Rootstock Combinations Research Articles

The effectiveness of using various types of stimulating substances for the propagation of clonal rootstocks of pome crops in arid zone conditions

The purpose of the research is to identify the effectiveness of the use of various stimulating substances on the economic and biological parameters of plants of clonal apple rootstocks in the conditions of the arid zone of the Northern Caspian Sea (Astrakhan region). The objects were apple tree clonal rootstocks, scion and rootstock combinations. In the mother plantation of vertical layering, 10 breeding forms of rootstocks selected by various scientific institutions were studied. The control was the M series rootstocks, widely used and adapted in the south of Russia: M-9 for dwarf ones, M-26 for semi-dwarf ones, MM-106 for medium-sized ones. In a vertical mother plantation, there were studied variants for leaf treatments with Etamon Bio and Aminovit (control - treatment with water). Average for 2021–2023 foliar treatments significantly contributed to the high yield of first-grade rootstocks for rootstock forms 87-7-12 – 35.4 %; ‘Ural 8’ – 18.0 %; M-26 – 15.0 %; ‘Ural 5’ – 14.0 %; rootstock ‘Malysh Budagovskogo’ – 20.3 % in the variant with Etamon Bio treatment. In the variant with Aminovit treatment, the most number of first-grade layerings were obtained from the rootstock form 87-7-12 – 36.3 %; ‘Ural 8’ – 19.5 %; ‘Malysh Budagovskogo’ – 23.0 %. Foliar feeding with Etamon Bio and Aminovit had a positive effect on the length of the root system, an increase in the diameter of the trunk and an increase in the height of the rootstocks. In the first field of the nursery, the varieties were grafted onto rootstocks of varying vigor. The drugs for study were root formation stimulants Zircon; Ribav Extra; Kornevin. As a result, in comparison with the control, the survival rate of all rootstocks treated in the Zircon root formation stimulator was 100 %.

Grafting onto Tomato Rootstocks Improves Outcomes for Dry-farmed Tomato

Vegetable grafting can mitigate the negative effects of drought on crop production. Dry farming, which is the production of crops without irrigation during a dry growing season, can result in lower yields, smaller fruit, and a higher incidence of blossom-end rot (BER), which is a physiological disorder associated with drought stress. To determine the effects of grafting on yield and fruit quality of dry-farmed tomato (Solanum lycopersicum), three years of trials were conducted using different scion–rootstock combinations and ungrafted controls. In 2020, grafting onto rootstocks ‘DRO141TX’ and ‘Fortamino’ resulted in greater total yield and average fruit weight and a lower BER incidence for dry-farmed tomato than grafting onto the rootstock ‘Shincheonggang’ or using ungrafted plants. In 2021, grafting onto the rootstock ‘DRO141TX’ again increased yields and average fruit weight and decreased BER incidence when compared with ungrafted plants (‘Fortamino’ was not tested). Interactions were detected between different scion–rootstock combinations in terms of the degree of reduction of necrotic BER (BER resulting in a large, sunken, grey or black spot, making the fruit unmarketable) when grafted onto ‘DRO141TX’, with the scion ‘Azoychka’ having a 69% reduction in necrotic BER and the scion ‘Astrakhanskie’ having a 93% reduction in necrotic BER. In 2022, an interaction was detected between the rootstocks and scions in terms of their effect on large fruit (>0.33 lb) yield, with ‘BHN 871’ grafted onto ‘Fortamino’ producing the highest yields of large fruit and ‘Big Beef’ grafted onto ‘Fortamino’ producing the lowest yields. Overall, grafting onto the rootstocks ‘DRO141TX’ or ‘Fortamino’ improved diverse dry-farmed tomato outcomes in the Willamette Valley of Oregon, USA.

Effects of cultivar, planting density and rootstock on long-term economic performance of apple orchards in the Northeastern U.S.

