Response of a clingstone peach cultivar to regulated deficit irrigation

Abstract

Regulated deficit irrigation (RDI) involves inducing water stress during specific fruit growth phases by irrigating at less than full evapotranspiration. The objectives of this research were to study the effects of RDI perfomed at stage II of fruit growth and postharvest, on productivity of clingstone peaches, fruit quality as well as photosynthetic rate and midday leaf water potential. The research was conducted in a commercial clingstone peach (Prunus persica L. Batch cv. A-37) orchard in Greece. Trees were irrigated by means of microsprinklers and their frequency was determined using local meteorological station data and the FAO 56 Pennman-Monteith method. Photosynthetic rate was measured by a portable infrared gas analyzer. Midday leaf water potential was measured by the pressure chamber technique. During the years 2005 and 2006, the treatment RDII with irrigation applied at growth stage II of the peach tree did not affect productivity, fresh and dry mass of fruits. RDII reduced preharvest fruit drop in comparison to the control. RDII as well as the combined treatment RDII plus RDIP with irrigation applied at postharvest, at both years reduced shoot length of the vigorous shoots inside the canopy. RDII in comparison to the control increased the soluble solids content of the fruits and the ratio soluble solids/acidity. However it did not affect fruit acidity and fruit firmness. RDII as well as RDII plus RDIP in 2006 increased 'double' fruits and fruits with open cavity in comparison to the control and RDIP. Water savings were considerable and associated with the climatic conditions of each year. Key words: fruit drop, leaf water potential, photosynthetic rate, water savings Resposta de um cultivar de pêssego com caroço aderente à irrigação por défice regulado RESUMO: A irrigação por défice regulado (RDI) envolve a indução de défice de água durante fases específicas do crescimento das frutas, irrigando a taxas menores que a evapotranspiração. Os objetivos desse estudo foram verificar os efeitos da RDI no estágio II do crescimento das frutas e no periodo pós-colheita, avaliando a produtividade de pêssegos, a qualidade dos frutos, bem como a taxa fotossintética e o potencial da água na folha. A pesquisa foi desenvolvida em um pomar comercial de pêssegos com caroço aderente (Prunus persica L. Batch cv. A-37) da Grécia. As árvores foram irrigadas por meio de microaspersores e sua frequência foi determinada por meio de dados meteorológicos obtidos em estação automática e o método FAO 56 Pennman-Monteith para determinação de evepotranspiração. A taxa de fotossíntese foi medida por analisador de gás na faixa do infravermelho. O potencial da água na folha foi medido ao meio-dia usando a técnica da câmara de pressão.

Yield and Fruit Quality of Almond, Peach and Plum Under Regulated Deficit Irrigation

“…This reduction in peach yield was anticipated because other studies indicate similar negative RDI effects that are explained by a decrease in nutrient uptake and photosynthetic yield due to stomatal closure and reduction of the number of leaves, resulting from the decrease in shoot growth [16,39] . However, contrasting results have been reported from other studies, indicating that RDI applied to peach during Stage II did not affect fruit yield even under stress levels up to 35% ETC [40,41] . These results have been explained by the low water requirements of peach trees during Stage II to satisfy normal fruit growth without accentuating their fall, thereby maintaining fruit yield.…”

“…Also, the observed reduction in peach weight exceeded its recorded growth rate during RDI application, thereby indicating that the water deficit effect persisted during the final stage of fruit growth (Stage III), despite the trees being fully irrigated during this stage. This may be due to a reduction in vegetative growth in response to RDI during Stage II that continued to affect photosynthate accumulation in the fruit during Stage III [40] . In addition, fruit weight reduction in peach resulted from simultaneous declines in fruit dimensions and pulp and pit weights, likely because there was no significant difference in the pit/fruit ratio.…”

Influence of Irrigation Scheduling Using Thermometry on Peach Tree Water Status and Yield under Different Irrigation Systems

“…Regulated deficit irrigation (RDI) has been applied to peach trees, as an irrigation management strategy, for saving water [2][3][4][5]. RDI during the second stage of fruit development and postharvest stages on late maturing peach trees in deep soils could save 23%-35% of irrigation water [6].…”

Caracterização pós-colheita de frutos de bananeira 'BRS Platina' de primeiro ciclo, sob regulação do déficit de irrigação

“…Cotrim et al (2011), testando níveis controlados de água em mangueira, não constataram perdas significativas de produtividade e qualidade dos frutos. De acordo com Sotiropoulos et al (2010), a utilização de 35% da ETc na fase de crescimento de pêssegos não influenciou a acidez e a firmeza dos mesmos, em comparação ao tratamento-controle (100% da ETc). Perez-Pastor et al (2009), avaliando frutos de damasco (Prunus armeniaca L.) produzidos com déficit hídrico, obtiveram valores mais elevados do teor de sólidos solúveis totais, acidez total em relação àqueles do tratamento-controle, porém a firmeza do fruto não foi influenciada.…”