Sucker Growth Research Articles

Assessing Impact of Manual Topping and Suckericide Application at Different Stages on FCV Tobacco Quality and Yield

Tobacco (Nicotiana tabacum L.) topping is one of the essential practice to obtain good quality and adequate yield. The suckericide (Flumetralin as a best herbicide and plant growth regulator). For the purpose to compare topping as manual and herbicide application the experiment was conducted on flue cured Virginia (FCV) tobacco at Tobacco Research Station, Khan Ghari, Mardan during 2021-2022. The experiment was conducted in RCB design with three replications and five treatments (Control, Manual de-suckering, 1000, 1200, 1500 ml of Flumetralin ha-1). Treatments were applied at three stages (button stage, early flowering stage and late flowering stage). The data revealed that topping timing and maximum dose (1500 ml ha-1) of (Flumetralin) resulted maximum (896 cm-2) leaf area, less number (14) of sucker plant-1, lower (132 g) green weight and dry weight (20.30 g) of sucker plot-1, more cured weight (5.08 kg) of leaves plot-1 and maximum yield (3038) kg ha-1, lower nicotine contents (2.26) and less sugar contents (16.24) at button stage. Moreover, Flumetralin application on at button stage resulted less sucker growth and enhanced leaf yield. I suggest that the tobacco K399 with the application of suckericide and growth regulator (Flumetralin) have the potential to incorporate in further breeding program for low content of nicotine, reduced sugar content and high yield.

13C labeling unravels carbon dynamics in banana between mother plant, sucker and corm under drought stress.

Banana is a perennial crop and typically consists of a mother plant and one or more suckers that will serve as the next generation. Suckers are photosynthetically active, but also receive photo-assimilates from the mother plant. While drought stress is the most important abiotic constraint to banana cultivation, its effect on suckers or banana mats as a whole remains unknown. To investigate whether parental support to suckers is altered under drought stress and to determine the photosynthetic cost to the parental plant, we conducted a 13C labeling experiment. We labeled banana mother plants with 13CO2 and traced the label up to two weeks after labeling. This was done under optimal and drought-stressed conditions in plants with and without suckers. We retrieved label in the phloem sap of the corm and sucker as soon as 24 hours after labeling. Overall, 3.1 ± 0.7% of label assimilated by the mother plant ended up in the sucker. Allocation to the sucker seemed to be reduced under drought stress. The absence of a sucker did not enhance the growth of the mother plant; instead, plants without suckers had higher respiratory losses. Furthermore, 5.8 ± 0.4% of the label was allocated to the corm. Sucker presence and drought stress each led to an increase in starch accumulation in the corm, but when both stress and a sucker were present, the amount was severely reduced. Furthermore, the second to fifth fully open leaves were the most important source of photo-assimilates in the plant, but the two younger developing leaves assimilated the same amount of carbon as the four active leaves combined. They exported and imported photo-assimilates simultaneously, hence acting as both source and sink. 13C labeling has allowed us to quantify source and sink strengths of different plant parts, as well as the carbon fluxes between them. We conclude that drought stress and sucker presence, respectively causing a reduction in supply and an increase in carbon demand, both increased the relative amount of carbon allocated to storage tissues. Their combination, however, led to insufficient availability of assimilates and hence a reduced investment in long-term storage and sucker growth.

Growth and yield in taro (Colocasia esculenta (L.) Schott) grown using different planting materials and exposed to different morphological alteration treatments

Abstract This study aimed to compare cormels and suckers to determine the better planting material (PM) and to evaluate the effects of morphology-altering treatments on both shoot growth and corm yield in taro plants. The PMs used included cormel (PMC), suckers with two leaves (PMS2) and suckers with four leaves (PMS4). Morphological alteration (MA) treatment included removal of all suckers (MAS), excising the mother plant (MAM), and non-treated control (NMA). Data were collected weekly for non-destructive and at 12, 20, and 28 weeks after planting (WAP) for destructive measurements. Results of this study indicated that the SPAD values were higher in taro plants grown using cormel and morphologically non-altered plants. Removal of all suckers caused the mother plant to increase the number of leaves. The dry weight of the leaf blades, petioles and fibrous roots of the mother plant and the number of suckers decreased after the corm enlargement process took place. Fresh and dry weights of the corm increased at 20 WAP and then slowed down at 28 WAP. The moisture content of corm was relatively constant at 75%. Cormel could form on the fibrous roots and on suckers, but the total wet and dry weights of the cormels were decreased if the suckers were periodically removed. The growth of suckers was very dominant compared to the NMA plant when the mother plant was excised. Meanwhile, if all the suckers were removed, the growth of the mother plant was relatively comparable to that of the NMA plants.