An economic analysis of profitability using Net Present Value (NPV) was conducted using data from two long-term training system × rootstock field trials conducted in New York State from 2006 to 2016 (Dressel Farm in southeastern New York State and VandeWalle Farm in Western, New York State). We used trial data for the first 11 years and estimated values for years 12–20 using average data from the last 4 years of field data. The field trials compared four training systems with different planting densities (Slender Pyramid, 840 trees ha−1; Vertical Axis, 1282 trees ha−1; Slender Axis, 2244 trees ha−1; and Tall Spindle, 3262 trees ha−1) each evaluated with several rootstocks in an incomplete factorial treatment list and with two cultivars at each location. By the end of the trial (11 years) all combinations of planting density, rootstock and cultivar were profitable (NPV positive) at the VandeWalle site but at the Dressel site seven combinations of rootstock and planting density with ‘Fuji’ and two combinations with ‘Gala’ were not profitable. Projected profitability over 20 years using estimated yields and fruit quality for years 12–20 showed that all combinations would be profitable by year 20. Estimated 20-year NPV was greatest with the Tall Spindle system with the highest planting density compared to the other lower density systems. Economic performance was mostly driven by planting density, regardless of the rootstock selection. Among cultivars, ‘Honeycrisp’ had significantly higher profitability largely due to high fruit price). ‘Gala’ had intermediate profitability due to high yields and medium fruit price while ‘Fuji’ which had low fruit price had significantly lower profitability than ‘Gala’. Among rootstocks, there was a significant interaction with training system and cultivar, so the same rootstock was not the most profitable with every cultivar and system. With ‘Fuji’ the most profitable combination was on G.16 rootstock planted at the highest density, however, it was not significantly better than with G.11 or M.9. With ‘Gala’ at Dressel farm the most profitable combination was on G.11 in the Tall Spindle system (planted at the highest density) but it was not significantly better than with G.16, G.41, M.9 or B.9. With ‘Gala’ at VandeWalle farm the most profitable combination was on G.41 planted at the highest density but it was not significantly better than on G.11, G.16, M.9 or B.9. With ‘Honeycrisp’ the most profitable combination was on M.9 planted at the highest density but it was not significantly better than G.11, G.16, G.41 or B.9. A sensitivity analysis showed that among economic parameters affecting the long-term profitability of an orchard, fruit price and yield were vastly more important than other factors. Of intermediate importance were the discount rate and labor costs while of much lesser importance were tree costs and land costs.

Rootstocks on the Nutritional Status of Seedlings of the Main Mango Cultivars of the São Francisco Valley

ABSTRACT Mango is the fruit most exported by Brazil, with a significant increase in cultivated area in recent years. However, the orchards have been made up of seedlings produced by the grafting process, but without identifying the most suitable rootstock for each cultivar, which affects the competitiveness of mango farming, since the rootstock affects, among other factors, the growth and nutrient absorption from the canopy cultivar. The objective of this study was to evaluate the nutritional status and mineral nutrition of ‘Palmer,’ ‘Tommy Atkins,’ ‘Kent’ and ‘Keitt’ mango seedlings grafted onto the polyembryonic rootstocks Capucho, Coquinho and Espada. The experiment was carried out between October 2019 and May 2020 at the Fruit Growing Nursery of the Agricultural Sciences Campus of the Federal University of Vale do São Francisco (UNIVASF), in Petrolina-PE, in a 3 × 4 factorial scheme, corresponding to three polyembryonic rootstocks (Espada, Capucho and Coquinho) and four crown cultivars (‘Palmer,’ ‘Keitt,’ ‘Kent’ and ‘Tommy Atkins’), with five replications of ten plants each. Leaf contents of macronutrients (N, P, K, Ca), micronutrients (Cu and Fe) and silicon depend on the scion (Tommy Atkins, Palmer, Keitt and Kent) x rootstock (Espada, Capucho and Conquinho) combination. The leaf contents of S, Mg, B, Mn and Mo in the scion are affected by the rootstock adopted for mango propagation In general, for macro and micronutrient absorption purposes, the sword rootstock and the ‘Keitt’ cultivar are the best combination for most of the variables analyzed in the research. The effect of rootstock on the nutritional status of scion cultivars (Tommy Atkins, Palmer, Keitt and Kent) must be taken into consideration when interpreting crop nutrition.

