Growth and yield response of pepper (Capsicum annuum L .) to foliar application of carrageenan plant growth promoter

The study determined the growth and yield response of pepper ( Capsicum annuum L.) to varying concentrations and frequencies of Carrageenan Plant Growth Promoter (CPGP). The study was set-up in a split-plot randomized complete block design with three replications. The three varying application frequencies were designated as main-plots, and the four concentrations of CPGP, as sub-plots. Peppers applied with 120 ppm and two to three times application of CPGP significantly matured earlier based on number of days to flowering and number of days to first priming. The same treatment combination resulted in significantly taller plants and higher number of lateral shoots. In terms of yield, however, CPGP at 120 ppm applied three times gave significantly higher number and heavier weight of fruits. The concentration of 120 ppm CPGP applied thrice in growing pepper is shown in the study to be the best treatment combination, thus, is recommended to improve the growth and increase the yield of pepper.


Introduction
With the increasing demand for pepper worldwide, the market is expecting a continuous upward market trend up until 2025.It is projected that at the end of 2025, pepper market volume will be 840,000 T.However, there are indicated fluctuations of pepper production from 2007-2018(Globe Newswire, 2020).In the Philippines, pepper production is about 15 T/ha as of 2017 (DA-RFO2, 2017).
Depolymerized carrageenan through gamma-irradiation is a polysaccharide and a stimulant that has been a subject for researches in the recent years (Naeem et al., 2014;Abad et al., 2011Abad et al., , 2016Abad et al., , 2018)).Carrageenan is considered to be potent elicitors of plant defense responses (Mercier et al., 2001;Kloareg & Quatrano, 1998;Potin et al. 1999;Ning et al., 2003), as plant growth promoters (Hien et al., 2000;Kume et al., 2002;Naeem et al., 2011Naeem et al., , 2012Naeem et al., , 2014)), inducer of seed germination (Hien et al., 2000), shoot elongation (Hien et al., 2000& Natsume et al., 1994), root growth (Iwasaki & Matsubara, 2000), flower production (Darvill et al., 1992), antimicrobial activity (Luan, 2003), and have prominent effects on the physiological activities of plant (Abad et al., 2009;Bi et al., 2010;Kume et al., 2002;Naeem et al., 2011;Relleve et al., 2000Relleve et al., , 2005)).This is commercially known as carrageenan plant growth promoter (CPGP).This plant stimulant aims to increase the growth and yield of pepper to aid in the projected increase in pepper demand.There has not also been much studies concerning the effects of CPGP on pepper.According to Abad (2018), there have not been studies to credit the effect of carrageenan on vegetables.Factors like dosage and frequency, among others should be considered (MMSU, 2018).Hence, this study aimed to assess the impact of CPGP on Solanaceous crops and propose the ideal concentration and application frequency for farmers' adoption.The findings aim to contribute to the enhancement and stabilization of pepper production nationally.Additionally, the research sought to validate a technology capable of accelerating pepper growth and enhancing production capacity.

Characteristics of Pepper
Pepper, a significant crop with diverse uses, is characterized by its genetic and phenotypic variability.The Capsicum genus, which includes pepper, is a valuable resource for breeding programs due to its genetic diversity (Kole et al., 2019).This diversity is evident in Brazilian Capsicum frutescens, which shows variation in morphological and molecular traits, as well as resistance to viruses (Lima et al., 2017).Similarly, the parents and interspecific hybrids of different pepper species exhibit genetic diversity, particularly in fruit length and seed yield (Costa, 2016).This genetic diversity is further highlighted in a collection of Spanish pepper landraces, where differences in fruit characteristics and origin are associated with genetic separation (Pereira-Dias et al., 2019).These studies underscore the importance of understanding and utilizing the genetic diversity of pepper for breeding and conservation efforts.

Challenges in Pepper Production
Pepper production faces numerous challenges, primarily stemming from pest and disease pressures.Insect pests such as cutworms, aphids, armyworms, and flea beetles, among others, hinder pepper growth and affect fruit quality (Bloomfield, 2020).The challenges in pepper production, including pest and disease pressures, have been addressed in various studies, highlighting the use of integrated pest management, which has increased pepper yields but also led to the exacerbation of certain pest populations.For instance, Doğan (2016) explored alternative production practices and proposed a microbial-based production system for greenhouse-grown peppers.On the other hand, Mathews (2017) evaluated the effectiveness of a polyculture trap crop for organic management of stink bugs in peppers, finding that while it reduced pepper damage, it was not economically viable.These studies collectively underscore the need for a holistic approach to pepper production that addresses both pest and disease pressures and soil quality.