1-Naphthaleneacetic Acid (NAA) Reduces Sucker Growth in European Hazelnut (Corylus avellana L.)

Three 2-year field studies were conducted to evaluate 1-naphthaleneacetic acid (NAA) as a suppressant of suckers in European hazelnut (Corylus avellana L.). Treatments were basal-directed applications of NAA at 5, 10, and 20 g·L−1 a.i. applied once per season, and two sequential applications of NAA 10 g·L−1 a.i., 28 days apart, compared with 2,4-D (3.8 g·L−1 acid equivalent), and a nontreated control. Treatments were applied early in spring and repeated the following year. Both NAA and 2,4-D delayed sucker growth by 1.2- to 3.0-fold compared with the nontreated control, and response varied with experimental site and year. Sequential treatments of NAA significantly reduced sucker height and fresh weight 120 days after treatment. NAA applied in sequential treatments increased tree trunk cross-sectional area and canopy volume in two of the three experimental sites. Yield of hazelnuts increased when suckers were removed with NAA or 2,4-D compared with nontreated. Results indicate that NAA is an effective option to control suckers in hazelnuts and can help reduce herbicide and labor in sucker control.

Chemical analysis of compost using pineapple leaves and cow dung as bio-activator

The number of area planted with pineapple at Malaysia is now increasing, especially after the fruit was recognized as one of the key crop under National Key Economic Area (NKEA). In practice, the pineapple plant remains only for one round of harvest cycle. After the fruit harvest, the leaves is usually pruned in order to stimulate the growth of suckers for the subsequent planting cycle. The pineapple leaves contained immense potential to be developed into products such as compost. In this study, the pineapple leaves were developed into compost by using the cow dung as the bio-activator and its chemical composition was then compared with the commercial organic fertiliser by using the proximate analysis. The composting process was performed in a styrofoam box and the decomposition process took 24 days for the compost to reach the constant ambient temperature at around 35°C. At the end of the composting, the pile turned to darker black colour, and has inert earthy odour. The result showed that the compost produced using the pineapple leaves with the cow dung has 2.86% nitrogen content, 0.93% ash content, and 33.47 moisture level. These values are significantly lower in comparison to the commercial organic compost. The study signified the potential of the pineapple leaves to be developed into compost to improve the soil condition. Nevertheless, the method and its composition need to be expanded in order to improve its elements availabilities suitable as organic compost.

Effect of Temperature on Survival of Lost River Suckers with a Natural Infection of Ichthyobodo spp.

AbstractTo compensate for low natural survival of endangered Lost River Suckers Deltistes luxatus, the U.S. Fish and Wildlife Service and the Klamath Tribes have initiated captive rearing programs. We conducted laboratory experiments intended to determine the temperature for optimum growth of juvenile Lost River Suckers; however, due to an unanticipated infection with Ichthyobodo spp., we instead estimated survival in conjunction with temperature and parasite loads. Ichthyobodo spp. are common parasites that infest fish skin and gills; they are known to be present in Upper Klamath Lake and have been found in fish at both the federal and tribal fish‐rearing facilities. All fish held at mean temperatures of 16°C and 19°C survived the entire 65‐d experiment, whereas the median time to death was 27 d at 22°C, 8 d at 24°C, and 7 d at 26°C. Gill samples from all Lost River Suckers tested positive for Ichthyobodo spp. DNA, with a trend toward higher copy numbers in suckers that were held at a mean temperature of 22°C or warmer compared to those held at 19°C or cooler. Fish kept at all temperatures grew slowly. These results suggest that survival of Lost River Suckers with a natural infection of Ichthyobodo spp. was significantly impacted by temperature.