Effects of different dwarfing interstocks on the rhizosphere, endophytic bacteria, and drought resistance of apple trees

Rootstock is commonly used to enhance plant resistance to drought stress. However, it is necessary to investigate the effects of different rootstock, interstock, and scion combinations on rhizosphere and root endophytic bacteria under drought stress. We conducted a pot experiment to investigate how interstock [SH40, Jizhen 1 (J1), and Jizhen 2 (J2)] affects the drought tolerance and nitrogen (N) uptake and utilization of apple trees under drought stress. The results showed that the total dry weight, total chlorophyll content, carotenoid content, photosynthesis rate, and N absorption and utilization efficiency of apple trees decreased significantly, whereas relative electrolyte leakage increased significantly under drought stress. Membership function analysis showed that the apple plants with the J1 interstock had the greatest drought resistance. In addition, drought treatment significantly affected the diversity and composition of rhizosphere and root endophytic communities in all three rootstock/interstock/scion combinations. Further analysis revealed that the relative abundance of the plant pathogen Ralstonia was significantly increased in J2 drought-treated roots, compared to the other groups, whereas those of some potentially beneficial bacteria (0134_terrestrial_group, Phenylobacterium, Ellin6067, Kribbella, Chloronema, and Streptomyces) increased significantly in the J1 drought-treated sample. Co-occurrence network analysis showed that some potentially beneficial bacteria (Ellin6067, S0134_terrestrial_group, Pedomicrobium, and Subgroup_10) were significantly positively correlated with N content. These modifications of the rhizosphere and endophytic bacterial communities may influence the drought resilience and N uptake efficiency of different combinations of interstocks and scions. This study is a much-needed step towards understanding the stress response mechanism of scion–rootstock combinations.

Effect of different rootstocks and scion ages on the productivity of screenhouse grown tomato (Solanum lycopersicum)

This study aimed to assess the impact of utilizing diverse rootstocks grafted with scions of varying ages on the growth, yield, and fruit quality of tomatoes. Employing a Completely Randomized Design (CRD), the experiment featured three replications per treatment in a two-factor design. Results revealed that a 30-day-old scion exhibited a highly significant difference in tomato height gain at 15 and 30 days after transplanting (DAT) and statistically mirrored the performance of a 21-day-old scion at 60 DAT. A 25-day-old scion grafted onto wild eggplant demonstrated the greatest height gain among grafts but did not surpass the height of non-grafted tomatoes. Notably, the 30-day-old scion significantly influenced tomato height at 15 and 30 DAT. The 25-day-old scion of wild eggplant exhibited the highest height gain but failed to surpass the non-grafted tomatoes. A 21-day-old scion of eggplant yielded the highest plant and 240 sqm-based tomato yields. Interaction analysis revealed that a 30-day-old scion of eggplant produced the highest yield. Additionally, the 25-day-old scion of wild eggplant resulted in the largest fruit diameter, while the 21-day-old scion of black nightshade displayed the highest sugar content. Different scion and rootstock combinations yielded varying percentages of fruit color. Optimal profitability was achieved with a 30-day-old scion of eggplant, offering the highest net income, while the highest return on investment (ROI) was achieved with a 21-day-old scion of wild eggplant. Findings emphasize the importance of carefully selecting scion age and rootstock combinations to optimize tomato growth, yield, and quality, ultimately enhancing profitability in tomato cultivation.

Scion–Rootstock Combination Determines Pruning Responses in Young Almond Trees

Almond growers are seeking ways to reduce costs but maintain yield. Intensive planting systems with greater planting densities using trees on growth-controlling rootstocks, combined with mechanical pruning and shake-and-catch harvesting are becoming popular. In this study we examined the responses of six almond cultivars with distinctive architecture grafted onto five rootstocks with varying degrees of vigor control. Trees were planted in 2018 in a nursery row and left to grow without pruning until Winter 2021. Pruning involved a rudimentary hedging treatment akin to mechanical pruning. Branching and tree structure were recorded in 2020, before pruning, and again at the end of 2021, after one season’s growth following pruning. A rating system was developed to record qualitative data on central leader dominance and the number, length, basal diameter, and, in some cases, branching angle of axillary shoots and including scaffold branches. Relatively few changes were recorded in the basic growth habit of these trees in response to pruning. Before pruning, the most common rootstock effect was on axillary shoot production. After pruning, the most common rootstock effects were on scaffold branching and the length of subterminal axillary shoots. Further studies are required to determine how these differences produced by the interaction between pruning and rootstock may affect the productivity of fruit-bearing trees. Although in this study with young trees we were not able to record crop yield, the results highlight that it is mainly the scion–rootstock combination, with or without pruning, that determines the potential productivity of fruiting canopies. Scion–rootstock combinations that produce narrow upright canopies naturally with strong central leader dominance and highly branched canopies are preferred for superintensive growing systems with or without use of mechanical hedging.

