623 Lowbush Blueberry Response to Phosphorus Fertilizers with Different P: N Ratios

In three commercial fields with a history of low leaf P concentrations, triple super phosphate (TSP) (1 P: 0 N), monoammonium phosphate (MAP) (2.1 P: 1 N), and diammonium phosphate (DAP) (1.11 P: 1 N) with P at 67.2 kg·ha-1 were compared to a control in a randomized complete-block design with 12 blocks. In 1995, all fertilizer treatments were comparable in raising soil P concentrations, but MAP and DAP resulted in higher P leaf concentrations compared to the control. DAP was more effective than MAP in raising N leaf concentrations. Leaf concentrations of Mg, B, and Cu were lowered by MAP and DAP but not TSP. Stem density, stem length, flower buds per stem, flower bud density, and yield were raised by DAP. The same treatments were applied in May 1997 and in May 1999 to the same plots in the same fields. In 1997, by the time of tip dieback in the prune year of that cycle, foliar concentration of P and N averaged higher than in the previous cycle, but still were not up to the standard for N. Fruit yield for the second cycle averaged substantially higher for the controls and for all three treatments, most dramatically for the DAP. In 1999, with only two fields available, response to treatments depended on soil N availability. At the field where leaf N was lower in control plots, MAP and DAP were more effective than TSP in raising leaf P.

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Lowbush Blueberry Response to Different Phosphorus/Nitrogen Ratios

HortScience ◽

10.21273/hortsci.33.3.529d ◽

1998 ◽

Vol 33 (3) ◽

pp. 529d-529

Author(s):

J.M. Smagula ◽

W. Litten ◽

S. Dunham

Keyword(s):

Block Design ◽

Leaf Tissue ◽

Dry Weight ◽

Stem Length ◽

Nutrient Concentrations ◽

Flower Bud ◽

P Deficiency ◽

Lowbush Blueberry ◽

Triple Super Phosphate ◽

Leaf P

Lowbush blueberries (Vaccinium angustifolium Ait.) in three commercial fields were treated with 67.2 kg P/ha from triple super phosphate (TSP), monoammonium phosphate (MAP), or diammonium phosphate (DAP) and compared to a control in a randomized complete-block design with 12 blocks. Correction of P deficiency by fertilizers with different ratios of P to N was assessed by leaf nutrient concentrations. Samples of stems collected in July from three 0.03-m2 quadrats per treatment plot indicated MAP and DAP had no effect on dry weight of stem tissue, but increased average dry weight of leaf tissue. P and N Leaf concentrations were raised to higher levels by MAP and DAP than by TSP. TSP had no effect on leaf N concentrations but raised leaf P concentrations compared to controls. Stem length, flower buds per stem and flower bud density were increased by both MAP and DAP, but not TSP. MAP and DAP increased fruit yield by about 340 kg/ha compared to the control.

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310 Lowbush Blueberry Response to Soil- or Foliar-applied Zinc Fertilizers

HortScience ◽

10.21273/hortsci.34.3.496b ◽

1999 ◽

Vol 34 (3) ◽

pp. 496B-496

Author(s):

J.M. Smagula ◽

W. Litten ◽

S. Dunham

Keyword(s):

Foliar Application ◽

Leaf Tissue ◽

Stem Length ◽

Stem Density ◽

Flower Bud ◽

Tissue Samples ◽

Soil Application ◽

Lowbush Blueberry ◽

Zn Concentration ◽

Flower Bud Formation

Lowbush blueberries (Vaccinium angustifolium Ait.) in two commercial fields were treated with a preemergent soil application of ZnSO4 at 0.34 g Zn/m2 or a prune-year or crop-year foliar application of Zintrac (1.76 g Zn/L) in a RCB design with five treatments and nine blocks, using 1.5 x 15-m treatment plots. Prune-year foliar Zintrac treatments were applied 20 June and 30 June at 53.8 mL·m-2 or 20 June at 107.6 mL·m-2. A crop-year application of Zintrac at 53.8 mL·m-2 was made on 26 June at only one location. Composite leaf tissue samples taken 14 July of the prune year indicated that two applications of Zintrac at 53.8 mL·m-2 raised Zn concentrations at both locations more than a single application at twice the rate. Soil application of ZnSO4 did not raise leaf Zn concentrations compared to the control at either location. Crop-year leaf samples taken 6 July at the site that received the crop-year foliar treatment indicated no carryover effect of prune-year Zn treatments on leaf Zn concentration, but crop-year foliar application of Zn from Zintrac did raise leaf Zn concentrations compared to the controls. The characteristics of stems sampled in the fall of the prune year at each location (stem density, stem length, flower bud formation) were not meaningfully affected by any of the prune-year treatments. Blueberry yield was not affected by any of the treatments at either location. These data suggest that control plot leaf Zn concentrations of about 15 ppm in both fields were adequate. Raising the leaf Zn concentrations to about 80 ppm with two applications of Zintrac at 53.8 mL·m -2 had no effect on growth or yield.

