Influence Of Rootstocks Research Articles

Influence of rootstock on the productive behaviour of ‘Orange Red’ apricot under Mediterranean conditions

Introduction. 'Orange Red' is an apricot cultivar released in the United States and characterised by large fruit of very good quality for both the fresh market and processing. For this reason, this cultivar is greatly appreciated in Europe, especially in France. However, its production is erratic under Mediterranean climate conditions. Materials and methods. The influence of two rootstocks ('Manicot' apricot and 'GF31' Myrobolan plum) on the pro- ductive behaviour of 'Orange Red' was studied under Mediterranean conditions in Murcia (Southeast Spain). Results and discussion. 'Orange Red' grafted onto 'GF31' Myrobolan flowered slightly later than those grafted onto 'Manicot' apricot. However, differences in the date of ripening of fruits were small. On the other hand, the percentage of flower bud reten- tion and levels of floral fertility were higher when 'Orange Red' was grafted onto 'GF31' than onto 'Manicot', resulting in higher yields and fruits with a smaller weight. The increase in flower bud retention of 'Orange Red' grafted onto the rootstock 'GF31' was the main factor responsible for the increase in yield observed with this rootstock. Conclusion. Interaction between the cultivar and rootstock is presented as an interesting strategy for cultivar adapta- tion to different climatic areas. Spain / Prunus armeniaca / climatic factors / rootstocks / graft compatibility / flowers / fruit / yields

Produtividade e qualidade dos frutos da laranjeira 'Pêra' clone IAC em 16 porta-enxertos na região de Bebedouro-SP

Avaliou-se a influência de 16 porta-enxertos na produtividade, nas características físicas e químicas (sólidos solúveis totais-°Brix; acidez; ratio; porcentagem de suco; índice tecnológico e tamanho dos frutos) dos frutos da laranjeira 'Pêra' [Citrus sinensis (L.) Osbeck] e na incidência e severidade da clorose variegada dos citros (CVC). O plantio do experimento foi realizado em julho de 1993, com espaçamento de 6,0 m entre linhas e 3,5 m entre plantas (476 plantas/ha). O experimento foi conduzido sem irrigação. O delineamento experimental foi em blocos ao acaso, duas plantas por parcela, três repetições e 16 tratamentos, constituídos pelas seguintes cultivares porta-enxertos: tangerineira 'Sun Chu Sha Kat' (Citrus reticulata Blanco), tangerineira 'Pectinífera' (C. reticulata), 'Shekwasha' (C. depressa Hayata), tangerineira 'Pectinífera/Shekwasha' (C. depressa Hayata), tangerineira 'Batangas' (C. reticulata), tangerineira 'Oneco' (C. reticulata), citrangor [citrange (Poncirus trifoliata Raf. x C. sinensis) x C. sinensis], citrandarin [C.sunki hort. Ex Tanaka) x Poncirus trifoliata (L.) Raf. cv. English, tangerineira 'Sunki' (C. sunki), tangerineira 'Suen-Kat' (C. sunki), tangerineira 'Nasnaran' (C. amblycarpa Ochse), tangerineira 'Venezuela' (C. reticulata), tangerineira Heen Naran (C. lycopersicaeformis hort. ex Tan. ), limoeiro 'Cravo' (C. limonia Osbeck) x tangerineira 'Cleópatra' (C. reshni hort ex Tanaka), limoeiro 'Cravo' (C. limonia), tangerineira 'Cleópatra' (C. reshni). A intensidade da clorose variegada dos citros variou em função dos porta-enxertos e não se relacionou com a produção de frutos até a quarta safra. Os porta-enxertos estudados, com exceção da tangerineira Nasnaran, proporcionaram qualidade e produções iniciais de frutos similares aos do limoeiro 'Cravo'.

