Table 4: Nitrogen rate × N application timing × variety interaction in 2009 for rotten tubers as a percentage of total yield for Russet potatoes grown on sandy loam soils in the Mid-Atlantic.

Nitrogen rate   Goldrush       Norkotah All at planting 2-splits 3-splits   All at planting 2-splits 3-splits kg ha−1 % of total yield 0† 11.8 21.8 67 47.2 ab‡ 29.3 cdef 34.6 bcdef 24.5 ef 29.6 cdef 33.7 bcdef 134 31.2 cdef 31.9 bcdef 35.4 abcdef 35.3 abcdef 26.7 def 43.4 abc 201 23.2 f 50.8 a 33.0 bcdef 39.8 abcde 29.7 cdef 36.6 abcdef 268 36.4 abcdef 26.3 def 35.2 abcdef 31.6 bcdef 42.9 abc 41.9 abcd LSD0.10 15.9 Pr > F 0.0399

†No-fertilizer control plots were not included in Analysis of Variance and are included for informational purposes only. ‡Means with the same letter are not significantly different (P ≥ 0.10, Fisher’s Protected LSD) and any mean can be compared within the table.