Seedling Quality Research Articles

PRODUCTION OF AÇAÍ SEEDLINGS UNDER DIFFERENT SHADE LEVELS AND CONTROLLED RELEASE FERTILIZER

This study aimed to evaluate the production and quality of açaí seedlings regarding the presence and absence of controlled-release fertilization under different shading levels. The study was conducted at the experimental field of Embrapa - Acre, using a completely randomized design in a 4 x 4 factorial arrangement. The factors included four evaluation periods (60, 120, 180, and 240 days after transplanting) and four shading environments (20%, 30%, 50%, and 75%), along with the presence or absence of controlled-release fertilization. The following variables were analyzed: plant height, stem diameter, number of leaves, dry mass of leaves, stem, root, and total dry mass, as well as the seedling quality index and foliar levels of macro and micronutrients. The growth and development of açaí seedlings are influenced by the evaluation periods, shade environments, and the use of fertilization. Fertilization with controlled-release fertilizer and environments with30% and 50% shading improved the quality of açaí palm seedlings.

Morphological characterization of seeds and germination efficiency of Pinus patula var. longepedunculata and P. pseudostrobus var. oaxacana

Pinus patula and P.pseudostrobus are species of great economic importance for different communities in the Oaxaca State due tothe wood quality and wide use in forest commercial plantations and reforestation. The objective of this research was to evaluate themorphological variation of seeds and their germination efficiency of two pine species under greenhouse conditions. In 2022,selected seeds of outstanding phenotypes was obtained from the Instituto Nacional de Investigaciones Forestales, Agrícolas yPecuarias (INIFAP); three seed samples of 10 g per species were made, the number of seeds was counted, and the equatorial (DE)and polar (DP) diameters and shape coefficient (CF=DE/DP) were measured; sowing was carried out in 49 cavity trays with amixture of mountain forest soil, vermiculite®, agrolite® and Peat Moss® with a 4:1:1:2 ratio. Germination was counted daily andvigor indicators were determined: germinative energy (EG), energy period (PE), germinative speed (VG) and germination speedindex (IVG). Data were analyzed using t-Student tests and regression analysis (α=0.05) in the SAS program. Including days aftersowing (DDS) in the model, we found that between 78 and 84 % of the existing variation in the percentage of accumulatedgermination was explained in both species. P.pseudostrobus presented more spherical (CF=0.41) and heavier seeds (24.27 mg)with an energy period of 69 % at 22 DDS; on the other hand, P.patula has elongated (CF=0.31) and light seeds (8.20 mg) with agreater energy period of 83% at 20 DDS. Both species germinate after 15 days; however, P.patula has a higher germination rateand a higher germination percentage, it is necessary to use germplasm from outstanding phenotypes to guarantee the reproductiveefficiency of the seed and subsequent seedling quality.

Transient multi-indicator detection for seedling sorting in high-speed transplanting based on a lightweight model

Quality sorting of plug seedlings is an important part of factory nurseries, and deep learning is starting to become a core technology in this field. In response to the key problems of existing sorting systems with a single perspective and insufficient detection indicators, this paper innovatively proposes a lightweight multi-indicator detection model for plug seedlings, and an integrated transient sorting system for high-speed transplanting is designed. The new YOLOv5s model is composed of the ShuffleNet-V2 backbone, a channel attention mechanism neck, and a head block, and it can effectively extract image features of different seedling qualities. We built a dataset for pepper and tomato plug seedlings, and the experimental results showed that the model was highly accurate in detecting no seedlings, weak seedlings, damaged seedlings and strong seedlings, with an mAP of 94.23 %. Finally, in the verification of different operating speeds, the transplanting-sorting-replanting multifunctional system had the best integrated efficiency of 4200 plants per hour, and the average treatment time for single plug seedlings was only 0.86 s. Our method effectively can improve the performance of seedling quality sorting systems and provide technical support for factory nurseries.

Effects of Drip Irrigation-Fertilization on Growth, Flowering, Photosynthesis and Nutrient Absorption of Containerized Seedlings of Hibiscus syriacus L. (Haeoreum).

