Nurserymen Research Articles

Infected nursery stock and poor silvicultural practices contribute to development of Ceratocystis manginecans wilt and canker disease in Eucalyptus pellita

In Indonesia and Malaysia, Eucalyptus pellita has replaced large areas of Acacia mangium plantations as the latter species is highly susceptible to C. manginecans. This strategy may not be effective in the long term as E. pellita is also susceptible to Ceratocystis wilt and canker disease though it has higher tolerance than A. mangium. Furthermore, the pathogen has the capacity to evolve and adapt to new hosts. To highlight the need for careful sanitation in nurseries and the potential impact of wounding during silvicultural operations, two experiments were conducted to (i) demonstrate the ability of cryptic Ceratocystis infections in nursery plants to develop into Ceratocystis wilt and canker disease after planting out and (ii) assess the risk of Ceratocystis infection and disease development from different wound types. In the nursery, three-month-old mini-cuttings of seven E. pellita clones were artificially wounded and inoculated with two isolates of Ceratocystis manginecans near the base of the stem. The disease incidence and lesion length were measured one month later, just prior to planting out. After four months of growth in the plantation, the trees were harvested and stems sliced longitudinally to measure the length of xylem discolouration. Six of 36 ramets of susceptible clones died and the length of xylem discolouration was significantly greater in susceptible clones than in tolerant clones. The second experiment was based on inoculation of 12-month-old plantation-grown trees of one clone of E. pellita with one isolate of C. manginecans using six different wounding methods. The inoculated wounds on the trees all produced xylem discolouration, except for those that only penetrated the outer bark. Disease incidence was greater at stem heights of 30 to 90 cm than on the basal stem or branch stub. The experiment emphasised the importance of minimising the risk of C. manginecans infection following wounding in the nursery and in the field as the discolouration is an indication of xylem blockage that can lead to tree mortality.

Deep learning guided variable rate robotic sprayer prototype

This paper presents the development of a robotic sprayer that combines artificial intelligence with robotics for optimal spray application on citrus nursery plants grown in an indoor environment. The robotic platform is integrated with an embedded firmware of MobileNetV2 model to identify and classify the plant samples with a classification accuracy of 100 % which is used to dispense variable rate spraying of pesticide based on the health status of the plant foliage. The disease detection model was developed through the edge impulse platform and deployed on Raspberry Pi 4. The robot navigates through an array of plants, stops beside each plant, and captures an image of the citrus plants. It feeds the image into the deployed embedded model to generate a disease inference that informs the variable rate application of spray during real-time actuation. To test the spraying performance of the prototype within the growing environment, water sensitive cards were placed in each plant's canopy. After spraying, the samples of water sensitive cards were collected and quantified using a smart spray app to determine the classification accuracy as well as the extent of spray coverage on the citrus samples. The robot spray coverage results show an average spray coverage of 87 % on lemon foliage when compared with 67 % for navel orange, during the spray performance test of the robot.

Species composition of phytophages on ornamental plants

Goal. Monitoring the phytosanitary status and determining the species composition of phytophages on decorative coniferous and deciduous plants. Methods. Field — determination of the species composition of pests and the dynamics of the number of main species; laboratory — determination of pests selected on experimental plots. Research was conducted in accordance with generally accepted methods in entomology and plant protection. Results. In the industrial plant nursery of open soil «Megaplant» located in the Kyiv region, Fastiv district, village The monitoring of the phytosanitary state of ornamental plant plantations was carried out in Trilys. The natural saturation of harmful organisms and the level of their harmfulness were studied. Conclusions. It has been established that plants in industrial nurseries in open ground are damaged by a large number of insects and mites. The most dangerous and widespread on conifer ornamental plants were 8 pests from the following families coccids (Coccidae), bark beetles (Scolytidae), adelgids (Adelgidae), snout beetles (Curculionidae) and spider mites (Tetranychidae); 9 most harmful species from the following families were noted on decorative leafy plants: crambid Snout Moths (Crambidae), mealybugs (Pseudococcidae) and аrmored scales or diaspidids (Diaspididae), eriophyidae mites (Eriophyidae), aphids (Aphididae), snout beetles (Curculionidae), scarab beetles (Scarabaeidae).