Influence of rootstock, irrigation level and recycled water on growth and yield of Soultanina grapevines

Recent studies have revealed complex interactions among grapevine rootstocks, soil water status, and water quality in terms of yield and growth. Understanding these interactions is essential to optimise yield and its quality, especially in regions with limited or degraded water resources. Thus, a study was conducted to investigate the effect of rootstock (41B, 1103P, and 110R), irrigation level (0.50, 0.75 and 1.00 of ET, evapotranspiration), and water quality (fresh and recycled water) on vegetative characteristics and on yield quantitative and qualitative components of potted Soultanina vines for a 3-year-period. Vine growth was inhibited by irrigation with recycled water and that inhibition became more severe by increasing the irrigation level and from one season to the next season. Furthermore, recycled water reduced yield by 50% and grape juice from these vines exhibited higher pH and titratable acidity values and lower total soluble solids. Rootstock significantly affected shoot growth, an effect which varied with age and within the growing season. Vines grafted on 41B developed more leaf area and produced higher yield than vines grafted on the other two rootstocks. Decreasing in the irrigation level dramatically reduced all vegetative parameters without affecting fruit quality and yield components. A significant interaction was detected between rootstock and irrigation level in terms of yield. Vines on 41B produced the highest yield of vines irrigated at 1.00 ET, and produced higher yields than vines grafted on 110R when irrigated at 0.75 ET, but the differences in yield among rootstocks disappeared at the 0.50 ET level.

Influence of rootstock, irrigation level and recycled water on water relations and leaf gas exchange of Soultanina grapevines

The effects of rootstock variety (41B, 1103P and 110R), irrigation level (0.50, 0.75 and 1.00 of the evapotranspiration) and water quality (recycled versus freshwater) on water relations and gas exchange of potted Soultanina grapevines were investigated during two growing seasons. An early reduction of predawn leaf water potential ( Ψ pd) was detected for vines irrigated with recycled water in both the seasons. However, assimilation rate ( A) and stomatal conductance ( g s) were reduced only late in the first year at higher irrigation levels. This was consistent with the higher reduction of Ψ pd at these treatments indicating that the development of a water deficit due to salt accumulation reduced gas exchange. At midday during 1998, leaves on vines grafted on 1103P and 110R had lower leaf water potentials and higher g s and A. An opposite effect was however observed early in June the following season, although later in that season no differences were detected among rootstocks. That differentiation of rootstock effect between seasons may have been induced by alterations in source/sink relations due to differences in yield among rootstocks and its effects on leaf area. Irrigation level strongly affected water relations and gas exchange. Both A and g s were significantly correlated with soil moisture. A differentiation in these relations was observed among rootstocks late in 1998 which probably resulted from the change in leaf area development among rootstocks during that period.

Comparison of nutritional efficiency among hydroponic grafted young coffee trees for N, P, and K

Grafted Coffea arabica L. plants were grown hydroponically in a greenhouse for an evaluation of their nutritional efficiency under the influence of different rootstocks. Four C. arabica genotypes were used as scions: 'Catuai Vermelho IAC 15', 'Oeiras MG 6851', and lines H 419-10-3-1-5, and H 514-5-5-3. The three latter are cultivars resistant to the Hemileia vastatrix, pathogen of the orange rust. Rootstocks were three genotypes of Coffea canephora Pierre et Froenher: Apoata LC 2258, Conilon, and Robustao Capixaba (Emcapa 8141), and one C. arabica genotype: Mundo Novo IAC 376-4. Rootstocks Apoata LC 2258 and Mundo Novo IAC 376-4 were outstanding. Cultivars Conilon and Robustao Capixaba did not increase the nutritional efficiency of the scions. 'Oeiras' and H 419-10-3-1-5 had considerable nutrition efficiency when used as non- grafted plants.

Scions influence apparent transpiration efficiency of Vitis vinifera (cv. Shiraz) rather than rootstocks

Carbon isotope discrimination (D) is used to determine differences in apparent transpiration efficiency amongst genotypes of many C3 plant species. In this present study the possible influence of certain commercially-available rootstocks on apparent transpiration efficiency in grapevines was investigated. Variation in was studied for Shiraz and each of six rootstock varieties when grown either (1) on their own roots, (2) with Shiraz grafted as a scion onto different rootstocks (conventional graft) or (3) with rootstock varieties grafted onto Shiraz roots (reciprocal graft). When grown on own roots or as a reciprocal graft, there was significant variation in D. In contrast, there was no significant variation in D for Shiraz (as a scion variety) when grafted onto different rootstock varieties (conventional graft). These results imply a predominance by the scion genotype in determining variation in the leaf-level physiological characteristics that determine apparent transpiration efficiency under well-watered (and non-saline) conditions.

