Seedling Rootstocks Research Articles

Effect of chemicals on growth and buddability in rough lemon (Citrus jambhiri Lush) rootstock seedlings under semi arid irrigated ecosystem of Haryana

An experiment was conducted with the objective to advance and enhance the buddabiltiy in rough lemon (Citrus jambhiri Lush) seedlings comprising foliar application of T1 (GA3 50 ppm + Urea 0.5%), T2 (GA3 50 ppm + Urea 1%), T3 (GA3 100 ppm + Urea 0.5%), T4 (GA3 100 ppm + Urea 1%), T5 (NAA 50 ppm + Urea 0.5%), T6 (NAA 50 ppm + Urea 1%), T7 (NAA 100 ppm + Urea 0.5%), T8 (NAA 100 ppm + Urea 1%), T9 (ABA 50 ppm + Urea 0.5%), T10 (ABA 50 ppm + Urea 1% ), T11 (ABA 100 ppm + Urea 0.5%), T12 (ABA 100 ppm + Urea 1%) and T13 (Control) twice after 30 and 60 days after transplanting. Maximum seedling height 95.83cm and numbers of leaves 98.17/plant was measured in treatment T4 (GA3 100 ppm + Urea 1%)at 180 days after transplanting. Maximum stem diameter 7.16mm was measured in treatment T11 (ABA 100 ppm + Urea 0.5%). The highest per cent seedlings 57.14, 76.19 and 95.24% attained buddable stage in treatment T11 at 150 DAT, 165 DAT and 180 DAT respectively. Overall, foliar spray of ABA (100 ppm + Urea 0.5%) twice at 30 and 60 DAT resulted in 57% buddable seedling over control (14%) in rough lemon rootstock 150 DAT.

Fruit Maturity and Quality of Splice-grafted and One-cotyledon Grafted Watermelon

Splice grafting with both cotyledons removed from the rootstock may significantly increase watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] grafting efficiency, eliminate rootstock regrowth, and reduce costs of watermelon transplant production. We evaluated the efficacy of antitranspirant and sucrose treatments on the survival of splice-grafted transplants and assessed the effects of grafting method and rootstocks on fruit yield and quality. First, in a greenhouse experiment, four commercial antitranspirants, applied to rootstock seedlings before splice grafting, increased transplant survival 21 days after grafting (DAG) from 7% to 35% to 68% (P < 0.0001). In a second greenhouse experiment, survival of splice-grafted seedlings was 91% for plants that received 2% sucrose solution + antitranspirant, compared with 67% for plants receiving 2% sucrose alone and 25% for plants that received only water (P < 0.0001). Finally, in a field experiment we compared splice- vs. one-cotyledon grafting with two rootstocks (‘Shintosa Camelforce’ and ‘Tetsukabuto’) vs. nongrafted plants. At 54 days after transplanting (DAT), survival of all grafted transplants averaged 96% with a plant vigor rating of 7.7/10 (10 = most vigorous), compared with 84% survival (5.8/10 vigor rating) for nongrafted transplants. Flowering was delayed by an average of 2 days for splice-grafted watermelon (37 DAT) vs. one-cotyledon grafted and nongrafted plants (P < 0.0001), but harvest date was the same for all treatments (70 DAT). Fruit were harvested 0, 7, and 14 days after fruit reached physiological maturity, and there was no difference in total yield or fruit quality between grafted and nongrafted treatments, with two exceptions. Fruit with splice-grafted ‘Shintosa Camelforce’ rootstock had the firmest flesh (8.2 N) compared with nongrafted transplants (5.3 N), and lycopene increased from 16.7 µg·g−1 at physiological maturity to as high as 31.4 µg·g−1 when harvested 7 days after physiological maturity (P = 0.0002). These results indicate that application of sucrose with antitranspirant to rootstock seedlings before grafting can increase the survival of splice-grafted watermelon, and splice-grafted watermelon perform similarly to one-cotyledon grafted and nongrafted watermelon plants in field production.