The amount of irrigation and fertilization should be considered first for the production and standardization of high-quality H. syriacus L. seedlings using container seedlings. This study was conducted to investigate the optimal conditions suitable for container cultivation of hibiscus by analyzing growth and physiological responses according to the control of irrigation and fertilization. Therefore, in this study, H. syriacus L. for. Haeoreum (3-year-old hardwood cutting propagation), a fast-growing, was transplanted into a 40 L container. The irrigation amount per container was adjusted (0.2, 0.3 and 0.4 ton/yr/tree), and the amount of fertilizer applied (0, 69.0, 138.0 and 207.0 g/yr/tree). The growth rate according to the irrigation-fertilization treatment was higher in the 0.3 ton-138.0 g/yr/tree irrigation-fertilization treatment (p < 0.001). Total biomass yield and seedling quality index (SQI) were highest in the 0.3 ton-138.0 g/yr/tree irrigation-fertilization treatment (p < 0.001). The higher the fertilization concentration, the faster the flowering and the longer the flowering. The photosynthetic capacity of H. syriacus L. was reduced in bare root seedling cultivation and container-non-fertilized treatment. The chlorophyll fluorescence response was also affected by bare root cultivation and containerized seedling cultivation fertilization. Nutrient vector diagnosis showed "nutritional suitability" in the 0.3 ton-138.0 g/yr/tree treatment. Overall, containerized seedling cultivation was superior in growth, photosynthetic performance, photochemical efficiency, and nutrient storage capacity compared to bare root cultivation. These results be expected to contribute not only to the industrial production of excellent container seedlings of H. syriacus L. but also to the production of other woody plants.

The effect of solid matrix priming with biostimulants on seed germination and seedling quality of carrot (Daucus carota L.) under abiotic stress conditions

The effect of solid matrix priming with biostimulants on seed germination and seedling quality of carrot (Daucus carota L.) under abiotic stress conditions

Compost with spent mushroom substrate and chicken manure enhances rice seedling quality and reduces soil-borne pathogens.

Using cultivated soils for rice seedlings can reduce the sustainability of arable land and thus giving negative impacts to food production. As a substitute, spent mushroom compost (SMC), which has high water-holding capacity and nutrient content, shows great potentials. To determine the impacts of the proportion of SMC and paddy soil on seedling quality, rhizosphere microbial characteristics, and fungal pathogens in rice seedling substrates, we conducted a 21-day pot experiment for rice seedling under five treatments: CK, 100% paddy soil; R1, 20% SMC and 80% paddy soil; R2, 50% SMC and 50% paddy soil; R3, 80% SMC and 20% paddy soil; and R4, 100% SMC. The results showed that incorporating SMC into the substrate, especially at 50% volume (R2), increased seedling growth and vitality at the seedling growth stage without external fertilization. Moreover, the SMC amendment increased microbial activity and promoted rice seedling recruitment of plant growth-promoting rhizobacteria (PGPR) and fungi (PGPF). In addition, using SMC significantly reduced the abundance of pathogenic fungi, especially Magnaporthe grisea. Overall, the multi-faceted benefits exhibit the strong possibilities of using SMC in sustainable rice productions.

Improvement of seedling quality of red jabon (Neolamarckia macrophylla (Roxb.) Bosser) through seed sowing techniques and seed invigoration

Red jabon (Neolamarckia macrophylla) is one of potential tree species, but there are some problems in its cultivation. Intermediate seed character and very small seed sizes with little food reserves often cause the low germination, low growth of the seedlings, and the sowing of the seeds to be too dense, resulting in an abnormal number of seedlings. The purpose of the research was to improve the seed germination and seedling quality of red jabon by adjusting the sowing density and seed invigoration treatment using hormonal and biopriming. Two experiments were conducted, that is, (1) identification of optimal seed density on the several combinations of sowing media (top soil, rice husk and compost) and (2) evaluation of the most suitable hormonal priming (GA3) and biopriming (liquid organic fertilizer, LOF) applications. The use of top soil media with a seed density of 0.5 g/400 cm2 can produce the highest pure live seed (PLS), that is, 721.67 seedlings/0.5 g. The seed treated by hormonal and bio-priming significantly affected the seed germination and seedling growth. Soaking seed in GA3 100 ppm for 4 days produced the highest of the PLS (764 seedlings/0.5 g), followed by soaking in LOF for 3 days and GA3 50 ppm for 4 days. The highest seedling height was generated from soaking the seeds using LOF for 3 days. The highest root collar diameter and biomass of red jabon seedlings were obtained from the treatment of seeds immersed in the GA3 50 ppm for 3 days. The best quality index value of red jabon seedlings was produced from the treatment of seeds immersed in the hormone GA3 50 ppm for 3 days. In general, a sowing density of 0.5 g/400 cm2 in top soil media and seed soaking treatment in GA3 50 ppm or LOF for 3 days can improve germination and growth of red jabon seedlings.

