An atempt to explain differences in the yielding ability of potato cultivars based on differences in cumulative light interception, utilization efficiency of foliage and harvest index

1987 ◽  
Vol 30 (4) ◽  
pp. 551-568 ◽  
Author(s):  
D. E. Van Der Zaag ◽  
J. H. Doornbos
1990 ◽  
Vol 70 (4) ◽  
pp. 965-977 ◽  
Author(s):  
J. M. CLARKE ◽  
C. A. CAMPBELL ◽  
H. W. CUTFORTH ◽  
R. M. DePAUW ◽  
G. E. WINKLEMAN

A field study was carried out in four environments to determine the effects of available water and cultivar on N and P uptake, translocation, and utilization efficiency of wheat (Triticum spp.) cultivars with varying grain yield potential and protein concentration. Two common wheat (T. aestivum L.) cultivars, Neepawa and HY320, and two durum (T. turgidum L. var. durum) cultivars, DT367 and Wakooma, were studied. HY320 and DT367 had higher grain yield potentials and lower protein concentrations than Neepawa and Wakooma. Total plant N and P uptake was proportional to available water, and was strongly associated with dry matter accumulation. From 67 to 102% of plant N and 64–100% of P present at harvest had been accumulated by anthesis. Postanthesis uptake of N and P was greater under moist than under dry environments. There were few cultivar differences in uptake of N or P, and any differences observed were related to variations in plant dry matter. Nitrogen harvest index ranged from 71 to 85% and P harvest index ranged from 81 to 93%. Both indices responded to environment in the same way as grain harvest index; there were no cultivar differences for either N or P harvest index. From 59 to 79% of N and 75 to 87% of P present in vegetative tissues at anthesis was translocated to the grain; translocation did not vary among cultivars. The efficiency of utilization of N and P in production of harvest biomass and grain was directly proportional to water availability and was greater in the high yield cultivars HY320 and DT367 than in Neepawa and Wakooma. There was no evidence that selection for N uptake, translocation, or utilization efficiency would be useful in wheat breeding.Key words: Triticum aestivum L., T. turgidum L. var. durum, nitrogen harvest index, phosphorus harvest index


2004 ◽  
Vol 84 (2) ◽  
pp. 589-598 ◽  
Author(s):  
B. J. Zebarth ◽  
G. Tai ◽  
R. Tarn ◽  
H. de Jong ◽  
P. H. Milburn

One approach for reducing the contribution of potato (Solanum tuberosum L.) production to nitrate contamination of groundwater is to develop cultivars which utilize N more efficiently. In this study, variation in N use efficiency (NUE; dry matter production per unit crop N supply) characteristics of 20 commercial potato cultivars of North American and European origin were evaluated in 2 yr. Cultivars were grown with or without application of 100 kg N ha-1 as ammonium nitrate banded at planting. The recommended within-row spacing was used for each cultivar and no irrigation was applied. Plant dry matter and N accumulation were determined prior to significant leaf senescence. Crop N supply was estimated as fertilizer N applied plus soil inorganic N measured at planting plus apparent net soil N mineralization. Nitrogen use efficiency decreased curvilinearly with increasing crop N supply. Nitrogen use efficiency was lower for early-maturing cultivars compared to mid-season and late-maturing cultivars. A curvilinear relationship was obtained between plant dry matter accumulation and plant N accumulation using data for all cultivars. Deviations from this relationship were interpreted as variation in N utilization efficiency (NUtE; dry matter accumulation per unit N accumulation). Significant differences in NUtE were measured among cultivars of similar maturity. Nitrogen uptake efficiency (NUpE; plant N content per unit crop N supply) and soil nitrate concentration measured at plant harvest were uniformly low for all cultivars when crop N supply was limited, but varied among cultivars when N was more abundant. This suggests that potato cultivars vary more in terms of N uptake capacity (plant N accumulation in the presence of an abundant N supply) than in terms of NUpE. Key words: Solanum tuberosum, N mineralization, dry matter accumulation, N accumulation, N utilization efficiency


1997 ◽  
Vol 48 (2) ◽  
pp. 231 ◽  
Author(s):  
M. P. Bange ◽  
G. L. Hammer ◽  
K. G. Rickert

A simple framework was used to analyse the determinants of potential yield of sunflower (Helianthus annuus L.) in a subtropical environment. The aim was to investigate the stability of the determinants crop duration, canopy light interception, radiation use efficiency (RUE), and harvest index (HI) at 2 sowing times and with 3 genotypes differing in crop maturity and stature. Crop growth, phenology, light interception, yield, prevailing temperature, and radiation were recorded and measured throughout the crop cycle. Significant differences in grain yield were found between the 2 sowings, but not among genotypes within each sowing. Mean yields (0% moisture) were 6·02 and 2·17 t/ha for the first sowing, on 13 September (S1), and the second sowing, on 5 March (S2), respectively. Exceptionally high yields in S1 were due to high biomass assimilation associated with the high radiation environment, high light interception owing to a greater leaf area index, and high RUE (1·47–1·62 g/MJ) across genotypes. It is proposed that the high RUE was caused by high levels of available nitrogen maintained during crop growth by frequent applications of fertiliser and sewage effluent as irrigation. In addition to differences in the radiation environment, the assimilate partitioned to grain was reduced in S2 associated with a reduction in the duration of grain-filling. Harvest index was 0·40 in S1 and 0·25 in S2. It is hypothesised that low minimum temperatures experienced in S2 reduced assimilate production and partitioning, causing premature maturation.


