Applications of cow manure and bagasse biochar on the growth and flavonoids of white turmeric ( Curcuma zedoaria )

. Cow manure and bagasse biochar are expected to increase yield of white turmeric ( Curcuma zedoaria ) and reduce the use of chemical that can trigger global warming. This study aimed to obtain the response of adding cow manure and bagasse biochar on the growth and flavonoids in white turmeric. This research was held in July 2022 – June 2023, located at faculty agriculture experimental field and CV Che-Mix Pratama. The method used completely randomized design with two factors and 3 replications. The first factor was cow manure dose 0, 100, 200, and 300 g perpolybag and the second was bagasse biochar 0, 80, 160, and 240 g perpolybag. Variables consisted number of leaves, number of tillers, diameter, stem dry weight, rhizomes wet weight, rhizomes dry weight, and flavonoids percentage. The data were analyzed using analysis of covariance with a 5% level test and continued with Duncan’s Multiple Range Test at 5% level. Dose 300 g of cow manure was the best treatment to generate the best number of leaves, number of tillers, plant diameter, stem dry weight, rhizomes wet weight and dry weight. The highest flavonoids at 0.06% was found in 100 g of cow manure and 240 g of bagasse biochar.


Introduction
White turmeric (Curcuma zedoaria) is one of the spices or medicinal plants that is useful for warming the body, maintaining immunity, and as an alternative medicine for tumor diseases [1].The white turmeric rhizome contains secondary metabolic compounds, one of which is flavonoids which are antioxidant compounds, acting as inhibitors of tyrosine kinase activity, an enzyme that plays an important role in the development of cancer cells [2].The use of chemical fertilizers in white turmeric cultivation can trigger global warming because their manufacture emits carbon dioxide (CO2) gas [3].The potential for eutrophication increases as a result of excessive use of chemical fertilizers especially with high phosphate content.Reducing the use of excess chemicals can be achieved with cow manure and bagasse biochar as a supplier of soil organic matter especially for white turmeric cultivation.Cow manure is able to increase the activity of microorganisms in the soil, and improve soil structure by increasing the number and stability of soil aggregates so as to facilitate root development while supporting sustainable agriculture.Furthermore, biochar is organic waste that can improve soil fertility and is able to retain water and nutrients so that they are more available to plants.Fertilization with organic waste will be in line with aim to preserve the ecosystem [4].This study aims to determine whether there is a real effect in the use of cow manure and bagasse biochar simultaneously on the growth and yield of white turmeric.

Methodology
The research was conducted from July 2022 to June 2023 at faculty agriculture experimental field and CV Che-Mix Pratama.The tools used include hygrometer, campbell stokes, destilator, oven, spectrophotometer, optilab, and plant photosynthesis meter.The materials used were white turmeric rhizomes, cow manure, bagasse biochar, water, polybags, NaOH, HCl, distilled water and aquabidest.The method used was a completely randomized design with two factors and 3 replications.The first factor was cow manure dose 0, 100, 200, and 300 g perpolybag and the second factor was bagasse biochar 0, 80, 160, and 240 g perpolybag.The variables consisted number of leaves, number of tillers, diameter, stem dry weight, rhizomes wet weight, rhizomes dry weight, and percentage of flavonoids.The data were analyzed using analysis of covariance with a 5% level test and if there was a significant difference it is continued with Duncan's Multiple Range Test at 5% level.The research method is experimental which includes preparation, seeding, planting, stress treatment, harvesting, and laboratory testing of flavonoid content.