Digital Twins and Data-Driven in Plant Factory: An Online Monitoring Method for Vibration Evaluation and Transplanting Quality Analysis

The plant factory transplanter is a key component of the plant factory system. Its operation status directly affects the quality and survival rate of planted seedlings, which in turn affects the overall yield and economic efficiency. To monitor the operation status and transplanting quality of a transplanting machine in a timely manner, the primary task is to use a computerized and easy-to-use method to monitor the transplanting units. Inspired by the latest developments in augmented reality and robotics, a digital twin model-based and data-driven online monitoring method for plant factory transplanting equipment is proposed. First, a data-driven and virtual model approach is combined to construct a multi-domain digital twin of the transplanting equipment. Then, taking the vibration frequency domain signal above the transplanting manipulator and the image features of the transplanting seedling tray as input variables, the evaluation method and configuration method of the plant factory transplanter digital twin system are proposed. Finally, the effect of the transplanter is evaluated, and the cycle can be repeated to optimize the transplanter to achieve optimal operation parameters. The results show that the digital twin model can effectively use the sensor data to identify the mechanical vibration characteristics and avoid affecting transplanting quality due to mechanical resonance. At a transplanting rate of 3000 plants/h, the transplanting efficiency can be maintained at a high level and the vibration signal of the X, Y, and Z-axis above the transplanting manipulator is relatively calm. In this case, Combined the optimal threshold method with the traditional Wiener algorithm, the identification rate of healthy potted seedlings can reach 94.3%. Through comprehensively using the optimal threshold method and 3D block matching filtering algorithm for image threshold segmentation and denoising, the recognition rate of healthy seedlings has reached over 96.10%. In addition, the developed digital twin can predict the operational efficiency and optimal timing of the detected transplanter, even if the environmental and sensor data are not included in the training. The proposed digital twin model can be used for damage detection and operational effectiveness assessment of other plant factory equipment structures.

Humic substances extracted from organic compounds and their influence on the morphophysiological characteristics of tomato seedlings

The tomato seedling is one of the main inputs in the production process, and its quality is a strategic factor, making agriculture more competitive. It is possible to produce seedlings of exceptional quality using humic substances extracted from organic compounds, through the composting process. The humic acids present in humic substances play an important role in the release of nutrients, such as N, P, K, improvement of the chemical properties of the soil, elevation of the root system. In this scope, the disposal of organic waste for the composting process can be an economically sustainable alternative. From this, the objective of the research was to test the production of tomato seedlings through the application of humic acids and fulvic acids from the process of composting organic waste. The study was carried out at the State University of Bahia - UNEB, in Euclides da Cunha - BA, using a commercial cultivar. The materials used in the composting process were: coconut fiber, quixabeira soil, cattle manure and humus. Morphophysiological characteristics such as seedling height, stem diameter, chlorophyll content, root length, root volume, fresh and dry mass of tomato roots were evaluated in a completely randomized design with 3 compounds and 5 doses, totaling 15 treatments and 5 repetitions for each compound dose, with a 3x5 factorial scheme. The doses used were 0.0; 0.5; 1.0; 2.0 and 4.0 mL plant-1. Based on the main results, it was possible to conclude that the dose of 0.5 mL plant-1 allowed greater root volume (0.70 cm³), root fresh mass (0.46 g), root dry mass (0.27 g), root length (15.2 cm), seedling height (18.4 cm), stem diameter (0.50 mm), and chlorophyll content (44.5 ug cm-2), in relation to other doses, being, therefore, recommended for root growth of tomato seedlings in semi-arid conditions.