Seaweed Extracts and Botanicals
The use of seaweed-based biostimulants in agriculture has gained significant attention due to their ability to enhance plant growth and resilience, improve soil health, and mitigate abiotic and biotic stresses (Nanda et al., 2021;Nabti et al., 2017;Mukherjee & Patel, 2019;Begum, 2018).These biostimulants, derived from seaweed extracts, contain a range of beneficial compounds and nutrients, including plant growth regulators, macronutrients, and micronutrients (Nanda et al., 2021;Begum, 2018).They can be applied through various methods, such as foliar treatments, and have been shown to promote soil microflora, increase plant growth-promoting bacteria, and suppress pathogens.Furthermore, seaweed extracts have been found to enhance seed germination, plant growth, and yield, and improve the nutritional quality of agricultural crops (Nabti et al., 2017;Mukherjee & Patel, 2019;Begum, 2018).
Seaweed extracts have been shown to have significant biostimulant properties, impacting seed germination, plant establishment, and growth (Ali, 2021).These extracts contain a range of growth regulators and nutrients, including cytokinins, auxins, gibberellins, and macronutrients, which contribute to their beneficial effects on plant growth and yield (Begum, 2018).They also play a role in mitigating abiotic stress in plants, such as drought, heat, and salinity (Moyo, 2021).However, further research is needed to fully understand their efficacy and chemical interactions for sustainable crop management (Seiber et al., 2014;Ertani et al., 2013).

Carrageenan
Carrageenan, a polysaccharide mixture extracted from red seaweeds, has been found to have various applications.Shukla et al. (2016) and Zia et al. (2017) both highlight its potential in agriculture, with Shukla discussing its role in promoting plant growth and defense responses, and Zia focusing on its use in controlled drug delivery systems.
Carrageenans are utilized in their oligomer forms in biological applications due to their superior gelling and viscosity properties, often prepared through chemical or enzymatic hydrolysis.However, in recent years, there has been significant interest in radiation processing for carrageenan degradation, resulting in low molecular weight oligomers.This technology has led to the synthesis of value-added products such as plant growth promoters and protectors (Ali, 2014).

Carrageenan Plant Growth Promoter (CPGP)
The Carrageenan Plant Growth Promoter (CPGP) is a product developed through collaboration of the Philippine Nuclear Research Institute of the Department of Science and CPGP functions as a foliar growth promoter, enriched with micro and macro elements alongside phytohormones that enhance photosynthetic activity.
An analysis conducted by VitalGro, the producer of CPGP, revealed the presence of essential elements within the formulation.The product has been shown to increase rice yield by an average of around 20% and enhance resistance to the tungro virus (Abad 2018).This aligns with the broader perspective of plant growth-promoting microorganisms (PGPM) in rhizosphere engineering for sustainable agriculture, which emphasizes the role of PGPM in improving soil structure, health, fertility, and functioning to support plant growth under normal and stressed environments (Hakim, 2021).

