Os resultados deste estudo representam o primeiro relatório do efeito do ácido naftalenoacético (NAA) sobre a qualidade da colheita de pré e pós de frutas de cera de maçã. As árvores de cera de maçã foram tratadas com spray de 0; 5; 10 e 20 mg L-1 NAA em condições de campo, durante 2008 a 2011. Os experimentos foram conduzidos em delineamento inteiramente casualizado (DIC), com seis repetições. Folha, teor de clorofila, fluorescência da clorofila, o rendimento fotossintético, a taxa de fotossíntese líquida, o teor da matéria seca dasfolhas e sólidos solúveis totais e K + conteúdo da maçã de cera aumentaram significativamente após os tratamentos com 10 mg L-1. Atividade Poligalacturonase diminuiu significativamente com tratamentos NAA. A aplicação de 5 mg L-1 NAA aumentou em 27% os brotos e reduziu 42% a queda de frutos em comparação com o controle. Além disso, mais proteína e atividade fosfato sintase de folhas, frutificação, crescimento do fruto, maior tamanho do fruto e rendimento foram registrados nas NAAs, nas plantas tratadas. No armazenamento, os frutos tratados apresentaram maior TSS e firmeza, e menos perda de peso, escurecimento, acidez titulável, respiração e produção de etileno em relação ao controle. Conclui-se que a pulverização com 5 e 10 mg L-1 NAA uma vez por semana, em condições de campo, produziu melhor crescimento do fruto a produção da maçã cera e mantendo melhor qualidade dos frutos na conservação pós-colheita.

Results of this study represent the first report of the effect of Naphthalene Acetic Acid (NAA) on the pre and post harvest quality of wax apple fruit. The wax apple trees were spray treated with 0, 5, 10 and 20 mg L-1 NAA under field conditions during 2008 to 2011. The experiments were carried out in Completely Randomized Design (CRD) with six replications. Leaf chlorophyll content, chlorophyll fluorescence, photosynthetic yield, net photosynthetic rate, drymatter content of leaves and total soluble solids and K+content of wax apple fruits were significantly increased after treatments with 10 mg L-1. Polygalacturonase activity significantly decreased with NAA treatments. The application of 5 mg L-1 NAA increased 27% more bud and reduced 42% less fruit drop compared to the control. In addition, higher protein and phosphate synthase activity of leaves, fruit set, fruit growth, larger fruit size and yield were recorded in NAA treated plants. In storage, treated fruits exhibited higher TSS and firmness and less weight loss, browning, titratable acidity, respiration and ethylene production than the control. It is concluded that spraying with 5 and 10 mg L-1 NAA once a week under field conditions produced better fruit growth and yield of the wax apple and maintained better fruit quality in postharvest storage.

This study investigated the effects of gibberellin (GA3) on the fruit development, pigmentation and biochemical properties of wax apple. The wax apple trees were rubbing treated with 0, 20, 50 and 100 mgGA3/l under field conditions. The localized application (rubbing) of 50 mg GA3/l significantly increased the fruit set, fruit length and diameter, color development, weight and yieldcompared to the control. In addition, GA3 treatments significantly reduced the fruit drop. With regard to the fruit quality, 50 mg/l GA3 treatment increased the juice content, K+, TSS, total sugar and sugar acid ratio of wax apple fruits. In addition, higher vitamin C, phenol, flavonoid, anthocyanin, carotene content, PAL and antioxidant activities were recorded in the treated fruits. There was a positive correlation between the peel colour and TSS content and between the PAL activity and anthocyanin formation in the GA3-treated fruit. It was concluded that rubbing with 50 mg/L GA3 at inflorescence developing point of phloem once a week from the tiny inflorescence bud until the flower opening resulted in better yield and quality of wax apple fruits and could be an effective technique to safe the environment from excessive spray.