scholarly journals EVALUATION OF FERTILITY PRACTICES FOR VIDALIA ONIONS

HortScience ◽  
2005 ◽  
Vol 40 (3) ◽  
pp. 885e-886
Author(s):  
George E. Boyhan ◽  
Reid L. Torrance ◽  
Ronald H. Blackley ◽  
M. Jefferson Cook ◽  
C. Randell Hill

Fertilizer rates of N, P, K were evaluated over 4 years (2000–03) as were different sources of experimental and commercial fertilizers. The highest total yields and yields of jumbos (≥7.6 cm) occurred with nitrogen rates of 140–168 kg·ha–1. Neither phosphorus nor potassium rates had an affect on total yield. Phosphorus rates of 0-147 kg·ha–1 and potassium rates of 0–177 kg·ha–1 were evaluated. Increasing nitrogen fertilizer resulted in increasing leaf tissue nitrogen, but did not affect P, K, Ca, or S. Increasing phosphorus fertilizer increased leaf tissue phosphorus only slightly (p = 0.060) with no affect on other leaf nutrient levels. Increasing potassium fertilizer did affect leaf tissue potassium 2 out of 4 years with none of the other leaf nutrient levels affected. Several fertilizers were also evaluated including an experimental fortified peat (10%N), calcium nitrate, ammonium nitrate, diammonium phosphate, 5–10–15 (56 kg·ha–1 N), 18-6-8 liquid, 14–0–12 8%S liquid, 19–8–19 slow-release at rates of 140 and 168 kg·ha–1 nitrogen. All were used to supply 168 kg·ha–1 nitrogen unless noted otherwise. P and K were supplied according to soil test recommendations unless they were part of the fertilizer formulation. There were no differences between the different fertilizer sources for total yield and differences in jumbo yields only occurred one year out of three years of testing and for medium (≥5.1 and <7.6 cm) yields there were differences two years out of three years of testing.

HortScience ◽  
2007 ◽  
Vol 42 (3) ◽  
pp. 653-660 ◽  
Author(s):  
George E. Boyhan ◽  
Reid L. Torrance ◽  
C. Randy Hill

This is a compilation of several studies that were performed to address specific grower concerns or questions about onion fertilization, to assess onion fertility, to make adjustments in soil test recommendations, and to test specific fertilizers for clients covering the 1999–2000 to 2004–2005 seasons. The synthesis of these studies was to evaluate levels of nitrogen (N), phosphorus (P), and potassium (K) fertilizers and their effect on yield, graded yield, and leaf tissue nutrient status in short-day onions over 6 years. In addition, various fertilizers were evaluated for their effect on these parameters. There was a significant increasing quadratic effect on yield from increasing N fertilizer from 0 to 336 kg·ha−1 with an R2 of 0.926. Maximum calculated yield was at 263 kg·ha−1 N fertilizer; however, the yield at this rate did not differ, based on a Fisher's least significant difference (P ≤ 0.05), from our current recommendations of 140 to 168 kg·ha−1 N. Jumbo (7.6 cm or greater) yield performed in a similar fashion. Phosphorus fertilizer rates from 0 to 147 kg·ha−1 had no effect on total yield, but did affect jumbo yields, which decreased linearly with an R2 of 0.322. Evaluations of P fertilizer in the 2001–2002 and 2002–2003 seasons only, when the exact same P fertilizer rates were used, showed a decreasing quadratic effect for jumbo yields with the lowest jumbo yields at 83 kg·ha−1 P fertilizer and jumbo yields increasing with 115 and 147 kg·ha−1 P fertilizer rates. Potassium fertilizer rates from 0 to 177 kg·ha−1 had a quadratic affect on total yield, with the highest yield of 52,361 kg·ha−1 with 84 kg·ha−1 K fertilizer rate. As would be expected, N and P fertilizer rates affected leaf tissue N and P levels, respectively. In addition, N fertilizer rates affected leaf tissue calcium (Ca) and sulfur levels. Potassium fertilizer rates had a significant linear effect on leaf tissue K 3 of 6 years. In addition, K fertilizer rates had a significant effect on leaf tissue P levels. Several fertilizers, including Ca(NO3)2 and NH4NO3, along with complete fertilizers and liquid fertilizers, were used as part of a complete fertilizer program and showed no differences for total yield or jumbo yield 4 of 5 years of evaluation when applied to supply the same amount of N fertilizer. Based on the results of this study, soil test P and K recommendations for onions in Georgia have been cut 25% to 50% across the range of soil test levels.