Effects of CPGP on Field Crops
Research conducted by Abad et al. (2018) at the PNRI-DOST demonstrated that in field experiments conducted in Regions II, III, and IV-A in the Philippines, there was a notable increase in the yield of mungbean and peanut ranging from 16% to 51% with RMC-PGP concentrations ranging from 50 to 200 parts per million (ppm).The study highlighted the variation in the optimal concentration of RMC-PGP depending on the specific varieties of mungbean and peanut suitable for a particular location.Another project led by the Philippine Rice Research Institute (PhilRice) investigated the synergistic mechanism of RMC in promoting the growth of rice under greenhouse and field conditions.Yap (2018) reported higher seed germination rates, increased tiller and panicle production, and higher yields with the application of 300-400 ppm RMC-PGP in rice cultivation.Additionally, Centeno (2016) conducted field trials in Bulacan, suggesting that carrageenan could enhance rice plant resistance against natural disasters, leading to stronger and healthier crops compared to those treated solely with commercial fertilizers.The application of carrageenan PGP, along with chemical fertilizers, resulted in yield increases ranging from 15% to 40%, an increase in grain weight by 65.4%, and improvements in panicle length by 3.5% to 12.5%.
A range of studies have demonstrated the potential of gamma irradiation and carrageenan in enhancing plant growth and yield.El-sayed (2024) found that low doses of gamma irradiation significantly improved the growth and yield of cumin plants, while higher doses had a negative impact.These findings are consistent with the work of Relleve et al. (2000), who identified a specific molecular weight range of kappa carrageenan that promoted optimal weight gain in rice seedlings.Bi et al. (2010) further explored the effects of kcarrageenan on the growth of chickpea and maize, observing significant enhancements in growth characteristics with various elicitor treatments.
In tobacco plants, Moreno et al. (2020) and Kössler (2021) both observed increased biomass and altered plant architecture and metabolism, with Moreno attributing these changes to the expression of a carotenogenic gene, and Kössler to the expression of lycopene β-cyclase.These studies justify the research of Castro et al. (2012), whereon carrageenan revealed significant improvements in leaf biomass and physiological parameters of tobacco plants.Oligo-carrageenans (OC), kappa (K), lambda (L), and iota (I) applied to tobacco leaves resulted in increased leaf biomass and chlorophyll levels, as well as upregulation of essential metabolic pathways.Hashmi et al. (2012) investigated the impact of irradiated carrageenan on the performance of fennel, observing significant enhancements in growth attributes, essential oil yield, and active constituents at optimal concentrations.Similarly, Naeem et al. (2012) studied the effects of irradiated carrageenan on mint and Madagascar periwinkle, noting significant improvements in growth attributes, herbage yield, and essential oil yield at specific concentrations.This is further supported by Youssef et al. (2020), who demonstrated that the combination of chemical nitrogen fertilizers, organic and bio-fertilization, and antioxidants can also improve the herb, fruit, and essential oil yields of fennel.

Effects of CPGP on Vegetable Crops
In a study by Pamati-an et al. (2020), the effects of irradiated carrageenan (IC), commercial foliar fertilizer, and tap water on cherry tomatoes were compared.Various growth parameters such as stem length, stem diameter, leaf area, number of days to flowering, number of days to priming, number of branches, and number of harvested fruits were recorded.The results indicated that irradiated carrageenan had a significant impact compared to the other treatments.The study concluded that IC enhances the growth of cherry tomatoes during the vegetative stage, potentially resulting in earlier harvests and improved production.

Carrageenan Irradiation
In an interview, Dr. Lucille Abad highlighted the irradiation process involved in carrageenan, emphasizing that it breaks down large molecules into smaller ones, making carrageenan more easily absorbed by plant leaves.She also emphasized that irradiated carrageenan is safe because it is not radioactive (MMSU, 2018).Hashmi et al. (2012) and Sarfaraz et al. (2011) both found that irradiated carrageenan and sodium alginate, respectively, significantly improved the growth and physiological attributes of fennel.
However, Khan et al. (2015) noted that gamma-irradiation of fennel seeds caused slight variations in volatile flavor compounds, with no significant loss of major flavor compounds.observed similar effects of irradiated carrageenan on plant growth, physiological attributes, herbage yield, and essential oil content and yield in corn mint.They found that un-irradiated carrageenan had no significant effect on these parameters, similar to deionized water.In a study by Ali (2014), results indicated that un-irradiated carrageenan performed the least among carrageenan-influenced treatments in various parameters related to germination, growth, physiology, biochemical attributes, and yield and quality characteristics of Eucalyptus citriodora.This is consistent with the findings of Singh (2017), who demonstrated that gamma irradiated carrageenan can mitigate the harmful effects of drought stress on lemongrass, improving its biochemical characteristics and essential oil production.

Experimental Design and Treatments
The field experiment was conducted in a 6

Seed Sowing and Seedling Establishment
Seedling trays with 104 holes were used for seed sowing and seed germination.
Pepper seeds were primed with water for 12 hours, then air dried before sowing.The growth media was a mixture of garden soil and vermicompost (1:1).One seed was sown per cell with the provision of adequate light and water.