2011 ◽  
Vol 62 (3) ◽  
pp. 208 ◽  
Author(s):  
H. L. Li ◽  
Y. Luo ◽  
J. H. Ma

Radiation-use efficiency (RUE, g/MJ) and the harvest index (HI, unitless) are two helpful characteristics in interpreting crop response to environmental and climatic changes. They are also increasingly important for accurate crop yield simulation, but they are affected by various environmental factors. In this study, the RUE and HI of winter wheat and their relationships to canopy spectral reflectance were investigated based on the massive field measurements of five nitrogen (N) treatments. Crop production can be separated into light interception and RUE. The results indicated that during a long period of slow growth from emergence to regreening, the effect of N on crop production mainly showed up in an increased light interception by the canopy. During the period of rapid growth from regreening to maturity, it was present in both light interception and RUE. The temporal variations of RUEAPAR (aboveground biomass produced per unit of photosynthetically active radiation absorbed by the canopy) during the period from regreening to maturity had different patterns corresponding to the N deficiency, N adequacy and N-excess conditions. Moreover, significant relationships were found between the RUEAPAR and the accumulative normalised difference vegetation index (NDVI) in the integrated season (R2 = 0.68), between the HI and the accumulative NDVI after anthesis (R2 = 0.89), and between the RUEgrain (ratio of grain yield to the total amount of photosynthetically active radiation absorbed by the canopy) and the accumulative NDVI of the whole season (R2 = 0.89) and that after anthesis (R2 = 0.94). It suggested that canopy spectral reflectance has the potential to reveal the spatial information of the RUEAPAR, HI and RUEgrain. It is hoped that this information will be useful in improving the accuracy of crop yield simulation in large areas.


2011 ◽  
Vol 150 (1) ◽  
pp. 3-22 ◽  
Author(s):  
M. J. GOODING ◽  
M. ADDISU ◽  
R. K. UPPAL ◽  
J. W. SNAPE ◽  
H. E. JONES

SUMMARYNear isogenic lines (NILs) varying for alleles for reduced height (Rht) and photoperiod insensitivity (Ppd-D1a) in a cvar Mercia background (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht8c+Ppd-D1a, Rht-D1c, Rht12) were compared at a field site in Berkshire, UK, but within different systems (‘organic’, O, in 2005/06, 2006/07 and 2007/08 growing seasons v. ‘conventional’, C, in 2005/06, 2006/07, 2007/08 and 2008/09). In 2007 and 2008, further NILs (rht (tall), Rht-B1b, Rht-D1b, Rht-B1c, Rht-B1b+Rht-D1b, Rht-D1b+Rht-B1c) in both Maris Huntsman and Maris Widgeon backgrounds were added. The contrasting systems allowed NILs to be tested in diverse rotational and agronomic, but commercially relevant, contexts, particularly with regard to the assumed temporal distribution of nitrogen availability, and competition from weeds.For grain, nitrogen-use efficiency (NUE; grain dry matter (DM) yield/available N; where available N=fertilizer N+soil mineral N), recovery of N in the grain (grain N yield/available N), N utilization efficiency to produce grain (NUtEg; grain DM yield/above-ground crop N yield), N harvest index (grain N yield/above-ground crop N yield) and dry matter harvest index (DMHI; grain DM yield/above-ground crop DM yield) all peaked at final crop heights of 800–950 mm. Maximum NUE occurred at greater crop heights in the organic system than in the conventional system, such that even adding just a semi-dwarfing allele (Rht-D1b) to the shortest background, Mercia, reduced NUE in the organic system. The mechanism of dwarfing (gibberellin sensitive or insensitive) made little difference to the relationship between NUE and its components with crop height.For above-ground biomass: dwarfing alleles had a greater effect on DM accumulation compared with N accumulation such that all dwarfing alleles could reduce nitrogen utilization efficiency (NUtE; crop DM yield/crop N yield). This was particularly evident at anthesis in the conventional system when there was no significant penalty for severe dwarfism for N accumulation, despite a 3-tonne (t)/ha reduction in biomass compared to the tallest lines. Differences between genotypes for recovery of N in the grain were thus mostly a function of net N uptake after anthesis rather than of remobilized N. This effect was compounded as dwarfing, except when coupled with Ppd-D1a, was associated with delayed anthesis. In the organic experiments there was greater reliance on N accumulated before anthesis, and genotype effects on NUE were confounded with effects on N accumulated by weeds, which was negatively associated with crop height. Optimum height for maximizing wheat NUE and its components, as manipulated by Rht alleles, thus depend on growing system, and crop utilization (i.e. biomass or grain production).


