Comparison of total tuber yields from inner and guard rows used in potato (Solanum tuberosum L.) fertiliser experiments

1991 ◽  
Vol 31 (3) ◽  
pp. 393
Author(s):  
NA Maier ◽  
AB Frensham ◽  
KSR Chapman ◽  
CMJ Williams

Total tuber yields were compared for inner and outer (guard) rows from 4 phosphorus (P) and 3 nitrogen (N) field experiments conducted during 1985-86 in South Australia, and from 5 N and 2 potassium (K) field experiments conducted during 1985-86 and 1987-88 in Tasmania. All fertiliser treatments were banded along the rows, either at planting or part at planting and the remainder sidedressed after emergence. The inter-row spacings were in the range 76-86 cm and the cultivars used were Kennebec, Coliban and Russet Burbank. Analysis showed that at only 1 of the 14 sites (site 6 in South Australia) was the mean total tuber yield for the inner 2 rows significantly (P<0.01) less than the mean total tuber yield for all 4 rows. However, the difference was small (0.8 t/ha or 1.9%) and of little practical importance. The relationships between mean (� s.e.) total tuber yield and rate (kg/ha) of applied nutrient (0-240 P, 0-320 N, 0-400 K) for inner and guard rows showed that differences between means were small and usually within standard error ranges at all sites. There were no consistent differences in the magnitudes of the standard errors of the means for inner and guard rows for all rates and types of nutrient applied. No significant cross-feeding occurred in these fertiliser experiments, which suggests that omission of guard rows from experiments where the fertiliser treatments are applied along the rows should not result in serious errors of interpretation of tuber yield response.

1994 ◽  
Vol 34 (6) ◽  
pp. 825 ◽  
Author(s):  
NA Maier ◽  
AP Dahlenburg ◽  
CMJ Williams

Data are presented from 3 field experiments that studied the effects of nitrogen (N) up to 360 kg N/ha, phosphorus (P) up to 100 kg P/ha, and potassium (K) up to 480 kg K/ha on tuber yield and the concentration of N, P, and K in petioles of youngest fully expanded leaves (P-YFEL) of potato cvv. Kennebec and Atlantic sampled when the length of the longest tubers was 10-15 mm. Data on the significance of relationships between total N and P, total N and nitrate-N, and chloride and nitrate-N in P-YFEL are also presented. At 1 site, Atlantic yielded 18% higher than Kennebec; at another, it yielded 21% less. Significant K x cv. and N x cv. interactions occurred at some sites. Increasing rates of applied N significantly increased total N concentrations in P-YFEL at all sites and nitrate-N concentrations at sites that were N-deficient. At 1 site, increasing the rate of applied P from nil to 100 kg P/ha significantly increased total N concentration from 2.8 to 3.4%. Total N concentrations in P-YFEL of Atlantic were significantly lower than Kennebec. For total N, there were significant N x K and P x cv. interactions. There was no significant interaction between N, P, and K in their effects on nitrate-N concentration in P-YFEL. At all sites, the application of N and P significantly increased P concentrations in P-YFEL, and mean concentrations were significantly greater in Kennebec than Atlantic. At sites deficient in K, the application of K significantly decreased P concentration. Significant N x cv. and P x cv. interactions occurred at 2 sites. At both K-deficient and non-responsive sites, increasing rates of applied K significantly increased K concentrations in P-YFEL. Differences between cultivars in K concentration were not significant at 2 sites, and although significant at the third, the difference (0.2%) was of little practical importance. At 2 sites, significant N x K and K x P interactions were found. Significant positive linear relationships were found between total N and P concentrations in P-YFEL for both the experimental sites (r = 0.46-0.84) and commercial crops (r = 0.43-0.61). Except at site 1 (r = 0.85), total N and nitrate-N concentrations were not highly correlated. For 1 experimental site and for all the growing regions, there were significant negative linear relationships between nitrate-N and chloride concentrations in P-YFEL (r = -0.38 to -0.83). We suggest that the synergism between total N and P and the negative correlation between nitrate N and chloride are important factors to be considered to ensure reliable interpretation of early-season, petiole plant test data for these nutrients in potato crops; that the critical P and total N concentrations are different for Kennebec and Atlantic; and that when K is not yield-limiting, the main effects and interactions between K and total N, P, or nitrate-N do not confound the use of these nutrients in P-YFEL to assess the P, N, or K status of potato crops.


