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Article

A Preparation Containing Rhizobial Lipochitooligosaccharides Improves Pea Productivity in the Field

1
Institute of Soil Science and Plant Cultivation, State Research Institute, Czartoryskich 8 Str., 24-100 Puławy, Poland
2
Department of Genetics and Microbiology, Maria Curie-Sklodowska University, Maria Curie-Sklodowska Sq. 5, 20-031 Lublin, Poland
*
Author to whom correspondence should be addressed.
Agronomy 2026, 16(12), 1133; https://doi.org/10.3390/agronomy16121133
Submission received: 27 April 2026 / Revised: 2 June 2026 / Accepted: 8 June 2026 / Published: 10 June 2026
(This article belongs to the Section Farming Sustainability)

Abstract

The effect of biopreparations containing rhizobial nod factors (lipochitooligosaccharides, LCOs) on pea growth and yield was tested under field conditions. Experiments were conducted using Pisum sativum cv. Batuta as a model, which was grown on two different soils in very similar weather conditions. Rhizobial metabolites were applied at three different concentrations and the effect of the treatment was studied at flowering and at full maturity of plants. At both sites an increase in the root nodule number and mass, acceleration of the plant growth rate, and increase in the mass of roots and aboveground parts of plants after the application of preparations containing LCOs were observed. Despite adverse climatic conditions (low rainfall from flowering to maturity), the application of preparations with LCOs resulted in a significant increase in the pea yield, ranging from 11 to 16%, which supports the use of such preparations in pea field cultivation.