Growth variables
Plant growth variables affect assimilate production which in turn has implications for yield formation.Dose of cow manure had a significant effect on the number of leaves, diameter, and number of tillers (table 1).Based on the results of the analysis of covariance showed that the treatment of cow manure had a significant effect on the number of leaves.The number of leaves with the control treatment produced 6.00 leaves, significantly different from the cow manure 300 g perpolybag treatment of 9.35 leaves (an increase of 55.83% from the control treatment).[5], the Nitrogen (N) element in fertilizer as much as that absorbed by plants is used for the formation of protein as a constituent of plant organs, especially in plant tissues that are actively dividing (meristem) both in leaves, branches, roots, and stems.
The plant diameter of the control treatment produced an average of 12.44 mm, not significantly different from cow manure 100 g perpolybag which produced an average of 15.58 mm or cow manure 200 g perpolybag which produced an average of 15.29 mm.However, the control treatment is significantly different from the cow manure 300 g perpolybag treatment which produces an average of 17,05 mm (an increase of 37.06% from the control treatment).[6], pseudo-stems of plants from the Zingiberaceae family play a role in the formation of assimilates which in turn affect the yield in the form of rhizomes.
The number of tillers in the cow manure 300 g perpolybag treatment resulted in an average of 3.11 tillers (an increase of 152.84% from the control treatment), significantly different from the cow manure 100 g perpolybag treatment with an average of 1.65 tillers and the control treatment with an average of 1.23 tiller.The Nitrogen content in the fertilizer contributes to the process of tuber formation through tillers [7].More N content in the composition of planting media supplied by fertilizers will stimulate the growth of tillers so that the harvest will be obtained with a greater number of rhizomes because the tillering factor affects the number of rhizomes [8].

Yield variables
Dose of cow manure had a significant effect on stem dry weight, rhizomes wet weight, and rhizomes dry weight (table 2).These results are then used for testing rhizomes for flavonoid content as a secondary metabolite compound.Based on the results of the analysis of covariance, it shows that the treatment of cow manure has a significant effect on the dry weight of the stalk.Cow manure 300 g perpolybag treatment with a weight of 87.88 g (increased 192.83% from the control treatment) was significantly different from the control with a weight of 30.01 g and cow manure 100 g perpolybag with a weight of 54.11 g.The weight of stalks as plant biomass is influenced by the manipulation of nutrient-rich planting media, one of which is supplied by fertilizers.Plant dry weight reflects the accumulation of organic compounds that plants successfully synthesize from organic and inorganic compounds, especially water and carbon dioxide.[9] macronutrient content in fertilizers is an important component that affects soil quality to support plant growth.
Plant growth with cow manure 300 g perpolybag produces a wet weight of 388.76 g (an increase of 248.26% from the control treatment) was significantly different from cow manure 200 g perpolybag with a yield of 194.04 g, cow manure 100 g perpolybag with a yield of 193.21 g, and the control treatment with a wet weight of 111.63 g.The application of manure 300 g perpolybag in addition to providing better nutrient availability can also improve soil chemical, physical, and biological properties.[10], efforts to apply fertilizer to the soil can increase rhizome yield and growth parameters.
Cow manure 300 g perpolybag treatment that produced rhizomes dry weight of 123.32 g (an increase of 269% from the control treatment) was significantly different from cow manure 100 g perpolybag of 55.34 g and the control treatment with a weight of 33.42 g. [11] nutrients especially Nitrogen (N), Phosphate (P), and Potassium (K) in cow manure play a role in general plant growth and function in the production of assimilates.[12], high N and K elements in fertilizer can result in the dry weight of a plant and higher yields.

Flavonoid content of white turmeric rhizome
The test results showed different flavonoid content responses in each treatment.Nutrient and water stress is one of the causes of activating secondary metabolite compounds as a selfdefense effort against unwanted conditions.The test results are shown in Figure 1.The highest result of flavonoid content was in the P1B3 (100 g perpolybag fertilizer and 240 g perpolybag biochar) at 0.06%.[13], in stressful conditions when the availability of water and nutrients supplied by cow manure is very little, it causes a plant response to unwanted conditions by activating secondary metabolite compounds as a self-defense effort.[14], when plants interact with pathogens, pests or biotic and abiotic stresses, plants will activate various defense mechanisms, including the induction of secondary metabolite biosynthesis.

Flavonoid percentage
Cow manure and bagasse biochar dose (g)

Conclusion
The use of cow manure and bagasse biochar together did not increase the growth and yield variables of white turmeric.The dose of cow manure 300 g perpolybag can increase the number of leaves, diameter, number of tillers, stem dry weight, rhizomes wet weight, and rhizomes dry weight of white turmeric.The highest flavonoid content was in P1B3 (100 g perpolybag cow manure and 240 g perpolybag bagasse biochar).
This research was funded by Universitas Sebelas Maret through the Fundamental Scheme Research Program 2023.

Table 1 .
Plant growth with fertilizer and biochar treatments.
Notes: Numbers followed by the same letter in one column indicate not significantly different at DMRT 95% confidence level, (-): There is no interaction.

Table 2 .
Crop yield with fertilizer and biochar treatments.