm ) Selection 2001 2002 2003 2001 - 03 2001 2002 2003 X 251617 2.0 e 21.7 28.6 bcd 52.3 bcd 0.008 c 0.04 0.06 b P1 LL 26.7 a - d 9.9 20.8 cd 57.4 bcd 0.20 ab 0.09 0.05 bc 295 - 3 31.8 a - d 26.4 41.4 ab 99.6 ab 0.26 ab 0.06 0.11 ab 159 - 5 23.0 a - e 28.9 21.7 cd 73.6 bc 3.02 a 0.06 0.06 b Standard mahaleb 27.5 a - d 26.8 25.6 bcd 79.9 bc 0.21 ab 0.05 0.07 ab Dwarf mahaleb 24.4 a - d 20.4 20.4 cd 65.2 bcd 0.22 ab 0.04 0.05 bc 10 - 4 32.3 a - d 19.6 35.2 bc 87.1 abc 0.30 ab 0.06 0.08 ab 294 - 3 34.5 abc 24.9 45.2 ab 104.6 a 0.39 ab 0.08 0.11 ab 0.09 ab 155 - 1 16.9 b - e 27.4 29.9 bcd 74.2 bc 0.10 b 0.08 Standard Mazzard 11.6 cde 13.0 14.5 cd 39.1 d 0.11 b 0.08 0.04 bc P2 Small 23.5 a - e 13.4 28.7 bcd 65.6 bcd 0.05 b 0.06 0.07 b 759 - 2 28.4 a - d 17.1 25.9 bcd 71.4 bc 0.25 ab 0.08 0.14 a 163 - 1 28.9 a - d 22.5 32.2 bcd 83.6 bc 0.38 ab 0.09 0.11 ab 141 - 1 38.3 ab 18.3 30.6 bcd 87.2 abc 0.20 ab 0.07 0.10 ab NY 34 36.6 ab 17.9 37.8 bc 92.3 ab 0.18 ab 0.06 0.08 ab 297 - 2 29.6 a - d 22.5 39.4 bc 83.0 bc 0.19 ab 0.05 0.10 ab 162 - 1 32.5 a - d 12.7 40.7 b 85.9 bc 0.23 ab 0.07 0.09 ab 136 - 2 25.9 a - d 24.5 22.7 cd 88.7 abc 0.23 ab 0.06 0.08 ab Small Turkish 29.3 a - d 23.7 39.1 bc 92.1 ab 0.14 b 0.07 0.11 ab 299 - 3 22.4 a - e 13.3 17.2 cd 59.2 bcd 0.02 b 0.05 0.03 c 156 - 5 44.8 a 16.6 49.3 a 110.7 a 0.64 ab 0.11 0.11 ab P50 10.8 de 22.7ns 9.0 d 42.5 cd 0.09 b 0.04ns 0.02 c X Mean separation within columns by Duncan = s multiple range test , P = 0.05 ; ns = non significant . y Table 5 . Mahaleb clones at Site 2 , Stockton ; fruit maturity ( color ) at harvest on June 9 , 2003 . Clone Pink Light red Dark red Mahogany Dark mahogany 251617 0.40 ab 1.3 bc 13.5 cd 70.0 ab 14.8 bc 159 - 5 0.11 ab 2.2 bc 18.8 cd 66.2 ab 12.7 bc 155 - 1 0.15 ab 2.5 bc 24.1 bc 63.7 ab 8.5 bcd 156 - 5 0.14 ab 0.1 d 12.5 cd 78.0 a 9.3 bcd 162 - 1 0.00 b 2.4 bc 21.6 bcd 64.6 ab 11.4 bc 136 - 2 0.04 ab 2.1 bc 25.5 bc 61.6 ab 10.8 bc 141 - 1 0.00 b 1.9 bc 21.8 bcd 66.3 ab 10.0 bcd 163 - 1 0.14 ab 2.7 bc 28.4 bc 54.1 bc 14.7 bc 294 - 3 0.00 b 3.2 bc 27.2 bc 57.8 abc 11.8 bc 295 - 3 0.04 ab 0.6 cd 22.6 bcd 69.8 ab 7.0 cd 297 - 2 0.09 ab 0.4 cd 11.2 d 63.4 ab 24.9 a 299 - 3 0.28 ab 0.5 cd 50.7 a 38.2 bc 10.3 bcd 759 - 2 0.08 ab 4.4 bc 27.2 bc 59.8 abc 8.5 cd 10 - 4 0.00 b 1.4 bc 