The effect of varieties of true shallot seed and paclobutrazol concentrations on growth and production of shallot plant

The increasing demand for shallots is inversely proportional to the quality of the current production. Efforts to improve and increase quality of production are selection of good varieties and add plant regulatory substances has also become the focus of many researchers in their effect on plant growth. Therefore, research was carried out on the effect of the varieties and also plant regulatory substances namely paclobutrazol on the growth and production of shallot plants. This research was carried out at the Teaching Farm, Faculty of Agriculture, Hasanuddin University from August to November 2021. This research was carried out as a factorial experiment in a split plot design, as the main plot, namely the botanical seed varieties of shallot (v) consists of 3 varieties, namely the Lokananta varieties (v1), Maserati varieties (v2), and Sanren varieties (v3), as a sub-plot, namely the concentration of paclobutrazol consists of 4 levels, namely 0 ppm (k0), 100 ppm (k1), 200 ppm (k2) and 300 ppm (k3). The research results showed that the interaction of the Sanren varieties with paclobutrazol concentration of 100 ppm gave the best results on the weight of fresh stover per plant (26.04 g), weight of dry stover per plant (19.23 g) and production per hectare (9.20 ton/ha). The Sanren varieties gave the best results on chlorophyll a (387.23 μmol.m−2), chlorophyll b (187.12 μmol.m−2), total chlorophyll (564.14 μmol.m−2) and number of tubers (1.81). Paclobutrazol concentration of 100 ppm gave the best results on plant height (43.07 cm) and number of leaves (6.24 strands), while paclobutrazol concentration of 200 ppm gave the best results on tuber diameter (23.13 mm) and paclobutrazol concentration of 300 ppm gave the best results on the number of tubers (1.54).


Introduction
The availability of quality shallot seeds is a problem in shallot production and causes a much lower reduction in productivity [1].The low productivity is caused by the continuous cultivation of tubers for planting material can worsen the quality and even the productivity of shallots [2].The use of tubers of the same varieties for generations also causes little opportunity to improve the nature/quality so that the competitiveness of Indonesian shallots tends to decrease [3].There are various ways to meet the increase demand for shallots in the community, so methods are needed with cultivation technology breakthrough that can increase shallot production [4].1230 (2023) 012200 IOP Publishing doi:10.1088/1755-1315/1230/1/012200 2 One way to obtain good quality seeds is by improving the genetic quality of the seeds.Improvement of seed quality can be done by selecting seed varieties that have high potential so that it affects the yield and adaptability of the varieties [5].Research Ambarwati and Yudono [6] mentioned that shallot production was influenced by one of the varieties.Various varieties show different characters and yield potential [2].
Utilizing new technology in shallot cultivation can use TSS seeds or True Shallot Seed [7].The formation of tubers can be assisted by the balance of stimulant and inhibitory plant growth hormones.Making use of growth inhibitors is necessary to focus energy in the tuber formation [8].Planting onion seeds to be able to grow and produce high, requires additional materials in the form of growth regulators [9].
Growth regulators function as exogenous compounds to stimulate, inhibit and work in modifying physiological processes in plants but do not act as nutrients.Based on its nature, Growth regulators are divided into two, namely those that stimulate growth and those that inhibit growth.Growth regulators become one of the main functions in increase production, for example include paclobutrazol [10].Paclobutrazol is growth regulator used to modify the physical structure of plants.Paclobutrazol acts on plants by inhibiting gibberellin biosynthesis [11].The occurrence of obstacles to the gibberellin biosynthesis is due to paclobutrazol causing the rate of cell division and elongation to be slower without causing toxicity to plant cells.The effect that was given and seen directly on plants was the reduction of vegetative growth.Reduction of vegetative growth in shallot plants, it will be able to stimulate growth in fruit / tubers [12].The research results obtained showed that the 125 ppm paclobutrazol treatment was able to suppress plant height growth and increase tuber weight [13].Based on this, research conducted on growth and production of varieties of shallot from botanical seeds or true shallot seed which was applied to paclobutrazol.

