CAB 11E Research Articles

THE INFLUENCE OF CONTROLLED ATMOSPHERE AND ROOTSTOCK ON THE QUALITY OF 'VAN' SWEET CHERRY

The effect of storage regimes - normal atmosphere (NA) and different kinds of controlled atmospheres (CA, = 2.5% O 2 + 10% CO 2 ; CA 2 = 2.5% O 2 + 15% CO 2 ; CA 3 = 2.5% O 2 + 20% CO 2 ) -, 4 rootstocks (Gisela 5, Prunus avium, CAB 11E and Maxma 14) and two harvest dates (June 12 and 16, 2003) on the quality of 'Van' sweet cherries were evaluated. One sample from each rootstock and harvest date was prepared and some sub-samples were analyzed at the laboratory, while the other sub-samples were stored at 0.5°C (±0.5) for 42 days, both in NA and CA. At the end of the storage period, all sub-samples were analyzed for fruit quality, using objective and subjective analyses. Storage regime, rootstock and harvest date significantly influenced all the studied parameters of quality: fruit weight, firmness, titratable acidity, soluble solids content, skin colour (L * C * H°), stem colour (L s *a s *) and sensory attributes. Fruit size, titratable acidity, L * (Lightness), and C * (Chroma) were higher on fruits from more vigourous rootstocks (Prunus avium). Fruits from trees on Prunus avium were the ones to have better appearance and taste after storage. The tasting panel considered that the fruits stored in controlled atmosphere (CA 2 ) had better quality and that fruits from harvest 2 were more attractive after storage than those of harvest 1.

Effect of Rootstocks on Growth and Yield of 'Carmen' ® Sweet Cherry

Rootstock evaluation for sweet cherry is still important, especially for new cultivars, since there are specific reactions known in productivity. 'Carmen' is a new promising Hungarian sweet cherry cultivar of moderate vigor so there is a need of information on growth and yielding performance on different rootstocks. In 2001 rootstock trial was planted with 'Carmen' in high density conditions: spacing is 4x2 m and the trees are trained to Hungarian spindle. The following rootstocks are tested: Prunus mahaleb seedlings CEMA (C500), clonal P. mahaleb SL 64, Bogdany, Egervar, Magyar; interspecific hybrids: Colt, Brokgrow (MaxMa 97), P. cerasus CAB 11E. The orchard is planted on light sandy soil, lime content is around 2.5 %, pH 7.7 and the soil compactness index (KA) is 24. The climate is typical to the central Hungarian flatland, yearly average temperature is 11.3 C, total sunshine is 2079 hours in a year, and rainfall is 560 mm/year. The trial is planted in randomized blocks; one plot consists of three trees, repeated four times. Based on the results the rootstocks significantly affected the tree growth, the cumulative yield and the single fruit weight. Largest trees are grown on Prunus mahaleb seedling CEMA (C500), followed by Egervar, Bogdany, and SL 64. Trees are moderate vigorous on Magyar, CAB 11E, Colt and Korponay. Smallest tree size was measured on Brokgrow (MxM 97). Best producing trees are on moderate vigorous Magyar and CAB 11E but the productivity of vigorous Egervar and CEMA was close to them.

Variation in xylem structure and function in roots and stems of scion–rootstock combinations of sweet cherry tree (Prunus avium L.)

To assess hydraulic architecture and limitations to water transport across scion–rootstock combinations (Prunus avium L. cultivar Van grafted on five differing size-controlling rootstocks: P. avium (vigorous) > CAB 11E > Maxma 14 > Gisela 5 > Edabriz (dwarfing)), we compared xylem anatomy, and calculated relative hydraulic conductivity (RC) and vulnerability index (VI) of roots (small, medium and large diameter) and stems. Water relations, leaf gas exchange and variations in growth were also determined. Roots exhibited larger-diameter xylem conduits (VD), greater RC and VI than stems in all Van–rootstock combinations. Moreover, there was a significantly higher vessel frequency (VF), lower VD, RC and VI in dwarfed trees, especially grafted on Gisela 5 than trees on the invigorating rootstocks, P. avium L., CAB 11E and Maxma 14. Anatomical constraints on water status imposed by the smaller VD (and/or in lower xylem thickness and root system length) of dwarfed trees imply a series of negative feedbacks, like a decrease in RC, stem water potential, leaf gas exchange and growth. On the other hand, Van grafted on CAB 11E and Maxma 14, with wide vessels and high VI, could be more susceptible to embolism, especially during periods of severe water stress, than trees on dwarfing rootstocks, which had small vessels and low VI.

