Response of Aeroponically Cultivated Baby-Leaf Lettuce (Lactuca sativa L.) Plants with Different Zinc, Copper, Iodine, and Selenium Concentrations

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Over two billion people worldwide suffer from micronutrient deficiencies. Biofortifying vegetables can enhance micronutrient intake through the diet. This study assessed the biofortification of indoor-grown baby-leaf lettuce using aeroponics. Various concentrations of Zn (from 10 to 450 µM), Cu (from 3 to 250 µM), I (0 and 5 µM), and Se (0 and 13 µM) were added, either separately or simultaneously, to the nutrient solution. The simultaneously biofortifying baby-leaf lettuce with these four minerals is a practical and convenient way to integrate these micronutrients into the diet without reducing the yield or quality of lettuce.

 

Here are some additional/specific comments to the article:

1. In the method, the author described the use of two nutrients, Zn (as Zn EDTA) and Cu (as Cu EDTA). I want to know what is the difference between Cu_1 and Cu_2 (or Zn_1 and Zn_2) and where is the difference? Is it the same substance? If it is the same substance, why is the experimental design not continuous, but separate for research and discussion. As shown in Table 1-4 and Figure 1-2

2. Leaf quality attributes: The concentration of total phenols, flavonoids, chlorophylls, and carotenoids, and the antioxidant capacity was determined at harvest in fresh leaves. Some methods used, were not sufficiently described. The authors refer to the previous publications, which are not always available. In this situation, it is difficult to repeat this experiment.

3. Line 188-189: The concentration of Cu in leaf of biofortified lettuce ranged from 0.682 to 1.132 kg⁻¹ FW. The “kg⁻¹ FW” change to “mg kg⁻¹ FW”. Please check it.

Line 259-260 The same problem also exists.

 

Author Response

Over two billion people worldwide suffer from micronutrient deficiencies. Biofortifying vegetables can enhance micronutrient intake through the diet. This study assessed the biofortification of indoor-grown baby-leaf lettuce using aeroponics. Various concentrations of Zn (from 10 to 450 µM), Cu (from 3 to 250 µM), I (0 and 5 µM), and Se (0 and 13 µM) were added, either separately or simultaneously, to the nutrient solution. The simultaneously biofortifying baby-leaf lettuce with these four minerals is a practical and convenient way to integrate these micronutrients into the diet without reducing the yield or quality of lettuce.

 

Here are some additional/specific comments to the article:

1. In the method, the author described the use of two nutrients, Zn (as Zn EDTA) and Cu (as Cu EDTA). I want to know what is the difference between Cu_1 and Cu_2 (or Zn_1 and Zn_2) and where is the difference? Is it the same substance? If it is the same substance, why is the experimental design not continuous, but separate for research and discussion. As shown in Table 1-4 and Figure 1-2

Response: The same fertilizer (Zn EDTA or Cu EDTA) was used in all the experiments. The difference between Zn_1 and Zn_2 (or Cu_1 and Cu_2) are the concentrations used, as reported in Table 1. The results obtained in the different experiments were kept separated because were collected in different experiments, but they were discussed together. More information about the experimental design were added at line 143-152. We did not test all the concentrations at the same time because we did not have enough aeroponic systems.

 

2. Leaf quality attributes: The concentration of total phenols, flavonoids, chlorophylls, and carotenoids, and the antioxidant capacity was determined at harvest in fresh leaves. Some methods used were not sufficiently described. The authors refer to the previous publications, which are not always available. In this situation, it is difficult to repeat this experiment.

Response: The methods used were better described at lines 184-194

3. Line 188-189: The concentration of Cu in leaf of biofortified lettuce ranged from 0.682 to 1.132 kg⁻¹ The “kg⁻¹FW” change to “mg kg⁻¹ FW”. Please check it.

Response: “mg” has been added

Line 259-260 The same problem also exists.

Response: “mg” has been added

 

 

Reviewer 2 Report

Comments and Suggestions for Authors

I reviewed the manuscript submitted by Puccinelli et al. for possible publication in Horticulturae. The idea of the manuscript is interesting, and the performed study is innovative in terms of Aeroponics cultivation, which also comes under the journal's scope.

Some of the suggestions are given below:

1-      The plagiarism of the manuscript is a little high (27%); please reduce it to 20% or below.

