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 rateGoldrushNorkotah
All at planting2-splits3-splitsAll at planting2-splits3-splits

kg ha−1% of total yield

6747.2 ab29.3 cdef34.6 bcdef24.5 ef29.6 cdef33.7 bcdef
13431.2 cdef31.9 bcdef35.4 abcdef35.3 abcdef26.7 def43.4 abc
20123.2 f50.8 a33.0 bcdef39.8 abcde29.7 cdef36.6 abcdef
26836.4 abcdef26.3 def35.2 abcdef31.6 bcdef42.9 abc41.9 abcd

Pr > F0.0399

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.