1. Introduction

Pea was domesticated no later than the sixth millennium B.C., together with wheat and barley [1]. Its primary areas of occurrence are Abyssinia and Afghanistan. Later, pea colonized Mediterranean areas and spread to other regions of Europe and Asia [2]. Currently, over 11 million tons of peas are produced worldwide, with the largest amounts recorded in the Americas and Europe [2].
Pea cultivation in Poland has a long history. It is cultivated for consumption and fodder purposes and is also used as a green fertilizer [3]. Pea plays a very important role in plant rotation systems as a crop interrupting the continuous cultivation of cereals. It is a vulnerable phytosanitary plant and very good forecrop [4,5,6]. Therefore, there is a need to explore its yield increase potential. One of such strategies is to focus on the process of biological nitrogen fixation (BNF) and legume–rhizobia interactions [7].
Pea, like other legume plants, can enter into symbiotic interactions with soil rhizobia, which provides access to atmospheric nitrogen reduced by bacteria in the process of biological nitrogen fixation [5,6]. It is estimated that symbiotic reduction of atmospheric nitrogen can satisfy even the total requirement of legumes [8,9,10,11]. It is therefore not surprising that the beneficial effects of inoculating them with rhizobia were noticed as early as the late nineteenth century. The first biopreparations containing such microorganisms were produced commercially in the United States over a century ago, and their use still brings significant benefits for farmers [12,13].
Satisfactory effects of using biopreparations containing living rhizobia cells are most often achieved in the case of sites where the soil is inhabited by rhizobia populations of very low numbers, or where these bacteria are completely absent from the soil microbiome. In such a case, inoculant strains, which are selected for the highest possible efficiency of biological nitrogen fixation, colonize all or most of the nodules formed on plant roots, which results in a high probability of a significant increase in plant yield.
The solution described above does not work in the case of soils inhabited by numerous and diverse populations of rhizobia. Such populations are composed mainly of strains with low efficiency in biological nitrogen fixation, because natural selection processes will favor rhizobia that invest in their reproduction rather than symbiotic dinitrogen reduction [14,15]. On the other hand, the high number of rhizobia in the autochthonous soil populations and their competition with inoculant strains prevent strains introduced into the environment as biopreparations from colonizing the emerging nodules. As a result, the inoculation of seeds with high-yielding strains does not bring the expected yield-forming effect. Therefore, in such situations, a different solution should be applied, which involves interfering with the exchange of molecular signals between the host and the microsymbiont. If this leads to the formation of a larger number of root nodules than would be natural, even if they are colonized by strains with relatively low productivity, higher plant yields can be expected due to the resulting greater supply of nitrogen compounds that the plants can use [7]. The development of effective symbiosis requires an exchange of numerous signals which are secreted into the rhizosphere. Among them are molecules secreted by plants, such as flavonoids [16,17], jasmonates [18], aldonic acids [19], xanthones [20], and alkaloids [21], and secreted by rhizobia, such as LCOs [17,22], capsular polysaccharides, cyclic beta-glucans, lipopolysaccharides [23], exopolysaccharides [24], and homoserine lactones [25]. Plant flavonoids and rhizobial LCOs are the most important molecular signals responsible for initiation of symbiotic reactions and nodule development.
Each legume species can produce and secrete numerous flavonoid compounds [26], which are inducers of the expression of bacterial nod genes. The transcriptional activity of these genes results in the synthesis of proteins responsible for the production and secretion of LCOs [16,17,22,27,28]. Lipochitooligosaccharides released from bacterial cells are recognized by numerous specific receptors in plant cells [29], which leads to the activation of signal transmission pathways and, ultimately, to the activation of numerous plant genes [30,31]. Then, the level and distribution of phytohormones, such as auxins [32,33], gibberellins [34], or cytokinins [35,36], can be observed.
As a consequence, morphological changes such as deformation of root hairs and initiation of cortical cell division, can be observed in the plant root system. These new meristematic cells that appear in the primary root cortex will give rise to meristems responsible for the growth and development of root nodules. Rhizobia invading root hairs penetrate plant tissues and colonize the developing primordia of nodules. Finally, mature and infected nodules develop [37,38].
Rhizobial lipochitooligosaccharides act at nano- to picomolar concentrations [28]; however, they can be diffused in soil or degraded by common soil microorganisms such as Bacillus or Paenibacillus [39]. Moreover, there are many studies indicating that various plants such as pea [40,41], alfalfa [42,43,44,45] or tomato [46] can produce chitinases that degrade LCO molecules released into the soil by rhizobia. This may disrupt rhizobium–legume symbiosis, and the application of preparations containing LCOs may counteract it, enhancing plant nodulation and expanding the range of plant tissues that can be colonized by nitrogen-fixing microsymbionts. Additionally, this may also result in improved growth of root systems, thereby supporting plants with water and nutrients [47,48,49].
Rhizobial LCOs have great potential for improving symbiotic relationships between legumes and their nitrogen-fixing bacterial symbionts. Therefore, different formulations containing such molecules are tested for their suitability in legume production. The most advanced studies were conducted for soybean, where numerous laboratory and greenhouse experiments performed years ago [50,51,52] were followed by field trials [53] and enabled the introduction of modern bioproducts to the market [54,55,56,57].
Unlike North America, in Europe the most important legume in terms of crop size is pea [2], considered as “plant-based meat alternatives in the EU” [58]. The beneficial effect of LCOs isolated from cultures of Rhizobium leguminosarum on pea growth and yield was presented in our previous papers [59,60,61]. However, such greenhouse experiments conducted in semi-controlled conditions may provide different results than field experiments. Therefore, the aim of this study was to investigate the effect of preparations containing LCOs on pea growth and yielding in natural soil and climatic conditions. Based on previously conducted greenhouse experiments, it was assumed that a preparation containing rhizobial LCOs could be an effective yield stimulator for peas grown in soils containing moderately numerous populations of autochthonous rhizobia, and the conducted research aimed to test this hypothesis. The experiments were conducted during the same growing season on two different soil types at sites located close to each other. This eliminated the variability resulting from varying weather conditions, which very often have a significant impact on pea yields [62].

