Relationship Between Basal Corn Stem Nitrate N Content at V6 Growth Stage and Grain Yield

jpa ◽  
1988 ◽  
Vol 1 (4) ◽  
pp. 322-326 ◽  
Author(s):  
Edwin J. McClenahan ◽  
Randy Killorn
Keyword(s):  
Weed Science ◽  
2012 ◽  
Vol 60 (3) ◽  
pp. 510-515 ◽  
Author(s):  
Ryan M. Terry ◽  
Paul T. Marquardt ◽  
James J. Camberato ◽  
William G. Johnson

Volunteer corn (VC) in hybrid corn has become more prevalent in recent years and can reduce grain yield. Nitrogen (N) management can influence VC interference in corn. Field experiments were established to determine the effects of N fertilizer management and VC interference on hybrid corn growth and grain yield. Treatments consisted of three VC densities (control, 0 plants m−2; low density, 1 plant m−2; high density, 4 plants m−2) and six N fertilizer treatments (0 kg N ha−1, 67 kg N ha−1 at planting, 67 kg N ha−1 at planting + 133 kg N ha−1 at V5 corn growth stage, 67 kg N ha−1 at planting + 133 kg N ha−1 at V10 corn growth stage, 200 kg N ha−1 at V5 corn growth stage, and 200 kg N ha−1 at V10 corn growth stage). The effect of VC on hybrid corn was dependent on N rate. When 200 kg N ha−1 was applied, regardless of application timing, hybrid corn dry weight, hybrid corn N content, and hybrid corn grain yield were reduced by the high VC density. However, when VC grain yield was added to hybrid corn grain yield, VC density did not affect total grain yield. When 0 and 67 kg N ha−1 were applied, neither hybrid corn dry weight nor hybrid corn N content was affected by either VC density, but the high VC density reduced hybrid corn grain yield for both N rates by 19% and total grain yield by 9 and 10%, respectively. Application timing of N fertilizer had no effect on hybrid corn dry weight, N content, or grain yield. However, late N fertilizer applications (200 kg N ha−1 at V10 and 67 kg N ha−1 at planting +133 kg N ha−1 at V10) resulted in greater VC N content, VC grain yield, and total yield. Assuming the harvestability of VC, the ability of a late N treatment (V10) to maximize total grain yield allows growers to use a late N application to reduce the competitive effects of VC in hybrid corn.


2016 ◽  
Vol 206 ◽  
pp. 125-132 ◽  
Author(s):  
Alyne O. Lavinsky ◽  
Kelly C. Detmann ◽  
Josimar V. Reis ◽  
Rodrigo T. Ávila ◽  
Matheus L. Sanglard ◽  
...  

2020 ◽  
Vol 63 (5) ◽  
pp. 1169-1179
Author(s):  
Manyowa Norman Meki ◽  
Jaehak Jeong ◽  
Thomas Gerik ◽  
June Wolfe ◽  
Louis Hassell ◽  
...  

HighlightsThe APEX model was adapted to simulate detasseling in inbred corn for hybrid seed production.The adapted model satisfactorily predicted detasseling effects on LAI, grain yield, and N content.An inbred corn model could be applied to evaluate best management practices for inbred corns.Abstract. Hybrid seed corn production comprises approximately 10% of the entire corn acreage in the U.S. Because of seed corn’s high economic value, and to maximize yields, seed corn growers often over-irrigate or apply nitrogen (N) fertilizers equal to or in excess of those recommended for commercial hybrid corn. Detasseling female corn inbred lines during hybrid corn seed production is critical to ensure the purity of seeds. In addition to the removal of tassels, detasseling also results in the removal of several leaves, which may lead to reduced seed yields. The objective of this study was to adapt the Agricultural Policy/Environmental eXtender (APEX) model to simulate the detasseling of female inbred corns in hybrid seed production. An APEX inbred corn model was developed to simulate the effects of detasseling and leaf removals on the development of inbred corn, leaf area index (LAI), grain yield, and grain N content. Growth characteristics of inbred corn were parameterized in APEX using data from a field study conducted in Nebraska. Overall, the APEX inbred corn model successfully predicted the effects of detasseling on LAI, grain yield, and grain N content under the conditions of the field experiment. There was a significant correlation between simulated and measured LAI (Pearson r = 0.86 and R2 = 0.74 at p = 0.05). The computed paired t-test and permutation test p-values indicated no significant differences between measured and simulated LAI. The mean simulation percent difference and percent bias (PBIAS) were respectively 4.2% and 4.7%, while measured and simulated LAI values had an average root mean square error (RMSE) of 0.14. The APEX model predicted grain yield with RMSE of 120 kg ha-1, mean simulation percent difference of 0.48%, and PBIAS of 0.26%. Like LAI, predicted grain yields exhibited significant correlation with field data (Pearson r = 0.99 and R2 = 0.97 at p = 0.05). Similarly, computed paired t-test and permutation test p-values indicated no significant differences between measured and simulated grain yields. Grain N content was predicted with RMSE of 6.75 kg N ha-1, mean simulation percent difference of 1.46%, and PBIAS of 2.45%. Predicted and measured grain N content values were correlated (Pearson r = 0.81 and R2 = 0.65 at p = 0.05), while the t-test and permutation test p-values indicated no significant differences between measured and predicted grain N content. Overall, detasseling effects were better predicted for grain yield than for LAI and grain N content as indicated by a Nash-Sutcliffe efficiency (NSE) of 0.92 compared to NSE values of 0.47 for LAI and 0.43 for grain N content. In conclusion, the hybrid seed corn industry could benefit from the application of inbred corn models that could allow growers to evaluate and identify optimal irrigation and N management practices for inbred corn, similar to the benefits that have been obtained with model simulation for commercial hybrid corn grain production systems. Keywords: APEX parameterization, Detasseling, Inbred corn, Leaf area index.


