If a crop is to be irrigated at 0.75 IW/CPE ratio with 5 cm depth, it should be irrigated after – (RJ ARO Agro 2022)

✅Explanation:
-IW = Irrigation Water
-CPE = Cumulative Pan Evaporation
The Questionstates that the crop needs to be irrigated when the ratio of Irrigation Water (IW) to Cumulative Pan Evaporation (CPE) reaches 0.75. We also know that the irrigation depth should be 5 cm.

• We can set up the equation:
-IW/CPE = 0.75
-We know IW = 5 cm
-So, 5/CPE = 0.75
-Rearranging, CPE = 5/0.75 = 6.66 cm
Therefore, the crop should be irrigated after the cumulative pan evaporation reaches 6.66 cm.