APS_JANUARY2024

J ournal of the A merican P omological S ociety

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19 Table 1. Mean maximum daily temperatures, mean daily solar radiation, and total precipitation for April to August in 2022 and 2023. 367 Temperature (°C) Solar radiation ( MJ∙m -2 ) Total precipitation (mm) 368 Month 2022 2023 2022 2023 2022 2023 369 April 17.7 20.4 23.06 19.91 115 14 370 May 23.8 25.6 17.84 21.63 127 40 371 June 29.7 30.3 22.55 23.18 40 72 372 July 32.0 31.4 20.05 20.24 53 86 373 August 30.9 29.1 19.38 17.89 36 107 374 19 Table 2. Mean new shoot growth and total shoot dry weight of elderberry plants after treatments in 2022 and 2023. i 375 376 Root pruning Transplanting New shoot growth (cm) Total shoot dry wt. (g) 377 Table 1. Mean maximum daily temperatures, mean daily solar radiation, and total precipitation for April to August in 2022 and 2023. 19 Table 2. Mean new shoot growth and total shoot dry weight of elderberry plants after treatments in 2022 and 2023. i 375 376 Root pruning Transplanting New shoot growth (cm) Total shoot dry wt. (g) 377 Table 2. Mean new shoot growth and total shoot dry weight of elderberry plants after treatments in 2022 and 2023. i Table 2. Mean new shoot growth and total shoot dry weight of elderberry plants after treatments in 2022 and 2023. i 375 376 Root pruning Transplanting New shoot growth (cm) 377 Table 1. Mean maximum daily temperatures, mean daily solar radiation, and total precipitation for April to August in 2022 and 2023. 367 Temperature (°C) Solar radiation ( MJ∙m -2 ) Total precipitation (mm) 368 Month 2022 2023 2022 2023 2022 2023 369 April 17.7 20.4 23.06 19.91 115 14 370 May 23.8 25.6 17.84 21.63 127 40 371 June 29.7 30.3 22.55 23.18 40 72 372 July 32.0 31.4 20.05 20.24 53 86 373 August 30.9 29.1 19.38 17.89 36 107 374 Total shoot dry wt. (g)

treatment treatment treatment

treatment treatment treatment

2022 2022 2022

2023 2023 2023

2022 2022 2022 96 Ab 77 Bb 79 Bb 58 Cb 96 Ab 77 Bb 79 Bb 58 Cb 96 Ab 77 Bb 79 Bb 58 Cb

2023 2023 2023

378 379 380 381 382 383 384 385 386 387 388 389 390 391 378 379 380 381 382 383 384 385 386 387 388 389 390 391 378 379 380 381 382 383 384 385 386 387 388 389 390 391

NRP NRP NRP NRP NRP RP RP RP RP RP

T T T T NT NT NT NT T T NT NT

788 Ab 569 Cb 716 Bb 482 Db 788 Ab 569 Cb 716 Bb 482 Db 788 Ab 569 Cb 716 Bb 482 Db

899 Aa 714 Ca 855 Ba 670 Da 899 Aa 714 Ca 855 Ba 670 Da 899 Aa 714 Ca 855 Ba 670 Da

103 Aa 103 Aa 103 Aa 87 Ca 87 Ca 98 Ba 63 Da 87 Ca 98 Ba 63 Da 98 Ba 63 Da

Significance Significance Significance Year (Y) Year (Y) Year (Y) Root pruning (RP) Transplanting (T) Root pruning (RP) Transplanting (T) Root pruning (RP) Transplanting (T) Y x RP

<0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001 0.001

<0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 0.077 <0.001 <0.001 <0.001 0.077 0.077 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

Y x RP Y x RP Y x T RP x T Y x T Y x T RP x T RP x T Y x RP x T Y x RP x T Y x RP x T

392 i NRP = no root pruning, RP = root pruning, T = transplanting, NT = no transplanting. Means within a column followed by the 393 same letter are not significantly different, P ≤ 0.05. Means within a column followed by the same uppercase letters and means 394 within a row followed by the same lowercase letters are not significantly different, P ≤ 0.05. Mean differences are based on a 395 one degree of freedom F-test. 396 392 i NRP = no root pruning, RP = root pruning, T = transplanting, NT = no transplanting. Means within a column followed by the 393 same letter are not significantly different, P ≤ 0.05. Means within a column followed by the same uppercase letters and means 394 within a row followed by the same lowercase letters are not significantly different, P ≤ 0.05. Mean differences are based on a 395 one degree of freedom F-test. 396 392 i NRP = no root pruning, RP = root pruning, T = transplanting, NT = no transplanting. Means within a column followed by the 393 same letter are not significantly different, P ≤ 0.05. Means within a column followed by the same uppercase letters and means 394 within a row followed by the same lowercase letters are not significantly different, P ≤ 0.05. Mean differences are based on a 395 one degree of freedom F-test. 396 i NRP = no root pruning, RP = root pruning, T = transplanting, NT = no transplanting. Means within a column followed by the same letter are not significantly different, ≤ 0.05. Means within a column followed by the same uppercase letters and means within a row followed by the same lowercase letters are not significantly different, P ≤ 0.05. Mean differences are based on a one degree of freedom F-test.

the RP + NT treatment. However, in 2023, NRP + NT had less dry weight than RP + T. When containers were removed and roots in spected, the root tips in the RP and NRP treat ments were in contact with the container walls. Roots in the T treatments had also reached the container walls but were less densely distrib uted when compared with the tightly bound roots in the NT treatments. When data were analyzed, the two-way in teraction of year x root pruning was signifi cant ( P = 0.003) (Table 3) for root dry weight.

For both years, plants with the RP treatment had less root dry weight than those with the NRP treatment. In 2022 and 2023, the reduc tion in root dry weight was 34.0% and 30.5%, respectively. Additionally, the two-way inter action of year x transplanting was significant ( P < 0.001) for root dry weight. Transplanting increased root dry weights in both years, but weights were lower in 2022 than in 2023. The two-way interaction of root pruning and trans planting was also significant ( P < 0.001). For NRP and RP treatments, NT reduced root dry