Crinkled leaf of cotton is due to

-Manganese toxicity may occur on soils that are strongly acidic, below pH 5.2.
-Leaves may appear crinkled and cupped, with stunted growth, sometimes called "crinkle leaf."
-Liming to raise soil pH to the range of 5.8 to 6.5 decreases Mn availabilty and increases the availability of P, which may help reduce the toxic effects of Mn.