The growth tree saplings Shorea platyclados with various shades and NPK fertilizer

Shorea platyclados, known to the public as Meranti Bukit, is one of the species whose existence is difficult to find, so efforts are needed for its preservation, namely by propagation techniques with natural saplings that are expected to produce optimal growth.S. platyclados, including types that can grow with a light intensity of 30–50% and therefore require shade for early growth, needs NPK fertilizer to get optimal growth. This study aims to obtain the appropriate dose of NPK fertilizer and optimum light requirements for the growth of natural saplings by measuring the percent of life, height, diameter, and number of leaves. The design used is a random group design (rack) with 5 additional treatments of NPK fertilizer doses, namely control (0 gr), 0.25 gr, 0.50 gr, 0.75 gr, and 1 gr, and 4 shade blocks, namely without shade (0%), shade 50%, shade 60%, and shade 70%. The results showed that the application of NPK fertilizer significantly affected the number of leaves. The result is an increase in the number of leaves at a dose of 1 g with a value of 17 (strands) and 0.75 g with a value of 15 (strands). The provision of shade blocks has a significant effect on the diameter parameters. The best result is an increase in diameter at 70% shade, with an average diameter of 1,984 mm. NPK fertilizer application shows a 100% life percentage, and shade application shows a 100% life percentage.


Introduction
S. platyclados is a large tree with a straight, cylindrical trunk up to 50 meters high and a trunk diameter of up to 180 cm above buttresses.so much sought after because it is great potential for various kinds of basic building materials with a very high market value [1].This type of meranti is unique because of the flat tips of the branches [2][3].This meranti grows and is widespread in the hills or mountains between 700 to 1,300 meters above sea level [4].
The existence and abundance of Shorea species in Indonesia have decreased due to forest conversion and also overexploitation, including the type of S. platyclados, so efforts are needed to preserve it with ex-situ conservation efforts [2].Saplings are one of the propagation techniques that is expected to produce good growth in S. platyclados.To help improve the growth and quality of natural seedlings, it is necessary to add fertilizer.The potential of NPK fertilizer is very good to be used to increase the IOP Publishing doi:10.1088/1755-1315/1315/1/012074 2 available nutrients for plants, and NPK fertilizer is a type of compound fertilizer that contains complete macronutrients with sufficient concentrations for plant growth and contains three nutrients, namely 15% nitrogen, 15% phosphorus and 15% % potassium in the form of K2O [5].
To achieve optimal growth of natural saplings, it is necessary to use shade.Shade plays a role in minimizing the entry of sunlight; rainwater and shade are also closely related to temperature and humidity.Shade can also reduce evaporation and transpiration.Meranti is a semi-tolerant species, all plants respond to sunlight differently depending on the species.So shade regulation on the growth of natural saplings of S. platyclados is very important to produce maximum growth because it is related to evaporation and photosynthesis in plants [6].This study aims to obtain the optimum dose of NPK fertilizer for the growth of S. platyclados, as well as the optimum light requirements for the growth of S. platyclados natural seedlings.

Study Area
This research was carried out from May 2022 to September 2022 in the Faculty of Agriculture, University of North Sumatra green house.

Research procedure
The stages of the activities carried out in this study included: 1. preparation of planting media, while the media used in this study were topsoil under S. platyclados stands and then prepared in polybags with a size of 15 x 20 cm; 2. harvesting clam seedlings, procuring the seeds by taking natural S. platyclados seedlings ranging from 30 to 40 cm in the Martelu Purba Nature Reserve; 3. Shading preparation: Shading as a block or barrier in this experiment was obtained by using paranet with different densities.The shade framework is made with a height of 1 meter from the ground, the length and width of the shade are adjusted to the size of the poly bag; 4. application of NPK fertilizer: treatment of adding NPK fertilizer with various doses as follows: A0 = without NPK fertilizer, A1 = 0.25 gr, A2 = 0.50 gr, A3 = 0.75 gr, A4 = 1 gram with the frequency of fertilization carried out at the beginning of the observation or the first month then continued in the 3rd month of observation; 5. Seed maintenance: Plant maintenance activities carried out on meranti seedlings include watering twice a day evenly using a sprayer.Weeds are regularly cleaned every week so as not to damage the seedlings.