2-      The title of the manuscript is not attractive or technically sound. I suggest changing the title of the manuscript. For example Response of aeroponically cultivated baby-leaf lettuce (Lactuca sativa) plants with different zinc, copper, iodine, and selenium concentrations. Or any other suitable.

3-      The abstract can be improved.

4-      Keywords: if authors will change the title (as suggested above), please delete those keywords already mentioned in the title.

5-      Introduction: What is the main purpose of this study? Are you looking to see only the response of different zinc; copper; iodine and selenium concentrations by taking aeroponics as the cultivation method, or do you want to know the response of these factors, particularly in the aeroponics system?  Because still much information regarding aeroponics is not scientifically proven and needs researcher’s proper intention. The issues with the aeroponic system are well justified in a review study published in the Journal of Plant Interactions Modern plant cultivation technologies in agriculture under controlled environment: A review on aeroponics. In addition, if you see the response of zinc; copper; iodine and selenium concentrations especially in aeroponics, this study’s results are very important and innovative. If your purpose is this, please specify and revise your introduction according to aeroponics perspective.

6-      Line 49-50 close-loop hydroponics systems should be changed with soilless systems.

7-      Line 51 Among hydroponic cultivation systems should be among soilless systems.

8-      Line 51, where plant's roots are suspended in the air and frequently sprayed with the nutrient solution [33], changes to where the plants roots are suspended in the air and frequently or internally sprayed with the nutrient solution [33].

9-      Lines 51-52. You can add/use the below studies to justify your results. The below studies have published lettuce in aeroponics systems using different treatments. Influence of Atomization Nozzles and Spraying Intervals on Growth, Biomass Yield, and Nutrient Uptake of Butter-Head Lettuce under Aeroponics System. Agronomy 2021, 11, 97, Effects of droplet size and spray interval on root-to-shoot ratio, photosynthesis efficiency, and nutritional quality of aeroponically grown butterhead lettuce. Int J Agric & Biol Eng, 2022; 15(1): 79–88.

10-  Material and method: It suggested adding some information about aeroponics systems, such as developed by yourself or purchased from the market, how you control the spraying time and interval time; what the test selected nozzle type (because in aeroponics mainly three nozzles are used air-based, centrifugal and foggers).

11-  What was the droplet size of the atomized nozzle? For your reference, please see the studies mentioned above.

12-  Please provide the pH and EC values for the aeroponic nutrient solution, with a variation of one week (each day values).

13-  Lines 61-66, the sentence is too big; please be concise.  

14-  Line 74, as described later in the text. Please revise this

15-  Lines 76-77 90-L tank (67 x 41 cm, height 32 cm), closed on the top by a plastic tray hosting 380 plants (1400 plants m−2), and contained 77 30-L of nutrient solution at the bottom. I have questions about the above statement below.

16-  World 90-L tank is incorrect identification; please change it to the growth box.

17-  The total height of the system is 32 cm; if we reduce the water depth (30-liter water volume), the space for roots growing will decrease more. I think it’s not a recommended height for growing lettuce by selecting aeroponics growth box of small size as the studies mentioned earlier reported that they got lettuce roots growing up to 50-65 cm. What is your justification for this?

18-  What was the plant density in each aeroponics system?

19-  Lines 78-79 The nutrient solution was taken from the bottom of the tank by an external pump, sprayed on the plant roots for 30 seconds every 10  minutes, then collected again at the bottom. How did you apply the nutrient solution to plants? Did you spray manually.?

20-  Please provide the specifications of the external pump, including size, operating pressure, manufacture, etc.

21-  Line 82-83 The nutrient solution had a pH 82 of 5.6 and an electrical conductivity of 2.37 dS m−1. Are these results of the first time or after some days? What was the interval for changing the nutrient solution, weekly or otherwise? Please specify.  

22-  Which instrument was used to measure the EC and pH? Please specify,  

23-  Line 87, Air temperature and relative humidity were kept at 24.0 °C and 65%-70%, respectively. How did you keep this? Please specify,  

24-  I suggest adding colorful figures instead of black and white.

25-  The results and discussion section are well justified.

26-  The conclusion can be improved. Currently, only results are discussed. What are the recommendations and suggestions of this study?