Perceptions of commercial plants and tree nurseries in the use of native forest tree species for urban landscaping activities in municipalities of Los Baños and Bay, Philippines

Abstract Urban greening using native forest tree species (NFTs) has been increasingly recognized to achieve more livable, healthier, and resilient cities. However, despite having diverse genetic reserves, full utilization of NFTs in the country has not been fully realized. This restricts the mass production of seedlings for urban greening activities. As such, this study was carried out to determine the perceptions of commercial plants and tree nurseries in the use of NFTs for urban greening in municipalities of Los Baños and Bay, Philippines using the snowball sampling technique of Key Informant Interviews (KII). A total of 32 respondents were interviewed. Out of 85 species of trees identified, 51.16% (Los Baños) and 35.29% (Bay) were native. Most buyers planted their seedlings in private gardens (37.62%), subdivisions (12.38%), and private resorts (11.90%). About 18% of respondents sourced out their propagules from local sellers, followed by purchasing ready-to-plant seedlings from nearby towns (e.g. Talisay, Batangas) (14.11%) and Mt. Makiling Forest Reserve (10.58%). Unfamiliarity (21.69%) with the potential of native species seemingly impedes their popularity as urban trees. Over 23% of respondents believed that native trees help enhance the urban biodiversity and more than 43% have mentioned that buyers used leaves as the basis for species selection. Meanwhile, seedlings of seed origin are the most common (about 35%) mode of seedling production. Finally, the study revealed that Pterocarpus indicus is the topmost common native forest tree species being used for urban greening in the subject municipalities and therefore warranted to be used for further studies.

Research and application progress of apple dwarf rootstock breeding and nursery tree propagation technology in China

Research and application progress of apple dwarf rootstock breeding and nursery tree propagation technology in China

Study of the Procurement of Landscape Plant Nurseries in Sukamantri Village Tamansari Sub-district Bogor Regency

Abstract Nurserymen play an important role in the landscape industry by producing and providing plants according to the required specifications. Sukamantri Village is one of the centers of landscape plant production and sales in Bogor Regency. The main problem faced by the nursery is the fluctuating demand for landscape plants, which can cause a shortage or excess of plant stock. This research was conducted in Sukamantri Village, Tamansari Sub-district, Bogor Regency, from November 2022 to February 2023. This study aims to obtain information on the variety of plants in the nurseries and analyze the problems in order to obtain recommendations for the development and sustainability of the nursery. Data obtained through surveys, interviews, and secondary data. They were analyzed quantitatively and qualitatively using the SWOT approach regarding internal and external factors in the procurement of landscape plants. The results show the variety of plants includes indoor and outdoor ornamental plants, herbal plants, and fruit plant seedlings. The problem faced is the decline in domestic and foreign sales. Some of the recommended strategies include developing human resource skills, improving production technology, better planning production, promoting on social media, and expanding the market by strengthening networks.

Review and Current Status of Systena frontalis (Coleoptera: Chrysomelidae): An Insect Pest Associated with Nursery Production Systems1

Abstract Systena frontalis (F.) (Coleoptera: Chrysomelidae) is an insect pest of nursery production systems throughout the Midwest, Southeast, and Northeast regions of the United States. The original scientific name was Galleruca frontalis F. before reclassification of the genus to Systena. There is minimal information in the scientific literature providing evidence that S. frontalis is native or an introduced species. In addition, the overwintering life stage is unknown. However, records indicate that S. frontalis is native to North America based on reports of this beetle being found in 5 provinces of Canada and 31 states in the United States. Records also indicate that the adult may be the overwintering life stage. Current management strategies implemented to reduce feeding damage caused by S. frontalis adults to container-grown nursery plants are associated with foliar spray applications of contact insecticides. However, applying contact insecticides to plant material in nursery production systems is labor intensive and not cost efficient. Application of systemic insecticides to the growing medium is a management strategy that nursery producers can use to reduce feeding damage caused by S. frontalis adults. Research demonstrates that the systemic insecticides dinotefuran and thiamethoxam protect container-grown nursery plants 45 d after application. Therefore, based on empirical, scientific-based research, applying systemic insecticides before S. frontalis adults are active provides practical and cost-effective plant protection from adult feeding damage during the growing season, thereby allowing nursery producers to grow, market, and sell container-grown nursery plants.