Effects of experimental flow manipulations on water quality, hypoxia, and growth of Threatened Salish sucker (Catostomus sp. cf. catostomus) and juvenile coho salmon (Oncorhynchus kisutch)1

The Salish sucker (Catostomus sp. cf. catostomus) is a federally Threatened species in Canada, inhabiting small lowland streams along with juvenile coho salmon (Oncorhynchus kisutch) in southwestern British Columbia and adjacent Washington State. Experiments were conducted in two ponds to determine the effects of reduced flow on dissolved oxygen, growth of stocked Salish sucker and juvenile coho salmon (Oncorhynchus kisutch), and fish movement using passive integrated transponder (PIT) tags. Sequential flow reduction in the first experiment resulted in a significant decrease in dissolved oxygen (9.1 to 3.1 mg·L−1) and Salish sucker growth (23% decline), although lower dissolved oxygen and growth were confounded with decreased temperature. Flow reduction in a second split-pond experiment including coho salmon resulted in significantly lower dissolved oxygen (6.9 to 2.9 mg·L−1), a 51% reduction in growth of coho salmon, but no detectable change in Salish sucker growth. PIT tag detections demonstrated increased use by both species of a well-oxygenated refuge in the flow reduction treatment, indicating sublethal effects of hypoxia on fish behaviour and habitat use. These experiments demonstrate the induction of severe hypoxia by reduced flows under eutrophy, with the potential for negative impacts on Salish sucker and juvenile coho salmon growth and habitat use.

Effect of planting media on growth of pineapple CV. madu seedlings by stem cutting technique

Generally, pineapple sucker is used as the main planting material for commercial cultivation of pineapple. Pineapple sucker is usually obtained either from the stalk or the stem of a pineapple plant. Research to study the effect of planting media using mineral soil as the main component for the mixture on the growth of sucker by stem cutting technique was conducted. The objective of this research is to study the effects of mineral soil-based mixed planting media on the growth of pineapple suckers produced cultivated via stem cutting of Madu pineapple. The research was conducted at the Pineapple Nursery of the Faculty of Sustainable Agriculture, UMS Sandakan, from March 2019 until September 2019. The treatments used in this research were, soil as T1 (100%); Soil:coco peat as T2 (1:1,v/v); Soil:peat soil as T3 (1:1,v/v); Soil:sand as T4 (1:1,v/v). The data obtained showed there is a significant difference in the number of a successfully germinated sucker. However, no significant difference was detected for the sucker growth parameters. Planting media T3, soil: coco peat recorded the highest number of successfully germinated suckers (12.25). Meanwhile, for growing media, suggested T2 soil: peat soil were recorded the highest for root length (15.53 cm), leaf number (18.00), and stem diameter (2.18 cm) at 60 days after transplant (DAT).

Assessment of soil carbon accumulation during different growth stages of banana after land conversion from a secondary forest

Soil carbon (C) is the critical component in climate change mitigation and in improving land productivity. Banana plantation has a high potential to restore lost C pools due to its agronomic management practices which do not involve devastating activities such as burning of biomass and removal of plant residues. The understanding of C storage and its accumulation in a time series (during the growth of banana) after land conversion from a secondary forest is crucial to address climate change mitigation efforts and provide essential information on types of crops, site preference to improve the strategies and effective technique responsible for future soil C rehabilitation efforts. Hence, the objective of this study was to determine the soil C accumulation during different growth stages of banana cultivation after the land conversion from a secondary forest in Sungai Rual, Jeli Kelantan, Malaysia in the year 2018. Soil samples were consecutively collected from the five main growth stages of banana (sucker growth stage, inflorescence stage, flowering stage, bunch development stage, and maturation and sucker development stage). Ten soil samples were taken at each stage using a soil auger at depths of 0–20 and 20–40 cm to analyze for soil texture, pH, total C, soil organic matter, total N, and C/N ratio. The soil textures in the secondary forest and banana farm were sandy clay loam and sandy loam, respectively. Different growth stages of banana exerted a significant effect on the soil pH. However, total N of secondary forest and different growth stages of banana at two different soil depths were insignificant which could be attributed to the characteristics of the soil textures. This study overall did not show any significant statistical difference in the amount of soil organic matter and soil total C accumulated in all the five banana growth stages as they were still in the process of recovering the soil C content. This information can help to understand the trend and soil C storage capacity, and C accumulation process of the banana cultivation site after being converted from a secondary forest. Further, this finding of this study also facilitates the understanding on the role of the agricultural land as a C sink and source.