1977 ◽  
Vol 54 (4) ◽  
pp. 125-136 ◽  
Author(s):  
J. Augustin ◽  
R. E. McDole ◽  
G. C. Painter

2005 ◽  
Vol 85 (1) ◽  
pp. 59-65 ◽  
Author(s):  
S. S. Malhi ◽  
L. Cowell ◽  
H. R. Kutcher

A field experiment was conducted to determine the relative effectiveness of various sources, methods, times and rates of Cu fertilizers on grain yield, protein concentration in grain, concentration of Cu in grain and uptake of Cu in grain of wheat (Triticum aestivum L.), and residual concentration of DTPA-extractable Cu in soil on a Cu-deficient soil near Porcupine Plain in northeastern Saskatchewan. The experiment was conducted from 1999 to 2002 on the same site, but the results for 2002 were not presented because of very low grain yield due to drought in the growing season. The 25 treatments included soil application of four granular Cu fertilizers (Cu lignosulphonate, Cu sulphate, Cu oxysulphate I and Cu oxysulphate II) as soil-incorporated (at 0.5 and 2.0 kg Cu ha-1), seedrow-placed (at 0.25 and 1.0 kg Cu ha-1) and foliar application of four solution Cu fertilizers (Cu chelate-EDTA, Cu sequestered I, Cu sulphate/chelate and Cu sequestered II at 0.25 kg Cu ha-1) at the four-leaf and flag-leaf growth stages, plus a zero-Cu check. Soil was tilled only once to incorporate all designated Cu and blanket fertilizers into the soil a few days prior to seeding. Wheat plants in the zero-Cu treatment exhibited Cu deficiency in all years. For foliar application at the flag-leaf stage, grain yield increased with all four of the Cu fertilizers in 2000 and 2001, and in all but Cu sequestered II in 1999. Foliar application at the four-leaf growth stage of three Cu fertilizers (Cu chelate-EDTA, Cu sequestered I and Cu sulphate/chelate), soil incorporation of all Cu fertilizers at 2 kg Cu ha-1 and two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 0.5 kg Cu ha-1 rate, and seedrow placement of two Cu fertilizers (Cu lignosulphonate and Cu sulphate) at 1 kg Cu ha-1 increased grain yield of wheat only in 2001. There was no effect of Cu fertilization on protein concentration in grain. The increase in concentration and uptake of Cu in grain from Cu fertilization usually showed a trend similar to grain yield. There was some increase in residual DTPA-extractable Cu in the 0–60 cm soil in Cu lignosulphonate, Cu sulphate and Cu oxysulphate II soil incorporation treatments, particularly at the 2 kg Cu ha-1 rate. In summary, the results indicate that foliar application of Cu fertilizers at the flag-leaf growth stage can be used for immediate correction of Cu deficiency in wheat. Because Cu deficiency in crops often occurs in irregular patches within fields, foliar application may be the most practical and economical way to correct Cu deficiency during the growing season, as lower Cu rates can correct Cu deficiency. Key words: Application time, Cu source, foliar application, granular Cu, growth stage, placement method, rate of Cu, seedrow-placed Cu, soil incorporation