Effects of Potassium Levels on Plant Growth, Accumulation and Distribution of Carbon, and Nitrate Metabolism in Apple Dwarf Rootstock Seedlings.

Nitrogen (N) is one of the most required mineral elements for plant growth, and potassium (K) plays a vital role in nitrogen metabolism, both elements being widely applied as fertilizers in agricultural production. However, the exact relationship between K and nitrogen use efficiency (NUE) remains unclear. Apple dwarf rootstock seedlings (M9T337) were used to study the impacts of different K levels on plant growth, nitrogen metabolism, and carbon (C) assimilation in water culture experiments for 2 years. The results showed that both deficiency and excess K inhibited the growth and root development of M9T337 seedlings. When the K supply concentration was 0 mM and 12 mM, the biomass of each organ, root-shoot ratio, root activity and NO3– ion flow rate decreased significantly, net photosynthetic rate (Pn) and photochemical efficiency (Fv/Fm) being lower. Meanwhile, seedlings treated with 6 mM K+ had higher N and C metabolizing enzyme activities and higher nitrate transporter gene expression levels (NRT1.1; NRT2.1). 13C and 15N labeling results showed that deficiency and excess K could not only reduce 15N absorption and 13C assimilation accumulation of M9T337 seedlings, but also reduced the 15N distribution ratio in leaves and 13C distribution ratio in roots. These results suggest that appropriate K supply (6 mM) was optimal as it enhanced photoassimilate transport from leaves to roots and increased NUE by influencing photosynthesis, C and N metabolizing enzyme activities, nitrate assimilation gene activities, and nitrate transport.

Quality of rubber tree rootstock seedlings grown in protected environments and alternative substrates

This study aimed to evaluate the quality of Hevea brasiliensis seedlings, a GT1 clone, produced in protected environments in a variety of substrates. The treatments consisted of 13 substrates composed of combinations of cattle manure, soil from a ravine, medium vermiculite, superfine vermiculite and washed fine sand and two environments: a greenhouse with 50% shade using aluminized screen and a plant nursery with 50% shade using a Sombrite® screen. There were no replications of the environments; therefore, each one was considered an experiment. For each environment, a completely randomized experimental design with five replications was used to evaluate the substrates. Subsequently, the average squares of the residuals of individual variance analyses of these treatments (substrates) were evaluated, and because they did not exceed an approximate ratio of 7:1, a combined analysis of experiments was performed with Sisvar software. Two hundred eighty days after sowing, the dry weight, plant height, stem diameter, diameter at five centimeters above soil and the seedling quality indices were evaluated. Results indicated that substrates with a low amount of manure and sand and a high amount of vermiculite (S9 and S13) produced rubber tree seedlings of high-quality. The environment with greater radiation availability was better for the development of high-quality rubber tree seedlings.

Verification of the Field Productivity of Rehmannia glutinosa (Gaertn.) DC. Developed Through Optimized In Vitro Culture Method.

Rehmannia glutinosa (Gaertn.) DC is a perennial plant belonging to the family Scropulariidae. The root of R. glutinosa is used in oriental medicine and mainly grown using rootstock rather than seed cultivation, which gives rise to several problems including root rot, and results in a low productivity and poor quality. To solve the challenges involved in R. glutinosa seed cultivation, our team previously used the formative features and genetic analysis of R. glutinosa to determine the optimal in vitro tissue culture conditions for producing sterile culture seedlings and rootstocks of R. glutinosa. The aim of the present study was to identify differences between R. glutinosa standard rootstock seedlings (SR), R. glutinosa culture rootstock seedlings (CR), and culture seedlings (CS) under field conditions. The reproductive characteristics of the aerial part were more robust while the area and length of leaves were smaller for SR than those for CR and CS. The characteristic that differed the most in SR was flowering, which did not occur in CR and CS. In addition, the fresh and dry weights of the subterranean parts of CR and CS were two-fold greater than those of SR. Fourier transform near-infrared (FT-NIR) analysis showed only slight differences between the chemical constituents of SR and its culture products, which was confirmed by measuring the content of catalpol, an indexing substance. Catalpol had a reduced content in the culture products compared to SR. However, this difference was not significant. Our findings will be useful for the identification of the best seedling type of R. glutinosa to enable its mass production.