1968 ◽  
Vol 8 (34) ◽  
pp. 606 ◽  
Author(s):  
ICR Holford

The nitrogen, phosphorus, and potassium requirements of sugar cane were studied in relation to the concentration of these elements in the leaf tissue of three varieties of sugar cane grown commercially in Fiji. Percentage yields of sugar cane in fertilizer field experiments were highly correlated with leaf nutrient levels in the control plots, provided leaf sampling was carried out during the maximum growth period of mid- January to mid-May. For each nutrient there was a marginal zone of leaf concentration below which crops always gave significant yield responses to applied nutrients and above which crops failed to respond. Marginal zones for crops sampled during mid-March to mid-May were 1.4-2.0 per cent for nitrogen, 0.13-0.21 per cent for phosphorus, and 0.9-1.5 per cent oven dry leaf for potassium. Within the deficient range of leaf nutrient concentrations there was little relationship between optimum rates of fertilizer required to correct the deficiency and leaf nutrient levels of unfertilized cane. Because of the lateness of sampling, any indication of fertilizer requirement would only be applicable to a subsequent ratoon crop.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 527b-527
Author(s):  
W.H. Tietien ◽  
P. Nitzsche ◽  
W.P. Cowgill

Environmental concerns about nitrate contamination of groundwater have prompted renewed interest in optimizing fertilizer rates. A field study was initiated to study the influence of preplant and drip fertigation rates of nitrogen on the yield of hell peppers grown on Quakertown (QkB) silt loam soil. Preplant nitrogen rates of 0, 56.7, and 113.5 kgha were incorporated into the plots before transplanting. The three fertigation rates (0, 17 and 34 Kg/mulched hectare) were injected through the drip irrigation starting one week after transplanting and repeated at three week intervals. Proplant nitrogen applications variably influenced early pepper yield. and did not significantly influence total yield. Early pepper yield was not influenced by drip fertigation rate, however, total yield increased as the fertigation rate increased. The dry weather conditions of the 1993 growing season may have influenced the responsc of pepper yield to the fertilizer treatments. Further studies are required to determine the optimum fertilization program for bell peppers grown under Northern New Jersey's edaphic conditions.


1970 ◽  
Vol 38 (2) ◽  
pp. 163-169 ◽  
Author(s):  
Semiha Güler

Effects of nitrogen on the leaf chlorophyll (chl), yield and yield attributing characters of potato as tuber number and mean tuber weight were studied. Correlation coefficients between the investigated characters were determined. Five nitrogen rates (0, 150, 200, 250 and 300 kg/ha) and four potato cultivars (Burren, Slaney, Anna and Emma) were used in the study. First, second, third class tuber yields and total tuber yield, tuber number per plant, and leaf chl were significantly influenced by both nitrogen rate and cultivar, whereas mean tuber weight was affected only by cultivar. Maximum total yield was obtained at 200 kg N/ha. There was significant linear relationship between leaf chl and N applied (R2=0.91). There were significant correlations between chl and yield and yield related characters. Total yield significantly correlated with leaf chl. Correlations between first class yield and total yield as well as total yield and tuber number per plant were highly significant.   Key words: Potato; Solanum tuberosum L.; Leaf chlorophyll; Nitrogen; Yield DOI: 10.3329/bjb.v38i2.5141 Bangladesh J. Bot. 38(2): 163-169, 2009 (December)  


1974 ◽  
Vol 54 (3) ◽  
pp. 535-539 ◽  
Author(s):  
R P. WHITE ◽  
D. C. MUNRO ◽  
J. B. SANDERSON