Adaptability of variety and rootstock combinations of peach and nectarine in the Russia subtropics

The article presents the results of research into a collection of peaches and nectarines cultivated at the Federal Scientific Research Center of the Russian Academy of Sciences in Sochi. The experiment was conducted in open ground, plot area is 0.5 hectares, planting pattern is 5x2.5m, 5x2, 5x1.5m. In 2019, the Center’s assortment was replenished with 28 variety-rootstock combinations of peach and nectarine based on eight varieties (Pamyat Simirenko, Redhaven, Zolotoy Yubiley, Osenniy Rumyanets, Obilny, Orion, Pyatnitsa 13, Silver Roma) of different ripening periods on four clonal rootstocks: Kuban 86, BP, Best, VVA. The physiological and biochemical characteristics of variety-rootstock combinations of peach and nectarine, resistant to abiotic factors in the humid subtropics of Russia, have been studied. The object of study is peach leaves. Physiological analyzes were carried out in the plant physiology and biochemistry department using classical methods: water deficiency of peach leaves was determined according to Pochinok; tissue hydration - according to Gunar; water holding capacity - according to Arland; dry matter - by drying in a drying cabinet to constant weight. Leaves were collected from June to August. Agricultural technology is generally accepted for peach culture. Brown forest soils. It has been established that the best varieties of peach and nectarine in terms of ability to retain water during the dry period are: Redhaven (AP), Pyatnitsa 13 (AP), Pyatnitsa 13 (Best), Pyatnitsa 13 (BP) with low water deficit (11.06-4. 78%) and high water-retaining system of leaves (64-76%). They were distinguished by an increase in the turgor of leaf tissues to 66.33-69.27%, which is considered a sign of plant adaptability to disturbances in the water-thermal regime.

Features of growth and production processes in own-rootedand grafted cherry plum trees

In 2022-2023, a comparative study of the growth and productivity of own-rootedand grafted cherry plum trees planted in 2020 according to the 5×2 m scheme was conducted at the Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery. The objects of research are plants of the varieties ‘Shatyor’, ‘Zlato Skifov’ and ‘Kubanskaya Kometa’, own-rooted and grafted on clone rootstocks SVG-11-19 and 13-113. Differences in biometric indicators in own-rootedand grafted trees of all studied varieties have been established. The height of trees at the age of 5 years varied depending on the graft -rootstock combination from 2.0 (‘Zlato Skifov’/SVG-11-19) up to 3.1 m (‘Shatyor’/13-113). The height of the own-rootedtrees was 15-20 % less than that of the trees grafted on the rootstock 13- 113. The ‘Kubanskaya Kometa’ and ‘Shatyor’ varieties showed a significant decrease in height when grafted on the SVG-11-19 rootstock. The trees of the ‘Zlato Skifov’ variety (less than 2.1 m) were the weakest in the experiment. Differences in the length of annual increments and leaf area were revealed. The productivity of cherry plum trees in the initial period of fruiting depended both on varietal characteristics and on the method of growing planting material. The most productive variety was a Shatyor with a load yield of more than 11 kg/der. The greatest differences in productivity, depending on the rootstock, were noted in the ‘Kubanskaya Kometa’ variety: from 7.3 to 12.9 kg/der. The average productivity of trees of the ‘Zlato Skifov’ variety did not exceed 5.5 kg/der. The ‘Kubanskaya Kometa’ and ‘Shatyor’ varieties have an advantage in productivity in trees grafted on the SVG-11-19 rootstock compared to own-rootedones. The fruits of own-rootedtrees of all varieties were smaller than those grafted on the rootstock SVG-11-19. To increase the yield of the ‘KubanskayaKometa’ and ‘Shatyor’ varieties, seedlings grafted on the SVG-11-19 rootstock should be used. For a low-growing variety of ‘Zlato Skifov’, the optimal result can be obtained when planting plantings, both with own-rootedseedlings and grafted on rootstock 13-113.