2. Materials and Methods

2.1. Plant Growth Conditions

The field studies were conducted at the Agricultural Experimental Station in Grabów [52.40589° N, 21.50223° E], which belongs to the IUNG-PIB in Puławy. Seeds of pea (Pisum sativum cv. Batuta) characterized by a germination capacity of 92.0%, clearness of 99.8%, and mass of 1000 seeds of 245 g were used in this study. The experiment was established in four replications with the method of equivalent blocks (split-plot-split–block) (Figure S1) on two different soils (according to the WRB classification): site 1: Luvisol formed from light loams classified as a good rye complex and quality class R IVb; site 2: Luvisol formed from light loams classified as a very good rye complex and quality class R IIIb. The content of the determined components of the mentioned soils is shown in Table 1.
The number of pea rhizobial microsymbionts was estimated by the most-probable-number (MPN) method [63] at 9.2 × 102 and 1.5 × 103 live cells/g of soil for sites 1 and 2, respectively. Immediately before sowing, seeds were soaked (for 1 h) in distilled water (control) or in preparations of LCOs (diluted 1:1, 1:10, or 1:100 v/v in distilled water), using 10 mL of water or LCO preparation per 1 kg of seeds. Seeds were sown on 18 April at a depth of 4 cm at a density of 100 seeds/m2.
The course of weather conditions throughout the pea vegetation period was assessed based on the amount of precipitation (mm) and mean daily air temperature (°C) (Figure 1).
The critical period for soil moisture in pea cultivation is flowering and pod setting. Rainfall during the flowering period was very low, at 2.8 mm (a drought occurred), while during pod setting it was adequate, at 46.4 mm. However, the distribution of rainfall during this period was very uneven; for example, on 22 June (the pod setting stage), rainfall amounted to 41.4 mm.
The following fertilization was applied in the experiment (kg/ha): N—0; P2O5—40; K2O—60. Weeds were eliminated using Boxer 800 EC and Fusilade Forte 150 EC herbicides applied at 2.5 and 1.0 L/ha, respectively. Each experimental plot had an area of 48 m2; harvest was done in an area of 44 m2 using a classic plot combine harvester (Wintersteiger AG, Ried im Innkreis, Austria).

2.2. Isolation of LCOs from Bacterial Cultures

Rhizobial LCOs were isolated from liquid cultures of Rhizobium leguminosarum bv. viciae strain GR09 [64]. Briefly, liquid cultures of Rlv GR09 (100 mL aliquots of TY medium in 250 mL flasks) were prepared and, after 24 h of growth, logarithmic cultures of bacteria were induced with sterile pea seed flavonoid extract at a final concentration of 10 µM [65] and incubated at 28 °C for 48 h. To isolate LCOs, one liter of the flavonoid-induced rhizobial culture was extracted twice with 0.2 volumes of n-butanol. The organic fraction was separated and dried in a rotary evaporator (Rotavapor–R, Bűchi, Flawil, Switzerland). Subsequently, three dilutions of this mixture were prepared, 1:1 v/v, 1:10 v/v, and 1:100 v/v (LCO preparation:water), and used in both experiments. The amount of LCOs was determined by conversion of amino sugars to methyl glycosides and gas chromatography/mass spectrometry (GC/MS) analysis [66]. The concentration of LCOs was approximated based on the assumption that a single molecule of an LCO contains on average four GlcNAc residues. The calculated content of GlcNAc in the LCO preparation was about 320 nM. In the seed dressing mixtures used in the field experiment, the LCO concentrations were approximately 160, 32, and 3.2 mM, respectively, in the formulations diluted with water at a ratio of 1:1, 1:10, and 1:100 (v/v).

2.3. Determination of the Growth Rate (GR)

Plants were harvested at flowering (BBCH 60) and at full maturity (BBCH 80). After each harvest, the fresh and dry weights of individual plant organs were determined. The roots were weighed after rinsing on coarse metal sieves. The dynamics of the weight increase were used to calculate the growth rate (GR) using the Evans [67] formula:
GR = (W2 − W1) (T2 − T1)−1 (g day−1),
where:
W1—dry weight of plants at the beginning of the measurement period (BBCH 60, flowering);
W2—dry weight of plants at the end of the measurement period (BBCH 80, full maturity);
T1—the beginning of the measurement period (BBCH 60, flowering);
T2—the end of the measurement period (BBCH 80, full maturity).