Above- and below-ground morpho-physiological traits indicate that biochar is a potential peat substitute for grapevine cuttings nursery production

The growing demand for grapevine planting materials, due to growing global viticulture, is promoting research studies to improve vineyard sustainability. In greenhouse nurseries, peat is the most common growing medium component used although is an expensive and non-renewable material. Indeed, the reduction of peat exploitation is receiving great attention, and currently, several materials are being investigated as peat substitutes for composing the cultivation substrates. Biochar, a carbon-rich, recalcitrant charred organic co-product of the pyrolysis or gasification process, has emerged as a potentially promising replacement for soilless substrates in nursery plant material propagation. Although several studies carried out at greenhouse nurseries have shown that biochar, can improve plant growth, only a few studies have focused on the production of grapevine plant material. To fulfil this knowledge gap and push forward the sustainability of the nursery sector, we evaluated above and below-ground morpho-physiological traits of one-year-old potted grapevine cuttings growing with 30% volume of four different biochar types (i.e., from pyrolysis and gasification) mixed with commercial peat. The present study shows that biochar can be used in growing media mixes without adverse effects on roots, improves soil water retention and leaf water potential, and improves the effects on soil microbiology.

Sweet Pepper Farming Strategies in Response to Climate Change: Enhancing Yield and Shelf Life through Planting Time and Cultivar Selection

Climate change is an important concern worldwide. This huge change is causing a negative impact on crop productivity throughout the whole world and shows some drastic effects on sensitive crops including sweet pepper and other kinds of chilies. These stresses have a negative effect on vegetable growth, fruit quality, and fruit yield. Besides these stresses, accurate planting time is the utmost factor in increasing the crop potential and its productivity. Therefore, this study aimed to evaluate the optimal planting date and best-performing cultivar for sweet pepper to maximize crop productivity, growth, yield, and fruit shelf life under the impacts of climate change. The experiment was conducted in Multan, Pakistan (30° 25 N and 71° 30 E). In this experiment, four planting dates (10 January, 25 January, 10 February, and 25 February) with three cultivars (Ganga, Winner, and Savio) were grown with three replications (each year) during 2020 and 2021. Our findings showed that plant growth, fresh and dry biomass, yield, and yield attributes were statistically higher in earlier plantings, and lower in delayed planting. Regarding the cultivars in both years, ‘Winner’ performed better in all growth and yield parameters as compared to other growing cultivars. Lower weight loss and decay incidence were reported in ‘Winner’ cultivar. Additionally, ‘Winner’ cultivar showed a higher sensory score as compared to the other cultivar in both years. From the results, we conclude that the nursery of sweet pepper plants should be planted on the 25 January to attain higher crop productivity, and the cultivar ‘Winner’ showed promising effects so it should be planted for better yield.

A method for evaluating the effects of gentle remediation options (GRO) on soil health: Demonstration at a DDX-contaminated tree nursery in Sweden

Healthy soils provide valuable ecosystem services (ES), but soil contamination can inhibit essential soil functions (SF) and pose risks to human health and the environment. A key advantage of using gentle remediation options (GRO) is the potential for multifunctionality: to both manage risks and improve soil functionality. In this study, an accessible, scientific method for soil health assessment directed towards practitioners and decision-makers in contaminated land management was developed and demonstrated for a field experiment at a DDX-contaminated tree nursery site in Sweden to evaluate the relative effects of GRO on soil health (i.e., the ‘current capacity’ to provide ES). For the set of relevant soil quality indicators (SQI) selected using a simplified logical sieve, GRO treatment was observed to have highly significant effects on many SQI according to statistical analysis due to the strong influence of biochar amendment on the sandy soil and positive effects of nitrogen-fixing leguminous plants. The SQI were grouped within five SF and the relative effects on soil health were evaluated compared to a reference state (experimental control) by calculating quantitative treated-SF indices. Multiple GRO treatments are shown to have statistically significant positive effects on many SF, including pollutant attenuation and degradation, water cycling and storage, nutrient cycling and provisioning, and soil structure and maintenance. The SF were in turn linked to soil-based ES to calculate treated-ES indices and an overall soil health index (SHI), which can provide simplified yet valuable information to decision-makers regarding the effectiveness of GRO. The experimental GRO treatment of the legume mix with biochar amendment and grass mix with biochar amendment are shown to result in statistically significant improvements to soil health, with overall SHI values of 141 % and 128 %, respectively, compared to the reference state of the grass mix without biochar (set to 100 %).