The influence of quince rootstock forms on the survival and growth of pear varieties in the nursery

Pear is an important cash crop, the quality, variety and types of which vary depending on the place of growth. It is believed that undersized rootstocks not only simplify the technology of its cultivation, but also accelerate the entry into fruiting. Currently, the selection of existing high-quality varieties compatible with low-growing rootstocks is a serious problem faced by gardeners growing this crop. The aim of the study was to identify the compatibility of local adaptive pear varieties with rootstock forms of quince and to study the biometric indicators of rootstock-graft combinations when grown in a nursery. The assessment of the impact of undersized quince rootstocks on the survival and development of local pear varieties in the nursery was carried out according to generally accepted methods from 2016 to 2022. The study of the parameters of accretion and development of the components of graft was evaluated visually. Biometric data were obtained by instrumental and computational methods from a random sample of healthy plants. The most promising variety – rootstock combinations in the nursery were identified, their biometric parameters were determined and a visual assessment of compatibility in the nursery was carried out. According to all the studied indicators, the best rootstock for pear varieties was the form of quince rootstock No. 1.

Effects of Rootstock and Location on Open Field ‘BHN 589’ and ‘Nebraska Wedding’ Grafted Tomato Yield

Grafted tomato (Solanum lycopersicum) production is popular, particularly in high tunnels, because grafted plants can mitigate soilborne disease incidence in highly infested soils and increase water and nutrient use efficiency and crop yield and quality. However, these potential benefits are not as well documented in open field production systems with less disease pressure. The objective of this study was to quantify the effect of tomato grafting on fruit yield, number, and size across 2 years (2018 and 2019) and three diverse open-field production environments in Nebraska (Lincoln, North Platte, and Dwight). At each location, a scion from one of two determinant fresh market tomatoes, ‘Nebraska Wedding’ (heirloom) or ‘BHN 589’ (commercial hybrid), were grafted onto one of two rootstocks, ‘Estamino’ and ‘Maxifort,’ and the nongrafted scion cultivars were controls. In year 2, a fertilizer treatment was introduced (0 and 50 kg·ha−1 N). Ripe tomatoes were harvested weekly, sorted as marketable or cull, counted, and weighed fresh. No marketable or total yield benefits of grafting were observed in 2018 for any scion by rootstock combination across locations. Marketable yield of grafted plants was reduced by 32% in Lincoln. However, grafted ‘Nebraska Wedding’ plants (regardless of rootstock) in North Platte (with coarse-textured, lower organic matter soil) increased fruit number (but not yield) by 50% to 63%. In 2019, grafting ‘BHN 589’ to ‘Maxifort’ increased total tomato yield by 24% across all locations. The heirloom variety Nebraska Wedding did not benefit from grafting in 2019. ‘Estamino’ rootstock did not increase tomato yield, number, or size for either scion variety in either year. Nitrogen fertilizer increased yield as expected in 2019, but grafted plants did not perform better than nongrafted under reduced nitrogen fertility. Results from this study suggest that grafting is not consistently beneficial to ‘BHN 589’ and ‘Nebraska Wedding’ in open field production systems in Nebraska, particularly if there are no known soilborne disease issues.