2.4. Nodule Number and Mass

To determine the nodule number and root and nodule mass, ten randomly selected plants were excavated at flowering from the topsoil (24 cm deep). Nodules were detached from the roots, washed, and dried.

2.5. Determination of Seed Yield and Yield Components

The number of pods per plant, the number of seeds per pod, the number of seeds per plant, and the thousand-seed weight were determined upon harvest at the full maturity stage. The moisture content was measured using Seed Moisture Meters–SM10 (Foss, Hilleroed, Denmark). Seed yield at the full maturity stage was calculated for 14% moisture content.

2.6. Statistical Analysis

The results are expressed as mean values per four experimental plots. Data were processed by analysis of variance (ANOVA) and regression analysis in Statistica v.13.1 software. Least significant differences were indicated at a significance level of p ≤ 0.05. Homogeneous groups were identified. Values marked with the same letters in columns or rows do not differ significantly. In multiple regression analyses the independent variable was the number of nodules per plant or the mass of nodules per plant, whereas the dependent variable was pea seed yield (linear regression, 95% confidence interval).

3. Results

Phenological observations of growing pea plants were conducted during the vegetation period. A relatively short flowering phase was recorded, suggesting that the plants were grown under stress conditions—this can be speculated in drought stress. At flowering, the water shortage and uneven distribution of rainfall could probably result in a low dry mass of plants ranging from 1.59 to 1.91 g/plant and from 1.83 to 2.19 g/plant grown at sites 1 and 2, respectively (Table 2).
The application of rhizobial LCOs in most cases resulted in a significant increase in the fresh and dry mass of roots of plants grown at site 1 as well as the dry mass of roots of plants grown at site 2. However, the differences in the concentration of LCOs in the applied preparation had no significant effect on the studied traits in some cases.
The application of LCOs resulted in an increase in the mass of pea organs, including stems, siliques, seeds, and roots harvested at full maturity (Table 3).
For plants grown at site 1, the best results were obtained after the application of LCOs in a 1:100 dilution. The mass of stems, siliques, seeds, and roots increased by 9%, 38%, 11%, and 20%, respectively, and the differences were significant for siliques. For plants grown at site 2, a significant increase in the mass of siliques was also observed after the application of LCOs, but the most efficient dilution was 1:10 (28% increase) (Table 3).
The number and mass of root nodules were also increased after the LCO treatment (Table 4). For plants grown in localization 1, no beneficial effect of LCOs on nodule dry mass was observed; however, in both experiments, a significant increase (by 48% or 55%) in nodule number and nodule wet mass (by 29% or 32%) was recorded.
The growth rate coefficients calculated for pea plants grown in both localizations differed from each other; however, in both experiments, a significant beneficial effect of LCOs was observed, especially from sowing to flowering. It can be supposed that treating plants with a preparation that increases the number of root nodules indirectly influences the physiological and developmental processes that stimulate the growth of roots and aboveground parts of plants (Table 5).
The analysis of the pea yield and yield structure showed that, regardless of the concentration of LCOs in the applied preparation and soil properties, the use of such biostimulators enhances pea productivity under field conditions (Table 6).
At site 1, the best results were obtained after the application of the LCO preparation in a 1:10 dilution. The crop yield, number of pods per plant, and number of seeds per plant increased significantly by 16%, 9%, and 18%, respectively, compared with the control group. At site 2, similar results were obtained after the application of LCOs in a 1:100 dilution, where a significant increase by 16%, 12%, and 14% was recorded for the crop yield, number of pods per plant, and number of seeds per plant, respectively. In both experiments, neither the number of seeds per pod nor the mass of 1000 seeds was changed after the LCO treatment, which suggests that yield responses were primarily associated with pod number and total seed number per plant.

