Agronomic performance of normal-leafed and semi-leafless pea (Pisum sativum L.) genotypes

Pea (Pisum sativum L.) is a major pulse crop important as feed and food. Due to the symbiosis with N-fixing bacteria, it is a valuable component of low-input cropping systems. The traditional cultivation of peas was limited by their high susceptibility to lodging. This problem was reduced, though not completely solved, by a semi-leafless mutant. Almost all modern cultivars carry this mutant. It is still an open question as to whether the lack of leaflets may have impaired the productivity. In organic farming, there is still interest in normal-leafed peas as they can better compete with weeds. To compare the two leaf types, 24 normal-leafed and 30 semi-leafless genotypes were evaluated in three environments. Semi-leafless genotypes had a higher seed (51%) and straw (40%) yield, but most normal-leafed genotypes were older or less adapted than the semi-leafless ones. Some newer normal-leafed cultivars achieved the same yield level, but their cultivation is only possible in mixtures with a supporting crop. Nitrogen content in seed (10%) and in straw (30%) was lower in semi-leafless genotypes. A negative correlation of yield and N content was observed in both leaf types. However, semi-leafless peas had a higher N yield in seed and in straw. No correlation between N yield in seed and straw was found, so it is possible to combine a high seed yield with a high N yield in the straw. This is particularly important in organic production systems, where peas are also grown to provide N to the following crop.