Evaluation of Natural Spring Freeze Tolerance of Five Pecan Scion–Rootstock Combinations

Pecan [Carya illinoinensis (Wangenh.) K. Koch] is a member of the Juglandaceae family. During spring, pecan trees break their bud dormancy and produce new leaves and flowers. Carbohydrates stored in roots and shoots are thought to support the bloom and early vegetative growth during this time until new leaves start the full photosynthetic activity. Spring freeze is known for its damaging effects on pecan bud and flower growth and development. Pecan shoots with leaves and flowers from five scion–rootstock combinations were collected hours before and after a recent spring freeze (below 0 °C for 6 hours, 21 Apr 2021, Perkins, OK, USA). Morphologies of the leaf, bud, and catkin were visually observed, and the morphologies of the anther and pollen in paraffin sections were investigated by light microscopy. Soluble sugar and starch from bark and wood were analyzed using the anthrone reagent method. The Kanza–Mount showed the maximum damage to terminal leaves, buds, and catkins, whereas Maramec–Colby had the minimum damage only to leaves. Pollen grains were shrunk and reduced in number in the anthers in the protandrous Pawnee scions, whereas no pollen damage was observed in the protogynous Kanza scion. Furthermore, bark soluble sugar levels increased in all the scion–rootstock combinations after the freeze, which may indicate a physiological response to the cold stress. Overall, the extent of spring freeze damage of pecans is affected by the growth stage, types of scion and rootstock, and the scion–rootstock interactions. Furthermore, in addition to low temperature, scion–rootstock interactions also affected the starch and soluble sugar contents in wood and bark tissues.

Performance of grafting loquats combined onto loquat and quince rootstocks on different dates

This study was carried out during February 20 to July 1, 2023, at the lath house in the College of Agricultural Engineering Sciences, University of Sulaimani, Kurdistan Region, Iraq, and aimed to investigate the impact of rootstock type and grafting time on grafting success of loquat on two rootstocks, loquat and quince, which were used for grafting the local selection cultivar of loquat at three different times (February 20, March 10, and March 30) during the dormant season. The experiment was laid down in a factorial Randomized Complete Block Design (RCBD), involving 6 treatments, each with 5 grafts and 3 replications, resulting in 90 grafts. Data analysis was performed using analysis of variance (ANOVA), and means were separated using Duncan’s multiple range tests (P≤0.05). The loquat and quince rootstocks were grown through seed sowing and cuttings, respectively. Cleft grafting was employed as the grafting method, ensuring the cambium layers of the scion and stock in contact. Grafting success percentage, shoot length, shoot diameter, number of leaves per budling, leaf area, and chlorophyll content were evaluated. Results showed that loquat rootstock exhibited a significantly higher grafting success percentage (97.78%) compared to quince rootstock (84.44%). Regarding vegetative traits, loquat rootstock resulted in significantly longer shoots (11.74 cm) compared to quince rootstock (8.08 cm). The same rootstock showed a higher number of leaves per budling (8.47) and chlorophyll content (43.82 SPAD). Also, the highest significant grafting success percentage (100%) was achieved from the combination of loquat rootstock and two grafting times (February 20 and March 30). The combination of rootstock type and grafting time led to varying shoot characteristics.

The selection of intra-inter specific Cucurbita rootstocks for grafted melon seedlings

This study was conducted to select promising Turkish local Cucurbita rootstocks among intraspecific and interspecific hybrids for grafted melon seedling based on hybrid success rate, hypocotyl traits and graft compatibility. Rooting potentials, root system architecture and plant growth parameters of the rootstocks grafted with melon were also evaluated. Two lines of C. maxima (male parent) and eleven lines of C. moschata (female parent) at S5 generation were used. In addition, six winter squash lines were used as male parent and six pumpkin lines were used as female parent in intraspecific hybridization program. Intraspecific hybrid combinations had quite high number of seeds per fruit as compared to interspecific hybrid combinations. The highest number of seeds per fruit was obtained from HMO2 × OMO2 (359) and OMO5 × HMO8 (314) hybrid combinations. Hypocotyl lengths of all hybrid cucurbit rootstock combinations ranged from 32.96 mm (RS17) to 73.35 mm (RS8) and hypocotyl thicknesses ranged from 2.71 mm (RS2) to 3.55 mm (RS8). Graft success rates varied between 96.6 – 100% in winter squash and pumpkin intraspecific hybrids and between 87.1 – 100% in interspecific hybrids. Significant differences were seen in root architecture parameters (root length, root volume, mean root diameter, root surface area and root dry matter weight) of intraspecific and interspecies hybrid Cucurbita lines. The findings of the study indicated that the intraspecific and interspecific local cucurbit rootstock candidates developed within the rootstock breeding program showed promise as viable options for commercial use as rootstocks for grafted melon seedlings. Research about the effects of selected intraspecific and interspecific hybrid Cucurbita rootstock candidates on earliness, fruit quality and yield parameters of grafted melon will continue.
 Keywords: Cucurbita maxima; Cucurbita moschata; Rootstock breeding; Root system architecture; Melon

