Prediction of Time to Anthesis of a Selection of Sunflower Genotypes

Goyne, P. J.; Schneiter, A. A.; Cleary, K. C.

doi:10.2134/agronj1990.00021962008200030012x

Cited by 7 publications

(7 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is important to compare the performance of OILCROPmodel ability to capture crop responses to density. Although SUN with that of existing models that predict emergence PI was clearly the principal determinant of leaf number and (Angus et a!., 1981) or flowering (Goyne et al, 1990).…”

Section: Discussionmentioning

confidence: 76%

“…The Angus et al (1981) model had the opposite tendency. The model of Goyne et al (1990) seeks to predict the duration of the emergence-midanthesis phase; it is based on the responses of development to temperature in each of the emergence-bud visible (VE to Rl, Schneiter and Miller, 1981) and bud visible-anthesis (Rl to R5.1) phases. Four categories of response (from very quick to slow) are identified for each of these phases, and are reflected in the values of the parameters of the response functions.…”

Section: Discussionmentioning

confidence: 99%

“…The two outliers were sowings that received no rain for 20 and 30 d after sowing. 1982-1983 and 1985-1986 seasons, with predicted values estimated using either OILCROP-SUN or the best of 16 combinations of the Goyne et al (1990) model. outliers, the RMSE (root mean square error; Willmott, 1982) for predictions of time to emergence was 3.7 d. A linear regression forced through the origin had a slope of 0.96, and was not significantly different (P = 0.05) from 1.…”

Section: Model Validationmentioning

confidence: 99%

See 2 more Smart Citations

OILCROP‐SUN: A Development, Growth, and Yield Model of the Sunflower Crop

Villalobos¹,

et al. 1996

View full text Add to dashboard Cite

Crop simulation models are important tools for agronomic management strategy evaluation, particularly under rainfed conditions. This paper describes the structure and testing of OILCROP‐SUN, a process‐oriented model of the sunflower (Helianthus annuus L.) crop. The model simulates organ biomass and N content, leaf area index, and soil water and N balances with a daily time step. Daily weather data, soil physical and chemical characteristics, and initial contents of water and N are required inputs. Three cultivar‐specific parameters synthesize crop responses to temperature and photoperiod during development, and two cultivar‐speciflc parameters define potential grain number per capitulum and potential kernel growth rate. Tested against independent data sets, the model generated good predictions of the durations of the sowing‐emergence (range 7 to 32 d; root mean square error [RMSE], observed vs. simulated: 3.7 d) and emergence‐anthesis phases (range 52 to 146 d; RMSE between 2.9 and 4.3 d, depending on the cultivar). The model also simulated seasonal crop biomass and leaf area dynamics for irrigated and rainfed crops sown at two densities satisfactorily, as well as aerial biomass (range 5 to 15 t ha−1; RMSE 1.7 ha−1) and grain yield at maturity (range 1.0 to 6.2 t ha−1; RMSE 0.8 t ha−1) for irrigated and rainfed crops sown at a range of population densities (0.5 to 10 plants m−2). We conclude that OILCROP‐SUN can be used to simulate biomass and grain yields over a wide range of conditions.

show abstract

Section: Discussionmentioning

confidence: 76%

Section: Discussionmentioning

confidence: 99%

Section: Model Validationmentioning

confidence: 99%

See 1 more Smart Citation

OILCROP‐SUN: A Development, Growth, and Yield Model of the Sunflower Crop

Villalobos¹,

et al. 1996

View full text Add to dashboard Cite

show abstract

“…Although there is some common ground, the overall impression is one of fragmentary coverage, results which sometimes appear contradictory, and differing assumptions for the descriptive frameworks. For example, predictive approaches for time to flowering have been based on genotype responses to temperature alone [6], or to temperature and photoperiod with [7] or without [8] a juvenile phase. Equally, there is still discussion as to whether sunflower development exhibits short-day, long-day or other responses to photoperiod.…”

Section: Control Of Crop Developmentmentioning

confidence: 99%

“…It could be argued that the quantitative descriptions developed by several groups (i.e. [6][7][8]) proved successful in predicting flowering dates over durations of the emergence-flowering phase that varied by up to almost 100 days between extremes [6,7,25], in spite of the fact that none of these frameworks incorporated the complexity suggested above. However, the important differences in the basic assumptions of these frameworks should be a sufficient argument for a re-evaluation of the issue.…”

Section: Control Of Crop Developmentmentioning

confidence: 99%

15e CONFERENCE INTERNATIONALE TOURNESOL Sunflower ecophysiology: some unresolved issues

Hall

2001

OCL

View full text Add to dashboard Cite

Summary :Major unresolved issues in sunflower ecophysiology constrain efforts to improve crop modelling, management, genetic analysis and breeding. Three issues are used here to illustrate this point. Firstly, much of the work on the duration of the emergence to flowering phase has considered the phase as a whole. It is argued that a more detailed analysis based on sub-phases is required, particularly in view of possible intraspecific variability in the durations of the basic vegetative and juvenile phases and evidence that photoperiod responses before, during and after floral initiation may differ between genotypes and even be of opposite sign for the same genotype. Secondly,contrasting responses of grain oil proportion to manipulation of plant population density and incident radiation appear to be linked to variations in kernel oil proportion rather than to kernel: hull ratio, and responses of grain oil proportion to changes in sowing date seem to have a similar origin. More effort should be focused on understanding the controls of oil mass per kernel. It is speculated that there may be a genotype-dependent limit to this variable. A third unresolved issue relates to the nature and strength of the linkage between post-anthesis stay-green and leaf photosynthetic functionality. These variables are poorly related during pre-anthesis senescence of leaves in the lower portion of closed canopies, and for sunflower this linkage appears much weaker than in other crop species. Current interest in post-anthesis stay-green as a possibly useful crop attribute requires clarification of this uncertainty.Keywords : sunflower, crop development, grain oil content, stay green.Résumé : D'importants points non résolus chez le tournesol limitent les efforts pour progresser dans la modélisation des cultures, leur conduite, les analyses génétiques et l'amélioration. Trois aspects sont considérés ici pour illustrer ce point. Premièrement, la plupart des travaux concernant la durée de la période comprise entre la germination et la floraison traitent cette phase comme un tout. Le besoin d'un analyse plus détaillée en considérant des sous-phases est évoqué, particulièrement face à la possible variabilité intraspécifique dans la durée de la phase végétative de base et la phase juvénile et à l'évidence d'une réponse photopériodique différente avant, pendant et après l'initiation florale. Cette réponse différente peut aller jusqu'à être de signe contraire pour le même génotype. Deuxièmement, des réponses contrastantes dans la proportion d'huile de la graine comme conséquence de la manipulation de la densité de la population et du rayonnement incident paraissent être plus liées à la variation dans la proportion d'huile de l'amande qu'au rapport coqueamande. La réponse de la proportion d'huile de la graine aux variations de la date de semis semble Article disponible sur le site http://www.ocl-journal.org ou http://dx

show abstract