Netted Gem potatoes (Solarium tuberosum L.) were grown at seed-piece spacings of 28, 38, and 46 cm with 90, 134, and 179 kg N/ha and 46, 93, and 139 kg K/ha. Prior to planting, 100 kg P/ha and 56 kg Mg/ha were broadcast. At planting 74 kg P/ha was combined with the N and K treatments and banded. Increased spacing resulted in increased yields of "A" size tubers (113–454 g) and the percentage of A size tubers in the total yield, whereas total yield was unaffected as spacing increased. Increased rates of N and K resulted in increased total yields and percentage of A size tubers. Specific gravity decreased slightly as N rates increased, but decreased markedly (from 1.099 to 1.091) as K increased. Spacing had no effect on specific gravity. Applied N and K had significant effects on leaf and petiole N, P, and K levels. Increased spacing had no effect on tissue nutrient levels.


1976 ◽  
Vol 27 (3) ◽  
pp. 391 ◽  
Author(s):  
D Martin ◽  
TL Lewis ◽  
J Cerny ◽  
DA Ratkowsky

The effect of four whole-tree sprays at monthly intervals on the fruit mineral element content and on the incidence of storage disorders in Merton apples was investigated for three years. Calcium nitrate, boric acid, zinc nitrate and naphthaleneacetic acid (NAA) were applied singly and in all possible combinations. There were no significant treatment interactions, which implied an absence of synergistic or antagonistic effects between spray components. Calcium nitrate was the only compound whose application consistently reduced the incidence of bitter pit and breakdown following cool storage for 4 months. In one year NAA reduced the incidence of these disorders, but it also reduced mean fruit size and increased the concentration of most of the mineral elements, including calcium, in the fruit at harvest. Zinc nitrate sprays had no effect. Boron application promoted the development of core flush in one year and of breakdown in two years, but did not affect the incidence of bitter pit. No relationship was observed between the levels of calcium and boron in the fruit.


2007 ◽  
Vol 87 (4) ◽  
pp. 985-988 ◽  
Author(s):  
Jerry A Ivany ◽  
Walter Arsenault ◽  
Delmar Holmstrom

Conventional tillage in potato production can reduce organic matter levels and cause soil loss. This study compared effects of conventional tillage and zone tillage on plant emergence, weed control, and yield parameters of Russet Burbank potato at nitrogen rates of 0, 50, 100 and 150 kg ha-1. Inconsistent plant emergence across years was likely due to variable weather and planting dates rather than tillage treatment. There were no significant differences between conventional and zone tillage on weed species, weed numbers, weed biomass, or tuber French fry colour. Marketable tuber numbers and total yield were reduced by zone tillage. Nitrogen rate had no effect on any of the variables with the exception that 150 kg ha-1 nitrogen reduced tuber specific gravity compared to the lower rates. Key words: Potato, zone tillage, conventional tillage, nitrogen fertility, tuber number, tuber yield


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Kelly A. Nelson ◽  
Peter P. Motavalli ◽  
William E. Stevens ◽  
John A. Kendig ◽  
David Dunn ◽  
...  

Research in 2004 and 2005 determined the effects of foliar-applied K-fertilizer sources (0-0-62-0 (%N-%P2O5-%K2O-%S), 0-0-25-17, 3-18-18-0, and 5-0-20-13) and additive rates (2.2, 8.8, and 17.6 kg K ha−1) on glyphosate-resistant soybean response and weed control. Field experiments were conducted at Novelty and Portageville with high soil test K and weed populations and at Malden with low soil test K and weed populations. At Novelty, grain yield increased with fertilizer additives at 8.8 kg K ha−1in a high-yield, weed-free environment in 2004, but fertilizer additives reduced yield up to 470 kg ha−1in a low-yield year (2005) depending on the K source and rate. At Portageville, K-fertilizer additives increased grain yield from 700 to 1160 kg ha−1compared to diammonium sulfate, depending on the K source and rate. At Malden, there was no yield response to K sources. Differences in leaf tissue K(P=0.03), S(P=0.03), B(P=0.0001), and Cu(P=0.008)concentrations among treatments were detected 14 d after treatment at Novelty and Malden. Tank mixtures of K-fertilizer additives with glyphosate may provide an option for foliar K applications.


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