Prediction of N, K and Mg on Leaves of Four Citrus Rootstocks Seedlings Using Hyper Spectral Data

Sufficient application of nutrients is one of the most important factors in the development of seedlings from quality citrus root stocks. Some of the key guides for preparing citrus fertilizer programs is by tracking the nutrient content of plants directly. This includes, however, an examination of a large number of leaf samples using costly and time-chemical techniques. It has been shown over the last 10 years that it is possible to quantitatively estimate such nutrient elements in citrus leaves using the spectral reflectance values obtained using hyperspectral spectroscopy. This technique is quick, non-destructive, cost-effective and eco- friendly. Therefore, estimating nitrogen, potassium, and magnesium in seedling leaves of citrus rootstocks by this approach would be useful in determining the seedlings ' mineral status. In this research,168 leaf samples from four citrus rootstocks seedlings (Volkamer lemon, Sour orange, Trifoliate orange and Balady Lime) were used to conduct three vegetation indices; normalized difference vegetation index (NDVI), normalized difference nitrogen index (NDNI) and modified chlorophyll absorption ratio index (MCARI) and subsequent nutrient estimates for N, K, and Mg concentration. Simple regression models and chemical analysis were used to produce the best model of estimation to predict the values of the three components. A high correlation coefficient (R2) was verified in the estimate of N (R2=0.982) with the lowest root mean square error (RMSE=0.0472) and k (R2=0.983) with the lowest root mean square error (RMSE=0.0491) and the lowest root mean square error (RMSE=0.0062) was also verified.

The nursery value of new Prunus persica seedling rootstocks for peach cultivars

The nursery value of new generative (seedling) rootstocks for peach, marked as BN-1, BN-3, BN-4, BN-7, BN-8, BN-45 was evaluated. The Prunus persica Mandżurska and P. persica Siberian C seedling rootstocks were used as controls. All of the rootstocks were budded with chip-buds of peach ‘Redhaven’ and ‘Inka’. Rootstocks BN-1, BN-3, BN-4, BN-7 and BN-8 showed much better growth in the nursery beds than rootstocks Mandżurska and Siberian C. More maiden peach trees were obtained on rootstocks BN-1, BN-3, BN-4, BN-7 and BN-45 compared to control rootstocks, although only on rootstocks BN-1 and BN-3 the differences were significant. The vigorous growth of rootstocks BN-1, BN-3, BN-4, BN-7 and BN-8 was beneficial to the quality of feathered maiden peach trees. Larger maidens with more laterals were obtained on these rootstocks in comparison to controls. With regards to the evaluated characteristics, the best nursery value showed rootstocks BN-1 and BN-3, even the rootstocks BN-4 and BN-7 are comparable to control rootstocks.

The Effects of Pre-germination Treatments on Seed Germination and Growth of Wild Guavas in the Kingdom of Eswatini, Southern Africa

