Potassium nutrition of irrigated potatoes in South Australia. 3. Effect on specific gravity, size and internal bruising of tubers

1986 ◽  
Vol 26 (6) ◽  
pp. 737 ◽  
Author(s):  
NA Maier ◽  
AP Dahlenburg ◽  
AB Frensham
Keyword(s):  
Specific Gravity ◽  
Potassium Chloride ◽  
Field Experiments ◽  
South Australia ◽  
Tuber Size ◽  
Potassium Sulfate ◽  
Positive Trend ◽  
Percentage Increase ◽  
Potassium Nutrition ◽  
Marginal Groups

The effects were studied of potassium sulfate and potassium chloride applied at rates up to 640 kg/ha K on tuber specific gravity, size and susceptibility to internal bruising. The field experiments from which these data were obtained were conducted during the 1982-83 and 1983-84 seasons throughout the main potato-growing areas of South Australia. For the deficient and marginal site groupings, there was a consistent positive trend in specific gravity as potassium sulfate rates increased up to 640 kg/ha K. There was a slight negative trend when potassium chloride was used. Potassium fertiliser had no consistent effect on specific gravity at sites in the non-responsive grouping. Petiole or tuber potassium concentrations were poorly correlated with specific gravity. In the deficient and marginal groups increasing rates of potassium increased the yield of 80-350, 350-450, 450-680 and greater than 680-g tubers. The percentage increase in yield was greatest for the larger size grades (350-450 g or larger). At sites in the non-responsive group potassium had no effect on tuber size. At 2 out of 9 sites the effect of potassium chloride on tuber size was significantly different from that of potassium sulfate. Potassium chloride at rates of 160 and 320 kg/ha K reduced the susceptibility of tubers to internal bruising at 3 out of 4 sites. Potassium sulfate was effective at 3 out of 6 sites but only at the highest rate tested (640 kg/ ha K). Susceptibility to internal bruising was significantly (P < 0.01) negatively correlated with both petiole and tuber potassium concentrations. Prognostic critical potassium concentrations above which internal bruising was minimised were 8.30% in petioles or 1.84% in tubers. These values were calculated using the Cate-Nelson separation.

Potassium nutrition of irrigated potatoes in South Australia. 2. Effect on chemical composition and the prediction of tuber yield by plant analysis

1986 ◽  
Vol 26 (6) ◽  
pp. 727 ◽  
Author(s):  
NA Maier
Keyword(s):  
Potassium Chloride ◽  
Relative Yield ◽  
South Australia ◽  
Dry Weight ◽  
Potassium Sulfate ◽  
Yield Response ◽  
Application Rates ◽  
The Mathematical Model ◽  
Potassium Magnesium ◽  
Chloride Concentrations

I compared the effects of potassium sulfate and potassium chloride fertiliser, at rates up to 1280 kg/ ha K, on the concentrations in petioles of the youngest fully expanded leaves and in harvested tubers of potassium, calcium (tubers only), magnesium, phosphorus, chloride and sulfur (petioles only) and on potassium: magnesium ratios in petioles. For the sites classified as deficient and marginal according to soil test potassium concentrations, increased application rates of potassium sulfate increased the potassium and sulfur concentrations and potassium: magnesium ratios in petioles and decreased magnesium, phosphorus and chloride concentrations. In tubers both potassium and magnesium concentrations increased as potassium sulfate rates increased, while calcium and phosphorus concentrations showed negative trends. Compared with potassium sulfate, potassium chloride resulted in higher potassium, calcium and chloride concentrations and lower sulfur concentrations. Chloride concentrations in petioles from many sites were much higher than those reported in other studies and were related to high chloride concentrations in irrigation waters. Significant correlations were obtained between bicarbonate- extractable potassium concentrations in the surface (0-1 5-cm) soils and potassium concentrations in petioles (r2 = 0.75***) and tubers (r2 = 0.84***). As bicarbonate-extractable potassium concentrations in the surface soils increased from 40 to 600 mg/kg, the potassium concentrations in tubers increased from 1.69 to 2.69% compared with an increase from 5.72 to 1376% in petioles. Significant correlations were obtained between relative yields ((mean treatment yields/maximum mean treatment yie1d)x 100) and potassium concentrations (dry weight basis) in petioles and tubers and potassium:magnesium ratios in petioles. The percentage of variance in relative yield accounted for by each regression was 67.9, 31.0 and 56.9% respectively. The potassium concentration in petioles was the most effective plant index to predict yield response to potassium. For petioles and tubers prognostic critical potassium concentrations of 11.30 k 0.26% and 2.19 � 0.11% respectively were established. Alternatively, a prognostic critical potassium:magnesium ratio of 14.8 � 0.8% was determined. The choice of the mathematical model used influenced the critical values obtained.