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Correcting Lowbush Blueberry Boron Deficiency with Soil or Foliar Application

HortScience ◽

10.21273/hortsci.35.5.827d ◽

2000 ◽

Vol 35 (5) ◽

pp. 827D-828

Author(s):

J.M. Smagula ◽

W. Litten ◽

S. Dunham

Keyword(s):

Foliar Application ◽

Block Design ◽

Dilution Effect ◽

Boron Deficiency ◽

Fertilizer Treatment ◽

Flower Bud ◽

Potential Yield ◽

P Deficiency ◽

Lowbush Blueberry ◽

Leaf P

In the acid podzol soils of Maine where most lowbush blueberries are grown, low availability of boron tends to keep foliar B concentration below the 24 ppm standard. To compare efficacy of soil and foliar boron application methods, 1.5 × 7.6-m treatment plots in a commer-cial lowbush blueberry field received soil-applied borate at 0, 1.1, 2.2, or 3.3 kg·ha-1 B with or without additional DAP (89 kg·ha-1 P) and ZnSO4 (3.3 kg·ha-1 Zn) or foliar-applied Solubor at 0, 0.24, 0.49, or 0.74 kg·ha-1 B with or without the additional DAP and Zn. These 16 treatments were replicated eight times in a randomized complete-block design. Leaf B concentrations were raised by all soil-applied borate treatments and by the 0.49 and 0.74 kg·ha-1 B foliar Solubor treatments, compared to the controls. When borate at 2.2 or 3.3 kg·ha-1 B was combined with DAP plus Zn a lower leaf B concentration was observed compared to B alone, possibly due to a dilution effect caused by an increase in DAP-induced growth. Leaf P deficiency (<0.125% P) was corrected when DAP and Zn were included in the fertilizer treatment. The greatest potential yield (flower buds/stem and flower bud density) was measured in treatment plots receiving a combination of DAP plus Zn and either borate at 2.2 kg·ha-1 B or Solubor at 0.74 kg·ha-1 B. With no additional treatments applied in 1999, leaf B concentrations were slightly higher in soil-treated and foliar-treated plots than in controls suggesting a small carryover from 1997-applied boron. Carryover may vary with rainfall.

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COMPARISON OF FISH HYDROLYSATE AND INORGANIC FERTILIZERS FOR LOWBUSH BLUEBERRY

HortScience ◽

10.21273/hortsci.30.2.187d ◽

1995 ◽

Vol 30 (2) ◽

pp. 187d-187

Author(s):

John M. Smagula ◽

Scott Dunham

Keyword(s):

Phosphoric Acid ◽

Stem Length ◽

Flower Bud ◽

Vaccinium Angustifolium ◽

Inorganic Fertilizers ◽

Lowbush Blueberry ◽

Leaf P ◽

Organic And Inorganic Fertilizers ◽

Experimental Plots ◽

Leaf N

A commercial lowbush blueberry (Vaccinium angustifolium Ait.) field deficient in leaf N and P was used to compare organic and inorganic fertilizers. In a RCB design with eight replications of 12 treatments, experimental plots received 33.6 or 67.2 kg·ha-1 rates of N (urea), P (23% phosphoric acid), N + P (DAP), N + P + K (5-10-5), or N + P + K (fish hydrolysate, 242). Fertilizer containing N alone was as effective in raising N leaf concentrations as those containing N and P. However, leaf P concentrations were raised more by fertilizer providing N and P than only P. Fish hydrolysate fertilizer was as effective as 5-10-5 in raising leaf N, P, and K concentrations in prune and crop year leaf samples. At the 67.2 kg·ha-1 rate, fish hydrolysate, N, NP and NPK increased stem length, N and NP increased flower bud density and fish hydrolysate, N and NPK increased yield compared to the control.

