The 2012 ASHS Annual Conference

Experiments were conducted in Mayagüez to study the effects of seed treatment with aqueous solutions of homobrassinolide (HBR) and nitrogen rates on the chlorophyll concentration, shoot growth, and abundance of aphids in papaya seedlings. ‘Tainung 1’ papaya seedlings were grown in nursery following standard practices, except for application of HBR (0 to 10 parts per million) and varying nitrogen rates. Increasing HBR and nitrogen rates resulted in increased chlorophyll concentration, enhanced shoot height, and increased shoot dry weight accumulation. Additionally, aphids were less abundant in seedlings exposed to HBR. Papaya transplants treated with HBR and receiving high nitrogen rates were ready to be transplanted to orchards sooner than transplants grown receiving lower nitrogen rates and without exposure to HBR.