Effects of planting bed and mineral fertilization on the production and growth of Extra Sweet pineapple (Ananas comosus L.) aerial suckers in the locality of Bonoua, a town in south eastern Côte d’Ivoire

The introduction of MD2 pineapple in the international fruit trade has helped to drastically reduce exports from Côte d’Ivoire, which has long been the European market leader with the smooth Cayenne variety. As a result, Ivorian producers must adopt MD2cultivation which involves sucker availability. This study aimed at assessing the effect of planting beds and manures on the growth and development of aerial suckers produced after fruit harvesting. The planting beds studied included: film-covered ridges (BAP), uncovered ridges (BSP) and flat soils (TP). The manures used included: F1: Urea + Potassium + Trace elements (Boron + Zinc), F2: Urea + Potassium + Nitrogen, Phosphorus and Potassium compound (NPK) / Magnesium Monoxide + Trace elements (Boron + Zinc), F3: Urea + Potassium and F4: Urea + Potassium / Nitrogen, Phosphorus and Potassium compound (NPK) / Magnesium Monoxide. The design was a split-plot. Planting bed was the main factor and manure was the secondary one. The results obtained showed that on the BAP and BSP planting beds, sucker growth and production were statistically identical and higher than those observed on TP. Moreover, manure did not have a significant effect on sucker production and growth. The results obtained make it possible to say that the BAP and BSP planting beds should be recommended with one of the manures for a sustainable production of suckers.

Different Planting Media in Barangan Banana (Musa Acuminata Colla) Breeding in Southeast Aceh

Many banana plants in Indonesia have been cultivated by the community, one banana plant that has a high potential and has a chance to be developed is barangan banana (Musa acuminata Colla). The aim of this study is to find out the response of the growth of banana suckers using different planting media. This study was conducted in Kumbang Jaya Village of Badar District of Southeast Aceh Regency, which took place from April to June 2017. A non factorial randomized block design (RBD) consisting of 3 levels of treatment with 4 replications was used as a research design in this study. The level of treatment is PM1: soil without mixture, PM2: soil + manure + sand (1: 1: 1) and PM3: soil + husk + sand (1: 1: 1). Parameters observed were plant height aged 2, 4, 6 and 8 weeks after planting (WAP), stem diameter aged 2, 4, 6 and 8 WAP and number of leaves aged 2, 4, 6 and 8 WAP. The results showed that different planting media had a very significant effect on plant height at 8 WAP, number of leaves aged 6 WAP and significantly affected the stem diameter of 8 WAP. But the effect was not significant on plant height aged 2, 4 and 6 WAP, stem diameter aged 2, 4 and 6 WAP and the number of leaves aged 2, 4 and 8 WAP. For plant height, stem diameter and number of leaves aged 2, 4 and 6 WAP, the growth produced by each treatment tends to be the same

New approaches for sucker selection in greenhouse banana to reduce nematode number in subtropics

Banana is grown in both tropical and subtropical regions of the world. It is also grown in the Mediterranean coastal region of Turkey. Many pests including plant parasitic nematodes cause damages to banana. The nematodes may both limit the growth of suckers from which reproduction of banana is achieved, and reduce fruit quality and quantity. The effect of nematodes on suckers based on distance to mother plant has not been fully understood. Therefore, this study was aimed to determine effect of the distance of sucker plants from mother plants to the nematode population, stem diameters, plant growth and yield. Nematode extraction was performed by a modified Baermann funnel method and nematodes were identified under the microscope. Results revealed that Helicotylenchus multicincitus was the most abundant one followed by Meloidogyne javanica and M. incognita, respectively. The yield of new seedlings obtained from the first sucker of the mother plant were 51, 46 and 48 kg/plant, while it was 32, 30 and 31 kg/plant in the control plots (sucker plants next to the mother plant). Overall, a positive correlation was determined about distance of sucker plant from mother plants and yield. Yield increases were observed as 59%, 53% and 55% in three greenhouses, respectively. In addition, yield and quality were enhanced because of lower nematode population. The suckers next to the mother plants were unable to grow due to the higher nematode density. It can be concluded that the efficiency of this application increases when used with integrated pest management strategies.

IMPROVED CONTROL ON UNWANTED BANANA PLANT (Musa spp.)

