Response of sweet corn (Zea mays saccharata L.) to plant spacing and granular organic fertilizer (GOF)

Demand for sweet corn occurs drastically, especially in big cities. One of the limiting factors for the growth of sweet corn plants is the size of the plant population and the nutrient status of the soil. Based on this, it is necessary to increase the yield of sweet corn, among others, by setting the right spacing and applying organic granular fertilizer at the right dose as a source of nutrients. The study was conducted in Mandai, Maros, and South Sulawesi using a randomized block design in factorial. Plant spacing is the first factor (J1=70x20 cm; J2=70x30 cm; J3=70x40 cm). The level of application of granular organic fertilizer is the second factor (G1= 1 t ha-1; G2=2 t ha−1; G3=3 t ha−1). The use of plant spacing and the application of granular organic fertilizers had no significant effect on plant height, number of leaves, leaf area, cob diameter, or number of rows per cob, but had a significant effect. on the parameters of cob length, cob weight without husk, the weight of 100 grains, number of seeds per row, and yield potential of sweet corn. In general, the best growth and yield of sweet corn was obtained at a spacing of 70 x 20 cm with the application of granular organic fertilizer (GOF) 3 t ha-1, namely 12.81 t ha−1.


Introduction
Zea mays L.var.Saccharata is the result of a recessive mutation and is a naturally occurring high-sugar maize variety, in which the peeled corn endosperm can be converted from sugar to starch [1].Sweet corn is harvested when it is immature (milk stage) and consumed as a vegetable.The difference between sweet corn and other corn varieties is that it is usually harvested when the seeds are dry and ripe [2].
Sweet corn is in great demand because it has a sweet taste when consumed and is currently increasingly popular [3].Farmers consider cultivating sweet corn is very profitable because it has a short 1230 (2023) 012216 IOP Publishing doi:10.1088/1755-1315/1230/1/012216 2 production life and a relatively high price, so it can provide greater profits.Sweet corn can grow in temperate to tropical climates.This shows that the sweet corn development business in Indonesia has good prospects.Sweet corn as a food ingredient is harvested when it is still young, usually consumed fresh, canned, and frozen or chilled [4].
Improving cultivation technology, especially setting spacing and fertilization, can increase the demand for sweet corn both in quality and quantity [5].Plant population and nutrient status are limiting factors in the growth of sweet corn.Nutrients, water, sunlight, and growing space are often the cause of competition between plants to fight over them, so it is necessary to regulate the distance between plants [6].Increasing the competitiveness of plants against weeds occurs at tight spacing.In addition, also with a narrow spacing will result in competition between plants so that relatively unfavorable results are obtained.Thus to get better results it is necessary to adjust the appropriate spacing plant.
The spacing plant is one of the cultivation technologies that can determine plant growth and yield.Setting the spacing must be done so that each plant has the same opportunity to grow.In addition, setting the spacing is also intended so that all plants have the same opportunity when carrying out activities in the field [6].
The right nutrients are needed by sweet corn to achieve optimal production.Plants get nutrients from the soil through fertilization with an organic fertilizer and organic fertilizer.Plant yields depend on several factors such as light, water, nutrients, and others.While the availability of inputs for plants can be affected by the planting space.Thus to achieve higher and optimal productivity, it is necessary to apply fertilizer according to plant needs [7].
Nutrient conditions in the soil greatly determine the yield of sweet corn.To achieve optimum results, sweet corn plants require adequate nutrient input.Nutrient input is obtained from fertilization which is usually in the form of chemical fertilizers.Granular organic are denser so that when they are given to plants they are easily blown away by the wind, and has granules that are more compact and drier compared to organic fertilizers in the form of powder (sand) [8].So fertilizer in granular form is easier to handle and apply to plants, while organic fertilizer in the form of sand will absorb moisture slowly, resulting in a slow release of nutrients.The aim of the research was to find out interaction between spacing with granular organic fertilizer (GOF) in sweet corn.

