title: Determination of coefficient defining leaf area development in different genotypes, plant types and planting densities in peanut (Arachis hypogeaeL.).
abstract: Rapid leaf area development may be attractive under a number of cropping conditions to enhance the vigor of crop establishment and allow rapid canopy closure for maximizing light interception and shading of weed competitors. This study was undertaken to determine (1) if parameters describing leaf area development varied among ten peanut (Arachis hypogeaeL.) genotypes grown in field and pot experiments, (2) if these parameters were affected by the planting density, and (3) if these parameters varied between Spanish and Virginia genotypes. Leaf area development was described by two steps: prediction of main stem number of nodes based on phyllochron development and plant leaf area dependent based on main stem node number. There was no genetic variation in the phyllochron measured in the field. However, the phyllochron was much longer for plants grown in pots as compared to the field-grown plants. These results indicated a negative aspect of growing peanut plants in the pots used in this experiment. In contrast to phyllochron, there was no difference in the relationship between plant leaf area and main stem node number between the pot and field experiments. However, there was genetic variation in both the pot and field experiments in the exponential coefficient (PLAPOW) of the power function used to describe leaf area development from node number. This genetic variation was confirmed in another experiment with a larger number of genotypes, although possible G × E interaction for the PLAPOW was found. Sowing density did not affect the power function relating leaf area to main stem node number. There was also no difference in the power function coefficient between Spanish and Virginia genotypes. SSM (Simple Simulation model) reliably predicted leaf canopy development in groundnut. Indeed the leaf area showed a close agreement between predicted and observed values up to 60000 cm2m-2. The slightly higher prediction in India and slightly lower prediction in Niger reflected GxE interactions. Until more understanding is obtained on the possible GxE interaction effects on the canopy development, a generic PLAPOW value of 2.71, no correction for sowing density, and a phyllochron on 53 °C could be used to model canopy development in peanut.
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Sahelian Center, Niamey, Niger; Department of Biology, Faculty of Sciences, University Abdou Moumouni, Niamey, Niger.
authors.forename: Oumarou
authors.initials: O
authors.lastname: Halilou
authors.affiliation: Centre d'Etude Régional pour l'Amélioration de l'Adaptation à la Sécheresse, Thiès-Escale, Senegal.
authors.forename: Halime Mahamat
authors.initials: HM
authors.lastname: Hissene
authors.affiliation: Department of Crop Sciences, North Carolina State University, Raleigh, NC 27695-7620, USA.
authors.forename: José A
authors.initials: JA
authors.lastname: Clavijo Michelangeli
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Sahelian Center, Niamey, Niger; Department of Biology, Faculty of Sciences, University Abdou Moumouni, Niamey, Niger.
authors.forename: Falalou
authors.initials: F
authors.lastname: Hamidou
authors.affiliation: Department of Crop Sciences, North Carolina State University, Raleigh, NC 27695-7620, USA.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Sinclair
authors.affiliation: Agronomy Group, Gorgan University of Agricultural Sciences and Natural Resources, Gorgan 49138-15739, Iran.
authors.forename: Afshin
authors.initials: A
authors.lastname: Soltani
authors.affiliation: Department of Biology, Faculty of Sciences, University Abdou Moumouni, Niamey, Niger.
authors.forename: Saadou
authors.initials: S
authors.lastname: Mahamane
authors.affiliation: International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Greater Hyderabad 502324, Telangana, India.
authors.forename: Vincent
authors.initials: V
authors.lastname: Vadez
keywords: Allometric model; Degree-days; Leaf area; Peanut; Phyllochron