Materials and methods
This research was carried out at the Teaching Farm location, Faculty of Agriculture, Hasanuddin University, Makassar from August to November 2021.The materials used in this research were shallot seeds from Lokananta, Maserati, and Sanren varieties, paclobutrazol and then, for optimize the research some materials were added, such as cow dung, compost, NPK fertilizer, roasted husks, Trichoderma harzianum, aquades, herbicides, and fungicides.The tools used were measuring cup, meters, digital scale, sprayers, hoes, filter, seeding tank, bucket, knife, scissors, caliper, raffia rope, ruler, nameplate and also stationery.Content Chlorophyll Meter (CCM) 200 + was used in observing plant physiological parameters.
The research was carried out in the form of a factorial experiment arranged in a split plot design, as main plot, namely the botanical seed varieties of shallot (v) consists of 3 varieties, namely the Lokananta varieties (v1), Maserati varieties (v2), and Sanren varieties (v3), as a sub-plot, namely the concentration of paclobutrazol consists of 4 levels, namely 0 ppm (k0), 100 ppm (k1), 200 ppm (k2) and 300 ppm (k3).Overall, there are 12 (3x4) treatment combinations.This research design was carried out by repeating three times for each treatment, then there are 36 experimental plots in total.
Implementation of research for the first stage began for the preparation of shallot seeds with three varieties, each of which was soaked before planting.Then the seeding of shallot seeds was carried out in the seeding tank.Preparation of land for transplanting was carried out such as land management.The processed land was then plotted as many as 36 experimental plots.Prior to transplanting, fertilization was carried out, namely organic fertilizer as basic fertilizer and the application of inorganic fertilizer was given at the age of 15 and 45 DAP.Shallots that were 50 days old then transferred to the experimental plot.Seedlings were planted using spacing of 15 x 10 cm.Application of paclobutrazol conducted at 20 and 35 days after planting.Prior to application, paclobutrazol was dissolved in aquades to obtain the desired concentration.The maintenance of shallots includes watering, replanting, weed control and pest and disease control.Shallot plants were ready to be harvested when they show signs such as plant fall, yellowing leaves and tubers visible on the soil surface.After that, post-harvest drying for ± 1 week and weighing the tubers as a component of production.Retrieval of research data through field observations carried out in each experimental plot, from the beginning to the time of harvest.There were two observed growth parameters were plant height (cm) and number of leaves (strands), then the physiological parameters were observed using Content Chlorophyll Meter (CCM) 200 + included chlorophyll a (μmol.m - ), chlorophyll b (μmol.m - ) and total chlorophyll (μmol.m - ).In addition, the production components observed were the number of tubers, then tuber diameter (mm), weight of fresh stover per plant (g), weight of dry stover per plant (g) and then production per hectare (ton/ha).
Observational data were then analyzed by analysis of variance.If the effect of treatment was obtained on the analysis of variance, further tests are carried out to distinguish the mean between treatments by means of the Least Significant Difference test or LSD with a 95% confidence level.

Results and discussion
3.1.Results 3.1.1.Plant height.The results obtained based on the analysis of variance showed significant effect on plant height with paclobutrazol concentration, while no significant effect on plant height of shallot with varieties and interaction between varieties and paclobutrazol concentration.Note: The numbers in the column followed by the same letters (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.
The results of LSD test in Table 1 showed paclobutrazol treatment with a concentration of 100 ppm (k1) gave the lowest average plant height, which was 43.07 cm and significantly different from that without paclobutrazol (k0) which had the highest average plant height, which was 46.92 cm, and the paclobutrazol treatment with a concentration of 200 ppm (k2) and paclobutrazol concentration of 300 ppm (k3).

Number of leaves.
The results obtained based on the analysis of variance showed very significant effect on the number of leaves with paclobutrazol concentration, while no significant effect on the number of leaves of shallot plants with varieties treatment and interaction between varieties and paclobutrazol concentration.Note: The numbers in the column followed by the same letters (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.
Based on the results of LSD test in Table 2 showed number of shallot leaves at the paclobutrazol with a concentration of 100 ppm (k1) gave lowest average number of leaves, which was 6.24 strands and significantly different from that without paclobutrazol (k0) which had the highest average number of leaves, which was 7.50 strands, and the paclobutrazol treatment with a concentration of 200 ppm (k2) and paclobutrazol concentration of 300 ppm (k3).

