The Effect of Fruit Shading on Yield in Pisum sativum L.

Fruits of Pisum sativum L. cv. Feltham First which initiatesonly one flower per flowering node, were selectively shadedunder varying levels of defoliation. The purpose of the experimentswas to ascertain whether the foliage could compensate for lossof the fruit's contribution to its own growth. There was evidenceof this, but fruit and seed weight per fruit and per plant werereduced by fruit shading at all levels of defoliation. The lossin yield due to shading suggested that the contribution fromthe fruit was at least 12 per cent. The number of seeds whichdeveloped to maturity was the yield component most affectedby treatment. There was no evidence to suggest that shadinghad a different quantitative effect on final weight at differentnodes, but it did increase flower abscission at the first foweringnode in an experiment done at low radiant exposure. In an experimentat higher radiant exposure, very few flowers abscised at theearlier nodes, but leaflet removal reduced final fruit yieldat the first flowering node to a greater degree than at thesecond. These differential responses could contribute to variabilityof seed size in a crop of vining peas. Pisum sativum, pea, fruit, pod, light, shading, photosynthesis, yield