The test for the significance of the difference of two means, when the standard errors of one observation are unequal, has been the subject of much recent discussion (Fisher 1935; Bartlett 1936; Welch 1937; Daniels 1938), but the appropriate treatment remains in doubt. A significance test for the difference of two means, on my principles, has already been given (Jeffreys 1937 a ), but is not altogether satisfactory, for two reasons. The result was, for large numbers of observations, K = P(q|θh ) / P(~Q|θH ) = (2/ π σ 2 + T 2 / σ 2 / m + T 2 / n ) 1/2 exp (-1/2 x - - y - ) 2 /σ 2 / m + T 2 / n ) (1) where x - and y - are the means in the two series, m and n the numbers of observations, σ and T the (estimated) standard errors of one observation. The most serious practical defect of this formula is that the numbers of observations are supposed large enough for the uncertainty of the standard errors to be neglected. This was due to a premature approximation and could be corrected easily; the resulting change would be similar to the difference between the normal layer and "Student's" formula, as has already been shown in other cases. There is, however, an other anomaly, less serious in practice, but of theoretical importance. We noticed at if T = 0, when the observations in the second series are exact, the first factor reduces to (2 m / π ) 1/2 , which is the usual form for the test of one new parameter, and is satisfactory. But if σ = T , and n is very large, so that the uncertainty of the true value in the second series is again negligible, should again expect the outside factor to reduce to (2 m / π ) 1/2 , since we are again comparing the mean of the first series with an accurate value. Actually it reduces to (4 m / π ) 1/2 . This is not of much practical importance, since if formula (1) gives k = 1, the correct formula would give k = 1/√2, and the result would still be indecisive, though slightly in favour of ~ q .


1992 ◽  
Vol 32 (1) ◽  
pp. 113 ◽  
Author(s):  
LA Sparrow ◽  
KSR Chapman ◽  
D Parsley ◽  
PR Hardman ◽  
B Cullen

Four field experiments were conducted to examine the yield response and cadmium (Cd) concentration of potatoes (Solanum tuberosum L. cv. Russet Burbank) grown with banded or broadcast phosphorus (P) fertiliser at rates up to 240 kg P/ha. The Cd content of the triple superphosphate (TSP) was 151 mg/kg. All 4 sites were on intensively cropped, high P-fixing krasnozem soils in north-western Tasmania, with concentrations of Colwell-extractable P ranging from 112 to 210 mg/kg. All sites showed economic yield responses to banded P, but broadcast P was much less effective except at the site where the response to banded P was least. Yield responses came mostly through increased tuber number, but at 1 site the tubers were also bigger. There was no effect of P on tuber size distribution or specific gravity. Increasing rates of banded TSP increased tuber Cd concentrations by 50-300% at the 3 sites where they were measured; broadcast TSP had little effect. Tubers from the site with pH 6.0 had much higher Cd concentrations than those from the sites with pH 6.5 and 6.6. Petiole Cd concentrations were about 5 times greater than tuber concentrations.


2001 ◽  
Vol 32 ◽  
pp. 141-146 ◽  
Author(s):  
Juauien Vallet ◽  
Urs Gruber ◽  
François Dufour

AbstractDuring winter 1999 three large avalanche events were triggered by explosives at SLF’s avalanche test site, Vallée de la Sionne, canton Valais, Switzerland. One important goal of these large-scale field experiments was to measure the release and deposition volumes of avalanches by photogrammetric methods. In this paper, the photogrammetric measurements of all three avalanches are summarized. For one avalanche event it was possible to realize the whole measuring procedure as planned, and to obtain volume measurements before and after the avalanche triggering In the other two avalanche events, the photographs before the triggering of the avalanche failed. Nevertheless the photographs taken after the avalanche provide valuable information on the fracture depth at the fracture line. The mean fracture depth of the largest avalanche was about 2.10 m, varying between 1 and 3.5 m over a width of > 1000 m. The total volume of the deposition of all three avalanche events was about 1300 000 m3. The deposits are distributed over a length of > 1000 m with depths up to 30 m. The difference between the released and deposited volumes proved that avalanches entrain a large amount of snow along the avalanche track. Furthermore, the snow distribution in the deposition zone provides important information about the behaviour of a dense flowing avalanche in the runout zone.


1993 ◽  
Vol 44 (4) ◽  
pp. 845 ◽  
Author(s):  
LA Sparrow ◽  
AA Salardini ◽  
AC Bishop

Field experiments were conducted at three sites on basaltic krasnozems to examine cadmium (Cd) responses of Russet Burbank potatoes to different rates of broadcast lime and banded phosphorus (P). Double superphosphate (DSP, containing 15 and 90 mg Cd kg-1) and triple superphosphate (TSP, 12 mg Cd kg-1)) were the sources of P. In a fourth experiment, lime was banded with the basal fertilizer. Despite producing a range of topsoil pH (1:5 H20) of 5.2 to 7.1, broadcast lime had no effect on tuber Cd concentrations. Lime had no effect when banded with the basal fertilizer, and the practice did not adversely affect yields. With broadcast lime, Cd availability from the fertilizer band may have been unaffected. However, there were also no lime x P interactions at any site, suggesting that lime also had no effect on the availability of Cd in the soil. It is possible that Tasmanian krasnozems, with their high organic matter and iron oxide content, restrict the availability of Cd in the soil such that pH change exerts little net influence on Cd availability. Increasing amounts of Cd applied in P fertilizer increased tuber Cd concentrations significantly, but the increases were less per unit of P than those found previously when TSP with 151 mg Cd kg-1) was used.