2004 ◽  
Vol 84 (1) ◽  
pp. 47-56 ◽  
Author(s):  
R. E. Karamanos ◽  
Q. Pomarenski ◽  
T. B. Goh ◽  
N. A Flore

Available Cu concentrations in prairie soils (DTPA-extractable Cu) are extremely variable, thus resulting in areas within fields that are Cu deficient. These areas are difficult to characterize by a soil test based on a composite field sample; thus, when they are identified in the growing season, foliar Cu application possibly represents the only method of correcting them. A project, carried out over a period of 8 yr that consisted of four experiments and a total of 22 trials, was designed to ascertain whether foliar Cu applications indeed provide a satisfactory means of correcting Cu deficiency. Experiments included comparison of foliar applications at Feekes growth stages 6 (first node of stem visible at base of shoot) and 6 plus 10 (sheath of last leaf completely grown out) to soil broadcast and incorporation of 4 to 5.5 kg Cu ha-1 as copper sulphate (CuSO4·5H2O) or seed placement of 2 kg Cu ha-1 in three forms (two oxysulphates and one sulphate); foliar application of a variety of products representing different chemistries (chelate, lignin sulphonate, humic acid, oxychloride and citric acid) on a number of wheat cultivars at Feekes growth stage 10 or one cultivar at Feekes growth stages 2 (beginning of tillering), 6, 10 and 2 plus 10. Foliar applications appear to provide a solution to Cu deficiency that is identified during the growing season. However, foliar applications were not always as effective as broadcast and incorporation of at least 4 kg Cu ha-1 in the form of CuSO4·5H2O, which still remains the preferred method to correct a Cu deficiency. Foliar application at Feekes growth stage 2 was ineffective, whereas a single foliar application at Feekes growth stage 10 was not as satisfactory as a single one at Feekes growth stage 6. Thus, the latter stage appears to be preferable; however, maximum grain yield in some cases was obtained by the combination of two foliar Cu applications, one each at Feekes growth stages 6 and 10. Responses of wheat to foliar Cu application were obtained on soils that contained DTPA-extractable Cu concentration of less than 0.4 mg kg-1. Foliar Cu applications did not have an appreciable effect on grain quality parameters, such as hectolitre weight, moisture or protein content. Key words: DTPA-extractable, Feekes growth stage, deficient, marginal, plant tissue


2012 ◽  
Vol 92 (2) ◽  
pp. 331-339 ◽  
Author(s):  
Noura Ziadi ◽  
Gilles Bélanger ◽  
Annie Claessens

Ziadi, N., Bélanger, G. and Claessens, A. 2012. Relationship between soil nitrate accumulation and in-season corn N nutrition indicators. Can. J. Plant Sci. 92: 331–339. Nitrogen management tools are required to optimize crop growth and yield while minimizing the likelihood of N losses to the environment. We previously determined that non-limiting N conditions for near maximum corn (Zea mays L.) grain yield are reached with the following threshold values for three in-season plant-based indicators of corn N nutrition determined at approximately the V12 stage of development: N nutrition index (NNI) = 0.88, leaf N (NL) concentration = 32.7 mg N g−1 leaf DM, and relative chlorophyll meter (RCM) values = 0.95. Our objective was to study the relationship between these plant-based indicators and soil NO3-N content in an effort to develop tools to reduce the likelihood of soil NO3-N accumulation without affecting grain yield. This study at 5 site-years in Québec consisted of six N fertilizer rates (20–250 kg N ha−1). The NNI, NL concentrations, RCM values, and soil (0–0.15 m) NO3-N content were measured weekly from July to early August, while soil NO3-N content to a 0.90-m depth was measured in late August and October. During the growing season from July to early August, the proportion of data points above the average soil NO3-N content was greater under non-limiting N conditions (NNI ≥ 0.88, NL concentrations ≥ 32.7 mg N g−1 leaf DM, or RCM values ≥ 0.95) than under limiting N conditions. Furthermore, the mean soil NO3-N content of the data points above the general average was much higher under non limiting than limiting N conditions in late August (167 vs. 78 kg NO3-N ha−1 for NNI and RCM; 166 vs. 112 kg NO3-N ha−1 for NL concentration) and October (68 vs. 49 kg NO3-N ha−1). High soil NO3-N accumulation during the season and at harvest occurs only when in-season plant-based N indicators are greater than their threshold values.


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