Leaf proteomic profiles in cacao scion-rootstock combinations tolerant and intolerant to cadmium toxicity

Cd contamination in cacao beans is one of the major problems faced by cocoa producing countries in Latin America. Cacao scion-rootstock combinations influence the Cd accumulation in the shoot of the plant. The objective of this work was to carry out a comparative analysis between cacao scion rootstock combinations (CCN 51/BN 34, CCN 51/PS 13.19, CCN 51/PH 16 and CCN 51/CCN 51), contrasting for tolerance to cadmium (Cd) toxicity, by means of leaf proteomic profiles, in order to elucidate molecular mechanisms involved in tolerance to Cd toxicity. Cacao scion-rootstock combinations were grown in soil with 150 mg Cd kg−1 soil, together with the control treatment. Leaf samples were collected 96 h after treatments were applied. There were alterations in the leaf proteome of the cacao scion-rootstock combinations, whose molecular responses to Cd toxicity varied depending on the combination. Leaf proteomic analyzes provided important information regarding the molecular mechanisms involved in the tolerance and intolerance of cacao scion-rootstock combinations to Cd toxicity. Enzymatic and non-enzymatic antioxidant systems, efficient for eliminating ROS, especially the expressions of APX and SOD, in addition to the increase in the abundance of metalloproteins, such as ferredoxins, rubredoxin, ALMT, Trx-1 and ABC-transporter were key mechanisms used in the Cd detoxification in cacao scion-rootstock combinations tolerant to Cd toxicity. Carboxylic acid metabolism, glucose activation and signal transduction were also important processes in the responses of cacao scion-rootstock combinations to Cd toxicity. The results confirmed CCN 51/BN 34 as a cacao scion-rootstock combination efficient in tolerance to Cd toxicity.

Effect of Different Rootstocks and Scions Compatibility Study on Rosa sp

An investigation entitled, “Effect of different rootstocks and scion compatibility study on Rosa sp.’’ was conducted to study the graft compatability and growth performance of grafted rose plants and the experiment was conducted in Vegetable Research Station, Tamil Nadu Agricultural University, Palur, Cuddalore district, Tamil Nadu during the year 2022. It was carried out using completely randomized design (CRD) with fifteen treatments (T1- Andhra red rose + Dog rose, T2-Andhra red rose + Button rose, T3-Andhra red rose + Ebb tide rose, T4- Andhra red rose +Fairy rose, T5- Andhra red rose + Edward rose, T6- Edward rose+ Dog rose, T7-Edward rose + Button rose, T8-Edward rose+ Ebb tide rose, T9-Edward rose + Fairy rose, T10-Edward rose+ Edward rose, T11-Damask rose + Dog rose, T12-Damask rose + Button rose, T13-Damask rose + Ebb tide rose, T14-Damask rose+ Fairy rose, T15-Damask rose+ Edward rose) and two replications. The results indicated a significant difference between the different treatment combination for graft union, success percentage, survival percentage, plant height (cm), leaf length (cm), leaf width (cm), days taken for leaf initiation. The experiment data revealed that the maximum graft success (90) and graft survival percentage (80), length of leaves (3.9 cm) and plant height (67.6) was recorded in the treatments T7 (Edward rose + Button rose). It can be concluded that the combination of rootstock as Edward rose and scion as Button rose is said to be most compatible and can be recommended for commercial cultivation.

Saline-Alkaline Stress Resistance of Cabernet Sauvignon Grapes Grafted on Different Rootstocks and Rootstock Combinations.