4. Discussion

The application of LCOs had a significant effect on the dynamics of root growth, which was probably followed by better growth of the aboveground plant parts, especially from emergence to flowering. During this period, the application of LCOs resulted in an increase in the root growth rate coefficient by 30% or 57% (depending on field localization) and an increase in the shoot growth rate coefficient by 13% or 14%. This is in agreement with other studies reporting improved root growth after the application of LCOs [68,69,70].
The average number of root nodules on the roots of pea plants grown in the field in both studied sites, which ranged from about 9 to 16 per plant, was lower than in previous greenhouse experiments where this value ranged from about 30 to 60 nodules per plant [60]. Research conducted nationwide shows that rhizobia symbiotic with peas are a common element of Polish soil microbiomes [71]. At both sites used in the study, an average abundance of rhizobia symbiotic for pea was found. Moreover, the cultivation history of the sites where the experiments were conducted shows that legume hosts for Rhizobium leguminosarum had been cultivated there regularly, suggesting that pea microsymbionts are a permanent component of the microflora of these soils. However, taking into consideration the low rainfall, especially in the 1st and 2nd decades of June, and some papers reporting negative effects of drought stress on nodulation [72,73,74], the effect of drought stress cannot be ruled out. It could be speculated that long-term drought may have contributed to the lower nodulation efficiency of plants than in the case of the greenhouse experiments where water shortage did not occur. Despite this, the comparison between the results of greenhouse (water-sufficient conditions) and field (probably drought stress) experiments showed that the increase in the nodule number was even higher (48% or 55%, depending on the localization) in the present field experiments than in previous greenhouse studies, where the number of nodules increased by 25% (Pisum sativum cv. Milwa) [60], by 5% (Pisum sativum cv. Klif) [60] and by 16% (Pisum sativum cv. Muza) [59] after LCO treatment.
Despite weather conditions unfavorable for pea yielding (low rainfall in June and July, from flowering to maturity), a significant increase in plant growth and yield was achieved. Comparing the effect of the LCO application on plants grown at the two studied sites, different effects on the mass of siliques and the mass of roots were observed. On the other hand, at both sites, a similar effect of LCOs was recorded in the case of the mass of stems (increase by 9% or 11%, depending on the site) or the mass of seeds (increase by 10% or 11%).
The beneficial changes in the growth and development of pea plants ensuing from the application of rhizobial LCOs resulted in higher pea crop yield. The increase in the yield was similar at both sites (13.5% and 14.3%, respectively), probably due to the effect of very similar climatic conditions—both experiments were located not far away. Interestingly, the best results were obtained at different levels of LCO supplementation (LCOs in a dilution of 1:10 at site 1 and 1:100 at site 2). This may suggest differences in the “biological properties” of these soils, which is plausible, taking into consideration that each soil may have a unique and characteristic microbial population [75], and different agrotechnical practices may change the structure of this population as well as enzymatic activities characteristic for the defined soil [76]. In turn, the observed statistically significant differences in the yield and yield structure (number per plant, seed number per plant, mass of 1000 seeds) in favor of site 2 (Table 6) probably result from the soil quality (site 1—class IVb; site 2—class IIIb).