Transplanting and Replanting
Seedlings were transplanted when they have reached a stable phase, 28 days after sowing.Planting distance was 0.5m x 0.8m.Irrigation followed immediately and replanting of missing hills was done as necessary.

Foliar Application of Treatments
Application of different treatments started from ten days after transplanting.It was done every ten days (Ali, 2014), in accordance to the designated frequency of application.A hand-held pressurized sprayer was used to apply the different concentrations of CPGP, with the aid of plastic sheets to prevent unwanted spread of applied treatments to other plots.The amount of solution sprayed increased as the plants grow.Treatments were applied early in the morning.
In a personal communication with Dr. Lucille V. Abad, inventor of the Carrageenan Plant Growth Promoter (CPGP), the base concentration is 10,000 ppm.Dilution for treatment application of the CPGP were 60 ppm, 120 ppm, 240 ppm, and 480 ppm with application frequencies of 2x, 3x, and 4x.

Harvesting
Harvesting was done six times for all treatments, starting when all of the plants per plot have at least one fruit that is ready for harvest.Fruits were harvested at the mature green stage, when the fruits have attained full size and appear waxy and shiny.Fruit picking was done by breaking the pedicel with an upward twist or by cutting the pedicle with a sharp knife or a pair of scissors.

Determination of growth attributes
Number of days to flowering.The number of days to flowering was counted from transplanting to the day when 50 percent of all the plants in each replication have at least three opened flowers.Number of lateral shoots.Lateral shoots were counted at 60 DAT.

Determination of yield attributes
Number, weight, and percent non-marketable fruits per plot.The number and weight of non-marketable fruits per plot were counted.The different indices used to identify damaged or non-marketable fruits were presence of holes, occurrence of alteration in coloration of fruits, the inside of the fruit is hollow and filled with frass, curled fruits, and rotten fruits.
Number, weight, and percent marketable fruits per plot.Fruits without the presence of holes, frass, rot, curling or any damage, per plot, were considered non-infested or marketable fruits, and were counted and weighed.
Total number and weight of fruits per plot and per plant.This is the cumulative (six harvestings) number and weight of infested plus non-infested fruits per treatment.
Computed yield per hectare.The total weight of marketable fruits harvested in a yield plot area (4 m 2 ) was converted into per hectare basis.

Ethical Considerations
There were several ethical considerations addressed in the study to ensure the integrity and responsible conduct of the research.
Environmental impact.The use of carrageenan as a plant growth promoter was chosen based on its natural origin and biodegradability.Care was taken to ensure that the application rates used in the study did not exceed environmentally safe levels, thus, minimizing any potential negative impact on the surrounding ecosystem.
Sustainability.The study prioritized sustainable agricultural practices by selecting a plant growth promoter that is derived from renewable resources.Carrageenan, extracted from seaweeds, is considered environmentally friendly and sustainable, aligning with the principles of sustainable agriculture.
Human and animal safety.The safety of researcher, field workers, and any local wildlife was paramount.Personal protective equipment (PPE) was used during the handling and application of the carrageenan solution to prevent any direct contact or inhalation.
Additionally, the fields were monitored to ensure that no potential harm came to animals that might come into contact with the treated plants.
Data integrity and reporting.The research was conducted with a commitment to transparency and honesty in data collection, analysis, and reporting.All findings, whether positive or negative, were reported accurately to contribute to the body of scientific knowledge without bias or manipulation.
Compliance with regulations.The study complied with all relevant local, national, and international regulations regarding agricultural research and the use of plant growth promoters.

Number of Days to Flowering
The frequency and concentration of CPGP application significantly influence the number of days to flowering in peppers.Applying CPGP three times resulted in the shortest time to flowering, 35.50 days, followed by twice application with a difference of 1.44 days.
Among different concentrations, 120 ppm led to the earliest flowering, 8.67 and 8.44 days earlier than negative and positive controls, respectively.Interaction effects between concentration and application frequency revealed that peppers sprayed two to three times at 120 ppm matured earliest, while four times at 240 ppm and two times at 240 ppm resulted in delayed flowering.