Nutrient management affects growth and quality of Berberis laurina seedlings, a medicinal species from South America

Nutrient management affects growth and quality of Berberis laurina seedlings, a medicinal species from South America

A Comparative Analysis of the Grafting Efficiency of Watermelon with a Grafting Machine

The rising age of the population in rural China and the labor intensity of grafting have resulted in a decrease in the number of grafters and a subsequent increase in their wages. Manual grafting can no longer satisfy the increasing demand for watermelon-grafted transplanting; thus, machine grafting will be an effective alternative. In order to accelerate the implementation of machine grafting in China, a comparative analysis between the automatic grafting machine (model 2TJGQ-800) and traditional hand grafting was conducted. The reliability and feasibility of machine grafting were evaluated through a comprehensive evaluation of the production capacity and grafting seedling quality. This study focuses on the grafting application of watermelon plug-tray seedlings. The scion and rootstock seeds were sown on 9 November 2022. Grafting experiments using an automatic grafting machine, skilled workers, and ordinary workers were conducted with the root-pruned one-cotyledon grafting method on 24 November 2022. The results showed that the machine grafting had a high uniformity and grafting speed. The grafting speed of the grafting machine was 774 plant·h−1 and 1.65–2.55-fold higher than the hand grafting. With training, workers can improve their grafting speed, but it will still be slower than machine grafting. In addition, there was no significant difference in the grafting survival rate between the machine grafting and hand grafting. However, using machine grafting, the success rate decreased from 100% to 90.07% and the rootstock regrowth rate increased from 18.44% to 72.69%. Incomplete rootstock cutting, clip supply failure, and grafting drop failure are the three main factors that result in machine grafting failure. In conclusion, the grafting machine has advantages in terms of grafting speed and uniformity. Upon improving the accuracy of the cutting mechanism and grafting success rate, it will be adopted by commercial nurseries.

The Effects of Paclobutrazol Seed Soaking on Biomass Production and Yield Formation in Direct-Seeded Rice

Direct-seeded rice has been widely adopted in Asia in recent years. However, its low and unstable yields severely limit the increase in rice production and directly affect food security. The aim of this research was to investigate the effects of different concentrations of paclobutrazol seed soaking on the biomass production and yield formation of direct-seeded rice and to find the optimal concentrations to provide a theoretical basis for the high-yielding cultivation of direct-seeded rice. Two rice varieties, Jiyujing and Jijing305, were used in this experiment, and the seeds were soaked in paclobutrazol at concentrations of 0, 50, 100, 150, and 200 mg L−1. The appropriate concentration of paclobutrazol seed soaking increased the yield of direct-seeded rice; this was attributed to the increase in the spikelet per unit area and the seed setting rate. However, the too-high paclobutrazol concentration was not conducive to a yield increase. Regression analysis showed that the appropriate concentration of paclobutrazol seed soaking was 100–105 mg L−1. The appropriate concentration of paclobutrazol for seed soaking ensured the seedling emergence rate; improved the seedling quality, stem tillers, and productive tillers; increased the efficient leaf area, chlorophyll content, and net photosynthetic rate, resulting in an increase in dry matter accumulation; coordinated the source-sink relationship and dry matter distribution; and promoted the material translocation from the “source” to the “sink”. In conclusion, using the appropriate concentration of paclobutrazol for seed soaking is an effective means of obtaining high yields of direct-seeded rice.

Leaf Angle as a Criterion for Optimizing Irrigation in Forest Nurseries: Impacts on Physiological Seedling Quality and Performance after Planting in Pots

Seedling species with different architectures, e.g., mean leaf angles, are often subjected to the same irrigation management in forest nurseries, resulting in wasted water and fertilizer and reduced seedling quality. We aimed to evaluate whether irrigation volumes applied to tree seedling species with different leaf angles affect the physiological quality in forest nurseries and, consequently, performance after potting. We submitted nine seedling species with different mean leaf angles to four daily water regimes (8, 10, 12, and 14 mm). In the nursery, the following physiological attributes were considered to assess seedling quality: leaf water potential, daily transpiration rate, SPAD value, chlorophyll a and b, anthocyanins, carotenoids, and total nutrient content. After potting, we evaluated height and stem diameter over 120 days. Leaf angle can be used as a criterion for optimizing irrigation in forest nurseries, avoiding water and fertilizer wastage, and increasing physiological seedling quality. Leaf angle measurements combined with concurrent assessments of leaf traits are helpful in further understanding the effects of leaf angle variation and water regime on seedling quality. For positive leaf angles, an irrigation volume of 8 mm is sufficient to increase physiological seedling quality. Conversely, seedlings with negative leaf angles show the opposite response, requiring the largest irrigation volume (14 mm) to increase physiological seedling quality, except when the mean leaf area is small and concentrated in the upper half of the stem, which facilitates the access of irrigation water to the substrate and thus satisfies seedling water requirements. For all species, up to 120 days after planting in pots, the effect of the irrigation volume that provides greater growth and physiological quality at the end of the nursery phase is not overcome by other irrigation volumes applied.