Dormancy is a condition where seeds will not germinate even when the environmental conditions (water, temperature and aeration) are permissive for germination. Wild guavas (Psidium guajava L.) are very popular in all agro-ecological zones of Eswatini. Farmers have shown an interest towards guava cultivation but have to cope with the shortage of quality propagation material. The demand is not fulfilled because of unavailability of superior seedling rootstocks, which might be due to poor seed germination and seedling growth. Nevertheless, it has been reported that guava seeds exhibited seed dormancy, which affects their growth and development. The experiment was carried out to study effects of different pre-germination methods on seed germination of guava. The study was conducted at the University of Eswatini, Luyengo Campus. The objective of the study was to get maximum germination of guava seeds in as short a time as possible. Four methods were used i.e., soaking in distilled water for five days at room temperature, soaking in hot water at 80ºC for three minutes, subjecting seeds to heat at 80ºC in oven for six minutes and soaking in 20% dilute sulphuric acid for three minutes. All these treatments significantly decreased days to germination of seeds compared with the control. Among the methods, treatment of guava seeds with 20% dilute sulphuric acid for three minutes was judged best with maximum germination percentage (93.3%); lowest germination mean time was observed in seeds soaked in distilled water (31 days). Highest plant height (44 mm) and highest stem girth of (3.37 mm) were recorded from seeds soaked in sulphuric acid after 150 days of sowing. Seeds without any pre-germination treatment showed poor germination (26.7%). On the basis of the findings, it can be recommended that propagators use sulphuric acid in seed priming for higher germination, growth and development.

Florida Citrus Nursery Trends and Strategies to Enhance Production of Field-Transplant Ready Citrus Plants

The Florida citrus industry is going through major changes and considerable replanting. Many growers are planting varieties, especially rootstocks, that are potentially productive under Huanglongbing (HLB; Candidatus Liberibacter asiaticus) prevalent conditions. However, the high demand for new plant material has put tremendous pressure on citrus nurseries and has created a bottleneck in production. Often it can take more than one year to produce field-transplant ready plants in nurseries; therefore, there is a critical need to accelerate plant production. This three-part study was conducted with the following objectives: (1) determine citrus nursery trends; (2) evaluate use of compost for rootstock germination; and, (3) evaluate use of compost for rootstock seedling growth. According to the nursery survey, rootstock seed germination and seedling growth were the most time-consuming, taking 6–8 months. Moreover, it was apparent from the survey results that 44% of the citrus nurseries were experimenting with potting mixes to achieve adequate plant growth and quality. Our greenhouse study demonstrated successful use of yard waste compost in place of peat moss in a potting mix. With use of 37% to 50% of compost in the potting mix, the overall germination rate and mean emergence time were improved to 70% in less than four weeks for US-897 rootstock as compared to no compost in the potting mix. In addition, 37% to 50% compost resulted in higher biomass accumulation in seedlings. When seedlings of rootstocks C-32 and Flying Dragon were grown with 37% to 50% compost, the growth rate and, therefore, percentage of successful budding were significantly increased as compared to no compost. In addition, substrate analysis indicated that a high compost potting media was rich in mineral nutrients, hence the use of fertilizer in nurseries could be minimized. Altogether, use of compost in place of peat moss seems promising and could accelerate germination and growth of rootstocks, reducing the production time as well as cost.

Effects of different fertilizer formulas on the growth of loquat rootstocks and stem lignification

Grafting is a common method of variety propagation in loquat breeding, the slow growth of rootstocks is a main factor limiting the expansion of this technique. This study aimed to evaluate the effects of seven different fertilizer formulas on the growth of loquat rootstock seedlings, five water-soluble fertilizer formulas, as well as organic fertilizer and controlled-release fertilizer were evaluated. An unfertilized control (CK) was also performed. Growth indicators including plant height, stem thickening and lignification, leaf area, root development, dry matter accumulation, spatial distribution of nutrient elements, and cross-sectional anatomy of stem were measured. The results showed that the addition of microelements in fertilizer could significantly delay the lignification process of the cambium, which exhibiting the greatest improvement in stem thickening. Phosphorus nutrition could significantly promote the occurrence of fibrous roots, while excessive phosphorus supply might disturb the absorption and utilization of nitrogen of roots, intensify the lignification process of the main stem, and then affect the growth of the aboveground part. The findings of this research could provide a theoretical basis for identifying an optimum fertilization formula and technique for promoting the rapid growth and accelerating the lignification process at different stages of loquat rootstock seedling growth.