Potassium nutrition of irrigated potatoes in South Australia. I. Effect on tuber yield and the prediction of tuber yield response by soil analysis

1986 ◽  
Vol 26 (6) ◽  
pp. 717 ◽  
Author(s):  
NA Maier
Keyword(s):  
Cation Exchange ◽  
Potassium Chloride ◽  
Cation Exchange Capacity ◽  
Tuber Yield ◽  
Relative Yield ◽  
South Australia ◽  
Exchange Capacity ◽  
Potassium Sulfate ◽  
Yield Response ◽  
Soil Test

Field experiments were conducted over 4 years at 25 sites throughout the main potato-growing areas of South Australia to calibrate the 0.5M sodium bicarbonate extraction procedure as a soil test for potassium and to examine the responses of irrigated potatoes to rates up to 1280 kg/ha K applied as potassium sulfate or potassium chloride either banded at planting or side-dressed after emergence. Potassium application at planting increased yield (P < 0.05) at 10 sites. The mean percentage yield deficit was 21%. There were significant correlations between relative yield and clay and sand contents, cation exchange capacity and bicarbonate-extractable potassium concentration in 0-15-cm surface soil samples collected before potassium fertiliser was applied. Percentage silt and pH were not correlated with relative yield. The bicarbonate-extractable potassium soil test accounted for 70% of the variance in relative yield compared with only 27% for percentage clay and 22% for cation exchange capacity. The prognostic critical bicarbonate-extractable potassium concentrations were: 153 -t 12 mg/kg for the Smith-Dolby bent hyperbola model, 143 mg/kg for the Cate-Nelson separation, and 133 or 176 mg/kg for the Mitscherlich model (concentrations at relative yields of 90 and 95% respectively). Yield responses are likely when soil bicarbonate- extractable potassium concentrations are below 120 mg/kg (deficient range), uncertain between 12 1 and 200 mg/kg (marginal range) and unlikely above 200 mg/kg (non-responsive range). Banding potassium chloride at planting significantly reduced yield compared with potassium sulfate at 2 out of the 14 sites used. The yield reductions occurred with potassium rates of 160 kg/ha or higher. There were significant increases in yield with side-dressing compared with basal application, at 2 of 5 responsive sites using rates of 320 kg/ha K or higher. None of the side-dressing treatments reduced tuber yields below control yields.

scholarly journals Effect of potassium sources on potato tuber yield and chip quality

2018 ◽  
Vol 36 (3) ◽  
pp. 395-398 ◽  
Author(s):  
Giovani O Silva ◽  
Antonio C Bortoletto ◽  
Agnaldo DF Carvalho ◽  
Arione S Pereira
Keyword(s):  
Specific Gravity ◽  
Potassium Chloride ◽  
Tuber Yield ◽  
Soil Analysis ◽  
Chip Color ◽  
Potassium Sulfate ◽  
Tuber Quality ◽  
Chip Quality ◽  
Potassium Sources ◽  
Red Latosol

ABSTRACT Many potato producers for fry industry changed from the use of potassium chloride to potassium sulfate, as there is a concept that the use of this source improves tuber quality. The aim of this work was to evaluate the effect of these two potassium sources on yield, specific gravity and chip color of potato chipping cultivars. The experiment was carried out on a Dystrophic Red Latosol, in Canoinhas, Brazil, in spring season 2016. Treatments consisted of two potato cultivars, BRSIPR Bel and Atlantic, and two sources of potassium, chloride and sulfate, applied in the furrow at the planting time, in rates based on soil analysis. Experimental design was a randomized complete block in a split-plot arrangement with four replications. Main plots were cultivars and subplots potassium sources. 100 days after planting each sub-plot was evaluated for yield, specific gravity and chip color. There was no significant effect of potassium source on yield components, specific gravity and chip color of BRSIPR Bel and Atlantic.