Fusarium solani associated with Cedrela odorata and Swietenia macrophylla and their sensitivity to conventional fungicides

Background / Objective. In the state of Yucatan, Mexico, 10 million forest plants were produced in the last five years for various conservation and restoration actions. The main limitations in the production of these plants in nursery are disease induced by the genus Fusarium spp., that cause stem and root rots and plant production losses of up to 50%. The objective of the work was to identify the causal agent associated with stem and root rot and necrosis of cedar (Cedrela odorata) and mahogany (Swietenia macrophylla) and their in vitro sensitivity to conventional fungicides. Materials and Methods. C. odorata and S. macrophylla plants were collected at three and six weeks of germination, respectively, with symptoms of necrosis and rot indicated; from where five fungal isolates were obtained and morphologically and molecularly identified. The Minimum Inhibitory Concentration (MIC) of spores and the Minimum Lethal Concentration (MLC) of six conventional fungicides of recurrent application in the region (Prochloraz, Carbendazim, Benomyl, Fosetyl Al, Captan and Mancozeb) were determined in vitro by the microdilution method and validate their effectiveness and viability in the management of this problematic. Results. The morphology and molecular sequences of the isolates were similar to the reported for Fusarium solani. The MIC of F. solani spores for Prochloraz, Carbendazim, Benomyl, Captan and Mancozeb were 2.44. 11.38, 14.06, 7.81 and 7.81 ppm, respectively; Fosetyl Al, did not inhibit spore germination normal mycelial growth of the fungus was observed at the concentration evaluated. Conclusion. Prochloraz and Mancozeb had the lowest MLC with 2.44 and 7.81 ppm, respectively.

Agro-technological aspects of growing branched annual apple nursery plants

The article presents an analytical review of Russian publications reporting the results of studies that search for optimal ways to affect apple plants in order to obtain branched annual plants. Since it has been proved that nursery plants of a certain age and quality are preferable for each type of intensive planting, as their use promotes the early maturity of trees thus ensuring a quick economic return on capital investments, it is currently relevant to study the production of apple tree planting material with specified biometric parameters. The use of mechanical impact on the above-ground part of grafted plants to suppress apical dominance is considered; the effectiveness of stimulating premature shoots in the crown area is confirmed. Much attention is paid by researchers to the chemical treatments of plants in the fields of fruit tree nurseries to improve the quality of annual plants. The use of cytokinin preparations and gibberellic acids is shown to be highly effective. The maximum effect on obtaining branched annual plants in most works was achieved in pomological apple varieties that are prone to the formation of premature shoots, with the budding on vegetatively propagated rootstocks of a first-grade commercial variety at a height of over 15 cm above the soil surface. One of the alternative ways of obtaining branched annual plants is wood grafting in spring and cultivation both in the field and in protected ground with a root-ball system. According to most researchers, the greatest effectiveness of the combined use of various techniques can be achieved only with strict adherence to conventional technologies for each method of cultivation.

The Use of Production Factors and The Allocation of Labor in Plant Nurseries in Sudaji Village, Buleleng Regency

The management of the nursery business in Sudaji Village is expected to be a reference in conducting business in the agricultural sector. The nursery business has a positive impact on business actors and the surrounding community in addition to obtaining optimal profits as well as being able to create employment opportunities for the surrounding community. This study aims to determine the management of plant nurseries through business characteristics, use of production factors, allocation of labor and analysis of business income to see the profits of the nursery business being undertaken. This research was conducted in Sudaji Village, Sawan District, Buleleng Regency from November 2022 to January 2023 with a total of eight respondents in nursery businesses in Sudaji Village. The analytical method used is quantitative and qualitative descriptive analysis. Based on an analysis of the characteristics of the plant nursery business in Sudaji Village, it shows that the business is included in the micro business category based on business turnover value, land ownership, number of workers in accordance with Government Regulation no. 7 of 2021 concerning Ease, Protection, and Empowerment of Cooperatives and Micro, Small and Medium Enterprises (PP UMKM). The allocation of manpower for the plant nursery business in Sudaji Village, Buleleng Regency utilizes the majority of local workers from Sudaji Village and Suwug Village. Suggestions for nursery entrepreneurs are to increase promotion and marketing through the digital market and farmers are expected to be able to take advantage of experience that is already qualified so that they can overcome the development of pests and diseases by starting to direct organic farming and environmentally friendly agriculture.