Photoselective coverings influence plant growth, root development, and buddability of citrus plants in protected nursery

Use of protective coverings can be an economically viable option in fruit nurseries than in fully mature commercial orchards. In protected nurseries, photoselective coverings can influence the growth of rootstocks, budding success, and budding growth of the budded scion cultivar. The effect of photoselective coverings (white, silver, green, red and stainless steel net house) along with open conditions (control) was studied on plant growth, nutrient uptake and root growth of rough lemon and Carrizo citrange rootstock seedlings which were subsequently budded with Kinnow and Daisy mandarin cultivar buds, respectively. The rough lemon plants under red net had better height, internodal length and budding success, while in open conditions, higher seedling diameter, root diameter, shoot and root dry weight, leaf number and secondary root number were recorded in rough lemon seedlings. The Carrizo seedlings in red net had better seedling diameter, internodal length, leaf area and number, shoot dry weight and budding success. The higher nitrogen, phosphorus, potassium and zinc levels were recorded in the leaves of rough lemon and Carrizo citrange under red shade net. The plant height of rough lemon seedlings was positively correlated to internodal length, budding success and leaf areaas well as leaf phosphorus and iron levels. The highest buddable seedlings were recorded in open conditions but, budding success in red shade net house. The highest sprout lengths of Kinnow and Daisy mandarin saplings were recorded in red net followed by green net and white net. Higher photosynthesis and stomatal conductance were recorded under red shade net, whereas lowest PAR interception was recorded in open conditions.

Моніторинг погодних змін та їх вплив на продуктивність цінного селекційного генофонду вишні (Cerasus vulgaris Mill.) у Лісостепу України

The authors have researched the weather peculiarities of the years 2017-2019 and their influence on the formation and realization of the productivity potential of the valuable industrial inland and foreign cherry cultivars. According to the research results the unfavorable weather phenomena, including long air and soil droughts, late spring frosts, dry winds et. became more frequent considerably in the Ukraine’s Lisosteppe during the periods of flowering and infructescense. The cherry trees ability to fructify sufficienly under a number of unfavourable environmental factors effects substantially this crop economic efficiency on the whole. The investigations have revealed the essential cv impact on the amount and quality of the cherry fruits. The explored crop certain varieties plants in the collection of the genetic fund of the Institute of Horticulture (IH) of NAAS of Ukraine are characterized with the constant infructescense during the entire study period. The following collection samples distinguished themselves (in the order of the improvement of the trait display): North Star’ < ‘Igrushka’ < ‘Favourite’ < ‘Meteor’ < ‘Malva’ < ‘Boguslavka’. The trees of the two latest cultivars (IH NAAS) formed very large fruits irrespective of the abiotic environmental factors influence. ‘Boguslavka’. Middle – ripening. Tree is middle – growing, the crown thick, orbicular, a little droop. Resistant to fungal diseases. Winter – hardy practically by all the components. Yield is high (t/ha under the planting plan 6x2,5 m on the seedling rootstock wild sweet cherry). The fruits are very large (7.6 g), dark red, oval, the separation from the fruit stem is dry. The stone is of more than middle size, the separation from the flesh easy. The consumption term is the first decade of July. The usage is universal. ‘Malva’. Middle – late ripening. The crown is branchy. Resistant to fungal diseases. Winter – hardy. The yield is up to 15 t/ha. The fruits are of more than middle size (4.2 g), dark red, the separation from the fruit stem is dry. The flesh is dark red, juicy. The stone is small (0.16 g). The taste qualities are as/follows: sour-sweet, the skin is astringe. The degustation evaluation is 7.7 points. The consumption term is the first decade of July.

