Growth and production of japanese taro (Colocasia esculenta var. antiquorum) by using plastic mulch and biofertilizer

Japanese taro (Colocasia esculenta var. antiquorum) production in Indonesia is around 20 tons/hectare, but it is still relatively low due to the low level of farmer management including fertilizing and watering especially in dry season. We determined the effect of plastic mulch and biofertilizer on the growth and production of japanese taro plants. This research used a split plot design. The main plot was plastic mulch consist of two levels, namely control and plastic mulch, while the sub-plots were biofertilizer, which consist of two levels: control and biofertilizer; and with four replications. Each plot planted with 22 plants. Parameters observed were plant height, leaf number, leaf width, fresh plant top weight, dry plant top weight, plant tuber yield, and number of tubers. The results are plastic mulch treatment had an effect on plant height with the largest average found in the mulch treatment of 55.98 cm, the largest average leaf width in the mulch treatment was 25.09 cm, the average fresh weight of the mulch plant was 197.03 g, and the average dry weight of mulch plants was 22.50 g. The biofertilizer treatment affected significantly on plant height, leaf number, and leaf width. Mulch was affects significantly on production of taro plants with the highest of weight of 881.50g/plant equal to 22 t/ha, and number of tubers found in the mulch treatment of 32 bulbs. However, the biofertilizer treatment was not significant in the production of taro plants. We conclude that the plastic mulch can increase the growth, yield and number of tubers, better than the biofertilizer and the combination of its combination especially in the dry season.


Introduction
Taro is a functional food crop, which has a great opportunity to be developed due to its various benefits, including for industrial purposes.In addition, it also has high economic value because most of the plant parts can be used for consumption [1].Taro tubers are also a good source of protein, vitamin C, riboflavin, niacin, thiamine and minerals [2].It has the advantage of economic potential because it is profitable and contains high nutritional value [3].It has a lot of fiber content, while the fat and protein content is low.Eliantosi and Darius [4] explained, japanese taro (Colocasia esculenta var.antiquorum) is a source of calcium, rich in collagen, and has relatively high calories but contains low carbohydrates.Because it is safe for people with diabetes [5].Such characteristics of taro, especially japanese taro, provide a great opportunity for further increased exports.Japanese taro should be commercially cultivated because it is economically profitable, especially in South Sulawesi [6,7].
Indonesia is the sixth largest supplier of japanese taro in 2019 with a share of 0.03% below Vietnam, Taipei, Myanmar and the United States.However, this number is still relatively low and has great potential for development considering that Indonesia's taro exports to the world experienced a moderate growth of 25% in 2019 and 89.9% in the last five years.In 2019 Japan became the eighth largest country for Indonesian taro exports.Especially for Japan, the average growth trend is 15.5% per year for the last ten years [8].China controls 99.6% of the total 154.6 thousand tons of taro imports to Japan than 2019.Actually Indonesia has started exporting Japanese taro in 2013 to Japan with a total of 6.3 tons of frozen taro with a value of 81,500 yen [9].
Meanwhile, japanese taro cultivation in Indonesia is relatively low, only around 20 tons per hectare [10].Japanese taro has been widely cultivated in Sulawesi, East Java and West Java [11].Actually, since 2008 Japanese taro has begun to be developed in South Sulawesi, especially in Bantaeng Regency, but until now its productivity is still difficult to increase, in other words, its production is still low.In 2019 the Provincial Government of South Sulawesi started assisting the massive development of Japanese taro businesses in 16 regencies in South Sulawesi but the results were still not satisfactory [12] and [13].
The low production of taro in Indonesia is caused by the low level of management of taro farmers, especially in the procurement of seeds, sub-optimal cultivation systems, improper fertilization and planting on land with low fertility levels [14].Provision of fertilizer greatly affects the yield of taro production in the future [2].The nitrogen element functions to form the vegetative organs of plants and is a constituent of chlorophyll which is useful in the process of photosynthesis, thus spurring the growth and production of taro plants [15].
Taro likes moist, well-drained soil and lots of organic matter [16].Based on the land suitability class criteria, land with a temperature of 25-32 ⁰C which is very suitable for taro plants and a total rainfall in the first four months is greater than 225 mm [17].[18] detailed, that mulch prevents water loss from the soil, stabilizes temperature, soil moisture, and suppresses weed growth, and creates conditions that suit the needs of plants, so that plants grow and developed.According to their potential.Because of that, the use of mulch can be a beneficial cultivation action for meeting the needs of plants, especially in terms of controlling soil moisture, in addition to controlling weeds.
[19] obtained, biofertilizer application on arrowroot plants (a type of tuber plant) has a significant effect on the leaf number, number of tillers, relative growth rate, net assimilation rate, number of tuber clumps, tuber diameter, tuber length, and tuber weight per clump.Leida used a biofertilizer containing five of the most productive species of bacteria of the genus Bacillus and four fungi of the genus Trichoderma.[20] using a biofertilizer containing functional microbes namely nitrogen fixing bacteria, phosphate solubilizing bacteria and organic matter degrading bacteria which are beneficial for plant growth and production.
Biofertilizer is a fertilizer containing microbes, useful for the supply of nutrients, especially in organic farming systems, and can control pests and plant diseases, resulting in increased plant growth and productivity.Usually contain microbes Bacillus, Pseudomonas, Rhizobium, Azosprillum, Azotobacter, Mikoriza, dan Trichoderma; can be single, or a combination of several types of microbes which are often called a microbial consortium [21].
Mulch is an environmental modification tool to increase crop production [22].In general there are two kinds; organic mulch (mainly from plant waste) and inorganic mulch made from synthetic materials, such as plastic mulch [23].Plastic mulch maintains soil moisture, stimulates microbial activity in the soil through improving soil agro-physical characteristic, warming the soil, improving soil physical conditions, suppressing weed growth and increasing growth and production yields [24].