Control and management of Phytophthora damage in forestry—A systematic mapping study

AbstractPlant pathogens in the genus Phytophthora are a severe threat to forest plantations, ecosystems and tree nurseries. Especially in forests and natural ecosystems, there is a lack of effective measures to control and manage these pathogens. In this study, we conducted a systematic mapping review to collate evidence regarding the control and management of forest Phytophthora in different production settings and ecosystems. The study aimed to reveal possible knowledge gaps, thus guiding future research priorities. We extracted information from nine databases, limiting the search to studies published during the time period from January 2010 to December 2022. The articles were shared between three reviewers who classified the reports using a set of inclusion/exclusion criteria. A total of 561 articles were included and mapped in a database using pre‐defined coding, and critically appraised for relevance and reliability. The analysis showed that biological or bio‐based measures were the most studied interventions, followed by genetics or breeding programmes, whereas chemical and silvicultural management approaches were less studied. Most of the studies were conducted in Europe, North America, Australia and New Zealand. Phytophthora cinnamomi has been the most studied species followed by P. ramorum. We discuss the current knowledge gaps in the implementation of existing research, likely due to a lack of holistic understanding of the processes over time and space, and suggest future research that is needed to manage Phytophthora in forest ecosystems.

The effect of different peat-free growing media and fertilization levels on the plant nutrition of Leucanthemum vulgare (lam.) and Dianthus barbatus (L.)

Research on peat-free substrates is increasing due to the environmental concerns associated with peat extraction and with the aim of promoting sustainable horticultural practices. Previous research has shown that green compost mixed with coconut coir dust and stabilized wood fiber can be a valuable peat-free alternative for growing media. This study extends this knowledge by exploring the possibility of reducing fertilization levels by exploiting the nutrient content of green compost. In this paper we tested two ornamental herbaceous perennial plants, Leucanthemum vulgare Lam. and Dianthus barbatus L. For each species, we carried out five different substrate mixtures: 1) peat:pumice 70:30 v v−1; 2) coconut coir dust:pumice 70:30 v v−1; 3) coconut coir dust:green compost 55:45 v v−1; 4) green compost:stabilized wood fiber 60:40 v v−1; and 5) coconut coir dust:green compost:stabilized wood fiber 40:30:30 v v−1. For each mixture, we explored three different levels of fertilization: i) no fertilizer application; ii) low dosage of a controlled-release fertilizer at 2 g L−1; and iii) high dosage of the same controlled-release fertilizer at 4 g L−1. Plant biomass, biometric parameters, eco-physiological parameters, and plant mineral content were measured as performance indicators. The results showed that the nutrient surplus provided by the peat-free substrate, particularly when it contains green compost, can enhance the growth potential of the plants. Adding green compost to non-peat substrates can be an opportunity to optimize plant nutrition while reducing the presence of peat in plant nurseries and the use of chemical fertilizers.

First Report of Phytopythium litorale Causing Root Rot on Kousa Dogwood in Tennessee and the United States.