Number of Days to First Priming
The frequency of CPGP application significantly affects the number of days to first priming in peppers, with a highly significant difference observed.Applying CPGP three times resulted in fruits appearing 2.28 days earlier than those sprayed twice.Regarding concentration, peppers treated with 120 ppm CPGP bore fruits 10 days earlier than controls, while variations in CPGP concentrations showed significant differences, with 120 ppm and 240 ppm leading to the earliest priming at 41.33 and 47.11 days, respectively.Interaction effects revealed that the frequency of application had no significant impact on first priming time at 120 ppm concentration, but four times of application across different concentrations showed promise in reducing days to first priming.These findings align with Pamati-an et al.'s (2020) research, demonstrating that cherry tomatoes treated with irradiated carrageenan experienced significantly earlier priming compared to controls and those treated with commercial foliar fertilizers.Their study involved five applications of irradiated carrageenan at a one percent solution every 14 days, similar to our findings where earlier flowering resulted in earlier fruiting.

Plant Height
Regarding plant height, varying frequencies of CPGP application did not yield significant differences.However, concentrations of 120 ppm and 240 ppm showed no significant difference between them, both resulting in heights of 69.73 cm and 69.67 cm, respectively, but differed significantly from control groups and other concentrations.
Interaction effects revealed that peppers sprayed two to three times with 120 ppm displayed taller plants, with heights of 70.43 cm and 69.40 cm, respectively.Similar findings in studies by Abad et al. (2018), Gatan et al. (2019), Bi et al. (2010), andHashmi et al. (2012) indicate that carrageenan foliar application significantly influences plant height, with various concentrations and frequencies producing notable effects.Carrageenan application enhances plant height by stimulating photosynthesis, carbon fixation, and enzymatic activity, such as Rubisco, glutamate dehydrogenase, and pyruvate dehydrogenase, leading to increased growth and development.Moreover, the activation of NADP(H)-synthesizing enzymes contributes to enhanced photosynthesis and ancillary plant processes, ultimately promoting growth (Castro et al., 2012;Munoz et al., 2011).

Number of Lateral Shoots
In terms of the number of lateral shoots, varying frequencies of Carrageenan Plant Growth Promoter (CPGP) application led to a highly significant difference.Plants treated with CPGP three times exhibited the highest number of lateral shoots at 11.94, comparable to twice and four times application frequencies with differences of 0.89 and 0.44, respectively.
Regarding concentration, 120 ppm yielded the greatest number of lateral shoots, not significantly different from 240 ppm, while 480 ppm showed comparable results to the positive control.Interaction effects revealed that the combination of 120 ppm concentration with three foliar applications resulted in the highest lateral shoot count, though not significantly different from treatments with 240 ppm applied thrice or 120 ppm applied four times.This trend aligns with findings by Bi et al. (2010) and Pamati-an et al. (2019), suggesting that carrageenan-treated plants exhibit significantly higher lateral shoot numbers compared to untreated or commercially sprayed plants.Spray applications of carrageenan have been associated with increased cell division in tobacco, leading to increased cell number without altering cell size.

Number of Marketable Fruits
The number of marketable fruits demonstrates significant variation influenced by both the frequency and concentration of CPGP application.Notably, applying CPGP three times resulted in a significantly higher yield compared to twice, with a difference of 218.22 fruits, while four-time application showed comparable yields to three-time application.
Regarding concentration, 120 ppm CPGP produced significantly more marketable fruits than 240 ppm, with a difference of 119.77 fruits, showing notable disparity from control groups.
Interaction effects between frequency and concentration were also significant, with 120 ppm concentration combined with three or four applications yielding the highest fruit counts.
Conversely, two-time application with the same concentration resulted in substantially fewer fruits.These findings align with research by Abad et al. (2018) and Gatan et al. (2019), demonstrating that carrageenan application enhances fruit yield in peanuts by increasing net photosynthesis and the number of seeds per pod.