Site, time and material
This research was conducted during the dry season from May to October 2020 in Sudiang Village, Makassar City, South Sulawesi, Indonesia; located in geographic coordinates 5°6 '24.30The results of soil analysis before treatment showed that the pH value was slightly acidic, the content of N, P, K, C-organic and CEC was low.However, based on the land suitability class criteria, it is still suitable for taro plants [17] then the land is suitable for the development of Japanese taro commodities.In this research we used equipment: analytical balance, cultivator, silver black plastic mulch, drip hose, and digital camera.The materials used in this study were taro plant tubers, NPK fertilizer, compost, biofertilizer "EF", analytical balance, cultivator, silver-black plastic mulch, drip hose, and digital camera.The materials used in this study were taro plant tubers, NPK fertilizer, compost, eco-farming brand biofertilizer, and pesticides.

Research technique
The study was designed according to Split Plot Design (SPD).The main plot was plastic mulch which consisted of 2 levels, namely control and plastic mulch and the sub-map was biofertelizer which consisted of 2 levels, namely control and biofertilizer "EF".Repeated 4 times, thus there are 16 plots measuring 550 cm x 110 cm and 15 cm height, with a 50 cm ditch width; each plot planted with 22 plants with a spacing of 50 cm x 40 cm.

Research stages.
Media preparation by cultivating the soil twice using a cultivator, then using the same tool to make beds 550 cm long, 110 cm wide and 15 cm high; distance between beds 50 cm.Then given basic fertilizer in the form of compost 800 grams per plant hole before planting; NPK 20 g/plant when the plants are 30 days old refers to [13].
The treatment application was in the form of installing mulch after the beds were ready for planting, by completely covering the surface of the beds, then punching holes right above the planting holes with a diameter of 8 cm.Application of biofertilizer according to recommended dose of EF biofertilizer 4 times: 4, 1.5, 2, and 4 liters per hectare respectively on day 0, 30, 60 and 90.Planting seeds in the form of tubers from healthy plants that are 5-6 months old with normal size or around 20-50 grams.Maintenance includes watering once a day for 60 minutes; Pest control is done manually or mechanically, weed control is done by pulling.backfilling manually using a hand shovel twice, namely 30 days and 75 days.
Harvesting was done at the age of 135 days after planting.

Parameters
Parameters measured included: height (length) of the longest frond, leaf number, leaf width, top fresh weight, and top dry weight; and weight of tubers yield, and number of tubers per plant.For the length parameter, a millimeter scale meter was used and for the weight parameter, an analytical scale of 0.