Kousa dogwood (Cornus kousa) is an economically important woody ornamental crop that exhibits creamy, white, pointed bracts in late spring, and reddish to pink drupe fruits in late summer and fall. It bears shiny dark green leaves that become reddish-purple to scarlet in the fall. In August of 2023, 3-year-old container grown C. kousa var. chinensis plants in a commercial nursery in Warren Co., Tennessee, exhibited severe yellowing, dieback and root rot symptoms (Fig. 1a and 1b). Dark brown to black lesions were observed in the root and crown region of the plants. Disease severity was 40% to 60% of root area affected, and disease incidence was approximately 40% of 1,000 plants. Surface-sterilized (10% NaOCl: 1 min) symptomatic root tissues were plated on V8-PARPH and incubated at 25°C. Sparse aerial mycelium, showing a distinct rosette or faint radiate to chrysanthemum colony pattern, was observed within four days of incubation (Fig. 2). All isolates produced ovoid or subglose, papillate, and proliferating sporangia in grass blade water cultures (Derviş et al. 2020). Sporangia measured as 19.18 to 24.80 µm X 18.08 to 22.16 µm (n = 50) with a length/width ratio of 1.06 to 1.11. Zoospores observed were between 7.07 to 9.98 µm in diameter (n = 50). Oogonia and oospores were not produced. The ribosomal internal transcribed spacer (ITS) and large subunit (LSU), as well as mitochondrial cytochrome oxidase subunit II (COX-II) genetic markers were amplified and sequenced using primer pairs ITS1/ITS4 (White et al. 1990), NL1/NL4 (Baten et al. 2014), and cox2-F/cox2-RC4 (Choi et al. 2015), respectively. The ITS, LSU, and COX-II sequences of isolates FBG6343, FBG6344 (ITS: PP458373 and PP461387; LSU: PP461390 and PP461391; COXII: PP477112 and PP477113) were 100% identical to those of MN306118, HQ643386, and MN206732, respectively. Based on the morphology (Nechwatal and Mendgen 2006) and sequence data, the isolates were identified as Phytopythium litorale (Nechw.) Abad, De Cock, Bala, Robideau, Lodhi & Lévesque. The pathogenicity test was performed on 3-year-old C. kousa var. chinensis plants grown in a 3-gal container to fulfill Koch's postulates. Kousa dogwood plants were drench inoculated (800 ml/plant) with a pathogen slurry (two plates of 7-day-old culture/liter) of isolates FBG6343 and FBG6364 (five plants per isolate). Control plants were drenched with agar slurry without the pathogen. The study was conducted in a greenhouse maintained at 21 to 23°C and 70% relative humidity with a 16-h photoperiod and irrigated twice a day for 2 min using an overhead irrigation system. Forty-five days after inoculation, plants showed dieback symptoms, and dark brown lesions developed in the roots of all inoculated plants. Isolates with morphology and sequences identical to those of FBG6343 and FBG6364 were recovered from root tissues of all inoculated plants. All control plants remained symptom-free, and P. litorale was not isolated from the root tissue. Previously, P. litorale was reported to cause disease on apple, kiwi, planatus, and rhododendron (Derviş et al. 2020; Li et al. 2021; Mert et al. 2020; Polat et al. 2023). To our knowledge, this is the first report of P. litorale causing root rot of kousa dogwood in Tennessee and the United States. Identification of this pathogen as the causal agent is crucial to developing timely management practices.

Biological Assessment of Green Waste and Dredged Sediment Co-Composting for Nursery Plant Cultivation

Co-composting efficiently reclaims dredged sediments (S) and green waste (GW), creating stable products for agricultural applications. However, the use of S-GW co-composts can be limited by legislative thresholds, especially for co-composts with a high S percentage. The evaluation of S-GW co-compost stability by biological assessment can allow for a better understanding of S and GW recycling, as well as the S-GW co-compost application. For this purpose, the microbial biomass, composition, respiration, and eco-enzyme stoichiometry (EST) were assessed, coupled with chemical analysis, in the co-composting of S and GW in different ratios. The Photinia x fraseri and Viburnum tinus L. growth was monitored in a plant trial, comparing the studied co-composts with a control substrate. The EST approach was applied as an indicator of the co-composting stability during the process and after the plant cultivation. The chemical and biological parameters confirmed the suitability of co-composting in the GW and S recovery and the EST approach highlighted a better stability for the 3S:1GW co-compost at the end of the process and after plant cultivation. Viburnum tinus showed a similar growth to the control, while Photinia x fraseri resulted in being more sensitive to the co-compost. The biological assessments were good indicators of the S-GW compost stability for their application in crop cultivation.