Eficiência de absorção, translocação e uso de cálcio, magnésio e enxofre por mudas enxertadas de Coffea arabica

O estudo da eficiência nutricional de plantas enxertadas de cafeeiro é importante para a seleção de combinações enxerto/porta-enxerto, visando ao desenvolvimento e produção máximos. O presente trabalho teve como objetivo avaliar, em cultivo hidropônico, a eficiência de absorção, translocação e uso de Ca, Mg e S por mudas enxertadas de Coffea arabica L., influenciada pelo porta-enxerto. O experimento foi realizado em casa de vegetação por um período de 170 dias, em vasos que continham areia, como substrato, e solução nutritiva circulante. Utilizaram-se, como enxerto, quatro genótipos de Coffea arabica L.: as variedades Catuaí Vermelho IAC 15 e Oeiras MG 6851 e as linhagens H 419-10-3-1-5 e H 514-5-5-3, e, como porta-enxerto, três genótipos de C. canephora Pierre et Froenher: Apoatã LC 2258, Conillon Muriaé-1, Robustão Capixaba (EMCAPA 8141) e um genótipo de Coffea arabica L.: Mundo Novo IAC 376-4, além da utilização de quatro pés-francos. Utilizou-se o delineamento experimental de blocos casualizados com quatro repetições. Os contrastes entre médias compararam as mudas de pé-franco com as associações enxerto/porta-enxerto. A eficiência de absorção, translocação e uso de Ca, Mg e S por mudas enxertadas de cafeeiro variou de acordo com a combinação enxerto/porta-enxerto. Somente a eficiência de translocação de Ca não foi alterada pela combinação enxerto/porta-enxerto. A linhagem H 514-5-5-3 foi beneficiada na eficiência de uso de Mg e produção de matéria seca pelos porta-enxertos Mundo Novo IAC 376-4 e Apoatã LC 2258, e na eficiência de uso de Ca e S apenas pelo Mundo Novo IAC 376-4.

Rootstock resistance to Fusarium wilt and effect on watermelon fruit yield and quality

The potential of grafted watermelon for resistance toFusarium oxysporum f.sp.niveum on some Curcurbitaceae,Lagenaria, Luffa, Benincasa and commercial rootstocks was evaluated. Effects of grafting on yield and quality of diseased plants were evaluated. All grafted plants and rootstocks were resistant to the three known races (0, 1, and 2) ofF. oxysporum f.sp.niveum except watermelon cv. ‘Crimson Tide’, which was susceptible to race 2. Fruit yield was positively (21–112%) affected byLagenaria rootstocks but negatively affected (200–267%) byCucurbita rootstocks when compared with the control. While only minor differences in fruit quality were determined in control and grafted plants onLagenaria rootstocks, the quality parameters for watermelon grafted ontoCucurbita rootstocks were lower than in the control. The reasons for low yield and quality might be due to an incompatibility betweenCucurbita rootstocks and watermelon. These results showed that rootstock influence on disease resistance as well as yield and quality of scion fruit is important in determining the potential use of grafting applications in watermelon.

Effect of Apple Rootstocks on Average `Gala' Fruit Weight at Four Locations after Adjusting for Crop Load

The influence of rootstock on average fruit weight was evaluated for a subset of data from a multilocation NC-140 apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] rootstock trial. Data for eight dwarf rootstocks were collected at four locations for 2 years. Analysis of covariance was used to evaluate the effect of rootstock on average fruit weight when crop density or number of fruit per tree was included in the linear model as a covariate. When number of fruit harvested per tree was used as a covariate, average fruit weight was not affected by rootstock in either year in Ontario. In Michigan and Virginia, rootstock and number of fruit per tree, but not the rootstock × number of fruit interaction, were significant, so common slopes models were used to estimate least squares means for average fruit weight. In general, trees on M.27 and P.1 produced the smallest fruit, and trees on B.9, M.9 EMLA, and Mac.39 produced the largest fruit. In New York the interaction of rootstock × number of fruit was significant, so least squares means were estimated at three levels of number of fruit per tree. Both years, at all levels of number of fruit, trees on M.26 EMLA produced the smallest fruit and trees on M.27 EMLA produced the largest fruit. Average fruit weight was most affected by number of fruit per tree when Mark was the rootstock. In general, results were similar when crop density was used as the covariate, except that trees on M.27 EMLA did not produce small fruit in Michigan and Ontario.

