Managing breadfruit yield with soil-applied nitrogen and biostimulants

Research was conducted in Puerto Rico to determine the effects of nitrogen (N) and biostimulant application on breadfruit (Artocarpus altilis) tree growth and fruit yield. The treatments were combinations of soil-applied N (standard rate, and 1.25 times the standard rate) and 3 options of soil-applied biostimulant (check with no biostimulant, a peptide-based complex, and a humic acid-based complex). N was applied monthly, while biostimulants were applied every 2 weeks. There were 10 trees per treatment. Trees treated with extra N were larger and had more fruits than trees receiving the standard N rate. Moreover, at a given N rate, application of biostimulants increased tree size and fruit number, but not the average fruit size. Fruit yield was significantly greater in trees treated with the peptide biostimulant and the high N rate than in the other treatments. The biostimulant and N treatments increased fruit yield by augmenting fruit number without significantly affecting fruit size, with total fruit yield tree^‑1 being positively correlated to tree size.