Weight of Marketable Fruits
The weight of marketable fruits is significantly influenced by both the frequency and concentration of CPGP application.While three-time and four-time applications did not significantly differ, three applications resulted in 6163.47 g of fruits, notably more than fourtime and two-time applications.Concentration also played a crucial role, with 120 ppm yielding 3858.82 g more than the negative control and 2831.20 g more than the positive control.Interaction effects showed that the combination of three-time application and 120 ppm concentration resulted in the heaviest fruit weight at 8614.63 g, consistently producing the highest growth attributes and yield components.These findings are consistent with local studies documenting increased crop yield at various concentrations of carrageenan, such as 'pechay' at 60 ppm and rice at 200 ppm.Hashmi et al. (2012) also noted increased yield attributes in Foeniculum vulgare Mill, attributed to enhanced water and nutrient uptake from the soil and efficient translocation of photosynthates and metabolites to plant sinks.

Number and Weight of Non-Marketable Fruits
Regarding the number of non-marketable fruits, neither the frequency of application nor the concentration of CPGP showed significant differences.Similarly, for the weight of non-marketable fruits, there were no significant effects observed for either frequency or concentration, although 120 ppm concentration yielded the heaviest weight at 618.51 g.
Interaction effects did not show any significant interactions between application frequencies and CPGP concentrations, although three-time application at 60 ppm concentration resulted in the lowest weight of non-marketable fruits.These findings suggest that while CPGP application may not affect the quantity of non-marketable fruits significantly, certain concentrations may influence their weight, albeit without statistical significance.

Total Number of Fruits
Regarding the total number of fruits, both the frequency and concentration of CPGP application played significant roles in influencing yield.Notably, three-time application consistently yielded the highest total number of fruits, closely followed by four-time application, with no statistically significant difference between them.Concentration-wise,

Total Weight of Fruits
Regarding the total weight of fruits, both the frequency and concentration of CPGP application significantly impacted yield.Notably, three-time application consistently yielded the highest total weight of fruits at 6739.56 g, followed closely by four-time application at 6453.92 g, with no statistically significant difference between them.Concentration-wise, 120 ppm CPGP resulted in the largest accumulation of fruit weight, surpassing control groups by 3918.98 g and 2839.13 g more than negative and positive controls, respectively.Interaction effects further emphasized the effectiveness of the combination of three-time frequency and 120 ppm concentration, yielding the highest fruit weight at 9246.61 g, significantly differing from all other treatments.These findings parallel those of Akhter et al. (2018), where threetime application of a plant growth regulator (PGR) resulted in maximum yield for sweet pepper, significantly differing from other treatments presented.

Conclusion
Based on the results, this study concludes that the interaction of three-time frequency of application and 120 ppm concentration of CPGP shortened the number of days to flowering and first priming.It also gave the highest plant height, number of branches, number and weight of marketable and non-marketable fruits, total weight of fruits per plot and computed yield per hectare.The concentration of 120 ppm CPGP foliar spray gave the best results in all growth and yield parameters tested in the study.Among the three frequencies tested, foliar application of CPGP three times in pepper yielded best results.
Lastly, the foliar application of CPGP at 120 ppm and 240 ppm reduced the rate of fusarium wilt infection in pepper plants.
-DOST), the National Crop Protection Center of the University of the Philippines-Los Baños, and the Philippine Rice Research Institute.This initiative, under the program "Plant Bio-Stimulant and Elicitors from Radiation-Modified Natural Polymers" of the Research and Development sector, aims to leverage radiation-modified carrageenan (RMC) as a plant growth promoter (PGP) to enhance integrated nutrition management strategies and improve plant health and resistance, ultimately increasing crop productivity.