Metodology
The research was conducted in Mandai, Maros, South Sulawesi, from April to August 2019.The materials used are maize seeds Bima variety, Granular Organic Fertilizer (GOF), Urea, SP-36, KCl, pesticides, and insecticides.The tools used are hand tractors, hoes, a bucket, a meter, an analytical scale, a caliper, and stationery.
The size in the study use plots with a size of 8 m x 6 m.The size of the canal between treatment plots was 30 cm in width and depth so that there would be no contamination of fertilizers or surface water flow between one treatment plot and another, as well as the distance between replicates made with a size of 100 cm.
Planting was carried out individually, with a different spacing (1 seed/hole), the depth of the hole was 3 cm, then the hole was covered with loose soil.The application of granular organic fertilizer (GOF) was given at 1 WAP according to treatment, while 50% Urea was applied as basic fertilizer along with SP-36 and KCl (100%), while 50% urea was given again at 10 DAP.Control pests and diseases were carried out preventively by using the fungicide dithane M-45 with a concentration of 2 g liter-1 of water.Harvesting is done when the cob husks have dried or are brown, the seeds have hardened, and a black layer of at least 50% has formed on each row of seeds.
This study was a factorial experiment using a randomized block design consisting of two factors.The first factor is setting the spacing consisting of J1 = spacing of 70 x 20 cm; J2 = spacing of 70 x 30 cm; and J3 = spacing of 70 x 40 cm.While the second factor is the dose of granular organic fertilizer which consists of three levels, namely: G1 = 1 ton ha-1 GOF; G2 = 2 ton ha-1 GOF, and G3 = 3 ton ha-1 GOF.So that there were 9 treatment combinations, each of which was repeated 3 times, thus there were 27 experimental units.
Experimental parameters planted are the height, number of leaves, leaf area, cob length, cob diameter, (GOF) the weight of cob without husk, weight of 100 grains, number of rows per cob, number of seeds per row, and yield potential.The data were then analyzed statistically with the analysis of variance (ANOVA).Data were analyzed using SPSS (Statistical Package for the Social Sciences) version 22.0 to determine the effect of treatment.If the treatment has a significant impact, further analysis was done using Duncan New Multiple Range Test (DNMRT) at the 5% significant level.

Response of sweet corn to plant spacing
Plant spacing had a significant effect on the height of sweet corn plants aged 70 days after planting but had no significant effect on plant heights at 30 and 50 days after planting.This is presumably because the spacing between 70x20 cm, 70x30 cm, and 70x40 cm is relatively the same as the competition between plants for nutrients, light, and water, thus showing plant height that has no significant effect at 30 and 50.At a spacing of 70x20 cm shows the highest planting height for each observation, and a spacing of 70x20 cm with the highest plant height obtained when the plants were 30 HST (78, 25 cm), 50 DAP (138.23 cm) and 70 HST (172.38 cm).The increase in plant height at narrow spacing is thought to be due to the denser plant stands.
Likewise, the number of leaves where the spacing had no significant effect at 30, 50, and 70 daps.This shows that genetics and environment greatly affect the number of leaves (growth, yield, and quality).The highest number of leaves was obtained at 70x40 cm at 30 and 50 DAP, namely 6.31 and 11.80, and at 70 DAP the highest number of leaves was obtained at 70x20 cm, namely 21.17.Leaf areas with different spacing had no significant effect.The highest leaf area was obtained at 70x30, namely 128.61.Plant spacing has a significant effect on length of cob.The highest cob length was obtained at a spacing of 70 x 30 cm, which is 16.5 cm.A spacing of 70 x 30 cm is the ideal spacing for obtaining the nutrients and water needed by plants.This is in line with the results of research that has been done [9] showing that 70x30 cm and a planting time of 4 WAP can affect the length of the cobs produced in sweet corn.Plant spacing had a significant effect on length of cob, diameter of cob, rows number per ear, and seeds number per row but had no significant effect on weight of cob without husk, 100-grain weight, number of rows per ear, number of seeds per row, and yield of sweet corn.The yield components include cob diameter (26.11 mm), and cob weight without husks (170.21g), the highest yield was obtained at a spacing of 70x20 cm.While the cob length (16.50 cm), the rows number per cob (15.21), seeds number per row (94.18), 100 grains (30.12 g), and the yield potential (11.38 t ha-1) were obtained at 70x30 cm.Note: The numbers followed by the same letter in the same column are not significantly different from the DMRT at the level of 5% (DAP = day after planting).