Response of Potato (Solarium tuberosum) Cultivars to Metribuzin

Weed Science ◽  
1984 ◽  
Vol 32 (4) ◽  
pp. 442-444 ◽  
Author(s):  
George H. Friesen ◽  
David A. Wall
Keyword(s):  
Solanum Tuberosum ◽  
Specific Gravity ◽  
Field Experiments ◽  
Hollow Heart ◽  
Tuber Size ◽  
Potato Cultivars ◽  
Solarium Tuberosum ◽  
Susceptible Cultivar

The response of 22 potato (Solanum tuberosumL.) cultivars to soil-incorporated and foliar applications of metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)one] at rates of 0.5 and 1.0 kg ai/ha, was evaluated in field experiments from 1979 to 1982. Metribuzin significantly reduced the yield of marketable tubers in several potato cultivars. Foliar applications generally resulted in more injury than soil applications. Yields were reduced primarily through stand reduction and a decreased number of tubers per plant. Neither tuber size nor specific gravity of tubers was significantly reduced in the cultivars studied. The most susceptible cultivar was ‘Alaska Red’, followed by ‘Rhine Red’, F72117, ‘Caribe’, and ‘Shepody’. Other cultivars evaluated were highly tolerant to metribuzin, irrespective of rate or method of application. There was an increase in hollow heart in cultivars ‘Atlantic’ and ‘Lemhi Russet’ following treatment with metribuzin.

Concentration of Impurities during Melting of Snow Made from Secondary Sewage Effluent

1986 ◽  
Vol 18 (2) ◽  
pp. 151-156 ◽  
Author(s):  
R. Zapf-Gilje ◽  
S. O. Russell ◽  
D. S. Mavinic
Keyword(s):  
Potassium Chloride ◽  
Chloride Solution ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Low Cost ◽  
Sewage Effluent ◽  
Potassium Chloride Solution ◽  
Laboratory Results ◽  
Solution Field ◽  
Concentration Of Impurities

When snow is made from sewage effluent, the impurities become concentrated in the early melt leaving the later runoff relatively pure. This could provide a low cost method of separating nutrients from secondary sewage effluent. Laboratory experiments showed that the degree of concentration was largely independent of the number of melt freeze cycles or initial concentration of impurity in the snow. The first 20% of melt removed with it 65% of the phosphorus and 90% of the nitrogen from snow made from sewage effluent; and over 90% of potassium chloride from snow made from potassium chloride solution. Field experiments with a salt solution confirmed the laboratory results.

scholarly journals Maternal (oral) hydration increases amniotic fluid volume

2016 ◽  
Vol 12 (2) ◽  
Author(s):  
Aneela Umber
Keyword(s):  
Specific Gravity ◽  
Amniotic Fluid ◽  
Fluid Volume ◽  
Urine Specific Gravity ◽  
P Value ◽  
Percentage Increase ◽  
Third Trimester ◽  
Amniotic Fluid Index ◽  
Oral Hydration ◽  
Amniotic Fluid Volume

Objective:To determine the effect of maternal (oral) hydration on amniotic fluid volume in patients with third trimester oligohydramnios. Design: Interventional study. Place and Duration of Study: Department of Obs & Gynae Unit III, Sir Ganga Ram Hospital, Lahore from May 2002 to October 2002. Patients and Methods: Twenty five women with third trimester oligohydramnios (AFI ?5.0cm) and twenty five controls with normal amniotic fluid volume (AFI 8-24 cm) were prospectively recruited for this study. Maternal urine specific gravity and amniotic fluid index were determined before and after maternal hydration by asking them to drink 2 L of water in 2-4 hours before repeat amniotic fluid index and recorded on printed proformas. Results: Hydration increased amniotic fluid volume in women with oligohydramnios (mean change in amniotic fluid index 4.3 cm, 95% confidence interval 4.02 to 5.06; P value <0.001); as well as in women with normal fluid volume (mean change in Amniotic fluid index 2.7 cm, 95% confidence interval 2.23 to 3.21; P value <0.01). However, percentage increase in mean AFI was 58.6% in the oligohydramnios group, which was significantly greater (P value <0.05) than the percentage increase of 28.4% in control group. Hydration was associated with decrease in urine specific gravity in both groups. Conclusion: Maternal (oral) hydration increases AFV in women with oligohydramnios as well as in women with normal AFV and may be beneficial in the management of oligohydramnios.