Scion-rootstock interaction affects the physiology and fruit quality of sweet cherry

Water relations, leaf gas exchange, chlorophyll a fluorescence, light canopy transmittance, leaf photosynthetic pigments and metabolites and fruit quality indices of cherry cultivars 'Burlat', 'Summit' and 'Van' growing on five rootstocks with differing size-controlling potentials that decrease in the order: Prunus avium L. > CAB 11E > Maxma 14 > Gisela 5 > Edabriz, were studied during 2002 and 2003. Rootstock genotype affected all physiological parameters. Cherry cultivars grafted on invigorating rootstocks had higher values of midday stem water potential (Psi(MD)), net CO(2) assimilation rate (A), stomatal conductance (g(s)), intercellular CO(2) concentration (C(i)) and maximum photochemical efficiency of photosystem II (PSII) (F(v)/F(m)) than cultivars grafted on dwarfing rootstocks. The Psi(MD) was positively correlated with A, g(s) and C(i). Moreover, A was positively correlated with g(s), and the slopes of the linear regression increased from invigorating to dwarfing rootstocks, indicating a stronger regulation of photosynthesis by stomatal aperture in trees on dwarfing Edabriz and Gisela 5. The effect of rootstock genotype was also statistically significant for leaf photosynthetic pigments, whereas metabolite concentrations and fruit physicochemical characteristics were more dependent on cultivar genotype. Among cultivars, 'Burlat' leaves had the lowest concentrations of photosynthetic pigments, but were richest in total soluble sugars, starch and total phenols. Compared with the other cultivars, 'Summit' had heavier fruits, independent of the rootstock. 'Burlat' cherries were less firm and had lower concentrations of soluble sugars and a lower titratable acidity than 'Van' cherries. Nevertheless, 'Van' cherries had lower lightness, chroma and hue angle, representing redder and darker cherries, compared with 'Summit' fruits. In general, Psi(MD) was positively correlated with fruit mass and A was negatively correlated with lightness and chroma. These results demonstrate that: (1) water relations and photosynthesis of sweet cherry tree are mainly influenced by the rootstock genotype; (2) different physicochemical characteristics observed in cherries of the three cultivars suggest that regulation of fruit quality was mainly dependent on the cultivar genotype, although the different size-controlling rootstocks also had a significant effect.

ROOTSTOCK AND STORAGE REGIME INFLUENCE ´SUMMIT´ CHERRY QUALITY

An investigation was conducted on the effect of 4 rootstocks and storage regimes - normal cold storage (NCS) and different kinds of controlled atmospheres (CA 1 = 2.5% O 2 + 10% CO 2 ; CA 2 = 2.5% O 2 + 15% CO 2 ; CA 3 = 2.5% O 2 + 20% CO 2 ) on the quality of 'Summit' sweet cherries. Fruit samples were harvested on June 12, 2003. One sample from each rootstock was harvested, and some sub-samples were analysed at the laboratory while the other sub-samples were stored for 42 days, both in NCS and CA. At the end of the storage period, all sub-samples were analysed for fruit quality, using objective and subjective parameters. Rootstock and storage regime significantly influenced all of the quality parameters: fruit weight, firmness, juice pH, titratable acidity, soluble solids content, skin colour (L*C*H°) and stem colour (L s *a s *). Fruit size and titratable acidity were higher on invigorating rootstocks. Fruit ripened later on Gisela 5, with firmness, pH juice and L*C*H° or a s * values being higher than those of fruit from the other rootstocks. Soluble solids content was higher after NCS than after CA. Fruits stored under CA 3 maintained a better objective quality. Fruits from trees on Cab 11E ripened earlier and were more attractive after storage. Tasting panels did not distinguish between fruits from CA 3 or CA 2 .

Flower and Foliar Analysis for Prognosis of Sweet Cherry Nutrition: Influence of Different Rootstocks

This research was aimed to study the interest of flower analysis as a tool for the prognosis of nutritional deficiencies on cherry trees and confirm the influence of rootstock on the mineral uptake by tree. This type of diagnosis is compared with foliar analysis. The trial was established on a calcareous clay-loam soil, where ‘Sunburst’ cultivar on eight rootstocks: CAB 6P, CAB 11E, Masto de Montañana 9 (MM 9), MaxMa 14, MaxMa 97, GM 61/1 (Damil), Colt and Sainte Lucie GF 64 (SL 64). The mineral elements analyzed were nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), manganese (Mn), zinc (Zn), sodium (Na), and copper (Cu). Rootstock influence on mineral nutrient uptake was observed for all mineral elements studied in flowers and for N, P, K, Ca, Mg, Fe, Mn, and Cu in leaves. The N, Ca, and Mn concentrations in flowers and leaves were significantly correlated, being more noticeable the correlation between leaf and flower Mn concentration (r = 0.86; p ≤ 0.01). A significant correlation was also found between the yield of the following year and element concentration in leaves. In general, the P. cerasus rootstocks (CAB 6P, CAB 11E, and MM 9) showed values of leaf mineral elements more adequate, and also higher values of leaf chlorophyll concentration.