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Response of Lowbush Blueberry to Several Organic Fertilizers

HortScience ◽

10.21273/hortsci.41.4.994c ◽

2006 ◽

Vol 41 (4) ◽

pp. 994C-994

Author(s):

John M. Smagula ◽

Ilse W. Fastook

Keyword(s):

Branch Length ◽

Organic Fertilizers ◽

Flower Bud ◽

P Deficiency ◽

Soil P ◽

Lowbush Blueberry ◽

History Of ◽

Flower Bud Formation ◽

Wild Blueberry ◽

Leaf N

Four organic fertilizers were evaluated in a commercial lowbush blueberry field with a history of N and P deficiency. In nonorganic production, diammonium phosphate (DAP) is the standard fertilizer for correcting N and P deficiency. Nitrogen a rate of 67 kg·ha-1 [Renaissance (8-2-6), ProHolly (4-6-4), Pro Grow (5-3-4), Nutri-Wave (4-1-2), or DAP (18-46-0)] was applied preemergent to 1.8-m × 15-m treatment plots. Leaf N and P were deficient (<1.6% and 0.125%, for N and P, respectively) in the unfertilized plots that served as controls. DAP and Pro-Holly raised leaf N to satisfactory levels (>1.6%). Only DAP raised leaf P concentrations (0.144%), compared to controls (0.122%). Leaf K was not deficient, but was raised by Pro-Holly. Soil pH was slightly lowered by Renaissance (4.2) and raised by Pro-Holly (4.4), compared to the control (4.3). Soil P concentrations were raised by DAP and soil S by Pro-Holly. Soil K was raised by all fertilizers except DAP, compared to the control. Pro-Holly and DAP were equally effective in increasing stem height, branching, branch length, flower bud formation, and yield, compared to the control and the other organic fertilizers. Pro-Holly could effectively substitute for DAP in organic wild blueberry production.

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Effect of Foliar Copper and/or Iron Application on Growth and Yield of Lowbush Blueberry

HortScience ◽

10.21273/hortsci.39.4.853e ◽

2004 ◽

Vol 39 (4) ◽

pp. 853E-854

Author(s):

John Smagula* ◽

Ilse Fastook

Keyword(s):

Block Design ◽

Foliar Spray ◽

Branch Length ◽

Growth And Yield ◽

Stem Density ◽

Flower Bud ◽

Lowbush Blueberry ◽

Randomized Complete Block Design ◽

Carry Over ◽

Better Than

In a commercial lowbush blueberry (Vaccinium angustifolium Ait.) field with low leaf Cu (<7 ppm) and Fe (<50 ppm) concentrations, nine 1.8 m × 15 m treatment plots were established in a randomized complete block design with 6 blocks. Copper Keylate® (Stoller Enterprises, Inc.) containing 5% Cu was used as a foliar spray in a volume of 626 L·ha-1. In a similar volume, the Stoller Enterprises Inc. product Fe Keylate®, containing 5% Fe (5% chelated Iron), was used to provide Fe. Ammonium sulfate (0.7%) was added to the solutions to enhance uptake. Treatment plots received either Cu Keylate® at 0.6 kg·ha-1 Cu or Fe Keylate® at 0.6 kg·ha-1 or a combination of both nutrients in one spray. Treatments included a 19 June prune - or crop-year application of Cu, Fe, or Cu + Fe, and a prune-year Cu + Fe June 7 and June 19. A plot receiving no treatment served as a control. Leaf Cu and Fe concentrations were raised to above satisfactory leaf concentrations (Cu >7 ppm, Fe >50 ppm) by their respective treatments. Concentrations were significantly higher for each element when they were applied together. Two applications were not better than only one. No carry-over effect was seen in the crop year. Crop-year applications of Cu and Fe were effective in raising their respective concentrations. Stem density, length, number of branches or branch length was not affected by treatments at the end of the prune year. Flower bud density and average number of flower buds per stem were not meaningfully affected by prune year Cu or Fe treatments. Berry yield was not influenced by any treatment suggesting that the Cu and Fe standards are too high.

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Phosphorus Fertility in the Strawberry Nursery

HortScience ◽

10.21273/hortsci.27.6.612b ◽

1992 ◽

Vol 27 (6) ◽

pp. 612b-612

Author(s):

Earl E. Albregts ◽

C. K. Chandler

Keyword(s):

Block Design ◽

Soil P ◽

Central Florida ◽

P Content ◽

Randomized Complete Block Design ◽

Nursery Production ◽

P Rate ◽

Rate Study ◽

Marketable Size ◽

Leaf P

The phosphorus content is usually high in soils on which strawberry production occurs in west central Florida because of moderate P levels in the virgin soil and yearly applications of P by the growers. A P rate study was conducted to test the calibration of P for strawberry nursery production, and a randomized complete block design with four replicates was used. Rates of 0, 11, 22, and 33 kg/ha P were applied to a Seffner sand which had an initial soil P level of 86 mg/kg using the Mehlich II soil extractant. Soil tests routinely show P soil concentrations up to 250 mg/kg or greater with 86 mg/kg rated in the high range. In this study the P applied to the beds was cultivated into the soil and six plants of two strawberry clones (Fl 87-210 and Fl 85-4925) were set in each plot on 28 May 1991. All nutrients except P were applied as needed during the season. Leaf P content of daughter plants on 20 Aug 1991 varied from 0.23 to 0.25% among P treatments and were not different because of P rates. All marketable size daughter plants were harvested on 8 Oct 1991. The number, total wt, and average wt of daughter plants were not different because of applied P rates.