Crop Load and Rootstock Influence on Dry Matter Partitioning in Trees of Early and Late Ripening Peach Cultivars

Effect of crop load on dry matter partitioning was studied on 3-year-old peach [(Prunus persica (L.) Batsch (Peach Group)] trees of the early ripening `Early May Crest' (EMC) grafted on `GF677' and Penta (Prunus domestica L.) rootstock and the late ripening `Flaminia' grafted on `GF677' rootstock [(Prunus persica × Prunus dulcis (Mill.) D. A. Webb] and grown outdoors in 230-L containers, for 2 years. Fruit thinning was carried out 10 days after fruit set to produce different crop loads. Trees were sampled destructively throughout two growing seasons and divided into above-ground and root components, for dry matter and carbohydrate analysis. At the end of the fruit development period, in the first year, total tree dry matter accumulation was related linearly to crop load even when the increase in crop load greatly decreased vegetative and root growth. Total dry matter accumulation was highest in EMC/`GF 677' at any specific crop load, and EMC trees on `GF677' allocated relatively more dry matter than EMC/`Penta' trees to vegetative and root growth, even under increasing fruit sink demand. Two consecutive years of heavy crops resulted in an inverse relationship between crop load and dry matter accumulation of trees, due to a major reduction of vegetative, root, and fruit growth. The percentage of dry matter partitioned to fruit decreased with the vigor of the rootstock, and EMC/`Penta' trees had the lowest harvest index at each specific crop load. The early ripening EMC/`GF677' trees which had twice the harvest index of `Flaminia'/`GF677' trees for any level of crop load. `Flaminia'/`GF677' trees had the largest canopy size. Starch content in the roots was lowest for cropping trees and depended on the rootstock and on the length of the fruit development period, being highest for the late ripening `Flaminia'/`GF677' trees. Individual fruit weight decreased with crop load, and the reduction of fruit size was related to rootstock and time of ripening.

Rootstock Influences Changes in Ion Concentrations, Growth, and Photosynthesis of `Hass' Avocado Trees in Response to Salinity

Effect of salinity (1.5, 3.0, 4.5, or 6.0 dS·m-1) on growth and physiology of 1-year-old `Hass' avocado (Persea americana Mill.) trees on one of three rootstocks, `Thomas', `Toro Canyon', or `Duke 7', was investigated to determine the relative salinity tolerance of these rootstocks and to determine possible reasons for any observed differences in tolerance. Leaves of trees on `Thomas' rootstock had the highest leaf Na+, Cl-, and necrosis compared to trees on the other two rootstocks. Exposure to salinity resulted in decreased growth of shoots on all rootstocks, but was greatest on `Thomas' and least on `Duke 7'. The oldest leaves on all rootstocks had the highest proportion of leaf necrosis, whereas younger leaves exhibited almost no necrosis. Salinity reduced net CO2 assimilation (A) and chlorophyll concentrations of scion leaves on all rootstocks, but more in older leaves than in younger leaves. Although the effects of salinity on A were greater for trees on `Thomas' on one measurement date, overall, rootstock differences in A were not significant for any leaf age. Differences in response to salinity among rootstocks were noted primarily in morphological traits such as growth and leaf necrosis, rather than physiological traits such as gas-exchange and water relations. Based on overall growth and physiological response to salinity, trees on `Thomas' performed poorest, whereas trees on `Duke 7' exhibited the greatest salt tolerance. The relative tolerance of the various rootstocks appeared to be due primarily to their ability to exclude Na+ and Cl- from the scion.

THE EVALUATION AND CLASSIFICATION OF GROWTH VIGOR OF THE PLUM CULTIVARS GRAFTED ON VARIOUS ROOTSTOCKS

The research activity carried out over a 30 years period by SCDP Valcea on the behavior of plum cultivars grafted on various rootstocks emphasized and allowed an evaluation of scion-rootstock relation and especially the modifications produced over the growth vigor of plants. 20 rootstocks were used for this research (7 of P. cerasifera, 3 of P. domestica, 8 of P. insititia and 2 interspecific hybrids). Seven of the rootstocks were vegetatively propagated. All the 15 cultivars used are P. domestica type. The growth vigor of the scion–rootstocks biosystem is one of the cultivars' characteristics affected by the rootstock influence. This phenomenon has a special importance for choosing and using of the most adequate culture systems of the European plum. The rootstocks used have different growth vigor and specific when are grown on own roots. This vigor proved determinant for the scion– rootstock system. The evaluation of the growth vigor of the grafted cultivars on various rootstocks allowed a classification of the rootstocks into five classes depending on the growth vigor. Inside each class, a scale from 1 to 3 was set up. Rootstocks were grouped as dwarf (none of the rootstocks), semi–dwarf (P. besseyi x americana, 'Saint Julien A', 'Pixy', 'Otesani 8', 'Voinesti B'), medium ('Gogosele galbene', 'Molive', 'Otesani 11', 'Rosior varatic'), vigorous ('Myrobalan galben', 'Gogosele negre'), very vigorous ('Marianna GF 8-1', and all the P. cerasifera rootstocks). The grouping of the rootstock into vigor classes allows a new vision on the European plum culture.