Comments on the Quality of English Language

N/A

Author Response

I reviewed the manuscript submitted by Puccinelli et al. for possible publication in Horticulturae. The idea of the manuscript is interesting, and the performed study is innovative in terms of Aeroponics cultivation, which also comes under the journal's scope.

Some of the suggestions are given below:

• The plagiarism of the manuscript is a little high (27%); please reduce it to 20% or below.

Response: The percentage of plagiarism, excluding bibliography, figures and tables, has been reduced to 20%

The title of the manuscript is not attractive or technically sound. I suggest changing the title of the manuscript. For example Response of aeroponically cultivated baby-leaf lettuce (Lactuca sativa) plants with different zinc, copper, iodine, and selenium concentrations. Or any other suitable.

Response: We changed the title of the manuscript according to the title proposed by the reviewer.

3-      The abstract can be improved.

Response: Done

4-      Keywords: if authors will change the title (as suggested above), please delete those keywords already mentioned in the title.

Response: Done

5-      Introduction: What is the main purpose of this study? Are you looking to see only the response of different zinc; copper; iodine and selenium concentrations by taking aeroponics as the cultivation method, or do you want to know the response of these factors, particularly in the aeroponics system?  Because still much information regarding aeroponics is not scientifically proven and needs researcher’s proper intention. The issues with the aeroponic system are well justified in a review study published in the Journal of Plant Interactions Modern plant cultivation technologies in agriculture under controlled environment: A review on aeroponics. In addition, if you see the response of zinc; copper; iodine and selenium concentrations especially in aeroponics, this study’s results are very important and innovative. If your purpose is this, please specify and revise your introduction according to aeroponics perspective.

Response: We were looking to see the response of different Zn, Cu, I and Se by taking aeroponics as the cultivation method. We choose this cultivation system because it could be more suitable, than e.g. floating system, for the cultivation in vertical farms, where the production of biofortified vegetables, which can be sold at a higher price, could help cover the high production costs.

More information about aeroponics has been added in the Introduction (Lines 76-81), and the suggested review cited.

6-      Line 49-50 close-loop hydroponics systems should be changed with soilless systems.

Response: Done

7-      Line 51 Among hydroponic cultivation systems should be among soilless systems.

Response: Done

8-      Line 51, where plant's roots are suspended in the air and frequently sprayed with the nutrient solution [33], changes to where the plants roots are suspended in the air and frequently or internally sprayed with the nutrient solution [33].

Response: Done

9-      Lines 51-52. You can add/use the below studies to justify your results. The below studies have published lettuce in aeroponics systems using different treatments. Influence of Atomization Nozzles and Spraying Intervals on Growth, Biomass Yield, and Nutrient Uptake of Butter-Head Lettuce under Aeroponics System. Agronomy 2021, 11, 97, Effects of droplet size and spray interval on root-to-shoot ratio, photosynthesis efficiency, and nutritional quality of aeroponically grown butterhead lettuce. Int J Agric & Biol Eng, 2022; 15(1): 79–88.

Response: The reference to Tunio et al., (2022) has been added at line 75.

10-  Material and method: It suggested adding some information about aeroponics systems, such as developed by yourself or purchased from the market, how you control the spraying time and interval time; what the test selected nozzle type (because in aeroponics mainly three nozzles are used air-based, centrifugal and foggers).

Response: More information added at lines 127-137. The company that supplied the aeroponic systems prefers not to provide details on the type of nozzle, but only the flow rate. Anyway, the same nozzle type was used in all aeroponic systems, and during all the experiments, thus ensuring the same irrigation conditions.

11-  What was the droplet size of the atomized nozzle? For your reference, please see the studies mentioned above.

Response: The company that provided the aeroponic systems prefers to do not share this information. Anyway, the same droplet size was used in all aeroponic systems, and during all the experiments, thus ensuring the same irrigation conditions.

12-  Please provide the pH and EC values for the aeroponic nutrient solution, with a variation of one week (each day values).

Response: More details about the management of the nutrient solution were added at lines 177-185.

13-  Lines 61-66, the sentence is too big; please be concise. 

Response: The sentence has been revised and divided in four sentences. 

14-  Line 74, as described later in the text. Please revise this

Response: This part of the sentence was removed.

15-  Lines 76-77 90-L tank (67 x 41 cm, height 32 cm), closed on the top by a plastic tray hosting 380 plants (1400 plants m−2), and contained 77 30-L of nutrient solution at the bottom. I have questions about the above statement below.