Response of sweet corn to granular organic fertilizer (GOF)
The application of GOF has no significant effect on these three parameters (plant heigh, leaves number, and area of leaf), because the competition for nutrients, water, or light at the three levels is the same.In the application of granular organic fertilizer of as much as 2 tons ha-1, the highest plant height was obtained at 30 (72.65), 50 (138.11),and 70 (74.28).Loose soil makes it easier for plant roots to penetrate deeper and has wide roots so that plants are stronger and better able to absorb nutrients and nutrients so that growth and production increase.By applying organic fertilizers besides being able to improve the physical and chemical properties of the soil, it can also improve the biological properties of the soil, namely by increasing the activity of soil microorganisms [8].
The highest number of leaves and leaf area were obtained by giving GOF at 30 (7.05), 50 (11.60),and 70 (22.91)DAP obtained from plants that were given fertilizer as much as 3 tons ha -1.This is presumably because the administration of 3 tons ha-1 can increase the element of N so that it can increase the number of leaves.An increase in the number of leaves due to granular organic fertilizer treatment with 3 tons ha-1 can overcome the effect of nutrient deficiency on plants [10].GOF is an organic fertilizer that has advantages over other organic fertilizers because it has a low C/N ratio, meaning it has a high nitrogen content of up to 1.48% [11].
The addition of nutrients and accelerating the availability of nutrients in the soil for plants is the role of GOF.Soil density, increased aeration and addition of soil organic matter can be obtained by using GOF, which reinforces the opinion [12] which states that the microbes present in granular organic fertilizers can produce enzymes (amylase, lipase, cellulase, and chitinase) so that they can help accelerate reformation.chemistry.The superiority of this granular organic fertilizer is also supported by the presence of growth hormone which has a good effect on the growth of sweet corn.Good leaf growth will allow plants to receive maximum light for the process of plant development and growth, which is expected to produce high yields as well [13].
GOF application had a significant effect on cob length and cob weight without husk, and 100 grains but had no significant effect on cob diameter, rows number per ear, seeds number per row, and yield.The highest yields on the parameters of length of cob (15.98), weight of cob without husk (172.5), and 100 grains (33.98) were obtained from plants that were given fertilizer as much as 3 tons ha -1 .The increase in cob weight without husks is thought to be closely related to the amount of photosynthate translocated to the cobs.The greater the photosynthate translocated to the cob, the fresh cob weight also increases.Giving granular organic fertilizer can increase the fresh weight of cobs without husks.[14] stated that the amount of energy from the sun that has been absorbed by the leaves will determine the amount of photosynthate produced and plant area of leaves is a factor that determines this.By applying granular organic fertilizers as organic matter providing nutrients and adjusting the spacing in such a way that light can be used by plants more efficiently, greater photosynthetic results will be obtained.Photosynthate greatly determines seed yield because some of the photosynthates are stored in the seeds.During the seed-filling period there is an increase in the accumulation of dry matter and nutrient deficiencies at this time will cause the seeds not to develop properly [15].
The highest yield of cob diameter (27.11), rows number per cob (15.24), seeds number per row (101.31), and sweet corn yield (12.58) were obtained from GOF 3 t ha-1.This is presumably because the phosphorus contained in GOF is a carbohydrate-forming material that has increased in the soil.With GOF, soil organic matter that is not available decomposes and decomposes and eventually becomes available nutrients for plants, with the help of GOF-causing microorganisms such as bacteria and fungi [16].[11] stated that the application of organic fertilizers causes easier absorption of plant nutrients which in turn can increase plant cell division, and increase crop yields.Note: The numbers followed by the same letter in the same column are not significantly different from the DMRT at the level of 5% (DAP = day after planting)

Response of sweet corn to interaction of plant spacing and Granular Organic Fertilizer (GOF)
Optimal spacing and appropriate fertilization are the most important factors to get maximum results [17].Increasing the survival of a plant is determined by reduced competition for space, moisture, and nutrients, as well as the availability of ideal nutrients due to the application of fertilizers that can be absorbed by plants [18].The interaction between plant spacing and GOF had no significant effect on plant height, number of leaves, leaf area, cob length, cob diameter, and number of rows per ear, but had a significant effect on cob weight without husk, number of row seeds, 100 grains, and yield potential.The highest cob weight without husk (176.66),number of seeds per row (103.18), 100 grains (32.68), and yield potential (12.81) were obtained at a spacing of 70x20 cm with GOF 3 t ha -1.Growth is the process of increasing the size 1230 (2023) 012216 IOP Publishing doi:10.1088/1755-1315/1230/1/0122166 of a cell or organism that is quantitative or measurable.Environmental factors with appropriate and sufficient capacity (availability of water, humidity, temperature, and sunlight) greatly affect the growth of a plant [19].The spacing system affects the nutrients and growth space obtained by plants, which in turn affects plant growth and production.Two treatment factors are said to interact if the effect of a treatment factor changes when the level of other treatment factors changes [20].Note: The numbers followed by the same letter in the same column are not significantly different from the DMRT at the level of 5%.

Conclusion
1. Spacing significantly effect on plant height 70 DAP, length of cob, diameter of cob, number rows of cob, and row seeds number.2. Use of Granular Organic Fertilizer (GOF) significantly effect on cob length, cob weight without husk, and 100 grains.3. The interaction between planting spacing and the application of Granular Organic Fertilizer (GOF) significantly effect on the weight of the cobs without husks, the number of row seeds, 100 grains, and yield potential 4. Spacing of 70 cmx20 cm by using Granular Organic Fertilizer (GOF) 3 t ha-1 gives yield potential of 11.24 t ha-1 1230 (2023) 012216 IOP Publishing doi:10.1088/1755-1315/1230/1/0122164

Table 1 .
Recapitulation of ANOVA of spacing and application of granular organic fertilizer (GOF) on sweet corn.
** and * each significantly different at an error rate of 1% and 5%, ns = not significant

Table 2 .
Response of sweet corn to plant spacing.

Table 3 .
Response of sweet corn to the Granular Organic Fertilizer (GOF).

Table 4 .
Effect of spacing and GOF of weight of cob without husk, seeds number per row, 100 grains, and sweet corn yield potential.