Relationships Between Seedling Traits and Mature Plant Yield in Sunn Hemp.

Sunn hemp (Crotalaria juncea L.) is a candidate species for rotation schemes as a green manure crop to improve soils and reduce root-knot nematode infestations. Also it can be used as a forage crop. The objective of this research is to identify the relationship between seedling and mature plant traits as a mean of predicting mature plant performance. A split-plot design with 6 replications was used that included 3 selection cycles (2004-2006) with 20 HS families each. The traits measured were plant height, number of leaves, inflorescence length, biomass, seed yield and seed quality at various time intervals. The results showed weak relationships between most seedling- and mature-plant traits (r ranged from -0.1372 to 0.5373). However, selecting the top 25% seedlings for stem height two weeks after planting with a follow-up selection for plant height after 2 more weeks resulted in plants with significantly higher seed yield and biomass production. The same was true when applying the same selection process for number of leaves per seedling. Therefore, there is the potential to eliminate plants and families with low potential yield at the seedling stage. This can give breeders the ability to use early indirect selection and cut down the costs of expensive field progeny tests as well as introduce more plants with high yield potential once the poor candidates have been eliminated.