Sweet cherry (Prunus avium) growth is mostly affected by rootstock and much less by budding height

The effects of several rootstocks and budding heights upon the growth of three cherry (Prunus avium) cultivars were investigated during the first 4 years of growth. The trial was established in 1998 in north‐east Portugal using ‘Burlat’, ‘Summit’, and ‘Van’ cultivars grafted onto Edabriz, Gisela 5, and Maxma 14 at 10, 20, and 30 cm above soil level, and onto Cab and Prunus avium (Mazzard) at 10, 30, and 60 cm above soil level. Total shoot length and trunk diameter were recorded at transplantation from the nursery and at the end of the 3rd leaf stage in the orchard. As early as at transplantation, the effects of budding height, rootstock, rootstock × budding height interaction, and cultivar were significant in the trunk cross‐sectional area (TCSA), being responsible for 11.6%, 9.6%, 9.3%, and 7.8% of the total variance, respectively. At the 3rd leaf stage, 79.2% of the expected variance was attributable to rootstock, and 4.1 % to budding height. TCSAs of the trees on Edabriz, Gisela 5, Cab 1 1E, and Maxma 14 were, respectively, 30%, 32%, 62%, and 74% of those on Mazzard. Increasing budding height decreased tree vigour for all the rootstocks. In the nursery, it was already noticeable that vigour reductions between extreme budding levels were evident, first on the rootstock Cab 11E (44%) and then in Gisela 5 (35%), Edabriz (22%), and P. avium (20%). In the 3rd year in the orchard, tree TCSA reduction on Edabriz and Gisela 5 was 30% and on Maxma 14 it was 15%, when comparing buddings made at 10 and 30 cm. The reduction for the trees on Cab 11E and P. avium was 24%, when comparing buddings made at 10 and 60 cm. In our trial conditions the rootstock was the main influencing factor on plant growth and budding height was revealed to be the second most determinant factor on tree growth, irrespective of rootstock vigour. Consequently, budding height, although not so decisive in dwarfing as with apple and pear trees, can contribute to cherry tree growth and can also control and help to manage canopy size and crop rentability.

Effect of pruning and plant spacing on the growth of cherry rootstocks and their influence on stem water potential of sweet cherry trees

SummaryThe aims of this work are to describe the effects of pruning and planting density on growth and water relations of ungrafted and grafted sweet cherry trees. A trial with cherry rootstocks ‘Prunus avium’, ‘CAB 11E’, ‘Maxma 14’, ‘Gisela 5’ and ‘Edabriz’ was begun in 1997. Pruning severities were applied to the rootstocks (0, 30, 60 and 90% of the vegetative growth was removed corresponding to P1, P2, P3 and P4 treatments, respectively) after planting to two plant spacings (S1 = 0.25 × 1.0 m and S2= 0.45 × 1.5 m). Canopy, root growth and leaf water potential (ψleaf) were quantified throughout the growing season. Pruning significantly affected root length and root weight of the rootstocks. Uncut plants (P1) showed a heavier and expanded root biomass (231 g and 108 m) than the intensively pruned plants (P4) (187 g and 75 m). The greater root biomass was obtained with the spacing/pruning combination, S1/P1 (285 g), and the smaller with S1/P4 (180 g) and S2/P4 (176 g). ψleaf varied significantly between the rootstocks and plant spacing but not with pruning. ‘Maxma 14’ and ‘P. avium’ attained the lowest values of midday ψleaf, –2.28 and –2.04 MPa, but the highest values of predawn ψleaf, –0.29 and –0.25 MPa, respectively. Generally, with high density (S1), the rootstocks exhibited lower predawn and midday ψleaf. In 1998, cultivars ‘Burlat’, ‘Summit’ and ‘Van’ were grafted onto rootstocks and a trial was installed in 1999. Predawn and midday stem water potential (ψstem) on cherry trees, measured in 2002, were affected significantly by the rootstock/genotype combination. Cultivars grafted on ‘P. avium’ and ‘Maxma 14’ showed the less negative midday ψstem, –1.36 and –1.42 MPa respectively, so these rootstock genotypes perhaps induced a higher drought resistance to the scion. Recorded data show that the scion-rootstock interaction with regard to production performance under water deficits may be an important consideration in cherry tree planting strategies.