Response: We hope we have satisfactorily answered the reviewer's questions.

16-  World 90-L tank is incorrect identification; please change it to the growth box.

Response: Changed according to the comment.

17-  The total height of the system is 32 cm; if we reduce the water depth (30-liter water volume), the space for roots growing will decrease more. I think it’s not a recommended height for growing lettuce by selecting aeroponics growth box of small size as the studies mentioned earlier reported that they got lettuce roots growing up to 50-65 cm. What is your justification for this?

Response: The nutrient solution, in the bottom of the growth box, has a height of about 7 cm, thus the free empty space available for root growth was about 25 cm. This space was enough in our experiments because we growth baby-leaf lettuce, with a shorter growing cycle and smaller roots than adult head lettuce. More information added at line 127-138.

18-  What was the plant density in each aeroponics system?

Response: As reported at line 131, 380 plants were host in each aeroponic system with a plant density of 1400 plants m-2.

19-  Lines 78-79 The nutrient solution was taken from the bottom of the tank by an external pump, sprayed on the plant roots for 30 seconds every 10  minutes, then collected again at the bottom. How did you apply the nutrient solution to plants? Did you spray manually.?

Response: The nutrient solution was sprayed onto the roots through a timed pump and nozzles. More information added at lines 127-138.

20-  Please provide the specifications of the external pump, including size, operating pressure, manufacture, etc.

Response: More information added at lines 127-138.

21-  Line 82-83 The nutrient solution had a pH 82 of 5.6 and an electrical conductivity of 2.37 dS m−1. Are these results of the first time or after some days? What was the interval for changing the nutrient solution, weekly or otherwise? Please specify. 

Response: pH 5.6 and an electrical conductivity of 2.37 dS m−1.. 22are the value of the fresh nutrient solution. The nutrient solution was added in each aeroponic system to keep the level above 7 cm, and never discharged during all the experiment. More information added at line 177-185.

23-  Line 87, Air temperature and relative humidity were kept at 24.0 °C and 65%-70%, respectively. How did you keep this? Please specify, 

Response: More information added at line 121. 

24-  I suggest adding colorful figures instead of black and white.

The white colour is okay.

25-  The results and discussion section are well justified.

26-  The conclusion can be improved. Currently, only results are discussed. What are the recommendations and suggestions of this study?

Some suggestions for future research have been added at the end of the conclusions.

 

 

Reviewer 3 Report

Comments and Suggestions for Authors

Abstract: Please extend the abstract to be 250-300 words.

Please clarify the treatment and experimental design for this study.

Please write the ideal concentration of Cu, Zn, I, or Se in the nutrient solution that have biofortified to human.

 

1. Introduction

Please write how are the biofortification will Cu, Zn, I, or Se in the nutrient solution led to an increase in their concentrations in lettuce leaves, without affecting growth or leaf quality of lettuce plants?

What are the ideal concentrations of copper (Cu), zinc (Zn), iodine (I), and selenium (Se) in lettuce should align with European regulations and dietary recommendations to ensure safety and efficacy.

Clearly state the research gaps in current literature, specifically focusing on the lack of studies on simultaneous biofortification with Cu, Zn, I, and Se.

Discuss why previous studies focused on individual or dual element biofortification and the potential challenges or toxicity concerns.

Elaborate on the advantages of aeroponics for nutrient delivery and plant health, especially in the context of micronutrient biofortification.

Discuss the potential for controlled environment agriculture (CEA) in improving consistency and efficacy of biofortification.

 

2. Materials and Methods

There are missing points in the M& M:

Lines 76-78; The authors mention that Each aeroponic system consisted of a 90-L tank (67 x 41 cm, height 32 cm), closed on the top by a plastic tray hosting 380 plants (1400 plants m−2), and contained

30-L of nutrient solution at the bottom. Please insert picture to this system and appeared the 1400plants per meter square.

Why the EC electrical conductivity of 2.37 dS m−1? The recommend to be 1.4-1.8 at maximum.

Is the lettuce cultivar red, blue, and green a factor?

What is the control treatment?

How much is the concentration of nutrient solution in mg/L for each element?

How does the author management the pH and EC to 5.8 and 2.37?