Influence of Nitrogen and Rootstock on Tree Growth, Precocity, Fruit Quality, Leaf Mineral Nutrients, and Fire Blight in `Scarlet Gala' Apple

The influence of four rootstocks and four levels of nitrogen supply on tree growth, precocity, fruit quality (size and color), leaf mineral concentrations, and fire blight [Erwinia amylovora (Burrill) Winstow et al.] severity in `Scarlet Gala' apple (Malus domestica Borkh.) trees was studied between 3 to 4 years. Trees that received an annual ground application of 0.15 lb (68 g) actual N as urea over four growing seasons had greater trunk cross-sectional area (TCA), higher yield, better fruit color, lower leaf N and less fire blight than those which received higher amounts of N. Trees on Malling (M.9) were more precocious and had higher yields in early years while trees on Malling-Merton 106 (MM.106 EMLA) and Malling-Merton 111 (MM.111 EMLA) had higher production 4 years after planting. Trees on Malling 26 (M.26 EMLA) had higher leaf Mg than those on other rootstocks. Trees on M.9 and M.26 EMLA had more fire blight damage than those on other rootstocks.

Influence of rootstocks on fruit drop in Kinnow mandarin under dense planting.

Influence of rootstocks on fruit drop in Kinnow mandarin under dense planting.

Performance of Eight Apomictic Selections as Apple Rootstocks

The apple (Malus ×domestica Borkh.) cultivars Starkspur Supreme Delicious and Melrose were planted in 1987 on eight apomictic apple rootstock selections made in Germany by Dr. Hanna Schmidt and on M.7. Selections 2 [M. hupehensis (Pamp.) Rehd. parentage] and 8 [M. sieboldii (Regel) Rehd. parentage] were similar to M.7 in precocity, cumulative yield per tree, and yield efficiency, while the other selections with M. sargenti Rehd. in their parentage were slower to flower and had lower yields and yield efficiencies. Selections 2 and 8 tended to result in larger trees than M.7, while the selections with M. sargenti parentage were generally similar to M.7 in size. Except for trees on M.7 and selection 2, `Starkspur Supreme Delicious' developed more severe symptoms of internal bark necrosis (IBN) than did `Melrose', which normally does not show IBN. However, `Melrose' showed IBN symptoms on selections with M. sargenti parentage. IBN symptoms were positively correlated with leaf Mn concentrations. Influence of rootstocks on other nutrient elements, although significant, were small compared to the effect on Mn. A significant interaction occurred between cultivar and rootstock in their effects upon branch morphology, mostly because fewer flowering spurs and more vegetative spurs were observed on `Melrose' than on `Starkspur Supreme Delicious' when grafted on Selection 2. These apomictic selections offered no advantage over M.7 as rootstocks for apples.

Leaf-macronutrient content and yield in grafted melon plants. A model to evaluate the influence of rootstock genotype

The melon ( Cucumis melo L.) cultivars Yuma and Gallicum were grafted onto three rootstocks of Cucurbita máxima: Shintoza, RS-841 and Kamel. The two melon varieties left ungrafted were used as control. The plants were grown under controlled conditions and fertilized constantly with both macro- and micronutrients. The total content of macronutrients (N, P, S, K, Na, Ca and Mg) and yield were determined in the aerial portion of both the control and grafted plants. A model was developed to determine the influence of the different rootstocks on the parameters analyzed, based on the differences between the control and grafted plants. Our results show that the use of the different rootstock genotypes causes little change in the leaf content of macronutrients, principally in N and Na. On the contrary, root genotype determined the yield. Finally, we found a strong relationship between the variations in foliar concentrations of N and Na and yield differences in grafted plants.

