Comparison of Split or Single Application of Gypsum for Wild Lowbush Blueberry (Vaccinium angustifolium Ait.)

Figures & data

TABLE 1 Effect of Single or Split Application of Gypsum and DAP on Soil Nutrient Concentrations at Two Maine Wild Blueberry Fields

Treatments	Rates (kg·ha^−1)	pH (CaCl2)	OM (%)	Ca (ppm)	S (ppm)	Mg (ppm)	K (ppm)	P (ppm)	Mn (ppm)	Zn (ppm)
CLARY HILL
Control	0	3.39 ^z b	12.83 a	206.68 ^y b	163.83 ^x b	33.41 a	95.38 a	15.74 ab	44.75 a	2.38 a
DAP	448	3.88 b	11.90 a	209.47 b	204.51 b	35.89 a	87.18 b	16.54 a	38.17 ab	2.03 ab
Gypsum (single)	4484	4.10 a	12.02 a	616.48 a	414.05 a	22.97 b	86.21 b	13.16 c	21.32 c	1.80 b
Gypsum (split)	2,242 × 2	4.08 a	12.20 a	729.98 a	488.48 a	24.18 b	95.85 a	13.56 bc	28.12 bc	2.03 ab
MARSHVILLE
Control	0	3.73 b	14.33 a	413.94 b	25.87 b	78.63 a	66.75 a	14.11 b	27.03 a	2.95 ab
DAP	448	3.69 b	15.52 a	458.63 b	27.93 b	85.81 a	78.46 a	20.24 a	26.38 a	3.42 a
Gypsum (single)	4484	3.87 a	14.43 a	880.20 a	278.07 a	36.32 b	67.02 a	13.77 b	17.36 b	2.61 b
Gypsum (split)	2,242 × 2	3.89 a	16.30 a	1010.92 a	266.81 a	42.98 b	82.03 a	15.14 b	25.81 a	3.20 ab
^zMeans within a column in each location not followed by the same letter are significantly different at P < 0.05 level using Ryan-Einot-Gabriel-Welsch (REGWQ) Test.
^yCa data at the Clary Hill field was log transformed for analysis but are presented as original means in the table.
^xS data at both fields were log transformed for analysis but are presented as original means in the table.

TABLE 2 Effect of Single or Split Application of Gypsum and DAP on Leaf Nutrient Levels and Yield of Two Wild Blueberry Fields in Maine

Treatments	Rates (kg·ha^−1)	N (%)	P (%)	Ca (%)	K (%)	Mg (%)	Fe (ppm)	B (ppm)	Al (ppm)	Mn (ppm)	Yield (kg·ha^−1)
CLARY HILL
Control	0	1.94 ^z b	0.154 b	0.436 a	0.532 a	0.131 a	40.06 a	21.78 a	120.97 a	2,275.0 a	5,240.0 b
DAP	448	2.27 a	0.180 a	0.374 b	0.552 a	0.119 a	40.42 a	23.87 a	77.32 a	2,111.7 a	8,248.0 a
Gypsum (single)	4,484	1.92 b	0.159 b	0.468 a	0.546 a	0.118 a	40.45 a	21.42 a	91.90 a	2,246.7 a	5,492.0 b
Gypsum (split)	2,242 × 2	2.00 b	0.163 b	0.467 a	0.558 a	0.123 a	42.63 a	21.60 a	105.03 a	2,153.3 a	5,313.0 b
MARSHVILLE
Control	0	1.47 b	0.116 b	0.459 ab	0.393 b	0.176 a	24.62 a	23.93 b	72.87 ab	1,116.2 bc	3,594.1 b
DAP	448	1.67 a	0.140 a	0.402 b	0.440 a	0.162 ab	26.63 a	27.02 ab	64.03 b	958.7 c	7,810.2 a
Gypsum (single)	4,484	1.56 a	0.130 a	0.524 a	0.432 a	0.163 ab	26.23 a	27.55 ab	78.52 a	1,420.2 ab	4,257.3 b
Gypsum (split)	2,242 × 2	1.60 a	0.134 a	0.528 a	0.432 a	0.153 b	27.65 a	28.97 a	71.37 ab	1,581.7 a	4,990.5 b
^zMeans within a column in each location not followed by the same letter are significantly different at P < 0.05 level using Ryan-Einot-Gabriel-Welsch (REGWQ) Test.

TABLE 3 Effect of Single or Split Application of Gypsum and DAP on Wild Blueberry Stem Characteristics at Two Maine Wild Blueberry Fields

Treatments	Rates (kg·ha^−1)	Stem density (number per 0.023 m^2)	Average stem length (cm)	Branched stem length (cm)	Unbranched stem length (cm)	Percent branching	Number of branches
CLARY HILL
Control	0	41.33 a ^z	10.16 ^y b	11.82 ^y b	8.84 ab	35.82 ^x b	0.764 ^y b
DAP	448	38.67 a	11.83 a	13.90 a	9.76 a	54.54 a	1.469 a
Gypsum (single)	4,484	40.58 a	10.05 b	11.79 b	8.51 b	41.82 b	0.774 b
Gypsum (split)	2,242 × 2	41.13 a	9.79 b	11.37 b	8.11 b	44.43 b	0.919 b
MARSHVILLE
Control	0	33.29 a	8.89 ^w b	8.88 b	8.89 b	32.23 c	0.691 ^w b
DAP	448	32.92 a	11.30 a	11.68 a	10.88 a	50.43 a	1.207 a
Gypsum (single)	4,484	32.83 a	9.27 b	9.07 b	9.86 ab	38.66 bc	0.765 b
Gypsum (split)	2242 × 2	33.38 a	9.79 b	9.61 b	10.03 ab	44.66 ab	0.960 ab
^zMeans within a column in each location not followed by the same letter are significantly different at P < 0.05 level using Ryan-Einot-Gabriel-Welsch (REGWQ) Test.
^yStem length and branched stem length data at the Clary Hill field was transformed (square root transformation) for analysis but are presented as original means on the table.
^xPercentage data was transformed using arcsin transformation and analyzed but are presented as the original percentage in the table.
^wBranch data at the Marshville field was log transformed for analysis but are presented as original means on the table.

TABLE 4 Effect of Single or Split Application of Gypsum and DAP on Wild Blueberry Flower Bud Formation at Two Maine Wild Blueberry Fields

Treatments	Rates (kg·ha^−1)	Flower bud density (number per 0.023 m^2)	Number of unbranched stem flower buds	Number of branched stem flower buds	Flower bud per stem
CLARY HILL
Control	0	51.79 a ^z	0.692 a	1.99 a	1.35 a
DAP	448	57.33 a	0.452 a	2.63 a	1.67 a
Gypsum (single)	4,484	51.54 a	0.672 a	2.03 a	1.27 a
Gypsum (split)	2,242 × 2	43.54 a	0.380 a	1.97 a	1.21 a
MARSHVILLE
Control	0	49.92 ab	1.18 a	2.18 ab	1.52 a
DAP	448	54.21 a	1.12 a	2.43 a	1.72 a
Gypsum (single)	4,484	37.13 b	1.00 a	1.81 b	1.27 a
Gypsum (split)	2,242 × 2	44.33 ab	1.10 a	1.89 ab	1.51 a
^zMeans within a column within each location not followed by the same letter are significantly different at P < 0.05 level using Ryan-Einot-Gabriel-Welsch (REGWQ) Test.