Chlorophyll a.
The results obtained based on the analysis of variance showed significant effect on chlorophyll a with varieties treatment, while no significant effect on chlorophyll a with paclobutrazol concentration and interaction between varieties and paclobutrazol concentration.Note: The numbers in the column followed by the same letters (a, b, c) mean that they were no significant different in LSD test with a significance level of 0.05%.
The results of LSD test in Table 3 showed the chlorophyll a of shallots plants at treatment of the Sanren varieties (v3) gave the highest average which was 387.23 μmol.m -2 and not significantly different from the Maserati varieties (v2) but significantly different from the Lokananta varieties (v1).

Chlorophyll b.
The results obtained based on the analysis of variance showed significant effect on chlorophyll b with varieties treatment, while no significant effect on chlorophyll b with paclobutrazol concentration and interaction between varieties and paclobutrazol concentration.Note: The numbers in the column followed by the same letters (a, b, c) mean that they were no significant different in LSD test with a significance level of 0.05%.
The results of LSD test in Table 4 showed the chlorophyll b of shallots plants at treatment of the Sanren varieties (v3) gave the highest average which was 187.12 μmol.m -2 and not significantly different from the Maserati varieties (v2) but significantly different from the Lokananta varieties (v1).

Total chlorophyll.
The results obtained based on the analysis of variance showed significant effect on total chlorophyll with varieties treatment, while no significant effect on total chlorophyll with paclobutrazol concentration and interaction between varieties and paclobutrazol concentration.Note: The numbers in the column followed by the same letters (a, b, c) mean that they were no significant different in LSD test with a significance level of 0.05%.
Based on the results of LSD test in Table 5 showed the total chlorophyll of shallots plants at treatment of the Sanren varieties (v3) gave the highest average which was 564.14 μmol.m -2 and not significantly different from the treatment of the Maserati varieties (v2) but significantly different from the treatment of the Lokananta varieties (v1).

Number of tubers.
The results obtained based on analysis of variance showed a very significant effect with varieties and significant effect on number of tubers with paclobutrazol concentration, while no significant effect on number of tubers with interaction varieties and paclobutrazol concentration.The numbers in the column followed by the same letters (a, b, c) and rows (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.
The results of LSD test in Table 6 showed the number of tubers of shallots plants at treatment of the Sanren varieties (v3) gave the highest number of tubers with 1.81 tubers and significantly different from the Lokananta varieties (v1) and the Maserati varieties (v2), while the paclobutrazol with a concentration of 300 ppm (k3) gave highest average number of tubers which was 1.54 tubers, which were no significantly different on the paclobutrazol concentration of 100 ppm (k1) and treatment of paclobutrazol concentration of 200 ppm (k2) and significantly different without paclobutrazol (k0).
3.1.7.Tuber diameter.The results obtained based on the analysis of variance showed significant effect on tuber diameter with paclobutrazol concentration, while no significant effect on tuber diameter with varieties treatment and interaction between varieties and paclobutrazol concentration.Note: The numbers in the column followed by the same letters (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.
The results of LSD test in Table 7 showed the tuber diameter of shallots plants at the paclobutrazol with a concentration of 200 ppm (k2) gave highest average tuber diameter which was 23.13 mm which showed result no significantly different with the paclobutrazol a concentration of 100 ppm (k1) and the paclobutrazol treatment with a concentration of 300 ppm (k3) but significant different from the treatment without paclobutrazol (k0).

Weight of fresh stover per plant.
The results obtained based on the analysis of variance showed significant effect on the weight of fresh stover per plant with treatment of interaction between varieties and paclobutrazol concentration, while very significant effect from the weight of fresh stover per plant with varieties and paclobutrazol concentration treatment.The results of LSD test in Table 8 showed Sanren varieties treatment (v3) on paclobutrazol with a concentration of 100 ppm (k1) gave highest results weight of fresh stover per plant which was 26.04 g and significant different from other treatments, while paclobutrazol with a concentration of 100 ppm (k1) on the Sanren varieties treatment (v3) gave the highest results weight of fresh stover per plant which was 26.04 g, but no significant different with paclobutrazol concentration of 200 ppm (k2) and significantly different with paclobutrazol concentration of 300 ppm (k3) and without treatment with paclobutrazol (k0).
3.1.9.Weight of dry stover per plant.The results obtained based on the analysis of variance showed significant effect on the weight of dry stover per plant with treatment of interaction between varieties and paclobutrazol concentration, while very significant effect on the weight of dry stover per plant with varieties and paclobutrazol concentration treatment.Note: The numbers in the column followed by the same letters (a, b, c) and rows (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.
The results of LSD test in Table 9 showed Sanren varieties treatment (v3) on paclobutrazol with a concentration of 100 ppm (k1) gave highest results weight of dry stover per plant which was 19.23 g and significantly different from other treatments, while the paclobutrazol treatment with a concentration of 100 ppm (k1) on the Sanren varieties treatment (v3) gave the highest results weight of dry stover per plant which was 19.23 g, but no significantly different with paclobutrazol concentration of 200 ppm (k2) and significantly different with the treatment of paclobutrazol concentration of 300 ppm (k3) and without treatment with paclobutrazol (k0).