Regardless of the biological and physicochemical differences between the soils at site 1 and site 2, the use of preparations containing LCOs significantly increased plant nodulation (Table 4). Furthermore, significant positive correlations were found between the number of nodules and pea yield (Figure 2), as well as between nodule mass and pea yield (Figure 3).
The use of LCOs resulted in a significant increase in the number of nodules at all LCO dilutions at site 1, and at 1:10 and 1:100 dilutions at site 2. A significant increase in fresh mass was also observed at 1:10 and 1:100 dilutions (site 1) and 1:1 and 1:100 at site 2, with no significant differences in nodule dry mass. This may be due to two reasons. First, the nodules formed on roots as a result of the LCO presence in plant tissues were at different stages of development [77], and some of them were young and small at flowering and were not able to significantly affect the fresh mass of nodules. Second, root nodules are organs with very high metabolic activity, and the biological process of nitrogen reduction is very energy-intensive [78,79]. Therefore, although plants transfer very large amounts of assimilates to these organs, a large portion is used to produce the energy necessary for rhizobia’s metabolic processes, and some is returned to the plant in the form of organic nitrogen compounds (amino acids, ureides) [80,81,82]. This may be the reason for the low dry matter accumulation in nodules and the significantly increased dry matter accumulation in seeds.
Taking into consideration that, at both sites, a similar increase in seed yield was obtained using all studied concentrations (site 1: 11%, 16%, 14%; site 2: 12%, 13%, and 16% for dilutions 1:1, 1:10, 1:100), it can be proposed that LCOs can be used at relatively low concentrations in the field, as this will be sufficient to achieve a significant increase in pea yield.
As shown above, there are indications that the observed yield increase after LCO treatment goes hand in hand with an increase in the number of root nodules. As mentioned in Section 2, only nodules that appeared effective were counted. Therefore, it can be speculated that increasing the number of effective nodules per plant may result in better nitrogen supply to the plants and thus may increase pea yield. However, this may not be the only explanation for this effect.
The stimulation of lateral root formation and mycorrhizal colonization after LCO treatment was reported for alfalfa [47] and for legume plant Lablab purpurea [83]. Further research showed that both arbuscular mycorrhizal fungi [84] and ectomycorrhizal fungi [85] produce molecules called Myc-LCOs with structural similarity to rhizobial LCOs, which function as signals regulating fungal growth and development [86]. Both rhizobial LCOs and Myc-LCOs can activate a signaling pathway called the common symbiosis pathway, which is essential for root nodulation as well as root colonization by arbuscular fungi [87,88,89].
Also, several papers have been published on the relationship between molecular sig-nals such as rhizobial LCOs and plant resistance to abiotic and biotic stresses. It was demonstrated that LCO treatment can alleviate water stress in soybean [74,90], could overcome the adverse impact of low temperature and low pH on legume root hairs [50], and can mitigate the adverse effect of soil compaction on yield of pea [70]. Moreover, increased resistance of soybean to powdery mildew was achieved [91] and activation of plant defense-related genes was reported after lipochitooligosaccharide treatment [92].
Based on the presented data, it cannot be excluded that the recorded yield-enhancing effect of treating plants with rhizobial LCOs results not only from an increase in the number of nodules, but also from one of the additional factors mentioned above. Nevertheless, it is worth emphasizing that preparations containing rhizobial lipochitooligosaccharides appear to be a good means of increasing pea yield in field conditions, regardless of the mechanisms involved.

