Fertilizer type and irrigation frequency affect plant growth, yield, and gas exchange of containerized strawberry cultivars

Geoffrey T. Lalk; Guihong Bi; Eric T. Stafne; Tongyin Li; Geoffrey T. Lalk; Guihong Bi; Eric T. Stafne; Tongyin Li

doi:10.48130/TIH-2023-0003

Figures (1) Tables (7)

Figure 1.
(a) Cumulative growing degree days (GDDs) and (b) outdoor daily air temperatures from 1 Mar to 15 June 2018 in Starkville, Mississippi, U.S. GDDs = (T_daily _max + T_daily _min)/2– T_base. T_base = 3 °C for strawberries. GDDs was calculated on a daily basis, and cumulative GDDs during certain time periods were estimated by summing up daily GDDs; Local outdoor air temperature data was obtained from the USDA Natural Resources Conservation Service website.

Cultivar	PGI^{1, 2}(cm)	SPAD	Number of crowns (per plant)	Visual score (1-5)³	Shoot dry wt. (g per plant)	Root dry wt. (g per plant)
Allstar	41.2 ab	31.9 def	4.1 ab	3.0 bcde	71.4	13.5 abcd
Chandler	37.4 c	30.1 f	4.3 ab	2.9 bcde	65.8	10.1 d
Darselect	39.5 abc	31.0 ef	3.8 ab	2.6 e	65.1	14.6 abc
Earlyglow	38.3 bc	32.9 de	4.0 ab	2.8 cde	63.7	11.9 cd
Evie 2	37.0 c	36.3 ab	3.8 ab	3.0 bcde	58.8	9.6 d
Honeoye	40.9 ab	35.3 bc	4.2 ab	3.8 a	81.5	16.5 ab
Jewel	41.6 a	30.4 f	3.5 b	2.7 de	67.5	12.9 abcd
L'Amour	38.5 abc	33.5 cd	4.4 ab	3.2 bc	75.9	17.3 a
San Andreas	37.6 c	37.5 a	4.2 ab	2.9 cde	64.4	12.3 bcd
Seascape	38.7 abc	35.7 abc	5.2 a	3.3 b	63.2	11.5 cd
P-value	<.0001	<.0001	0.040	<.0001	0.13	<.0001
¹ Plant growth index (PGI) = [plant height + widest width 1 + width 2 (width at the perpendicular direction to width 1]/3. ² Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05. ³ Plant visual quality was evaluated by a five-point scale, where 1 = poor quality with severe leaf damage over 70%; 2 = leaf damage of 50% to 70%; 3 = moderate quality with 20% to 50% leaf damage; 4 = good quality with minor leaf damage of less than 20%; 5 = excellent quality without any leaf damage. A dead plant was rated 0 for the visual score.

Table 1.

Vegetative growth of seven June-bearing ('Allstar', 'Chandler', 'Darselect', 'Earlyglow', 'Honeoye', 'Jewel', and 'L'Amour') and three day-neutral ('Evie 2', 'San Andreas', and 'Seascape') strawberry cultivars grown in Starkville, Mississippi in 2018.

Fertilizer¹	PGI² (cm)	SPAD	Visual score (1−5)	Yield in May (g per plant)	Daily water use (L per day)		Substrate moisture (%)	Pn (µmol·m⁻²·s⁻¹)
Fertilizer¹	PGI² (cm)	SPAD	Visual score (1−5)	Yield in May (g per plant)	19 June	26 June	Substrate moisture (%)	Pn (µmol·m⁻²·s⁻¹)
Organic	38.3 b	32.3 b	2.8 b	57.9 b	0.54 b	0.62 b	27.2 a	10.7 b
Conventional	39.9 a	34.6 a	3.2 a	67.9 a	0.65 a	0.73 a	24.6 b	12.0 a
P-value	0.0003	< 0.0001	< 0.0001	0.044	< 0.0001	0.0003	< 0.0001	0.0059
¹ Strawberry plants were fertilized with a conventional controlled release fertilizer or an organic fertilizer at comparable rates. ² Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05.

Table 2.

Effect of fertilizer type on plant growth index (PGI), leaf SPAD, visual score, yield in May, daily water use, substrate moisture, and net photosynthetic rate (Pn) of container-grown strawberries grown in Starkville, Mississippi.

Irrigation frequency¹	Fertilizer	Shoot dry wt (g per plant)²	Substrate moisture (%)
Once	Organic	60.3 b	21.21 b
Once	Conventional	68.1 b	21.21 b
Twice	Organic	60.7 b	30.55 a
Twice	Conventional	81.8 a	30.55 a
P-value		0.049	< 0.0001
¹ Seven June-bearing ('Allstar', 'Chandler', 'Darselect', 'Earlyglow', 'Honeoye', 'Jewel', and 'L'Amour') and three day-neutral ('Evie 2', 'San Andreas', and 'Seascape') strawberry cultivars were grown in 2-gal containers irrigated once or twice per day with the same total irrigation volume, and fertilized with a conventional controlled release fertilizer or an organic fertilizer at comparable rates. ² Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05.

Table 3.

Shoot dry weight affected by the interaction between irrigation frequency and fertilizer type and substrate moisture affected by the main effect of irrigation frequency of container-grown strawberries.