Mercier
et al. (2001)  found that carrageenans, a type of sulfated polysaccharide, effectively induced signaling and defense gene expression in tobacco leaves.This is consistent with the study byDjami-Tchatchou (2017), which showed that both azelaic acid and hexanoic acid, chemical elicitors, activated genes involved in systemic acquired resistance in tobacco cells.Similarly,Cai (2020) demonstrated that plant-derived compounds, ursolic acid and 4-methoxycoumarin, induced resistance responses in tobacco plants against Tobacco mosaic virus.These studies collectively suggest that various compounds, including carrageenans, azelaic acid, hexanoic acid, ursolic acid, and 4methoxycoumarin, can elicit plant defense responses.Gatan et al. (2019) conducted experiments to assess the effects of radiation-modified kappa-carrageenan (RMKC) on mungbean plants.They found that foliar application of carrageenan at a concentration of 60 ppm induced flowering, increased plant height, and enhanced seed yield.Additionally, comparisons with other treatments showed that RMKC was more effective than a seaweed-based commercial foliar fertilizer and other seaweed extracts irradiated at different dose levels.In another stuy, Ahmad et al. (2018) investigated the relationship between irradiation-mediated molecular weight reduction and structural modification of carrageenan, and its growth-promoting activity.They applied graded concentrations of irradiated carrageenan to peppermint plants and found that 80 mg/L of irradiated carrageenan had the most favorable effects on various growth parameters and enzymatic activities.Singh et al. (2017) studied the influence of different carrageenan concentrations on lemongrass under drought stress conditions.They observed that foliar application of gammairradiated carrageenan at a concentration of 80 mg/L alleviated the detrimental effects of drought stress and improved the biochemical characteristics and essential oil content of lemongrass significantly.On the other hand, Mousavi et al. (2018) investigated the efficacy of carrageenan in controlling C. campestris invasion in basil plants.They found that carrageenan treatment increased shoot length and leaf area of basil, decreased C. campestris infestation, and stimulated defense responses by activating the phenylpropanoid pathway and increasing PAL activity, phenols, antioxidants, and lignin content.
-Khormizi et al. (2022) found that vermicompost, an organic fertilizer, mitigated the adverse effects of salinity stress on fennel, improving various plant characteristics.Ahmad et al. (2018) concluded that irradiated carrageenan has advantages over unirradiated carrageenan due to reduced molecular weight and certain structural modifications, facilitating improved growth promotion.They found that irradiation-induced molecular weight reduction and structural modification contributed to the growth promotion activity, with 80 mg/L IC showing significant differences in essential oil content and yield compared to the control and un-irradiated carrageenan.On the other hand,Naeem et al. (2012) x 3 split plot arranged in Randomized Complete Block Design (RCBD) with three replications.The main plot indicates the frequency of foliar application and the sub-plot represents different carrageenan PGP concentrations.Fourteen plants were planted in every plot, having two rows and seven hills within each row.A total of 756 plants were used in the study.The following treatments were used in the study: Main Plot (Frequency of application) A1: Two Times (10 days after transplanting (DAT), and 20 DAT) A2: Three Times (10 DAT, 20 DAT, and 30 DAT) A3: Four Times (10 DAT, 20 DAT, 30 DAT, and 40 DAT) Number of days to first priming.This was counted from transplanting to the day when 50 percent of all the plants in each replication have at least one fruit ready for harvest.Plant height.Plant height was measured from the surface of the soil to tipmost part of the main stem.It was done at 60 DAT.
120 ppm CPGP resulted in the highest accumulation of fruits, surpassing control groups by a substantial margin.Interaction effects further underscored the effectiveness of the combination of three-time frequency and 120 ppm concentration, yielding the highest fruit count among all treatments.These findings are consistent with research byAbad et al.   (2018), suggesting that RMKC-treated plants exhibit improved flower and fruit development, particularly at a concentration of 60 ppm.Similarly,Gatan et al. (2019) demonstrated significant yield increases with the application of 60 ppm RMKC, highlighting the potential for enhanced yield with CPGP application.

Table 2
Summary data on the growth of pepper as influenced by frequency of application of CPGP and its concentration application enhances plant growth by influencing nutrient accumulation, enzymatic activity, and metabolic processes, potentially contributing to earlier flowering.ISSN 2799-1601 (Print) 2799-161X (Online) | 35 *Means within a column having the same letter(s) is/are not significantly different at 5% level by DMRT test.

Table 3
Summary data on the quantity, weight, and computed yield per hectare (CY/H) of marketable and nonmarketable fruits as influenced by frequency of application of CPGP and its concentration

Table 4
Summary data on the quantity and weight of marketable against non-marketable fruits per plant as influenced by frequency of application of CPGP and its concentration *Means within a column having the same letter(s) is/are not significantly different at 5% level by DMRT test.

Table 5
Summary data on the total number and weight of fruits, its computed yield per hectare, and the weight per fruit as influenced by frequency of application of CPGP and its concentration *Means within a column having the same letter(s) is/are not significantly different at 5% level by DMRT test.ISSN 2799-1601 (Print) 2799-161X (Online) | 41