5. Conclusions

The soils on which the experiments were conducted varied, and the weather conditions differed significantly from those in the greenhouse. Despite these differences, the same effect was achieved as in the greenhouse experiments: a significant increase in the number and weight of nodules and a subsequent increase in pea yield after applying the rhizobial LCO preparation. This supports the recommendation to use such preparations in field pea cultivation.

Supplementary Materials

The following supporting information can be downloaded at https://www.mdpi.com/article/10.3390/agronomy16121133/s1, Figure S1: Plan of field experiment (the layout of experimental plots was the same for Site 1 and Site 2).

Author Contributions

Conceptualization, J.P., A.P. and J.W.; methodology, J.P. and A.P.; validation, J.P. and A.P.; formal analysis, J.P. and A.P.; investigation, J.P., A.P. and D.K.; resources, J.P. and A.P.; data curation, J.P., A.P. and J.W.; writing—original draft preparation, J.P., A.P., D.K. and J.W.; writing—review and editing, J.W. and D.K.; visualization, J.P., A.P. and J.W.; supervision, A.P.; project administration, J.P. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

The raw data supporting the conclusions of this article will be made available by the authors on request.

Conflicts of Interest

The authors declare no conflicts of interest.

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Figure 1. Course of weather conditions throughout the pea vegetation period.
Figure 1. Course of weather conditions throughout the pea vegetation period.
Agronomy 16 01133 g001
Figure 2. Relationship between the pea yield and the number of nodules per plant.
Figure 2. Relationship between the pea yield and the number of nodules per plant.
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Figure 3. Relationship between the pea yield and the mass of nodules per plant.
Figure 3. Relationship between the pea yield and the mass of nodules per plant.
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Table 1. The composition of soils used in field experiments.
Table 1. The composition of soils used in field experiments.
DescriptionpHN-NO3N-NH4K2OP2O5MgOSBCuFeMnMoZnCorg.Humus
mg/kgmg/100 gmg/kg%
Site 1 5.37.35.524.015.85.30.684.41.862374.60.024.60.741.28
Site 25.812.52.916.818.45.41.266.52.965978.40.044.70.811.40
Table 2. Fresh and dry mass of pea vegetative parts at flowering (BBCH 60).
Table 2. Fresh and dry mass of pea vegetative parts at flowering (BBCH 60).
TreatmentFresh Mass (g/Plant)Dry Mass (g/Plant)
AbovegroundRootsAbovegroundRoots
Site 1
Control2.080.311.340.25
LCOs 1:12.310.381.580.33
LCOs 1:102.330.411.470.32
LCOs 1:1002.360.371.500.34
Site 2
Control2.260.441.530.30
LCOs 1:12.700.521.740.40
LCOs 1:102.480.491.820.37
LCOs 1:1002.660.491.710.41
LSD (p ≤ 0.05) Site × Concentration
of the preparation
n.s. *n.s.n.s.n.s.
Controlmean for
the concentration
of the preparation
2.170.371.430.27
LCOs 1:12.500.451.660.36
LCOs 1:102.400.451.640.34
LCOs d 1:1002.510.431.600.37
 LSD (p ≤ 0.05)0.1890.0360.1270.028
Site 1mean for the
site
2.270.371.470.31
Site 22.520.481.700.37
 LSD (p ≤ 0.05)0.1580.0290.1070.024
* not significant.
Table 3. Mass of pea vegetative parts harvested at full maturity (BBCH 80).
Table 3. Mass of pea vegetative parts harvested at full maturity (BBCH 80).
TreatmentPlant Organ Mass (g/Plant)
StemsSiliquesSeedsRoots
Site 1
Control4.640.563.800.10
LCOs 1:14.840.694.070.09
LCOs 1:104.930.744.200.10
LCOs 1:1005.060.774.200.12
Site 2
Control4.740.673.980.11
LCOs 1:15.130.694.190.12
LCOs 1:105.270.864.320.15
LCOs 1:1004.970.774.390.16