An improved method of controlling unwanted banana plant (Musa spp.) with a mixture of glyphosate isopropylamine 48.6 per cent w/v, metsulfuron-methyl 20 per cent w/w and water in the ratio 4:1:16 is reported in this paper. Field trials in an oil palm plantation showed that a single application of 0.5 ml to 0. 6 ml of this mixture soaked in bamboo stick was able to achieve 100 per cent mortality in a single application inserted into the basal region of the trunk of the banana plant. Follow-up treatment was not necessary as the treatment also prevented the growth of any suckers. On the other hand, although the conventional method of using 2,4-D amine 86.5 per cent w/v and water in ratio 1:6 was able to achieve 100 per cent mortality, it was unable to prevent the growth of suckers satisfactorily. The treatments were done on standing banana plants that have not been po/larded as is commonly done. Keywords: Musa spp., weed management, unwanted banana plant, glyphosate, metsulfuron-methyl, 2,4- D amine

Desuckering effect of KH2PO4 mixed with paclobutrazol and its influence on banana (Musa paradisiaca AA) mother plant growth

Abstract This study investigated the desuckering effect of a 2:1 mixture of KH2PO4 (KDP) and paclobutrazol (PBZ) and its influence on banana mother plant growth, fruit yield, and quality. The mixed reagent was injected into suckers sprouting from 5-month-old banana (Musa paradisiaca AA) plants after removing the above-ground part of the suckers. Compared to control plants, treatment with the KDP/PBZ mixture significantly reduced superoxide dismutase, peroxidase, and catalase activities but increased malondialdehyde content at sucker growth points and in adjacent tissue after 1 d. There was evidence of damage to the cellular structure at sucker growth points after 2 d of treatment, with an increase in intercellular space as well as rupturing and death of most cells. All suckers died 3 d later, resulting in a mortality rate of up to 100%, and there was no subsequent regrowth of the dead suckers; indicating that a single application of the KDP/PBZ reagent is a viable desuckering practice. Relative to the control, the treatment of suckers also indirectly increased the height and stem diameter of mother plants, which was associated with increased fruit yield (yield per plant, weight per hand, weight per fruit, transverse and longitudinal diameters of fruit fingers) and enhanced nutritional quality of the fruits (edible fraction, soluble solid, titratable acidity, vitamin C, and moisture content). These results indicate that a 2:1 KDP/PBZ mixture can effectively remove banana suckers while improving fruit yield and the quality of the mother plant. The proposed desuckering practice can help to address challenges associated with banana production such as difficulties in desuckering and preventing sucker regrowth, minimizing fertilizer waste, and high costs.

PP 1/304 (1) Control of suckers in orchards

Specific scopeThis Standard describes the conduct of trials for the efficacy evaluation of plant growth regulators used to control suckers in orchards. The principal requirement is to remove sucker growth without a negative impact of the plant protection product on the parent plant.Specific approval and amendmentFirst approved in 2017‐09.

Physiological differences between root suckers and saplings enlarge the regeneration niche in Eucryphia cordifolia Cav.

Many clonal plants produce vegetative recruits that remain connected to the parent plant. Such connections permit resource sharing among ramets, explaining the high survival rates of vegetative recruits during establishment under suboptimal conditions for sexual regeneration. We propose that differences in the regeneration niches of sexual and vegetative recruits reflect different physiological adjustments caused by parental supply of resources to the ramets. We conducted ecophysiological measurements in saplings and root suckers of Eucryphia cordifolia Cav., a tree species of the temperate rainforest of southern South America. We compared the following traits of saplings and suckers: gas exchange at the leaf level, crown architecture, daily crown carbon balance, biomass allocation to above-ground tissues (leaf-to-stem mass ratio, leaf mass area and leaf area ratio), xylem anatomy traits (lumen vessel fraction, vessel density and size) and stem ring width. We also correlated the growth rates of saplings and suckers with relevant environmental data (light and climate). Saplings showed morphological, architectural and physiological traits that enhance daily crown carbon balance and increase water-use efficiency, in order to supply their growth demands while minimizing water loss per unit of carbon gained. The radial growth of saplings diminished under dry conditions, which suggests a strong stomatal sensitivity to water availability. Suckers have low stomatal conductance, likely because the carbon supplied by the parent plant diminishes the necessity of high rates of photosynthesis. The low responsiveness of sucker growth to temporal changes in water availability also supports the existence of parental supply. The physiological differences between sexual and vegetative recruits satisfactorily explain the ecological niche of E. cordifolia, with saplings restricted to more closed and humid sites.