What is the experimental design? And treatments and replications

Please Re-arrange the M& M as follows:

Experimental site and environmental condition

Plant Material

Experimental design and treatments.

Nutrient solution management

Data collection

Plant growth

Leaf quality attributes

Mineral concentration

 

Results and discussion

The authors mention that using the concentrations of Cu, Zn, I, and Se tested in the present study, it is possible to simultaneously biofortify lettuce leaves with these minerals without reducing the yield and quality of leaves. My concern what about the concentration of these element that save to human using? Is this concentration save to human. Please we need full explain about this points?

 

 

Comments on the Quality of English Language

Moderate editing of English language required

Author Response

Abstract: Please extend the abstract to be 250-300 words.

According to the “instruction for authors” of “Horticulturae” the abstract should be at maximum 200 words. Anyway, the abstract has been improved.

Please clarify the treatment and experimental design for this study.

Done: lines 12-19

Please write the ideal concentration of Cu, Zn, I, or Se in the nutrient solution that have biofortified to human.

Done: lines 14-17

1. Introduction

Please write how are the biofortification will Cu, Zn, I, or Se in the nutrient solution led to an increase in their concentrations in lettuce leaves, without affecting growth or leaf quality of lettuce plants?

More information about biofortification have been added at lines 50-55. The information related to Cu, Zn, I and Se biofortification and toxic dose for plants are reported in the “results and discussion” section.

What are the ideal concentrations of copper (Cu), zinc (Zn), iodine (I), and selenium (Se) in lettuce should align with European regulations and dietary recommendations to ensure safety and efficacy.

Some information about the ideal concentration of copper (Cu), zinc (Zn), iodine (I), and selenium (Se) in lettuce were added at lines 56-61.

Clearly state the research gaps in current literature, specifically focusing on the lack of studies on simultaneous biofortification with Cu, Zn, I, and Se.

As stated at lines 69-71, the present study is the first report on simultaneous biofortification with Cu, Zn, I, and Se in aeroponically cultivated baby-leaf lettuce

Discuss why previous studies focused on individual or dual element biofortification and the potential challenges or toxicity concerns.

A short discussion has been added at lines 75-79.

Elaborate on the advantages of aeroponics for nutrient delivery and plant health, especially in the context of micronutrient biofortification.

Done: lines 86-91

Discuss the potential for controlled environment agriculture (CEA) in improving consistency and efficacy of biofortification.

 Information added at lines 92-95.

2. Materials and Methods

There are missing points in the M& M:

Lines 76-78; The authors mention that Each aeroponic system consisted of a 90-L tank (67 x 41 cm, height 32 cm), closed on the top by a plastic tray hosting 380 plants (1400 plants m−2), and contained

30-L of nutrient solution at the bottom. Please insert picture to this system and appeared the 1400plants per meter square.

We do not have picture. We have inserted a new figure (Figure 1)

Why the EC electrical conductivity of 2.37 dS m−1? The recommend to be 1.4-1.8 at maximum.

We used a standard nutrient solution for leafy vegetables grown in hydroponics, that we have previously used in some studieswith lettuce, e.g.:

Puccinelli, M., Malorgio, F., Incrocci, L., Rosellini, I., Pezzarossa, B., (2021). Effects of Individual and Simultaneous Selenium and Iodine Biofortification of Baby-Leaf Lettuce Plants Grown in Two Different Hydroponic Systems. Horticulturae 7, 590. https://doi.org/10.3390/horticulturae7120590

Puccinelli, M., Landi, M., Maggini, R., Pardossi, A., Incrocci, L., (2021). Iodine biofortification of sweet basil and lettuce grown in two hydroponic systems. Sci. Hortic. (Amsterdam). 276, 109783. https://doi.org/10.1016/j.scienta.2020.109783

Is the lettuce cultivar red, blue, and green a factor?

The colour of lettuce leaves (green) has been added at line 115.

What is the control treatment?

In the Control treatment only the standard nutrient solution was used. Information added at lines 165-166.

How much is the concentration of nutrient solution in mg/L for each element?

The concentrations in mg/L of minerals used for biofortification have been added to table 1.

How does the author management the pH and EC to 5.8 and 2.37?

Information about the management of the nutrient solution have been added at lines: 105-107.

What is the experimental design? And treatments and replications

Three replicates, each consisting of one aeroponic system, were used for each treatment (lines 155). The treatment details are reported in table 1. More information about treatments have been added at lines 157-166.

