Nitrogen Fertilizer and Growth Regulator Impacts on Tuber Deformity, Rot, and Yield for Russet Potatoes

Table 9

Nitrogen application timing × variety interaction in 2011 for rotten tubers as a percentage of total yield, marketable tuber yield, and total tuber yield for Russet potatoes grown on sandy loam soils in the Mid-Atlantic, averaged across N rates.

Nitrogen application timing	Rotten tubers			Marketable yield			Total yield
	Goldrush	Norkotah		Goldrush	Norkotah		Goldrush	Norkotah
	Percentage of total yield			kg ha^−1
No nitrogen^†	35.5	82.9		7871	1773		11603	9400
At planting	34.8 c^‡	85.2 a		7874 b	2811 c		11947 c	15698 ab
2-split	42.6 c	86.4 a		10396 a	2696 c		17354 a	16200 ab
3-split	48.0 bc	79.7 ab		8303 b	3970 c		15729 ab	14284 bc
LSD0.10	32.1			1835			2710
Pr > F	0.0131			0.0823			0.0458

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