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Pruning Method Affects Lowbush Blueberry Yields

HortScience ◽

10.21273/hortsci.30.4.784c ◽

1995 ◽

Vol 30 (4) ◽

pp. 784C-784

Author(s):

John M. Smagula ◽

Scott Dunham

Keyword(s):

Block Design ◽

Leaf Tissue ◽

Diammonium Phosphate ◽

Nutrient Concentrations ◽

Pruning Method ◽

Lowbush Blueberry ◽

Main Effect ◽

Leaf Nutrient Concentrations ◽

Leaf P

Flail mowing was compared to traditional pruning by oil fire over a 12-year period in two fertility experiments testing interactions with pruning method. In study one (1983–1986), urea at 0, 22.4, 44.8, 67.2, or 89.6 kg·ha–1 was applied preemergent in a split-block design with fertility as the main effect, and pruning method split within six blocks. Study two (1987–1994) continued the pruning and application of fertilizer on the treatment plots with similar rates, but diammonium phosphate (DAP) replaced urea as the fertilizer. Leaf tissue N concentrations were above the 1.6% standard and urea had no effect or decreased yield. There was no interaction of fertility and pruning and no effect of pruning method on yield. No interaction of fertility and pruning was found in study two, but DAP increased leaf P concentrations and yield and, after three cycles of mowing, yields had begun to decline in mowed plots compared to burned plots. No meaningful differences in leaf nutrient concentrations were found between plants in mowed and burned plots.

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Lowbush Blueberry Response to Phosphorus-containing Fertilizers: Assessment by Leaf Phosphorus Concentration and Content

HortScience ◽

10.21273/hortsci.32.3.537d ◽

1997 ◽

Vol 32 (3) ◽

pp. 537D-537

Author(s):

J.M. Smagula ◽

S. Dunham

Keyword(s):

Block Design ◽

Leaf Tissue ◽

Dry Weight ◽

Nutrient Concentrations ◽

Phosphorus Concentration ◽

P Deficiency ◽

Lowbush Blueberry ◽

Phosphorus Containing ◽

Leaf N Concentration ◽

Leaf P

Lowbush blueberries (Vaccinium angustifolium Ait.) in three commercial fields were treated with 67.2 kg P/ha from triple super phosphate(TSP), monoammonium phosphate (MAP), or diammonium phosphate (DAP), and compared to a control in a randomized complete block design with 12 blocks. Correction of P deficiency by fertilizers with different ratios of P to N was assessed by leaf and stem nutrient concentrations and contents (concentration × weight). Samples of stems collected in July from three 0.03 m2 quadrates per treatment plot indicated MAP and DAP had no effect on dry weight of stem tissue, but increased average dry weight of leaf tissue. Leaf nutrient concentrations and contents showed similar results; P and N were raised to higher levels by MAP and DAP than by TSP. TSP had no effect on leaf N concentration or content but raised leaf P concentration but not content, compared to controls.

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ORGANIC FERTILIZERS FOR LOWBUSH BLUEBERRY

HortScience ◽

10.21273/hortsci.41.3.495f ◽

2006 ◽

Vol 41 (3) ◽

pp. 495F-496

Author(s):

John M. Smagula ◽

Ilse Fastook

Keyword(s):

Branch Length ◽

Organic Production ◽

Organic Fertilizers ◽

Flower Bud ◽

P Deficiency ◽

Lowbush Blueberry ◽

History Of ◽

Flower Bud Formation ◽

Unfertilized Plot ◽

Leaf N

Acommercial lowbush blueberry field with a history of N and P deficiency was used to study the response to several organic fertilizers. Diammonium phosphate (DAP) is the standard fertilizer for correcting N and P deficiencyin non-organic production. At a rate of 67 kg N/ha Rennaisance (8–2–6), Pro-Holly (4–6–4), Pro Grow (5–3–4), Nutri-Wave (4–1–2), or DAP (18–46–0) was applied preemergent to 1.8 × 15 m treatment plots. An unfertilized plot served as the control. Leaf N and P were deficient in the controls. DAP and Pro-Holly raised leaf N to satisfactory levels (1.6%). Only DAP raised leaf P concentrations (0.144%), compared to controls (0.122%). Leaf K was not deficient but was raised by Pro-Holly. Pro-Holly and DAP were equally effective in increasing stem height, branching, branch length, flower bud formation, and yield. Pro-Holly could effectively substitute for DAP in organic wild blueberry production.

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