Leaf Angle as a Criterion for Optimizing Irrigation in Forest Nurseries: Impacts on Physiological Seedling Quality and Performance after Planting in Pots

Leaf Angle as a Criterion for Optimizing Irrigation in Forest Nurseries: Impacts on Physiological Seedling Quality and Performance after Planting in Pots

Comparison of the Eggs and Cocoons Quality of Some Mulberry Silkworm Hybrid Bombyx mori L.

Sericulture is one of the non-timber forest products (NTFPs) that can help Indonesians live better lives and support environmental improvement. Silk, as a product of sericulture, is one of the five NTFPs that Indonesia has identified as having the ability to boost the nation’s economy and alleviate poverty. However, there are several issues with the development of silk in Indonesia, chiefly issues with the quality of silkworm seedlings and low cocoon yield. Crossbreeding is one method used to boost egg output. This study aimed to evaluate the eggs and cocoons produced by various silkworm (Bombyx mori L.) crosses. The Pustarhut Laboratory hosted the research from May to August 2022. Twelve treatments were employed in the form of crosses using the Randomized Block Design (RBD) method, and each treatment applied three replicates. Overall, the findings demonstrated that the CE cross ((919 x 927) x (804 x p208)) produced eggs (652 eggs) and cocoons of higher quality than other crossings. However, although the egg numbers of CF cross ((919 × 927) × (p208 × 804)) and FC cross ((p208 × 804) × (919 × 927)) produced 622 and 631 eggs, respectively and were significantly different from CE cross, they still produced egg numbers above 600. In addition, they produced cocoon quality that was not significantly different from CE cross. All finding indicates that silkworms from CE, CF, and FC crosses can be used as an alternative to superior silkworm breeding to increase the productivity of silkworm rearing in Indonesia. Keywords: Bombyx mori, cocoon quality, double-cross, seed quality

Growth of tandem long-mat rice seedlings using controlled release fertilizers: Mechanical transplantation can be more economical and high yielding

The traditional soil-based rice seedling production methods for mechanical transplanting are resource-intensive, time consuming and laborious. The improvement and optimization of nutrient management in soil-less nursery raising methods like tandem long-mat seedlings (TLMS) are necessary for the resource-efficient cultivation of rice. In the present study, a controlled-release fertilizer (CRF)-polymer-coated compound fertilizer with 3 months release period (PCCF-3M) was applied as seedling fertilizer (SF), and five different dosages of SF (SF-0, SF-10, SF-20, SF-30, and SF-40) were compared with an organic substrate as the control (CK). Among all SF treatments, the best results were obtained with the application of 20 g/tray of SF (SF-20), as the seedling quality and machine transplanting quality were comparable to those of CK. In contrast, the lower dosages (SF-0 and SF-10) resulted in low nitrogen content and reduced shoot growth, while the higher dosages (SF-30 and SF-40) resulted in toxicity (increased malondialdehyde accumulation) and inhibited the root growth. Similarly, SF-20 increased panicle number (5.6–7.0%) and yield (4.3–5.3%) compared with CK, which might be related to the remaining SF entangled in the roots supporting the tiller growth of rice seedlings in the field. Moreover, SF-20 reduced the seedling block weight (53.1%) and cost of seedling production (23.5%) but increased the gross margin, indicating that it was easy to handle and economical. Taken together, our results indicate that SF-20 is a cost-effective way to promote the growth and transplanting efficiency of rice seedlings. To our knowledge, this study is the first to determine the optimum dosage of CRF for the soil-less production of rice seedlings.

Genomics and Transcriptomics Reveal Genetic Contribution to Population Diversity and Specific Traits in Coconut.

