Potato (Solanum tuberosum L.) Yield Response to Different Sulfur Rates and Sources

Sulfur (S) is the fourth most essential nutrient after nitrogen (N), phosphorus (P), and potassium (K) with a direct role in amino acid syntheses, such as methionine, cysteine, and N assimilation. Potato is a fast-growing vegetable crop with a small crop cycle; therefore, nutrient applications at the appropriate time, place, rate, and source are essential. The objective was to determine the effect of different S sources on the potato tuber yield, specific gravity, external tuber quality, and internal tuber quality. This study was conducted in 2021 and 2022, and three S sources were applied at two different rates (T1, 45 kg⋅ha−1; T2, 90 kg⋅ha−1) using a 3 × 2 factorial design. Three S sources were derived from the sulfate of ammonia (AS; SO42− source), magnesium sulfate (EPTOP; S0 source), and gypsum (SO42− source). Three potato cultivars were used for this study (Atlantic, Satina, and Red La Soda). The total and marketable yields indicated a positive response to the application of the S sources. Gypsum and EPTOP outperformed AS, and the lower rate (T1) performed better than the higher rate (T2). In one of the trials, the maximum yield difference between AS and gypsum was 33%. The maximum specific gravity for cultivar Atlantic was found with AS and gypsum, whereas Red La Soda and Satina did not respond to any S source. We did not report the treatment effects on the external and internal disorders when weather affected them.