23.3 bcd 60.3 ab 15.0 bc NY 34 0.05 ab 1.1 bc 28.9 bc 58.4 abc 11.6 bc P1 Large leaf 0.00 b 6.0 abc 30.1 bc 53.5 bc 10.4 bcd Dwarf mahaleb 0.20 ab 4.2 bc 28.4 bc 55.0 bc 12.2 bc Small Turkish 0.15 ab 0.3 cd 26.2 bc 57.3 abc 16.1 abc P2 Small leaf 0.20 ab 0.5 cd 15.7 cd 62.7 ab 20.9 ab P50 0.07 ab 11.7 a 31.4 bc 49.1 bc 7.7 cd Standard mahaleb 0.00 b 2.8 bc 28.0 bc 52.2 bc 17.0 abc Standard Mazzard 3.07 a 10.2 ab 44.8 ab 36.1 c 5.8 d x Percentage data arcsin transformed for analysis although actual means are shown ; mean separation within columns by Duncan = s Multiple Range test , P = 0.05 . y Fruit maturity was evaluated visually by assigning fruit to one of four color stages as follows : on a scale of 3 - 6 ( light red - dark mahogany ) , with light red ( 3 ) , dark red ( 4 ) , mahogany ( 5 ) and dark mahogany ( 6 ) , corresponding to CTIFL color chips 1 , 3 , 6 and 7 , respectively . y Table 6 . Survival of Mahaleb clones budded in 1996 with > Bing = clone IR 83 - 2 - 5 ( planted in 1998 at Site 3 , UCDavis ) . Survival as percentage of number planted 1998 % Survival in % Blown over x Clone nursery Spring 2001 11 / 9 / 99 10 / 6 / 00 9 / 14 / 01 9 / 12 / 02 9 / 02 / 03 159 - 5 96 30 70 70 60 60 60 155 - 1 33 33 100 100 100 100 100 156 - 5 100 71 80 70 60 60 60 162 - 1 68 20 70 70 50 30 30 136 - 2 71 40 70 50 40 40 17 141 - 1 70 50 90 60 60 40 40 163 - 1 55 40 90 70 60 60 60 294 - 3 81 30 80 80 50 40 40 295 - 3 64 25 78 33 11 11 11 297 - 2 80 33 62 62 62 62 62 299 - 3 77 56 80 70 60 50 50 759 - 2 83 60 80 80 60 40 40 758 - 1 88 43 100 100 100 100 80 10 - 4 83 33 70 70 50 50 30 11 - 4 80 25 75 75 75 75 75 NY 34 75 30 90 90 90 50 50 P1 Large leaf 78 20 90 90 80 80 80 Dwarf mahaleb 92 20 100 80 20 20 20 Medium Turkish 100 33 67 67 67 67 67 Small Turkish 67 17 83 83 83 83 83 P2 Small leaf 83 20 100 100 60 60 60 Colt 20 100 100 40 40 40 Standard mahaleb 40 60 60 50 50 50 Standard Mazzard 50 20 20 20 20 20 x % Blown over as a percentage of those reps alive Spring , 2001 . y Tree death in 1999 was due to lack of rooting ; no Phytophthora - related deaths were found . Tree death in 2001 appeared to be primarily due to being blown over or gopher damage . Table 7 . Mahaleb clones at Site 3 , UCDavis ; evaluation of bloom abundance , ( 2002 , 2003 ) , earliness