Use of a simple model to study factors affecting the size distribution of tubers in potato crops

1987 ◽  
Vol 109 (3) ◽  
pp. 563-571 ◽  
Author(s):  
K. Z. Travis
Keyword(s):  
Mathematical Model ◽  
Size Distribution ◽  
Field Experiments ◽  
Tuber Yield ◽  
Tuber Size ◽  
Simple Mathematical Model ◽  
Factors Affecting ◽  
Tuber Size Distribution ◽  
Two Parameters ◽  
Potato Crops

SummaryA simple mathematical model of the distribution of potato tuber yield between size grades is presented. It has two parameters, μ, a measure of crop tuber size and σ, a measure of the spread of yield across size grades. The model is shown to be useful for the analysis of field experiments, the prediction and physiological study of tuber size distribution, and the economic analysis of management decisions. The model is applied to a variety of dataandthe practical control of tuber size discussed.

Sensitivity of global gross primary production to elevated CO2

2021 ◽  
Author(s):  
Wenjia Cai ◽  
Iain Colin Prentice
Keyword(s):  
Field Experiments ◽  
Carbon Sink ◽  
Gross Primary Production ◽  
Light Response ◽  
Terrestrial Ecosystems ◽  
Percentage Increase ◽  
Terrestrial Plants ◽  
Fertilization Effect ◽  
Vegetation Models ◽  
The Impact

&lt;p&gt;Terrestrial ecosystems have accounted for more than half of the global carbon sink during the past decades and offset 25%-30% of current anthropogenic CO&lt;sub&gt;2&lt;/sub&gt; emissions. The projected increase in CO&lt;sub&gt;2&lt;/sub&gt; concentration will depend on the magnitude of terrestrial plants&amp;#8217; feedback to CO&lt;sub&gt;2&lt;/sub&gt;: i.e. the sensitivity of plant carbon uptake in response to elevated CO&lt;sub&gt;2&lt;/sub&gt;, and the strength of the CO&lt;sub&gt;2&lt;/sub&gt; fertilization effect (CFE) in a changing (and warming) environment. Projecting vegetation responses to future increases in CO&lt;sub&gt;2&lt;/sub&gt; concentration under climate change is a major uncertainty, as ecosystem models, field experiments and satellite-based models show large disagreements. In this study, using a recently developed, parameter-sparse model (the &amp;#8216;P model&amp;#8217;), we assess the sensitivity of GPP to increasing CO&lt;sub&gt;2&lt;/sub&gt; under idealized conditions, in comparison with other vegetation models and field experiments. We investigate the impact of two central parameters, the ratio of J&lt;sub&gt;max &lt;/sub&gt;to V&lt;sub&gt;cmax&lt;/sub&gt; (at a common temperature) and the curvature of the light response curve, on the sensitivity of GPP to CO&lt;sub&gt;2&lt;/sub&gt;. We also quantified the spatial-temporal trend of CFE using the &amp;#946; factor, defined as the percentage increase in GPP in response to a 100-ppm increase in atmospheric CO&lt;sub&gt;2&lt;/sub&gt; concentration over a defined period. We show how modelled &amp;#946; has changed over the satellite era, and infer the possible effect of climatic variables on changes of CFE from spatial patterns of the modelled trend in &amp;#946;.&lt;/p&gt;

Conversion of Potassium Chloride into Potassium Sulfate by Four-Compartment Electrodialysis: Batch Operation Process

2015 ◽  
Vol 54 (48) ◽  
pp. 11937-11943 ◽  
Author(s):  
Xu Zhang ◽  
Xiaoyao Wang ◽  
Xianchao Liu ◽  
Xiaozhao Han ◽  
Chenxiao Jiang ◽  
...  
Keyword(s):  
Potassium Chloride ◽  
Potassium Sulfate ◽  
Batch Operation ◽  
Operation Process

NITROGEN, POTASSIUM, AND PLANT SPACING EFFECTS ON YIELD, TUBER SIZE, SPECIFIC GRAVITY, AND TISSUE N, P, AND K OF NETTED GEM POTATOES

1974 ◽  
Vol 54 (3) ◽  
pp. 535-539 ◽  
Author(s):  
R P. WHITE ◽  
D. C. MUNRO ◽  
J. B. SANDERSON
Keyword(s):  
Specific Gravity ◽  
Seed Piece ◽  
Total Yield ◽  
Tuber Size ◽  
Solarium Tuberosum ◽  
Plant Spacing ◽  
Nutrient Levels ◽  
Spacing Effects ◽  
N Rates

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.

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