INFLUENCE OF ROOTSTOCK ON THE MINERAL CONCENTRATIONS OF FLOWERS AND LEAVES FROM SWEET CHERRY

The influence of rootstock on the mineral composition of scion leaves of fruit trees is generally accepted. The present work was carried out to corroborate if this influence is also evident for the mineral nutrient concentrations in flowers. The study was made in an experimental orchard of sweet cherry (Prunus avium, L. cv. ‘Van’) grafted on three rootstocks: Adara, SL 64 and Cok. Flowers and leaves were sampled at full bloom and 60 days after fuil bloom (DAFB) respectively. They were analyzed for nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu). Floral analysis showed that most nutrients were affected by the rootstock. P and Ca, contents behaved similarly for cherry flower and leaf 60 DAFB. The range of variation of K, Mg, and Cu in flowers, among rootstocks, was shorter than that of leaves. In contrast, the range of variation of Na, Zn, and especially Fe, in flowers was longer than that of leaves.

Rootstock Influences Seasonal Dry Matter and Carbohydrate Content and Partitioning in Above-ground Components of `Flordaprince' Peach Trees

Seasonal development of leaf area, leaf area index (LAI), dry matter, and carbohydrate content were measured from harvest 1992 to harvest 1993 in above-ground components of `Flordaprince' peach [Prunus persica (L.) Batsch] trees grafted on GF 677 (Prunus persica × Prunus amygdalus) and MrS 2/5 (Prunus cerasifera free pollinated) rootstocks, which widely differ in vigor. Whole trees were separated into fruit, leaves, shoots, 1-year-old wood and >1-year-old wood. Sampling dates were coincident with key fruit and tree developmental stages: dormancy, fruit set, pit hardening, and fruit harvest. Rootstock modified the vegetative vigor of the tree, the seasonal partitioning of dry matter, and starch content in above-ground components. Leaf area, LAI, and total above-ground dry matter were twice as high in the most vigorous combination (`Flordaprince'/GF 677), which gave the highest yield, but had the lowest harvest index. Rootstock vigor did not affect soluble sugar concentration in any of the canopy components. Starch content was greatest during dormancy and in the oldest wood of GF 677 trees. During fruit development, starch content rapidly decreased in 1-year-old wood and perennial components; at pit hardening it was four times greater in MrS 2/5 than in GF 677 trees. The vegetative-to-fruit dry mass ratio by pit hardening was 3:1 for MrS 2/5 and 9:1 for GF 677 trees. Competition with shoot growth apparently reduced fruit growth, particularly during Stage I and Stage II, as fruit size at harvest was significantly lower (17%) in GF 677 than in MrS 2/5 trees.

Influence of Root Pruning and Rootstock on Growth and Performance of `Golden Delicious' Apple

`Smoothee Golden Delicious' apple trees on nine rootstocks or interstems were mechanically root pruned annually for 9 years beginning the year after planting. Root pruning reduced trunk cross-sectional area (TCA) by 14% over the first 5 years and 22% in the last 4 years of the trial. Yield and fruit size were reduced by root pruning in most years with the fruit size effect obvious in June at the end of cell division. Interstem trees of MAC.9/MM.106 were larger than trees on M.9 and the following interstems: M.9/MM.106, M.9/MM.111, M.27/MM.111. Trees on seedling (SDL) rootstock were the largest and had the lowest yield per unit TCA and lower cumulative yield/tree than trees on M.7, MM.106, and MM.1ll. There was no interaction for any measure of growth or yield between root pruning and rootstock or interstem.

Influence of Rootstock on Seasonal Levels of N and K in Petioles of Two Grape Cultivars

Petioles were gathered at three times during the season: bloom, veraison, and harvest, in two trials `Chardonnay' (Ch) and `Cabernet Sauvignon' (CS). In each trial, scions were grafted onto 14 rootstocks. Petioles were analyzed for NO3-nitrogen, %N, and %K. Averaged over rootstocks, CH petiole NO3 levels were highest at harvest and lower at both bloom and veraison. A similar trend was seen in `Cabernet Sauvignon', although, on average, NO3 levels were higher on all sampling dates. In Ch, the rootstocks `Ramsey', `St George', and `110R' were among the highest in NO3, while Harmony and 1616C were among the lowest. In CS, O39-16 was among the highest in NO3, while 44-53M was among the lowest. In both cultivars and among all rootstocks, petiole NO3 was positively correlated with petiole %N in Ch, petiole K declined throughout the year, while in CS most rootstocks were relatively stable. In Ch, the rootstocks `Harmony', `1616C', and `44-53M' had high levels of K, while in CS `44-53M' was among the highest.