Please Re-arrange the M& M as follows:

Experimental site and environmental condition

Plant Material

Experimental design and treatments.

Nutrient solution management

Data collection

Plant growth

Leaf quality attributes

Mineral concentration

 Done

Results and discussion

The authors mention that using the concentrations of Cu, Zn, I, and Se tested in the present study, it is possible to simultaneously biofortify lettuce leaves with these minerals without reducing the yield and quality of leaves. My concern what about the concentration of these element that save to human using? Is this concentration save to human. Please we need full explain about this points?

In the case of the Mix treatment, the intake of the various minerals in the diet, respectively at the recommended doses, is reported on the lines 495-499.

Reviewer 4 Report

Comments and Suggestions for Authors

The paper describes the results of an experiment on the biofortification of baby-leaf lettuce growing indoor using aeroponics. The topics is interesting and the results could provide progress in current knowledge on the biofortification of vegetables with micronutrients. Overall the well-written manuscript can be considered for publication in the journal Horticulturae after minor revision have been made.

The hypothesis put forward in the study should be clearly formulated.

The number of plants in each treatment?

Autorzy powinni lepiej omówić znaczenie swoich ustaleń.

Sekcja 3.3. Biofortyfikacja za pomocą Se, I lub jednocześnie z Zn, Cu, Se i I (eksperyment Mix) – proponuję zacząć od rysunku 3A, następnie rysunków 3B, 3C i 3D.

Zalecenia dotyczące przyszłych badań, które mogą być oparte na wynikach badań należy dodać do sekcji "Wnioski".

Author Response

The paper describes the results of an experiment on the biofortification of baby-leaf lettuce growing indoor using aeroponics. The topics is interesting and the results could provide progress in current knowledge on the biofortification of vegetables with micronutrients. Overall the well-written manuscript can be considered for publication in the journal Horticulturae after minor revision have been made.

The hypothesis put forward in the study should be clearly formulated.

The goal of the work has been clarified in the Introduction (lines 104-110).

The number of plants in each treatment?

The number of plants per treatment has been added at line 155.

Section 3.3. Biofortification with Se, I or simultaneously with Zn, Cu, Se and I (Mix experiment) - I suggest starting with Figure 3A, then Figures 3B, 3C and 3D.

The order of plot in the Figure has been changed.

Recommendations for future research that may be based on the study results should be added to the "Conclusions" section.

Some suggestions for future research have been added at the end of the conclusions.

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

I reviewed the revised version of the manuscript. The authors have incorporated all changes. The manuscript can be considered for possible publication after minor corrections.

My previous comment was Line 51, where plant's roots are suspended in the air and frequently sprayed with the nutrient solution [33], changes to where the plants roots are suspended in the air and frequently or internally sprayed with the nutrient solution [33].

In this comment, there was a typo. Please change the word internally with intervals.

Change the hydroponics keyword with soilless farming.

Delete aeroponics from keywords, as it is already in the title.

If you do not have the droplet size information for the selected aeroponics atomizing nozzle, it would be better to add the name or type of the atomizing nozzle. Without this information, it won't be easy to justify your results from an aeroponics perspective. Aeroponics' main concept is providing nutrient solutions in the form of tiny droplets

Author Response

I reviewed the revised version of the manuscript. The authors have incorporated all changes. The manuscript can be considered for possible publication after minor corrections.

My previous comment was Line 51, where plant's roots are suspended in the air and frequently sprayed with the nutrient solution [33], changes to where the plants roots are suspended in the air and frequently or internally sprayed with the nutrient solution [33].

In this comment, there was a typo. Please change the word internally with intervals.

Response: Done (line 75)

Change the hydroponics keyword with soilless farming.

Response: Done

Delete aeroponics from keywords, as it is already in the title.

Response: Done

If you do not have the droplet size information for the selected aeroponics atomizing nozzle, it would be better to add the name or type of the atomizing nozzle. Without this information, it won't be easy to justify your results from an aeroponics perspective. Aeroponics' main concept is providing nutrient solutions in the form of tiny droplets

Response: The nozzles were micro sprinkler heads specifically designed and created by EdoRadiciFelici srl. The name of the nozzles is EdoMax0.5 and they are made of reinforced polyethylene. More information have been added at line 122.