Data analysis models
Using software to process Microsoft Excel data; data with analysis of variance (ANOVA) to determine the effect of the treatment being tried.If there is an effect, then it is further tested using the LSD test at the 5% level.The general model of the mathematical split plot design is applied which is stated as follows: Information: yij = observed value µij = average αij = main plot treatment effect Eα = random effect (α) βij = sub-plot plot treatment effect Eb= random effect (b) (αβij) = the interaction effect of main plot treatment and subplot treatment

Soil characteristics
Although statistically not significant, the application of mulch, biofertilizer, and mulch-biofertilizer combination tends to improve soil chemical characteristic to a better level.The mulch treatment increased soil pH from 6.1 to 6.88, soil organic C from 1.65% to 2.01%, and soil CEC from 15.64 me/g to 19.32 me/g.The biofertilizer treatment increased soil pH from 6.1 to 6.90, soil organic C from 1.65% to 2.05%, and soil CEC from 15.64 me/g to 20.26 me/g.The combined mulch-biofertilizer treatment increased soil pH from 6.1 to 6.93, soil C-organic from 1.65% to 2.09, and soil CEC from 15.64 me/g to 21.67 me/g.The combined mulch-biofertilizer treatment improved soil chemical characteristic better than the single mulch and biofertilizer treatment (table 2).

Plant height
Plant height is the maximum frond length at harvest age (135 days).The results of variance showed that mulch and biofertilizer had a significant effect on increasing plant height, but the mulchbiofertilizer interaction was not significant in increasing plant height.The LSD test showed that the biofertilizer gave an average plant height of 55.00 without biofertilizers.Giving mulch also had the effect of increasing plant height by 55.98 cm, significantly different from without mulch (table 3).11.18 Information: The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.

Leaf number
The results of variance showed that the biofertilizer had a significant effect on increasing the leaf number, but the mulch and mulch-biofertilizer interaction had no significant effect on increasing the number of plant leaves.LSD test shows that biofertilizer.produced an average leaf number, which was 6.53 leaves, which was significantly different from that without biofertilizer, which was only an average of 4.31 leaves (table 4).1.66 Information: The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.

Leaf width
Plant leaf width based on variance showed that mulch and biofertilizer had a significant effect in increasing plant leaf width, but the mulch-biofertilizer interaction was not significant in increasing plant leaf width.The LSD test showed that the application of biofertilizer resulted in an average leaf width of 25.16 cm which was significantly different from that without biofertilizer.Applicating mulch resulted in an average leaf width of 25.09 cm which was significantly different from that without mulch.The lowest average plant height is 19.8 cm (table 5).4.36 Information: The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.

Fresh weight of plant tops
Fresh weight of plant tops based on variance showed that mulch had a very significant effect, but biofertilizer and mulch-biofertilizer interactions had no significant effect on increasing plant fresh weight.The LSD test showed that mulching resulted in an average fresh weight of the tops of the plants of 197.03 grams which was significantly different from that without mulch.The lowest average plant fresh weight of 100.84 grams was found in the treatment without mulch (table 6).The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.

Dry weight of plant tops
Based on the variance of the results of measurements of plant top dry weight, mulch had a very significant effect on increasing plant top dry weight, but biofertilizer and mulch-biofertilizer interactions were not significant in increasing plant dry weight.The LSD test showed that the mulch produced an average dry weight of the top of the plant of 22.50 grams, which was significantly different from that without mulch.The lowest average plant dry weight of 12.97 grams was found in the treatment without mulch (table 7).The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.

Weight of tuber yield
Based on variance, mulch had a significant effect on increasing the yield of fresh tubers, but biofertilizer and mulch-biofertilizer interaction had no significant effect.The LSD test showed that mulch gave an average yield of fresh tubers of 1,073.99 grams, which was significantly different from that without mulch.The lowest average yield of plant tubers, 699.56 grams, was in the treatment without mulch (table 8).

