Response of maize seed number to solar radiation intercepted soon after anthesis

A versatile method for predicting maize (Zea mays L.) seeds per plant would be valuable for simulating maize yield with different population densities. The objective of this work was to characterize the form of the response of seeds per plant to intercepted photosynthetically active radiation per plant in the 10 d following silking and to test the generality of the response function across several hybrids at different locations. Data from the literature and results with 2 yr of field experiments at Temple, TX, on Houston Black clay (fine montmorillonitic, thermic Udic Haplusterts) and 1 yr in central Pennsylvania on Hagerstown silt loam (fine, mixed, mesic Typic Hapludalfs) were used to evaluate this seed number response. The data support a linear response function, with values being on a plateau when the potential number of seeds of a hybrid has been reached. A single regression equation was adequate for 10 hybrids at Temple and/or in central Pennsylvania. Several other hybrids at these or other locations showed significantly different responses. Prediction functions for other hybrids can be derived with similar linear models, with a plateau defined by the potential seeds per plant produced at low planting densities