Performance of ‘Sunburst’ sweet cherry grafted on different rootstocks

SummaryThe field performance of CAB 6P, CAB 11E, ‘Colt’, GM 9 ('Inmil'), GM 61/1 (‘Damil’), GM 79 (‘Camil’), Masto de MontanÄana 9 (MM 9), MaxMa 14, MaxMa 97 and Sainte Lucie GF 64 (SL 64) rootstocks grafted with one sweet cherry cultivar (P. avium ‘Sunburst’), were compared for the first nine years after planting. The orchard was located on a calcareous clay-loam soil, which was level-basin irrigated. While no trees of CAB 6P, ‘Colt’, ‘Damil’, MM 9, and MaxMa 97 rootstocks died, most of the trees on ‘Inmil’ and ‘Camil’ did die. ‘Damil’ proved to be the most dwarfing and low-yielding rootstock, whilst ‘Colt’, MM 9 and CAB 6P were the most invigorating rootstocks, although differences with CAB 11E and SL 64 by the ninth year after planting were not significant. An intermediate level of vigour, shown on MaxMa rootstocks, could indicate a semi-dwarfing potential for these selections. In general, P. cerasus rootstocks (CAB 6P, CAB 11E and MM 9) promoted greater cumulative yields and better yield efficiency than the other rootstocks. Leaf mineral analysis of trees showed element concentrations close to the optimum for the trees grafted on P. cerasus rootstocks, and they were better than for trees on ‘Damil’ and ‘Colt’. Leaf chlorophyll concentration, estimated by SPAD readings, was also generally higher for the trees on P. cerasus rootstocks. According to our results, the P. cerasus selections seem to be the best adapted rootstocks for cherry cultivars in heavy and calcareous soil conditions, under flood irrigation. However, they had the highest number of root suckers. The growing conditions were not favourable for the cherry rootstocks ‘Camil’, ‘Damil’ and ‘Inmil’.

Orchard response of micropropagated sour cherry and apple cultivars

The field performance of sour cherry and apple tissue-cultured (TC) trees has been investigated in comparison with standard-propagated (SP) trees. In sour cherry, TC trees were compared with trees grafted on mazzard and on the clonal rootstock cultivars ‘Colt’, CAB 6P and CAB 11E. The TC trees were the less productive and had the lowest production efficiency. The canopies of all the trees reached the same size at the end of the fifth season in the field. The CAB 6P clonal rootstock appeared the most interesting for high yield and good fruit size. In apple, the TC trees were the most vigorous and had the same cumulative production (1981–1986) as the trees on MM106 because of high yields from TC trees in 1985 and 1986. A noticeable difference between TC trees and those on MM106 existed in production efficiency and canopy size in favour of the trees on MM106. Only in 1986 the TC trees lost the juvenile character shown in the early years in the field.

The effect of paclobutrazol on in vitro rooting, transplant establishment and growth of fruit plants

The effect of paclobutrazol on in vitro rooting and growth of sour cherry (Prunus cerasus) rootstock CAB 11E clone, of S 749 × S 1490 (Prunus persica × Prunus kansuensis) hybrid rootstock, and of pear (Pyrus communis), cv. Abbe Fetel is reported. PP333 increased rooting of S 749 × S 1490 and of Abbe Fetel, particularly at a concentration of 0.5 mg/l (a.i.); moreover, it induced a rooting percentage as high as auxin in the former and hastened rooting of the latter. By contrast, paclobutrazol did not affect root production of 11 E. PP333-treated plants had shorter and thicker roots than controls but similar survival rates during acclimatization. Otherwise they grew less than controls during the first part of the acclimatization phase.

An alternative approach to plant regeneration from protoplasts of sour cherry ( Prunus cerasus L.)

Mesophyll protoplasts, of sour cherry ( Prunus cerasus), clones CAB 4D, CAB 5H and CAB 11E, gave differential cultural responses. Protoplasts in media based on Murashige and Skoog (MS) salts, supplemented with 9% (w/v) mannitol plus growth regulators underwent cell wall regeneration, cell colony and callus formation. Zeatin (Z) was needed in order to induce cell division for all three sour cherry clones. The protoplast-derived calli, of clones CAB 4D and CAB 5H, underwent rhizogenesis as an intermediate step towards shoot bud differentiation. Clone CAB 5H also gave direct shoot bud regeneration from the protoplast callus.

Storage of in vitro cultures of Prunus rootstocks

In vitro cultures of three Prunus clones (d. 1869, GF 677 and CAB 11E) were successfully stored at +8°, +4° and-3°C following the proliferation phase. Survival of cultures was dependent upon interactions of storage temperature, light, and age of subculture. Up to 100% of the cultures survived at the end of the trials after 170 (at +4°C) and 200 (at-3°C) days storage. Complete dardness appeared more suitable than 16-h (hour) photoperiod for successful storage at-3°C for up to 10 months. One or two weeks in normal growth room vefore storage at-3°C for up to 10 months. One or two weeks in normal growth room before storage enhanced the survival S-1. The proliferation of the cultures following storage at-3°C in the first subculture appeared similar to those under standard growth room conditions. Part of the results were presented as a poster at the 10th Congress of Eucapia in Wegeningen, The Netherlands, 19–24 June 1983.