Plum (Prunus rossica Erem.) fruit field and laboratory researces depending on the scion-stock combinations

The results of the field observations and biochemical researches of plum (PrunusrossicaErem.) fruits grown in the garden of intensive type with agrogenic soil in row spacing are presented in the article. The fruits of plum breeds Kubanskaya kometa и Naidena were gathered from the trees grafted on different stocks. The influene of the stock on the trees productivity, the fruit weight and biochemical structure of the plum fruits were studied. Basic chemical analyses, ascorbic acid concentration, antioxidant activity and fruit ash content were determined. The variation limits of the parameters under study depending on the used stock were shown. The best degustation evaluation parameters were found at the combinations of Kubanskaya kometa on stocks OPA-15-2 and Novinka, Naidena on OPA-15-2 (more than 4,5 points). The high positive correlation (r= 0.92) was marked between solutable solids and sugars content.The researches about the stock influence on the plum fruits titratable acidity change we have not found.The correlation between AA and ascorbic acid content in the fruits was determined (r =0.7). The decreasing row of the elements content in the plum fruits ash is the following: K>P>Mg>Ca>Mo>Cu>S>Ni>Fe≈Si>Mn. The proportion of K is from 18.67 (Naidena/ОРА-15-2) to 27.48 (Kubanskaya kometa/Novinka); P from 3.35 (Kubanskaya kometa/seedlings P.cerasifera Ehrh. to 6.39 (Kubanskaya kometa/Novinka), Mg from 1.11 (Nnaidena/ОРА-15-2) to 2.43 (Naidena/seedlings P.cerasifera Ehrh.) and Ca from 0.39 (Naidena/13-11) to 1.85 (Naidena/OPA-15-2) mass % respectively. The proportion of the rest elements is not more than 1 mass %. Under the OPA-15-2 stock influence the trees productivity and the single fruit weight increased, solutable solids, sugars and ascorbic acid concentration in the fruit in comparison with standard stock by the seedling rootstock of alycha (PrunuscerasiferaEhrh. seedlings). While ingrafting by Novinka stocks the parameters under study decreased.

Contribution of roots to growth and physiology of watermelon grafted onto rooted and unrooted seedlings of various bottle gourd rootstocks

A hydroponic experiment was conducted between April and May in 2018 by using an aerated Deep Water Culture (DWC) technique in a controlled growth chamber of Erciyes University, Agricultural Faculty in Kayseri, Turkey. To evaluate contribution of roots for growth and physiology a commercial watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] cultivar (Crimson Tide F1) was grafted onto two different bottle gourd (Lageneria siceraria) genotypes (39-01 and 47-02) and one commercial rootstock genotype (Argenterio) by using two propagation techniques (unrooted or rooted seedlings). Plants were grown in 8 L pots filled continuously aerated nutrient solution, in Randomized Block Design with 4 replications for 6 weeks. Results indicated that shoot and root fresh (FW) and dry (DW) weights, main stem length, total leaf area, leaf chlorophyll index (SPAD), photosynthetic activity of leaves of watermelon were significantly (P<0.001) affected by rooting type, genotype and genotype x rooting type interaction. Irrespective of rooting type, the grafted genotypes usually showed significantly higher performance in growth and physiological development than ungrafted control plants. Among graft combinations, the highest growth performance was shown by C.Tide/Argenterio while the lowest was shown by C.Tide/39-01. In terms of rooting type, watermelon plants usually showed a better performance in growth and physiological development when they were used as rooted seedlings compared to unrooted ones. Grafting watermelon onto unrooted seedlings caused a significant reduction in shoot FW by 21.6%, in shoot DW by 12.8%, in root FW by 29.5%, in root DW by 33.7%, in stem length by 11.5%, in total leaf area by 26.3%, in SPAD by 11.2% and in photosynthesis by 18.2%. All these clearly indicate that roots are playing very essential role in contribution to growth and development of plants, particularly at the beginning of growth stage. Therefore, our study suggested that grafting with unrooted seedlings is not a useful application strategy for watermelon plants grown under hydroponic conditions, even when they are grafted onto vigorous rootstocks.