1999 ◽  
Vol 68 (2) ◽  
pp. 235-244 ◽  
Author(s):  
Eiki KURODA ◽  
Naokuni HIGASHI ◽  
Takashi OKADA ◽  
Shin ABE ◽  
Mitsugu HIRANO ◽  
...  

2004 ◽  
Vol 55 (8) ◽  
pp. 855 ◽  
Author(s):  
R. K. Vandeleur ◽  
G. S. Gill

Fourteen wheat (Triticum aestivum L.) cultivars released to Australian growers over the last century were examined to determine the impact of crop breeding on competitive ability with weeds. In 1999 and 2000 the weed used in the field study was annual ryegrass (Lolium rigidum Gaud.) and in 2001 oats (Avena sativa cv. Marloo) was the weedy competitor. In 2 out of 3 years (1999 and 2001), when Puccinia recondita (leaf rust) infection was not a problem, there were consistent trends for improvement in yielding ability through breeding effort over time. In these 2 seasons the yielding ability of wheat increased by around 15 kg/ha.year as compared with a yield increase of only 4.7 kg/ha.year in 2000 due to a heavy P. recondita infection. In 1999 and 2000, when annual ryegrass was used as the weedy competitor, there was no systematic trend for changes in crop yield loss with time (r = 0.47 in 1999; r = 0.08 in 2000, P > 0.05). However, in 2001, when oat was used as the weed, there was a significant positive linear relationship (r = 0.81, P < 0.01) between the year of cultivar release and crop yield loss, indicating inferior competitive ability of the modern cultivars. Old cultivars such as Nabawa not only provided superior weed suppression, they were also more tolerant of weeds as indicated by the smaller yield loss. Plant height appeared to be an important contributor to the superior competitiveness of the standard height, older cultivars. Other morphological traits contributing to superior competitive ability included greater leaf length and width, light interception, and flag leaf length. To improve the competitive ability of modern wheats without compromising their yielding ability, morphological traits that enhance early crop vigour (size of leaf 1 and 2) and light interception without affecting harvest index may need to be incorporated from carefully selected germplasm.


2011 ◽  
Vol 150 (4) ◽  
pp. 460-472 ◽  
Author(s):  
E. WHITE

SUMMARYA detailed study of nitrogen use efficiency (NUE) and its components in three cultivars of winter wheat, Hereward, Rialto and Riband was undertaken in cultivar trials conducted in Northern Ireland in 1998 and 1999. Yield, grain N concentration, harvest index (HI), nitrogen harvest index (NHI), N uptake efficiency (NUpE), total N uptake, grain N off-take, N utilization efficiency (NUtE) and NUE itself all showed significant variation between sites. Cvars Hereward and Rialto had similar mean values across all the sites for many of the characteristics, with Riband usually differing. In all but one characteristic, grain N concentration, the responses of the three cultivars varied significantly from trial to trial and this, along with the substantial variation between sites, indicates that genetic control of the characteristics is partial. The amount of N applied as fertilizer accounted for little of the variation among the trials with weak associations for NUpE, which decreased, and grain yield, which increased with increasing fertilizer N. Neither grain yield nor NUE was associated with the amount of N taken up by the crop, but grain N concentration increased and NUtE decreased significantly. HI and NHI differed significantly among the cultivars, diverging at higher N uptakes, with Hereward and Rialto being similar and distinctly different from Riband. Grain yield was only weakly associated with NUpE but was strongly and positively associated with NUtE and NUE. The strong negative association between NUtE and NUpE highlights the potential and the urgency of understanding factors influencing uptake of nitrogen by crops. The extent of the non-genetic, i.e. environmental and management, variation in the characteristics, along with the relative similarity of the cultivar means, throws up a challenge to plant breeders, agronomists and researchers wishing to improve NUE genetically and through management. As with yield and other characteristics, a large number of trials will be required to identify consistent differences in NUE among cultivars. Thus, while mechanisms underlying NUE, NUpE and NUtE need to be understood, the possibility of using the HGCA UK Recommended List database to investigate NUE and identify cultivars with improved NUE should also be considered. Since in each of the HGCA trials cultivars have access to the same available N, and since grain yield=available N×NUE, grain yield itself is a surrogate for the NUE of cultivars. Grain N concentration is only determined in a few cultivars at present but could be used as an indicator of optimal N availability in individual trials, allowing variation in NUE of cultivars in response to agro-ecological factors on NUE to be studied.


Sign in / Sign up

Export Citation Format

Share Document