Production per hectare.
The results obtained based on the analysis of variance showed significant effect with treatment of interaction between varieties and paclobutrazol concentration and very significant effect on production per hectare with paclobutrazol concentration, while no significant effect on the production per hectare with varieties treatment.Note: The numbers in the column followed by the same letters (a, b, c) rows (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.
Based on the results of LSD test in Table 10 showed Sanren varieties treatment (v3) on paclobutrazol with a concentration of 100 ppm (k1) gave highest results production per hectare which was 9.20 ton/ha and between the other treatments significantly different, while paclobutrazol treatment with a concentration of 100 ppm (k1) on Sanren varieties treatment (v3) gave the highest results production per hectare which was 9.20 ton/ha but not significantly different with the treatment of paclobutrazol concentration of 300 ppm (k3) and significantly different with paclobutrazol concentration of 200 ppm (k2) and without treatment with paclobutrazol (k0).

Discussion
The varieties treatment had a significant effect on the parameters of chlorophyll a, chlorophyll b, total chlorophyll and number of tubers.The Sanren varieties gave the highest result of chlorophyll a, chlorophyll b, and total chlorophyll.Based on this research showed that the difference in chlorophyll result was caused by genetic factors.The opinion Biber [14] which stated that the difference in chlorophyll concentration results was influenced to morphology, age and also leaf genetic factors on plants.
As for the condition of some shallots plants that were attacked by the disease of Fusarium wilt causes plant physiology to be disturbed.It was supported by Suherman [15] when the chlorophyll content is low in a plant, while the need for chlorophyll formation has been met, then it can be known the presence of pathogens that disrupt plant physiology.The chlorophyll content of plants that had increased and decreased in value can be an illustration of the level of resistance in the plant varieties to disease.
The Sanren varieties gave yielded the highest number of tubers which was significantly different from treatment the other varieties.Different results in each treatment varieties were influenced by each of the genetic factors in these varieties.This was in corresponds with research Budianto et al. [16] that heritability in a broad sense for the number of tubers of the Ampenan cultivar was medium (21.05%).This number means that the character of the number of tubers was largely caused by genetic factors of a varieties and slightly influenced by the environment.
The paclobutrazol concentration treatment gave a significant effect on the plant height, number of leaves, number of tubers and tuber diameter.Paclobutrazol concentration of 100 ppm which gave the lowest plant height and number of leaves, result that occurs was because paclobutrazol to inhibit vegetative growth which was indicated by the low plant height and number of leaves produced at each treatment concentration when compared to without paclobutrazol.This was in corresponds with the statement Moko et al. [17] that was not giving paklobutrazol causes plant growth to run normally or without suppression of plant height so that 0 ppm treatment produces the highest plant height.According to Salisbury and Ross [18], the inhibition of plant height occurred due to the reaction process of kaurene oxidase into kaurenoic acid in the gibberellin biosynthesis reaction which resulted in the lack of gibberellins, causing the plants to become shorter.According to Widaryanto et al. [19] administration of paclobutrazol did not affect the formation of new leaves.Basically, paclobutrazol is a retardant that reduces of tissue metabolic activity and can inhibit the process of vegetative growth.Some measurements of the tuber part of the shallot plant included the number of tubers and tuber diameter.Application of paclobutrazol concentration of 300 ppm gave highest number of tubers while the application of paclobutrazol concentration of 200 ppm gave highest tuber diameter.The measurement of the tuber part of the shallot plant with various concentrations of paclobutrazol showed different results.According to Marshel et al. [20] that the administration of paclobutrazol with different concentrations produced different responses.Growth regulators absorbed by plants was influenced by the concentration of the given [21].
Tuber weight and size are a reflection of plant production, both plot and hectare scale.According to Tekalign and Hammes [22] that a high increase in the number of tubers can result in high tuber weights per plant and per hectare.The suppression of the gibberellin hormone will accelerate the initiation of tubers and tuber formation, supported by increased translocation of assimilation to tubers so that the tubers formed are of maximum size.According to Desta and Amare [23] stated that using paclobutrazol not only affects number of tubers but also affects tuber diameter.Application of paclobutrazol resulted positive effect in an increase tuber diameter.Tuber diameter basically depends on the activity of cell division that occurs in all cells in the tuber, but the rate of cell division and enlargement is not uniform in all parts of the tuber.The administration of paclobutrazol can affect vegetative growth by reducing the presence of gibberellins for elongation of tuber plant cells, that there is shift a in the use of carbohydrates that were originally used in vegetative growth so that they were allocated for tuber diameter formation.
The research results showed that the interaction of varieties and paclobutrazol concentration had an influence on the parameters of weight of fresh stover per plant, weight of dry stover per plant and production per hectare.Based on the combination of treatments in the form of several varieties of shallots and paclobutrazol concentration, the treatment of the sanren varieties with paclobutrazol concentration of 100 ppm gave the highest result.
Shallots with Sanren varieties was a variety that obtains high production results compared to the Lokananta and Maserati varieties.This is because each variety had different results potentials and characters, especially in tuber formation.According to Ayu et al. [24] that each different environmental condition can provide different growth and yield of a varieties also related to the ability to absorb water and different nutrients.Related to Differences in the ability of competition of each varieties due to different genetic potential.The growth rate of different plant varieties affects their potential and production.
The administration of paclobutrazol was able to produce an average component of the production of shallots which was higher than without the administration of paclobutrazol.This is in accordance with the statement of Salisbury and Ross [18] that paclobutrazol functions as a growth inhibitor substance that can cause stunting and photosynthesis process can work well and increase production.