Cultivar	First harvest date¹ (DAT)	Number of fruit (per plant)	Berry size (g per berry)	Soluble solids content (°Brix)	Fruit firmness (N)
Allstar	58.6 bc	6.9 c	8.8 e	10.5 a	1.89 abc
Chandler	65.7 a	4.6 cd	11.7 d	10.4 a	1.32 e
Darselect	54.0 def	4.7 cd	14.0 bc	11.5 a	1.48 de
Earlyglow	51.3 fg	3.9 cd	9.3 e	11.5 a	1.49 de
Evie 2	60.9 b	16.5 a	14.8 b	8.4 c	1.53 de
Honeoye	49.4 g	4.4 cd	10.1 de	10.4 ab	1.60 cde
Jewel	58.4 bcd	6.0 cd	10.2 de	10.3 ab	1.73 bcd
L'Amour	57.3 bcde	3.1 d	12.2 cd	11.1 a	2.00 ab
San Andreas	53.7 efg	5.0 cd	17.8 a	8.7 bc	2.17 a
Seascape	54.4 cdef	12.3 b	14.2 bc	10.9 a	1.65 cd
P-value	< 0.0001	< 0.0001	< 0.0001	< 0.0001	< 0.0001
¹ Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05.

Table 4.

Fruiting characteristics including first harvest date, number of fruit per plant, berry size, soluble solids content, and fruit firmness of seven June-bearing ('Allstar', 'Chandler', 'Darselect', 'Earlyglow', 'Honeoye', 'Jewel', and 'L'Amour') and three day-neutral ('Evie 2', 'San Andreas', and 'Seascape') strawberry cultivars grown in Starkville, Mississippi in 2018.

Cultivar	Strawberry yield in 2018 (g per plant)¹
Cultivar	April	May	June	Total
Allstar	5.0 c	52.0 cd	1.5 b	58.4 cd
Chandler	3.5 c	50.2 cde	1.9 b	55.7 cd
Darselect	18.6 ab	47.3 cde	0 b	65.8 cd
Earlyglow	17.9 ab	16.7 e	0.6 b	35.2 d
Evie 2	8.9 bc	170.6 a	56.8 a	236.3 a
Honeoye	24.4 a	16.6 e	0.5 b	41.5 d
Jewel	4.6 c	53.8 cd	0 b	58.5 cd
L’Amour	10.0 bc	25.3 de	0.5 b	35.8 d
San Andreas	23.4 a	61.1 c	5.3 b	89.8 c
Seascape	22.5 a	135.7 b	9.4 b	167.6 b
P-value	< 0.0001	< 0.0001	< 0.0001	< 0.0001
¹ Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05.

Table 5.

Monthly and total yield of seven June-bearing ('Allstar', 'Chandler', 'Darselect', 'Earlyglow', 'Honeoye', 'Jewel', and 'L'Amour') and three day-neutral ('Evie 2', 'San Andreas', and 'Seascape') strawberry cultivars grown in Starkville, Mississippi in 2018.

Cultivar	Daily water use (L per day)¹		Substrate moisture (%)
Cultivar	19 June	26 June	27 June
Allstar	0.67 ab	0.78	28.0 a
Chandler	0.58 abc	0.73	25.0 ab
Darselect	0.60 abc	0.66	23.1 b
Earlyglow	0.58 abc	0.67	26.8 ab
Evie 2	0.53 bc	0.65	26.9 ab
Honeoye	0.65 abc	0.72	27.5 a
Jewel	0.57 abc	0.62	27.3 ab
L'Amour	0.71 a	0.72	23.8 ab
San Andreas	0.54 bc	0.61	25.5 ab
Seascape	0.53 c	0.57	25.0 ab
P-value	0.0004	0.074	0.0037
¹ Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05.

Table 6.

Daily water use measured on two dates and substrate moisture measured on 27 June 2018 of seven June-bearing ('Allstar', 'Chandler', 'Darselect', 'Earlyglow', 'Honeoye', 'Jewel', and 'L'Amour') and three day-neutral ('Evie 2', 'San Andreas', and 'Seascape') strawberry cultivars grown in containers in Starkville, Mississippi.

Cultivar	Pn (µmol·m⁻²·s⁻¹)¹	g_s (mol·m⁻²·s⁻¹)	E (mmol·m⁻²·s⁻¹)
Allstar	9.8 d	0.10 a	4.37 ab
Chandler	11.2 bcd	0.12 a	4.73 ab
Darselect	10.3 bcd	0.072 a	3.16 b
Earlyglow	10.7 bcd	0.11 a	5.57 ab
Evie 2	11.2 bcd	0.11 a	4.61 ab
Honeoye	9.7 d	0.089 a	3.74 b
Jewel	9.9 cd	0.083 a	3.98 b
L'Amour	14.4 a	0.14 a	5.53 ab
San Andreas	13.4 ab	0.14 a	6.65 a
Seascape	13.0 abc	0.12 a	5.09 ab
P-value	< 0.0001	0.026	0.0006
¹ Different lower-case letters within a column suggest significant difference indicated by Tukey's HSD test at P ≤ 0.05.

Table 7.

Gas exchange measurements including net photosynthetic rate (Pn), stomatal conductance (g_s), and transpiration rate (E) of seven June-bearing ('Allstar', 'Chandler', 'Darselect', 'Earlyglow', 'Honeoye', 'Jewel', and 'L'Amour') and three day-neutral ('Evie 2', 'San Andreas', and 'Seascape') strawberry cultivars grown in containers in Starkville, Mississippi.