of bloom ( 2002 ) and leaf out , ( 2002 ) . Z Bloom abundance 2002 Y X Clone 2002 2003 Earliness of bloom Leafout 159 - 5 5.8 ab 2.7 b - g 27.1 bc 2.7 155 - 1 4.5 b 1.7 e - h 1.5 c 2.0 156 - 5 6.3 ab 2.7 b - g 26.2 bc 2.0 162 - 1 5.1 ab 3.5 a - d 44.9 abc 2.3 136 - 2 2.7 b 4.0 ab 80.0 a 2.3 141 - 1 5.2 ab 1.6 fgh 69.8 ab 2.2 163 - 1 5.0 ab 3.2 a - e 41.3 abc 2.0 294 - 3 6.1 ab 2.0 d - h 25.9 bc 2.5 295 - 3 4.4 b 2.2 c - h 39.7 abc 2.3 297 - 2 4.6 b 1.8 e - h 64.2 ab 2.4 299 - 3 4.4 b 1.6 fgh 41.0 abc 2.4 759 - 2 4.5 b 2.0 d - h 25.8 bc 2.3 758 - 1 4.7 ab 2.7 b - g 29.3 bc 2.0 10 - 4 5.0 ab 3.8 ab 54.5 ab 2.2 11 - 4 3.0 b 3.7 abc 80.0 a 3.0 NY 34 3.9 b 2.2 c - h 42.4 abc 2.7 P1 Large leaf 4.1 b 1.8 e - h 62.0 ab 2.5 Dwarf mahaleb 8.3 a 3.0 b - f 25.8 bc 2.2 Medium Turkish 3.0 b 4.5 a 15.0 bc 2.0 Small Turkish 4.0 b 3.6 abc 68.0 ab 2.8 P2 Small leaf 5.6 ab 2.8 b - g 38.6 abc 2.4 Colt 2.6 b 1.3 gh 64.4 abc 2.4 Standard mahaleb 5.7 ab 3.0 b - f 39.3 abc 2.2 Standard Mazzard 5.7 ab 1.1 h 27.1 bc 2.5 ns W Mean separation within columns by Duncan = s multiple range test , P = 0.05 ; ns = non significant . X Leafout rating : 0 = no vegetative bud break , 4 = full leafout , fully filled canopy . Y Earliness of bloom : of those floral buds present , what percentage have opened , 80 % = full bloom . Z Bloom abundance : 2002 B 0 = 0 to few floral buds apparent and expanded , 9 = dense distribution of floral buds , all expanded ; 2003 B 1 = 0 to 20 % of canopy filled with open buds , 5 = 81 to 100 % of canopy filled with open buds . Table 8 . Rooted cuttings of mahaleb clones budded in 1999 with > Bing = clone IR 83 - 2 - 5 ( planted February , 1999 at Site 5 , Stockton , CA ) ; survival and trunk cross - sectional area ( TCSA ) . 2 # Trees surviving TCSA ( cm ) Clone # Planted 4 / 6 / 00 11 / 9 / 01 11 / 26 / 02 10 / 18 / 00 11 / 9 / 01 11 / 26 / 02 X 156 - 5 7 7 7 7 241.5 c 567.9 c 786.5 d 163 - 1 7 7 7 6 264.3 c 581.4 c 908.5 cd 295 - 3 7 7 7 7 247.4 c 653.3 c 1040.7 c NY 34 7 7 7 7 274.5 bc 661.2 c 1554.1 a P1 Large leaf 6 6 6 6 266.4 c 634.0 c 1047.2 c Small Turkish 7 7 7 7 320.4 a 795.8 b 1037.8 c Standard mahaleb 7 7 7 7 259.8 c 671.6 c 1270.7 b Colt 7 7 7 7 310.5 ab 1048.5 c 914.5 a X Mean separation by Duncan = s multiple range test , P = 0.05 .