Research Parameters
The parameters to be observed in this study were survival percentage, increase in sapling height, increase in sapling diameter, and increase in number of leaves.

Data analysis
Data analysis was performed using the Statistical Package for the Social Sciences software (IBM SPSS 25) with the Analysis of variance (ANOVA) statistical test to see the effect on treatment and groups.

Correlation Analysis
Correlation analysis was performed on each parameter which was processed using IBM SPSS Statistics software.So the correlation coefficient between values can be written as: -1drd+1 [7].

Percentage of Natural Saplings Shorea platyclados
The percentage of plant life is the standard for determining the success of a nursery activity.Based on the results of the research conducted until the end of data collection, it was shown that 40 natural seedlings of S. platyclados lived well from the beginning of planting to the end of the study (Figure 1).The percentage of surviving meranti puppies that have been carried out is 100%.The results of this study indicate that the percentage of meranti puppies is in a good category because all of the puppies are alive.The potential of the percentage of natural saplings to live shows that the saplings are able to survive and adapt to the environment (climatic conditions, temperature, humidity, and sunlight) that are accepted by all the saplings planted.

Height Gain (cm)
The results of the Kolmogorov-Smirnov normality test and the results of the homogeneity test showed that all data taken on each plant parameter had normal and homogeneous height data.Based on the results of the analysis of variance in Table , a sig value of 0.164 (sig.> 0.05) was obtained, which means that the addition of NPK fertilizer did not have a significant effect on the height increase of natural saplings of S. platyclados, so DMRT was not necessary.The height gain of natural saplings in each treatment is shown in Figure 3. NPK fertilizer treatment showed no significant effect on height gain in natural saplings of S. platyclados.This is presumably due to the addition of fertilizer treatment that is not optimal.[8] which state that in carrying out fertilization it must be in accordance with the needs of plants, small dose will not affect plant growth.
Based on the results of the analysis of variance in Table .Shading gets a Sig.0.067 (Sig> 0.005), which means that the shade treatment was not significant to the increase in the height of natural saplings during the 12 weeks of observation.The average increase in the height of natural saplings to shade can be seen in Figure 4. Shading did not show a significant effect on the height gain of natural saplings of S. platyclados.This is thought to occur because Dipterocarpaceae plants are semi-tolerant plants

Diameter Gain(mm)
Diameter is the basic measurement of a circle.Stem diameter is defined as the length of the line between two points on a circle around the stem that passes through the center (axis) of the stem [9].Plant diameter measurements were measured using digital calipers which were observed for 12 weeks.The results of measuring the average diameter of S. platyclados plants every 2 weeks can be seen in the graph of Figure 5.The test results that have been carried out with the Kolmogorov-Smirnov test obtained a sig value of 0.200 (sig.>0.05) which assumed that the rate of increase in diameter of natural saplings of S. platyclados was normally distributed, and continued with the homogeneity test it was found that the data met the assumption of variance the same (homogeneous) this is indicated by a sig value of 0.309 (sig.>0.05) at.The results of variance in Table .Shows that the diameter observation on natural saplings of S. platyclados with the treatment of NPK fertilizer doses on natural saplings of S. platyclados had no significant effect where the sig value was 0.239 (sig.> 0.05).The treatment of fertilizer application had no significant effect on the parameter diameter of natural saplings of S. platyclados, but the response to the average diameter increase was relatively increased from the five treatments with the addition of NPK fertilizer doses.This difference occurs due to the provision of fertilizers that are not optimal.Based on these results, higher doses of NPK are needed for the growth of S. platyclados seedlings.This was further strengthened by the statement of [10] which stated that the growth in plant diameter was influenced by the content of P elements, the P element in the horizontal development of plants.Based on the results of the analysis of variance (ANOVA), it was shown that the addition of shading blocks had a significant effect on the diameter of the natural saplings of S. platyclados (Table 2).The results of the analysis of variance gave a sig value of 0.008 (sig.<0.05).So the DMRT follow-up test was carried out in Figure 7. Based on the results of the DMRT follow-up test, it can be seen that providing 70% shading shows optimal results for the growth rate of the natural tiller diameter with a value of 1.984 mm.Unshaded tillers were significantly different with 60% shading, 70% shading, but not significantly different with 50% shading.In this study, giving 70% shade to S. platyclados puppies showed optimal results, not proportional to the growth in height, even better under shade.This shows that shading is very influential on the growth of plant diameter.

