ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 55 Number 2
Effects of source-sink manipulations onseed yield of cowpea (Vigna unguiculata (L.) Walp.). I-Defoliation
Various defoliation treatments were imposed on nodule-dependent cowpea cv 'K 2809' plants grown in pots under simulated tropical conditions and were effective in creating markedly different final seed yields. Depending on the relative age of leaves removed, defoliation applied at the appearance of first flowers and which removed a nominal 50 per cent of the leaf area from this determinate cultivar reduced seed yields by 26 to 60 per cent compared with the undefoliated controls; the loss of relatively young leaves being most detrimental. Treatment effects on the supply of both carbon and nitrogen to fruits are discussed and guidelines for similar investigations are proposed.