Two field pea cultivars, Huka and Whero, were grown under dryland conditions in Canterbury, New Zealand, at 5 plant densities ranging from 25 to 163 plants/m2. Retention of flowers and pods and development of ovule initials were investigated. Flowers per plant, pods perplant, ovule initials per pod, peas per pod, and the area of photosynthetically active tissue per plant (plant area) were all inversely related to plant density. Although Huka produced more flowers, pods, and ovule initials than Whero, Whero had the greater plant area and lost fewer of these structures. This may be related to Whero's ability to maintain a higher photosynthetic area per reproductive structure. During pod filling the topsoil moisture content was low but water was available at greater depths. Plant area and plant area index had a greater effect on the retention and development of reproductive structures, especially ovule initials, than did soil moisture. Further work is required into the role of other plant and environmental factors on the development of flowers, pods, and ovules. Losses of reproductive structures could be reduced by a combination of plant breeding and improved agronomy.
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