Dissolve some of the water used for 100ml PDA, for example 50 ppm in 20ml of sterile distilled water. Add to the PDA that has been autoclaved and cooled to 50 degrees centigrade.

Hi, I believe that the carbendazim is not being completely dissolved in the stock solution, and/or it is not being uniformly distributed in the Petri dishes. I suggest the following steps:

1. Keep the autoclaved PDA molten at 50 oC in a water bath.

2. Prepare a stock solution of 0.1 g carbendazim in 10 ml SDW and ensure a uniform suspension by vortexing.

3. Aseptically add 500 microlitres of the carbendazim to the molten PDA.

4. Swirl the medium clockwise and anticlockwise in the water bath for at least 1-2 min to ensure thorough mixing of the 500 microlitres carbendazim before pouring into the Petri dishes.

All the best to you in your research.

Dear Dhinesh,

Make sure tht carbendazim is completely soluble in aqueous solution. If not it attributes to the variation in concentration during the assay which effects the growth and subsequently the results.

1. prepare the stock solution of carbendazim separately in the autocalved d/w or miliQ water (with a particular solvent like DMF, ethanol) to eliminate the precipitation of antifungal agent.

2. before pouring the molten media to petridish add the respective amt of carbendazium

3. mix the carbendazium and media, gently swril and allow for solidification.

4. then follow with the inncoulation of the pathogen

Other method is to analysis the dry biomass of the pathogen.

In this method,

1. PDB is prepared in different sets 50 / 100ml each

2. add the carbendazim solution of different concentration.

3. Inoculate the pathogen

4. Allow it to grow for a week

5. Separate the fungal mate by filtration using filter paper

4. Blot the water content (use the appropriate safety measures)

5. Note the weight with markings

6. Remove the water / moisture content by placing it in hot air oven (60C) until it reahces the constant weight. (might takes around 1 to 2days)

7. Again weight the weight of dry fungal biomass

8. Take the weight of untreated one as control

9. Find the Tolerant Index Using the formula

TI = (C-T)/C * 100; some times TI= (T/C) *100

10. this gives TI as well as the effect levels carbendazim for fungal inhibition.

References:

Valix and Loon, (2003); TI based grouping: Oladipo et al.(2018).

Preparation of 100 mL PDA with 50 ppm Carbendazim:

• Step 1: Calculate the required amount of carbendazim. 50 ppm = 50 mg/L. For 100 mL (0.1 L), you need 5 mg of carbendazim.
• Step 2: Prepare a stock solution (for accurate dilution): Dissolve 1 g (1000 mg) carbendazim in 10 mL sterile distilled water. This gives a 100 mg/mL stock solution.
• Step 3: Add the stock to PDA: For 50 ppm in 100 mL PDA: 5 mg ÷ 100 mg/mL = 0.05 mL (50 µL) of stock solution. Mix this into 100 mL molten, cooled PDA (≈50°C) and pour plates.

Hi,

You may use the web tool to calculate

https://www.alfa-chemistry.com/solution-dilution-calculator.htm

https://www.alfa-chemistry.com/mass-molarity-calculator.htm

Step 1: first prepare mother stock solution,if you will add 10 g of carbendazim in 1 liter distilled water you will get 10000 ppm of stock solution.

Step 2: By using a standard formula N1 V1=N2 V2 , 10000 ppm ×V1 = 50 ppm × 100ml ,we get v1 as 0.5 ml.

Step 3: we add 0.5 ml mother stock solution in 100ml of PDA medium then it will be 100 ml PDA with 50 ppm of carbendazim.