Contribution of roots to growth and physiology of watermelon grafted onto rooted and unrooted seedlings of various bottle gourd rootstocks

Contribution of roots to growth and physiology of watermelon grafted onto rooted and unrooted seedlings of various bottle gourd rootstocks

A Study of the Evaluation of the Pecan Drought Resistance of Grafted ‘Pawnee’ Trees From Different Seedling Rootstocks

To describe the influence of different pecan seedling rootstocks on drought stress resistance, 12 rootstocks of ‘87MX1-2.2’, ‘87MX5-1.7’, ‘Elliott’, ‘Frutoso’, ‘Giles’, ‘Major’, ‘Moore’, ‘Peruque’, ‘Posey’, ‘Riverside’, ‘San Felipe’, and ‘VC1-68’ were selected as rootstock treatments for grafting. In addition, the experimental materials for the grafted young ‘Pawnee’ tree treatments included the pressure-volume technique (PV technique) and cutting shoot transpiration methods to plot the PV and the cutting shoot transpiration curves, and the parameters calculated from the two curves were used to analyze the data produced by the subordinate function and cluster dendrogram methods. The results revealed that the different seedling rootstock treatments influenced the ‘Pawnee’ grafted trees to varying degrees on aspects of drought resistance, the ability to save water, the modulation of osmosis, and the sensitivity of the stomatal response. The order of drought tolerance for these different pecan seedling rootstock treatments from high to low was as follows: ‘Posey’, ‘Peruque’, ‘Riverside’, ‘87MX5-1.7’, ‘VC1-68’, ‘Elliott’, ‘87MX1-2.2’, ‘San Felipe’, ‘Moore’, ‘Major’, ‘Giles’, and ‘Frutoso’.

Phenotypic segregation of seedling UCB-1 hybrid pistachio rootstock

Key messageThe growth of UCB-1 pistachio rootstock seedlings in the earliest years is a poor predictor of subsequent growth. Therefore, rogueing during the 1st years of growth is not effective.The UCB-1 hybrid, produced from a controlled cross between Pistacia atlantica (female) and P. integerrima (male), is the main pistachio rootstock used in the USA. Variation has been observed in orchards planted with seedling UCB-1 rootstocks for over 20 years. Reduced vigor and stunting of some trees are of particular concern to growers due to decreased nut yield. This study was conducted to better understand the growth of non-grafted UCB-1, as well as between UCB-1 rootstock and Pistacia vera scions in commercial orchards. Phenotypic traits were evaluated in the non-grafted orchard. Grafted tree data were collected for both P. vera female scions and their UCB-1 seedling rootstocks in commercial orchards. The uniformity of tree height, trunk caliper, and canopy volume decreased annually during the first 5 years of growth. Individual tree growth was not linear and was poorly synchronized among siblings, causing the population to become increasingly less uniform as it aged. Consequently, growth in the earliest years is a poor predictor of subsequent growth. The strongest correlation was between growth parameters during the later years. There was a significant correlation between rootstock and scion caliper of the grafted trees in commercial orchards, with the least vigorous rootstocks producing the least vigorous scions. These data confirm the need to reliably rogue out seedlings that later will not be vigorous; however, our data show that rogueing based on the 1st years of growth is ineffective. This study suggests the need to develop predictive molecular markers for rootstock vigor.

Effect of scion varieties and wrapping materials on success of tongue grafting in Kiwifruit (Actinidia deliciosa) in Dolakha, Nepal