Coconut is an economically important palm species with a long history of human use. It has applications in various food, nutraceuticals, and cosmetic products, and there has been renewed interest in coconut in recent years due to its unique nutritional and medicinal properties. Unfortunately, the sustainable growth of the coconut industry has been hampered due to a shortage of good quality seedlings. Genetic improvement through the traditional breeding approach faced considerable obstacles due to its perennial nature, protracted juvenile period, and high heterozygosity. Molecular biotechnological tools, including molecular markers and next-generation sequencing (NGS), could expedite genetic improvement efforts in coconut. Researchers have employed various molecular markers to reveal genetic diversity among coconut populations and for the construction of a genetic map for exploitation in coconut breeding programs worldwide. Whole genome sequencing and transcriptomics on the different varieties have generated a massive amount of publicly accessible sequence data, substantially improving the ability to analyze and understand molecular mechanisms affecting crop performance. The production of high-yielding and disease-resilient coconuts and the deciphering of the complex coconut genome's structure can profit tremendously from these technologies. This paper aims to provide a comprehensive review of the progress of coconut research, using genomics, transcriptomics, and molecular markers initiatives.

Effects of different light quality and GA3 concentration on tobacco seedling growth, root characteristics, and carbon and nitrogen metabolism

Light quality and gibberellins affect growth, development and morphogenesis of plants. In order to improve the quality of tobacco seedlings under greenhouse conditions, the influence of different light sources and their interaction with foliar-applied gibberellic acid (GA3) on key growth and metabolic parameters in tobacco were examined. Light sources included white, red and blue lights while GA3 was applied in three concentrations, i.e., 0, 50 and 100 mg L-1. The survival rate of the seedlings was observed after transplanting. Morphological parameters like plant height, stalk diameter, and length, width and number of leaves increased maximally with higher concentration of GA3 under all three light regimes, however, light sources did not show any visible difference. Further, root vitality, chlorophyll content and the activities amylase and nitrate reductase increased significantly due to GA3 application and achieved highest values with blue light + 100 mg L-1 GA3. Supplementation of red and blue light along with foliar application of GA3 significantly increased the growth parameters including seedling height, stem diameter, root-shoot ratio, leaf length and root vitality. The contents of carbon metabolites including starch, soluble sugars, and reducing sugars improved significantly in plants grown under red and blue lights in combination with foliar application of GA3. The results of the present study depict that growing tobacco under blue light and the application GA3 is beneficial in terms of achieving increased growth, root characteristics, carbon and nitrogen metabolism of tobacco seedlings.

Leaf Angle as a Criterion for Optimizing Irrigation in Forest Nurseries: Impacts on Physiological Seedling Quality and Performance after Planting in Pots

Leaf Angle as a Criterion for Optimizing Irrigation in Forest Nurseries: Impacts on Physiological Seedling Quality and Performance after Planting in Pots

Linking the effects of nursery light and fertilization and post-transplant first summer irrigation on the field survival and growth of Pinus pinaster seedlings

Seedling size-related functional attributes of Mediterranean forest species are critical traits to be considered in nursery practices aimed at improving the survival and performance of seedlings exposed to summer drought in dryland reforestation projects. We looked at how nursery light regimes and nitrogen fertilization affected the survival and performance of Pinus pinaster Ait. under contrasting post-planting watering regimes. Seedlings grown in the nursery for 13 months were given low or high nitrogen doses and exposed to three light regimes (full sun, medium light and low light). After outplanting, half of the seedlings were watered fortnightly during the hottest months of the first summer and the other half were left unwatered. Seedling size-related variables (shoot height, basal diameter, stem volume and sturdiness quotient) were measured at the beginning and at the end of the study, and summer drought survival was checked three times. Our results showed that fertilization and the nursery light regime influenced initial seedling quality and transplant stress. Post-planting first summer watering also increased seedling survival probability. The medium-light and especially the full-sunlight regimes in the nursery decreased the probability of seedling mortality after outplanting. However, a low-light regime in the nursery negatively affected plant traits and increased the probability of post-planting seedling mortality. In comparison with low-N seedlings, high-N fertilization increased post-planting stress (evaluated in the change of sturdiness quotient after one field growth season), but did not affect survival.