Biofumigation Treatment Using Tagetes patula, Sinapis alba and Raphanus sativus Changes the Biological Properties of Replanted Soil in a Fruit Tree Nursery

Apple replant disease (ARD) may cause significant losses both in commercial orchards and in fruit tree nurseries. The negative effects of ARD may be limited by using biofumigation. The aim of the study was to assess the influence of this treatment on the biological properties of replanted soil in a tree nursery. In two-year experiment, apple trees of the ‘Golden Delicious’ cultivar were used. The trees were planted into soil from two sites. The soil from one site had not been used in a nursery before (crop rotation soil). The other soil had been used for the production of apple trees (replanted soil). Three species of plants were used in the replanted soil as a forecrop: French marigold (Tagetes patula), white mustard (Sinapis alba), and oilseed radish (Raphanus sativus var. oleifera). The following parameters were assessed in the experiment: the enzyme and respiratory activity of the soil, the total count of bacteria, fungi, oomycetes and actinobacteria in the soil, as well as the count and species composition of soil nematodes. The vegetative growth parameters of the apple trees were also assessed. The biological properties of the replanted soil were worse than those of the crop rotation soil. In the replanted soil, the organic matter content, enzyme and respiratory activity as well as the count of soil microorganisms were lower. The biofumigants, used as a forecrop on the replanted soil, significantly increased its enzyme activity and respiratory activity. Dehydrogenase activity increased more than twofold. Growth parameters of the trees were significantly improved. The height of the trees increased by more than 50%, and the leaf area, weight and total length of side shoots were higher as well. The density of nematodes in the replanted soil after biofumigation was significantly reduced, with a larger reduction in the marigold fumigated soil. Eight of the eleven nematode species were completely reduced in the first year after biofumigation treatment.

Molecular Identification and Pathogenicity of Fusarium Species Associated with Wood Canker, Root and Basal Rot in Turkish Grapevine Nurseries.

Fusarium species are agriculturally important fungi with a broad host range and can be found as endophytic, pathogenic, or opportunistic parasites in many crop plants. This study aimed to identify Fusarium species in bare-rooted, dormant plants in Turkish grapevine nurseries using molecular identification methods and assess their pathogenicity. Asymptomatic dormant plants were sampled from grapevine nurseries (43) in different regions of the country, and fungi were isolated from plant roots and internal basal tissues. The Fusarium strains were identified by performing gene sequencing (TEF1-α, RPB2) and phylogenetic analyses. Pathogenicity tests were carried out by inoculating mycelial agar pieces of strains onto the stem or conidial suspensions into the rhizosphere of vines (1103 Paulsen rootstock). Laboratory tests revealed that Fusarium species were highly prevalent in Turkish grapevine nurseries (41 out of 43). Gene sequencing and phylogenetic analyses unraveled that 12 Fusarium species (F. annulatum, F. brachygibbosum, F. clavum, F. curvatum, F. falciforme, F. fredkrugeri, F. glycines, F. nanum, F. nematophilum, F. nirenbergiae, F. solani, and Fusarium spp.) existed in the ready-to-sale plants. Some of these species (F. annulatum, F. curvatum and F. nirenbergiae) consistently caused wood necrosis of seedling stems, rotting of the basal zone and roots, and reduced root biomass. Although the other nine species also caused some root rot and root reduction, their virulence was not as severe as the pathogenic ones, and they were considered opportunistic parasites or endophytic species. This study suggests that Fusarium species might play an important role in root-basal rot, wood canker symptoms, and young vine decline in Turkish grapevine nurseries and that these species need to be considered for healthy seedling production.

EFFECT OF DE-TOPPING ON VARIOUS DATES OF GROWTH PARAMETERS OF PEACH NURSERY PLANTS

The research study was carried out to examine the effect of de-topping parameters of peach nursery plant. The experiment layout was Randomized Complete Block Design (RCBD) at “Nuclear Institute for Food and Agriculture Peshawar” (NIFA) Research Farm during the year 2021. On different dates de-topping were practiced (24 June, 30 June, 6 July and 12 July). The data revealed that the de-topping practice on 6 July showed significant results on days to sprout (65.33), bud success Percentage (94.83 %), number of leaves (251), number of branches (22) and internode length (7.36 cm), while practicing of de-topping on 12 July found better results in plant height (59.66 cm). The minimum results showed in days to sprout (54), bud Success percentage (94.64), plant height (32.33 cm) and number of leaves (225.67) which were de-topped on 24 July. Hence for better bud take success on peach rootstock the de-topping were practice on 6 July is recommended.