LSD (p ≤ 0.05) Site × Concentration
of the preparation
n.s. *0.068n.s.0.013
Controlmean for
the concentration
of the preparation
4.690.613.890.10
LCOs 1:14.980.694.130.10
LCOs 1:105.100.804.260.12
LCOs 1:1005.010.774.290.14
LSD (p ≤ 0.05)0.3970.0570.3180.010
Site 1mean for the
site
4.870.694.060.10
Site 25.030.754.220.13
LSD (p ≤ 0.05)n.s.0.046n.s.0.009
* not significant.
Table 4. Number and mass of root nodules at flowering (BBCH60).
Table 4. Number and mass of root nodules at flowering (BBCH60).
TreatmentNodule Number
per Plant
Mass of Nodules (g/Plant)
FreshDry
Site 1
Control9.80.240.076
LCOs 1:112.60.280.068
LCOs 1:1014.50.300.072
LCOs 1:10014.00.310.080
Site 2
Control10.60.310.089
LCOs 1:112.00.360.090
LCOs 1:1015.70.350.084
LCOs 1:10016.40.410.104
LSD (p ≤ 0.05) Site × Concentration
of the preparation
1.307n.s. *n.s.
Controlmean for
the concentration
of the preparation
10.20.270.082
LCOs 1:112.30.320.079
LCOs 1:1015.10.320.078
LCOs 1:10015.20.360.092
 LSD (p ≤ 0.05)1.0380.0260.007
Site 1mean for the
site
12.70.280.074
Site 213.70.360.091
 LSD (p ≤ 0.05)0.8920.0220.006
* not significant.
Table 5. Growth rate of pea plant parts during the vegetation period.
Table 5. Growth rate of pea plant parts during the vegetation period.
TreatmentAboveground PartRoots
from Sowing to Floweringfrom Flowering to Full Maturityfrom Sowing to Floweringfrom Flowering to Full Maturity
Site 1
Control24.8138.854.63−4.28
LCOs28.0940.867.28−6.48
Site 2
Control28.3336.775.55−5.43
LCOs32.5437.207.22−7.14
NIRn.s.2.041.44n.s.
Controlmean for
the concentration
of the preparation
26.5737.815.09−5.38
LCOs30.3139.037.25−6.81
NIR1.77n.s. *0.65n.s.
Site 1mean for the
site
26.4539.855.955,38
Site 230.4336.986.386.28
NIR1.141.57n.s.n.s.
* not significant.
Table 6. Yield and yield structure of pea.
Table 6. Yield and yield structure of pea.
TreatmentYieldPod
Number
Seed
Number
Seed
Number
Mass of 1000
(t/ha)per Plantper Plantin PodSeeds (g)
Site 1
Control2.155.1816.53.19244
LCOs 1:12.275.3817.13.18246
LCOs 1:102.375.6419.53.46254
LCOs 1:1002.345.3818.93.51240
Site 2
Control2.25 5.3018.03.40241
LCOs 1:12.435.8019.83.41233
LCOs 1:102.445.8519.53.33235
LCOs 1:1002.505.9320.53.46234
LSD (p ≤ 0.05) Site × Concentration
of the preparation
n.s. *n.s.n.s.n.s.n.s.
Controlmean for
the concentration
of the preparation
2.205.2417.253.29242
LCOs 1:12.355.5918.453.29239
LCOs 1:102.415.7519.503.39245
LCOs 1:1002.425.6619.703.48237
 LSD (p ≤ 0.05)0.1760.4321.417n.s.n.s.
Site 1mean for the
site
2.285.3918.003.33235
Site 22.415.7219.453.40246
 LSD (p ≤ 0.05)n.s.n.s.1.236n.s.n.s
* not significant.
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Podleśna, A.; Podleśny, J.; Wielbo, J.; Kidaj, D. A Preparation Containing Rhizobial Lipochitooligosaccharides Improves Pea Productivity in the Field. Agronomy 2026, 16, 1133. https://doi.org/10.3390/agronomy16121133

AMA Style

Podleśna A, Podleśny J, Wielbo J, Kidaj D. A Preparation Containing Rhizobial Lipochitooligosaccharides Improves Pea Productivity in the Field. Agronomy. 2026; 16(12):1133. https://doi.org/10.3390/agronomy16121133

Chicago/Turabian Style

Podleśna, Anna, Janusz Podleśny, Jerzy Wielbo, and Dominika Kidaj. 2026. "A Preparation Containing Rhizobial Lipochitooligosaccharides Improves Pea Productivity in the Field" Agronomy 16, no. 12: 1133. https://doi.org/10.3390/agronomy16121133

APA Style

Podleśna, A., Podleśny, J., Wielbo, J., & Kidaj, D. (2026). A Preparation Containing Rhizobial Lipochitooligosaccharides Improves Pea Productivity in the Field. Agronomy, 16(12), 1133. https://doi.org/10.3390/agronomy16121133

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