Number of Leaves (strands)
The results of the normality test with the Kolmogorov-Smirnov show that the data is normally distributed with a sig value of 0.200 (sig.> 0.05) then in the homogeneity test using the Levene test it is known that the data has a homogeneous (same) variance with a sig .>0.05).Then it is necessary to do a DMRT follow-up test.Based on the results of variance in Table .It shows that the treatment of NPK fertilizer doses on the growth of the number of leaves of natural saplings of S. platyclados had a significant effect where the results were sig 0.046 (sig.< 0.05).8.The results of Duncan's test showed that the best number of leaves was found in treatments A4 and A3.A4 showed results that were not significantly different from A3, but A4 was significantly different from treatments A0, A1, and A2.Each has a number of leaves of 6 strands, 9 strands, and 9 strands.This shows that the A4, A3 treatments were more efficient due the use of 1 gram and 0.75 gr of NPK fertilizer.The best results in the A4 treatment occurred because natural saplings of S. platyclados had sufficient organic matter content at the doses of NPK fertilizer of 1 gram and 0.75 gr.In accordance with the statement of [11] states that if the nutrients are fulfilled, the result of the increase in the number of leaves will increase.One of the nutrients contained in NPK is element N Shading can increase the number of leaves during the 12 weeks of observation.Based on the results of variance in Table 3. shading had no significant effect on the number of natural saplings of S. platyclados.The results of the variance gave a sig value of 0.094 (sig.> 0.05) so that it had no significant effect on the 5% test level so that the DMRT further test was not necessary.The addition of shade does not optimally affect the growth of natural seedlings of S. platyclados because light is a determining factor for survival as well as a means of photosynthesis.The average yield of the effect of shading on the number of leaves is 14 leaves.At the level of shading with a density of 60% produces a high value compared to other treatments.The number of leaves relates to the plant's ability to carry out ongoing photosynthesis.Leaves are responsible for capturing light and are the site of photosynthesis.

Correlation coefficient
The growth and yield of a plant are related to one another.To determine a relationship between plant growth and yield, a correlation analysis is needed.Based on Table 4, it is known that the correlation test values show that all observed parameters are positively correlated (close to 1).This shows that the increase in one parameter will follow the increase in other parameters.The positive correlation value that has the highest relationship is diameter and height with an r value of 0.745.Diameter correlated with a strong relationship to all research parameters while height and number of leaves correlated with an adequate relationship with an r value of 0.484.This indicates that an increase in diameter will increase the growth of other parameters.This is in accordance with the statement of [12] that two variables are correlated with each other if two variables are correlated with each other.

Conclusion
The growth parameters of height, diameter, and number of leaves every 2 weeks increased but did not achieve optimal results, because they were not significantly different between treatments.The dose of NPK fertilizer only had a significant effect on the increase in the number of leaves.The best treatment at the dose of 1 gram of NPK fertilizer was 17 (strands) and 0.75 gr with a growth of 13 (strands) during 12 weeks of observation.Shading only had a significant effect on the increase in diameter.The best shade is at 70% shade with a growth of 1.984 mm.

Figure 1 .
Figure 1.Graph of survival percentage of natural sapling of S. platyclados.

Figure 3 .
Figure 3.The average height gain of natural saplings of Meranti S. platyclados.

Figure 4 .
Figure 4. Shading for the average height of S. platyclados natural seedlings.

Figure 5 .
Figure 5. Graph of Natural Sapling Diameter of Meranti Plant S. platyclados for 12 weeks.

Figure 6 .
Figure 6.The average increase in diameter of natural seedlings of Meranti S. platyclados.

Figure 7 .
Figure 7. Duncan's test of shading on the average diameter increase of natural saplings of S. platyclados.

Figure 8 .
Figure 8. Duncan's test for the average number of leaves of Meranti natural saplings S. platyclados.

Figure 9 .
Figure 9. Shading for the average number of natural sapling leaves S. platyclados.

Table 1 .
Analysis of Natural Sapling Height Variation.

Table 2 .
Analysis of Variety of Natural Tiller Diameters.

Table 3 .
Analysis of Variety of Natural Tiller Diameters.

Table 4 .
Correlation coefficient calculation of S. platyclados offspring between parameters