Grafting the wine grape variety Cabernet Sauvignon onto salinity-tolerant rootstocks can improve salinity tolerance and grape yields in regions with high salinity soils. In this experiment, the effects of different rootstocks and rootstock combinations on the saline-alkaline stress (modified Hoagland nutrient solution + 50 mmol L-1 (NaCl + NaHCO3)) of Cabernet Sauvignon were studied. Correlation and principal component analyses were conducted on several physiological indicators of saline-alkaline stress. Salinity limited biomass accumulation, induced damage to the plant membrane, reduced the chlorophyll content and photosynthetic capacity of plants, and increased the content of malondialdehyde, sodium (Na+)/potassium (K+) ratio, and antioxidant enzyme activities (superoxide dismutase, peroxidase, and catalase). Significant differences in several indicators were observed among the experimental groups. The results indicate that the saline-alkaline tolerance of Cabernet Sauvignon after grafting was the same as that of the rootstock, indicating that the increased resistance of Cabernet Sauvignon grapes to saline-alkaline stress stems from the transferability of the saline-alkaline stress resistance of the rootstock to the scion.

Evaluation of pruning therapies in apple trees with fire blight

Ten experiments were conducted to evaluate the efficacy of methods to therapeutically remove fire blight cankers from apple trees with different age, vigor, training system and rootstock combinations in Washington, Oregon, Pennsylvania and New York, United States. Removal methods included pruning at varying distances from visible symptoms, utilization of a sanitizing agent and the use of a stub cut to minimize cankers on structural wood. Fire blight removal resulted in reductions of rootstock blight and tree death. Removal treatments resulted in fewer additional cankers compared to the no-treatment control in most trial sites and years. The standard best management practice (BMP) for removing fire blight was branch removal at 30 cm below the proximal edge of visibly cankered tissue with sanitized loppers. This practice significantly reduced the number of new systemically-caused symptoms compared to the no-treatment control in seven of nine experiments with significant reductions in five experiments. Aggressive removal, defined as BMP but branches removed approximately 76 cm from the proximal edge of visibly cankered tissue, generally did not improve the standard practice. Elimination of cutting tool sanitation did not result in more cankers than the standard practice. Breaking off diseased branches by hand provided a rapid removal method, but it resulted in a greater number of cankers in the orchard at the end of the season. In one of five experiments cutting which left a 13 cm stub distal to structural wood significantly reduced the number of cankers on structural wood compared to flush cut or 4 cm stubs.

Leaf chlorophyll contents in some European pear cultivars grafted on different rootstocks and its relation with growth and yield

Aim of study: To investigate the effect of different combinations of pear rootstocks and cultivars on the contents of leaf photosynthetic pigments and their relation with some growth and yield characteristics. Area of study: Ondokuz Mayis University, Samsun, Türkiye, in two years, 2021 and 2022. Material and methods: The pear cultivars ‘Santa Maria’, ‘Williams’, and ‘Deveci’ were grafted on eight rootstocks: two quince clonal rootstocks (BA29 and QA), five pear clonal rootstocks (FOX9, FOX11, OH×F333, OH×F87, FAROLD40) and Pyrus communis L. seedlings. Growth and yield attributes were calculated and chlorophyll and carotenoid contents were determined by the spectrophotometric method, using 99.8% methanol solvent for chlorophyll (chl) extraction. Main results: Chl a/b in the case of rootstocks, chl a and total carotenoids in the cultivars were found statistically significant; the ratio chl a/b ranged 1.71-2.30 in the case of rootstocks; in the case of cultivars chl a ranged from 17.77 (cv. ‘Santa Maria’) to 19.88 (cv. ‘Deveci’) μg mL-1, and carotenoids ranged 0.21-0.95 μg mL-1. Under the main impact of cultivars, rootstocks and their combinations, a significant difference was seen in the growth and yield attributes. Research highlights: A negative correlation coefficient was observed between photosynthetic pigments and morphological characteristics; however, the correlation coefficient was positive for canopy volume and annual shoot growth. Canopy management, especially with the use of rootstocks and cultivars that result in weaker growth, is helpful for improving chlorophyll content and yield performances.

The Effect of PGPR Applications on Bioactive Content and Fruit Characteristics of Different Apple Scion–Rootstock Combinations

The Effect of PGPR Applications on Bioactive Content and Fruit Characteristics of Different Apple Scion–Rootstock Combinations