1967 ◽  
Vol 7 (28) ◽  
pp. 453 ◽  
Author(s):  
JS Russell

Response experiments with Gabo wheat at four rates of ammonium sulphate (0, 11.5, 23, and 46 lb N an acre) were carried out at a number of widely-spread locations in the cereal growing areas of South Australia during six seasons in the period 1956-61. Considerable variability in grain and grain + straw yield and in the observed response to nitrogen fertilizer was found. Season and site effects were marked and season-site interactions were also observed. The mean grain yield response was 8.7, 7.2, and 5.1 lb grain for each lb of nitrogen applied as fertilizer at the rates of 11.5, 23, and 46 lb N an acre. These mean values are lower than those reported for other more humid wheat growing areas, but there are conditions where response is at a comparable level. The main difficulty lies in predicting these situations. Several aspects of the use of nitrogen fertilizer in a semi-arid environment are discussed.


2019 ◽  
Vol 56 (2) ◽  
pp. 312-319
Author(s):  
Marcin Kozak ◽  
Hans-Peter Piepho

AbstractANOVA, one of the most common statistical methods applied in agronomy, offers a variety of results we can report when analyzing designed experiments. The focus, of course, is on treatment means, but what should we report to characterize precision? Should we choose treatment standard deviations (SDs) or standard errors of the mean or standard errors of the difference (SEDs)? We discuss why treatment raw SDs should not be reported as the result of ANOVA, and point out that most of the time it is SEDs that should be provided.


2016 ◽  
Vol 155 (2) ◽  
pp. 261-281 ◽  
Author(s):  
S. E. ROQUES ◽  
D. R. KINDRED ◽  
S. CLARKE

SUMMARYTriticale has a reputation for performing well on poor soils, under drought and with reduced inputs, but there has been little investigation of its performance on the better yielding soils dominated by wheat production. The present paper reports 16 field experiments comparing wheat and triticale yield responses to nitrogen (N) fertilizer on high-yielding soils in the UK in harvest years 2009–2014. Each experiment included at least two wheat and at least two triticale varieties, grown at five or six N fertilizer rates from 0 to at least 260 kg N/ha. Linear plus exponential curves were fitted to describe the yield response to N and to calculate economically optimal N rates. Normal type curves with depletion were used to describe protein responses to N. Whole crop samples from selected treatments were taken prior to harvest to measure crop biomass, harvest index, crop N content and yield components. At commercial N rates, mean triticale yield was higher than the mean wheat yield at 13 out of 16 sites; the mean yield advantage of triticale was 0·53 t/ha in the first cereal position and 1·26 t/ha in the second cereal position. Optimal N requirement varied with variety at ten of the 16 sites, but there was no consistent difference between the optimal N rates of wheat and triticale. Triticale grain had lower protein content and lower specific weight than wheat grain. Triticale typically showed higher biomass and straw yields, lower harvest index and higher total N uptake than wheat. Consequently, triticale had higher N uptake efficiency and higher N use efficiency. Based on this study, current N fertilizer recommendations for triticale in the UK are too low, as are national statistics and expectations of triticale yields. The implications of these findings for arable cropping and cereals markets in the UK and Northern Europe are discussed, and the changes which would need to occur to allow triticale to fulfil a role in achieving sustainable intensification are explored.


2003 ◽  
Vol 43 (6) ◽  
pp. 631 ◽  
Author(s):  
L. A. Sparrow ◽  
K. S. R. Chapman

Thirteen field trials were conducted on ferrosols and tenosols in Tasmania to assess the response of potatoes (Solanum tuberosum L., cv. Russet Burbank) to basal (up to 250 kg/ha) and topdressed (up to 100 kg/ha) nitrogen fertiliser. Economic yield responses to basal nitrogen were obtained at 9 sites. Topdressing did not increase yield compared with equivalent rates of basal nitrogen, and often failed to compensate for a lack of nitrogen applied at planting. This lack of response may reflect the inability of the potato crop to make use of nitrogen applied during tuber bulking. Nitrogen fertiliser decreased tuber specific gravity at several sites. The effects of nitrogen on misshapen tubers, bruising susceptibility, crisp colour and hollow heart were inconsistent and often of no practical importance. However, at 2 sites, nitrogen fertiliser increased yields of misshapen tubers at the expense of processing tuber yields. At 1 of these sites, nitrogen topdressing decreased the yield of misshapen tubers. Otherwise, topdressing had similar effects on tuber quality to those of basal nitrogen. Growers should fertilise with nitrogen to optimise their yields. Optimum rates were greater in paddocks that had been continuously cropped for more than 10 years (average rate 193 kg/ha), than in those that had been in pasture (average rate 48 kg/ha).


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