Number of tubers
The results of variance in the calculation of the number of tubers per plant showed that mulch had a significant effect on increasing the number of plant tubers, but biofertilizer and mulch-biofertilizer interaction had no significant effect.The LSD test showed that the mulch produced an average number of tubers, namely 34 clumps, which was significantly different from that without mulch.The lowest average number of plant tubers was 24 clusters in the treatment without mulch (table 9).The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.
The mulching treatment significantly increased all parameters except the leaf number, while the biofertizer significantly increased only the height, leaf number and leaf width parameters and not the fresh weight and dry weight of plant tops, tuber weight and number of tubers per plant.
Plastic mulch treatment for taro plants increased plant growth factors, especially plant height, leaf number, and leaf width (table 3-7) and all of twoo production parameters (table [8][9].Allegedly because mulch functions effectively as a ground cover to suppress water loss through evaporation so that it can maintain soil moisture especially in the dry season [25].This relates to the planting period which took place during the dry season at the trial location.[26] found something in accordance with his research on chili plants that plastic mulch had an effect on the growth of chili plants and effectively suppressed weed growth.Another function of mulch is to stabilize soil temperature, suppress weed growth so that plants can grow better.Silver black plastic mulch can also reflect sunlight to plants, thus increasing the intensity of light received by plants which has an impact on increasing the rate of photosynthesis [27]. The mulch treatment of Japanese taro production increased significantly (table 8-9).The highest number of tubers was found in the mulching treatment of 32 tubers with a tuber yield of 881.50 g/24.2 m2 or equivalent to 32 tonnes/ha.The yield of taro plants was better with plastic mulch treatment than without plastic mulch.This is in accordance with [28] which explains, mulch and gives better yields, accelerates harvesting, controls weeds, increases the efficiency of water and fertilizer use compared to no mulch on radish plants.Research results from [23] proved that the use of silver black plastic mulch on chili plants increased the number and production of chili pods and had a higher number of pods than without rapids mulch.Improving soil quality, especially improving soil chemical characteristic, namely available K from 0.06 cmol/kg to 0.36 cmol/kg (table 2) strengthens the notion of the effect of mulch on the growth and production of the taro tested.The difference in available nutrient content could be due to not washing with percolation water.
Biofertilizers can also increase nutrient availability, improve soil aggregates, produce growthpromoting substances and are not harmful to the environment [32].However, the biofertilizer did not significantly affect the production of taro plants.This is in line with the results of the study by [33] where the application of biofertilizer also did not significantly affect the yield parameters of sweet potato plants, namely the number of tubers and tuber weight.
The results of taro plant production with biofertilizer have shown differences with without biofertilizer.The lowest average number of taro plant production was found without biofertilizer, and the highest average was in the biofertilizer treatment with the highest number of tubers of 28 with plant tuber yields of 718.75 grams.[34] reported biofertilizer has the ability to fix N from the air and phosphate solubilizing microbes which can increase the availability of P in the soil to become available P for plant growth, thereby affecting growth and increasing plant production.Biofertilizer can improve the availability of nutrients in the soil (table 2); Can increase the of phosphate capable of changing the form of fixed P into P which is more soluble and easy to plant [35].Biofertilizer affects the physical and chemical characteristic of soil, including soil structure and soil pH, organic matter which greatly affects plant growth and production [36].[37] explained, in general the function of biofertilizers which can increase the availability of nutrients in the soil, as a decomposer of organic matter in the soil and mineralization of organic elements such as P elements, can stimulate plant growth by forming enzymes so as to protect roots from pathogenic microbes, and as a biological agent in pest control and plant disease.The combination of mulch-biofertilizer treatment had no significant effect on the growth and production of taro plants.However, the growth and production of taro plants tends to be better than those without mulch and without biofertilizer.The mulch-biofertilizer combination showed a tendency to improve soil chemical characteristic (table 2).

Conclusion
The plastic mulch treatment had a significant effect on growth and production, especially the yield and the number of tubers, but the biofertilizer only had an effect on the growth of japanese taro plants.Plastic mulch has a better effect than biofertilizer and mulch-biofertilizer combination especially in the dry season.

Table 1 .
"S and 119°31'28.47"E.Analysis of soil samples was carried out at the Soil Fertility and Chemistry Laboratory, Faculty of Agriculture, Hasanuddin University and the Laboratory of Soil, Plants, Fertilizers, Water, Agency for Agricultural Research and Development, Maros.The characteristic of the soil in the study area is shown in table 1. Results of analysis of soil characteristic before treatment 1 gram was used.All plant parameters were measured at harvest age, namely at 135 days after planting.Similarly, sampling for post-treatment soil parameter.1230 (2023) 012080

Table 2 .
Results of analysis of soil characteristic after treatment

Table 3 .
Mean of plant height

Table 4 .
Mean of leaf number

Table 5 .
Mean of leaf width

Table 6 .
Mean of fresh weight of plant tops

Table 7 .
Mean of dry weight of plant tops

Table 8 .
Mean weight of tuber yield per plant Information: The numbers followed by the same letter in the same row (a and b) and or the same column (x and y) are not significantly different on the LSD test of 0.05.

Table 9 .
Mean of tuber number per plant