This study was conducted at Boch, Bhimeshwor-8, Dolakha, Nepal from January to May, 2019 to study the effect of scion variety and wrapping materials on growth performance of kiwi seedling rootstock. The field experiment was carried out in Factorial Randomized Complete Block Design using four replications. The treatments consisted of four scion varieties (Monty, Bruno, Hayward, Allison) grafted onto one year old kiwi seedling (Actinidia deliciosa) and two types of wrapping material (Grafting tape and Polyethylene plastic). The measured traits included sprout length, diameter, number of leaves, and number of sprouted bud per graft, graft success, mortality and survival percentage of grafts. The success rate of kiwi grafting was significantly affected by the scion variety and the wrapping materials. Allison variety showed the minimum days (61.72 days) to first sprouting and the maximum length of sprouts, diameter, number of leaves and number of sprouted bud per graft at the final observation. Monty variety showed the lowest growth performance. The maximum graft success (96.87%) and survival percentage of grafts (93.75%) was observed in Allison variety statistically at par with Bruno and Hayward and the lowest graft success(73.44%) and survivability(64.21%) was observed in Monty due to high mortality of the sprouted grafts. Grafting tape was superior to polyethylene plastic in terms of days to first sprouting (64.08 days), number of sprouted buds per grafts, number of leaves, graft success (92.18%) and survival of the grafts (87.01%) at the final observation. Interactive effect was found non-significant. In a nutshell, Allison is the best scion variety for grafting under the climatic condition of Dolakha and the grafting tape was the suitable tying material.

Effect of scion varieties and wrapping materials on success of tongue grafting in Kiwifruit (Actinidia deliciosa) in Dolakha, Nepal

This study was conducted at Boch, Bhimeshwor-8, Dolakha, Nepal from January to May, 2019 to study the effect of scion variety and wrapping materials on growth performance of kiwi seedling rootstock. The field experiment was carried out in Factorial Randomized Complete Block Design using four replications. The treatments consisted of four scion varieties (Monty, Bruno, Hayward, Allison) grafted onto one year old kiwi seedling (Actinidia deliciosa) and two types of wrapping material (Grafting tape and Polyethylene plastic). The measured traits included sprout length, diameter, number of leaves, and number of sprouted bud per graft, graft success, mortality and survival percentage of grafts. The success rate of kiwi grafting was significantly affected by the scion variety and the wrapping materials. Allison variety showed the minimum days (61.72 days) to first sprouting and the maximum length of sprouts, diameter, number of leaves and number of sprouted bud per graft at the final observation. Monty variety showed the lowest growth performance. The maximum graft success (96.87%) and survival percentage of grafts (93.75%) was observed in Allison variety statistically at par with Bruno and Hayward and the lowest graft success(73.44%) and survivability(64.21%) was observed in Monty due to high mortality of the sprouted grafts. Grafting tape was superior to polyethylene plastic in terms of days to first sprouting (64.08 days), number of sprouted buds per grafts, number of leaves, graft success (92.18%) and survival of the grafts (87.01%) at the final observation. Interactive effect was found non-significant. In a nutshell, Allison is the best scion variety for grafting under the climatic condition of Dolakha and the grafting tape was the suitable tying material.

Boron and calcium deficiency disturbing the growth of trifoliate rootstock seedlings (Poncirus trifoliate L.) by changing root architecture and cell wall

Boron (B) and calcium (Ca) are essential elements for plant growth. Both deficiencies inhibit root growth. However, the mechanism of inhibition is not well clear. Morphological characteristics of roots and changes in root cell wall grown at different B and Ca deficiencies were examined by using a hydroponic culture system. Both B and Ca deficiencies caused reduced plant biomass and root growth. Ca deficiency significantly decreased the fresh weight of root, stem, and leaves by 47%, 50%, and 62%, respectively, while B deficiency only reduced root fresh weight. The PCA combined with Pearson correlation analysis showed that there was significant different correlation among root parameters under B and Ca deficiency treatments when compared to control. The results of observation of transmission electron microscope showed that Ca deficiency reduced but B deprivation increased the thickness of the cell wall. Combining these technologies like X-ray diffraction, fourier transform infrared spectroscopy, homogalacturonan epitopes (JIM5 and JIM7), we confirmed that those changes above may be due to different changes in the degree of methyl esterification of pectin and glycoprotein of the cell wall. Taken together, we concluded that B deficiency can promote the formation of more low methyl esterified pectin to increase cell wall thickness, and then affect the morphological development of root system, while the formation of more highly methyl esterified pectin to increase cell wall degradation under Ca deficiency, which inhibited root elongation and formation of root branches.