Growth behavior of suckers derived from transplanted sago palm (Metroxylon sagu Rottb.)

During the growth of sago palm (Metroxylon sagu Rottb.), primary suckers appear from the main stem (MS) of transplanted suckers. Then, secondary suckers appear from the primary suckers. After the MS (trunk) is first harvested 10 and several years after transplantation, trunks can be harvested persistently using the primary, secondary, and subsequent suckers, which are designated as derivative suckers, growing with the MS. However, little knowledge exists about the growth behavior of derivative suckers. This study clarified how derivative suckers, especially the primary and secondary suckers, spread in the horizontal direction, and how they form a plant with the MS during the creeping growth stage. Most derivative suckers crept in the direction of about 70° subtended by the mother stem. However, two primary suckers that appeared early after transplantation crept in an obtuse angle to the creeping direction of the MS. As the reason for this obtuse angle direction, we considered the following four factors: (1) the existence of petiole, (2) distance from the sucker to the ground surface, (3) enlargement of the MS, and (4) space for sucker growth. The growth behaviors of the two primary suckers and the other derivative suckers differed. Therefore, in sago palm cultivation, the two primary suckers which appeared first from the MS were very important for formation of the framework of the plant with the MS, in terms of efficient utilization of space for the growth of derivative suckers.

Control of sucker growth on Vitis vinifera cv. Merlot with NAA derivatives

Six NAA esters (three known, three newly synthesized) were tested for the grapevine sucker control. Good results were achieved by E4, E5, E9 (8 % concentration) but E3 presented solubility problems. Suckering was reduced also in the second year, without repeating the treatment.

Radial growth response and vegetative sprouting of aspen following release from competition due to insect-induced conifer mortality

Eruptive bark beetle outbreaks such as the recent mountain pine beetle epidemic in western North America often result in substantial changes to species composition, abiotic factors, and a highly altered fuel complex. Little is known about the implications of these outbreaks to non-host species, such as aspen (Populus tremuloides Michx.), which may be beneficiaries due to release from competition. We investigated radial growth response in aspen following mountain pine beetle-induced conifer mortality in north-central Colorado through dendrochronological analysis using the percent growth change method based on 5-year and 10-year running medians, and we quantified regeneration responses in these areas compared to areas where beetle activity was largely absent. We hypothesized that growth in mature aspen would increase, expressed through wider annual growth rings, while vegetative regeneration (i.e. resprouting from the parent root system) would not increase in forests affected by bark beetles.Results showed a clear radial growth release in mixed aspen-conifer stands that were subject to extensive conifer mortality but not in forests that remained largely unaffected by beetles. Comparison of extent of suckering showed no significant differences, supporting our hypotheses and suggesting that additional resources due to release from competition were allocated towards radial growth rather than initiation of sucker growth, potentially indicating a trade-off between maintenance of existing stems and regeneration. Results from this study provide the first account of radial release detection in aspen following beetle-induced conifer mortality and help predict aspen persistence and future stand composition in these forests. Additional research, with a higher sample size and more time between sampling and bark beetle disturbance is highly recommended to confirm our findings and optimize release detection methods in aspen.

Position and Development of Differentiated Lateral Buds in Sago Palm (Metroxylon sagu Rottb.)

:During sago palm cultivation, many suckers appear from the mother stem as it grows. Some suckers are thinned out, but the rest are left to grow to be harvested several years later after harvesting of the mother stem (trunk). Proper management of the suckers from the mother stem is important to obtain successive sago trunks from a single transplantation. Nevertheless, little scientific knowledge exists about the sucker growth, even the development of its primordium. Our objective is to clarify the differentiation position and the development of the sago palm lateral bud, which is the sucker bud. Results show that in sago palm, the sucker bud differentiates inside of the connate part of the leaf petiole, which is opposite to the axil side. Swelling of tissue is first visible inside of the third leaf from the growth point (rbL 3). Sucker bud initiation is visible at almost all leaf positions lower than rbL 5. Furthermore, at each leaf position, one or two (rarely three) buds are observed. Differentiated buds usually elongate exponentially. Some develop more than two times on average. These sucker buds differentiate inside of the connate part of the thin leaf petiole, which split toward the base gradually as new leaves emerge. The differentiation position of the sucker buds and the thin leaf petiole are expected to be related closely to the further growth of the large sucker buds.