Conclusion
Research using varieties and paclobutrazol concentration gave a significant effect on the growth and production of shallots.There was an interaction between genetic factors of the Sanren varieties with paclobutrazol concentration of 100 ppm gave highest results on weight of fresh stover per plant (26.04 g), weight of dry stover per plant (19.23 g) and production per hectare (9.20 ton/ha).The genetic factor of the Sanren varieties gave the highest results on the parameters of chlorophyll a (387.23 μmol.m -2 ), chlorophyll b (187.12 μmol.m -2 ), total chlorophyll (564.14 μmol.m -2 ) and the number of tubers (1.81).The paclobutrazol concentration of 100 ppm treatment gave the best results by inhibiting vegetative growth on plant height (43.07 cm) and also number of leaves (6.24 strands) then, while paclobutrazol concentration of 200 ppm treatment gave the highest results on the parameter of tuber diameter (23.13 mm) and paclobutrazol concentration of 300 ppm treatment gave the highest results on the parameter number of tubers (1.54).

Table 1 .
The average plant height of shallots (cm) in the treatment of varieties and paclobutrazol concentration.

Table 2 .
The average number of leaves of shallots plants (strands) in the treatment of varieties and paclobutrazol concentration.

Table 3 .
The average chlorophyll a of shallots plants (μmol.m - ) in the treatment of varieties and paclobutrazol concentration.

Table 4 .
The average chlorophyll b of shallots plants (μmol.m - ) in the treatment of varieties and paclobutrazol concentration.

Table 5 .
The average total chlorophyll of shallots plants (μmol.m - ) in the treatment of varieties and paclobutrazol concentration.

Table 6 .
The average number of tubers of shallots plants (tubers) in the treatment of varieties and paclobutrazol concentration. Note:

Table 7 .
The average tuber diameter of shallots plants (mm) in the treatment of varieties and paclobutrazol concentration.

Table 8 .
The average weight of fresh stover per plant of shallots (g) in the treatment of varieties and paclobutrazol concentration.
Note: The numbers in the column followed by the same letters (a, b, c) and rows (p, q, r) mean that they were no significant different in LSD test with a significance level of 0.05%.1230

Table 9 .
The average weight of dry per plant of shallots (g) in the treatment of varieties and paclobutrazol concentration.

Table 10 .
The average production per hectare of shallots plants (ton/ha) in the treatment of varieties and paclobutrazol concentration.