Y-shaped and fruiting wall peach orchard training system in subtropical Brazil

ASBTRACT Peach as commercial crop in Brazil is usually grown in open vase training system. However, in the 1970s large orchards changed to the Y-shaped system and higher density of plants. This system is the most used in São Paulo state because it allows orchard densification. However, the longevity of the trees is reduced from 15 to 8 years being the excessive exposure of internal branches to solar radiation the main reason for the reduction. Aiming to offer new alternatives of training system for peach, an experiment was carried out to evaluate the fruiting wall in comparison to Y-shaped, using the cultivar Tropic Beauty budded onto cultivar Okinawa. Ten plants by treatment were used as repetition and microclimatic equipment was installed inside the plant to measure temperature and solar radiation. Values of soluble solids (°Brix) were 9.64 to fruiting wall and 9.59 to Y-shaped, not statistically different. However most of fruit physicochemical characteristics were favorable to the fruiting wall system: fruit weight (g) – 97.56 and 90.44; pulp yield (g) – 92.42 and 85.70; pulp firmness (Kg∙cm–2) – 4.27 and 3.50; titratable acidity (g citric ac.∙100 ml–1) – 0.76 and 0.71; and ratio – 12.79 and 13.58, respectively to fruiting wall and Y-shaped. Solar radiation transmission and maximum daily temperature values for the Y-shaped were higher when compared to fruiting wall at harvest. The obtained data show that the fruiting wall training system could be an alternative to Brazilian’s growers for producing superior fruit quality without yield reduction.

摘要 桃子作为巴西商业化栽培作物，通常采用开心形整枝（open vase training system）模式种植。20世纪70年代起，大型桃园逐步转向Y形整枝（Y-shaped system）并提高植株栽植密度。该系统因可实现桃园密植化栽培，成为圣保罗州目前应用最广泛的整枝模式。但该系统会使桃树寿命从15年缩短至8年，内膛枝条过度暴露于太阳辐射是导致寿命缩短的主要原因。为给桃树栽培提供新型整枝方案，本研究以嫁接于冲绳（Okinawa）砧木的热带美人（Tropic Beauty）品种为试材，开展了篱壁形整枝（fruiting wall）与Y形整枝的对比评价试验。试验每组设置10株桃树作为重复，并在植株内部安装微气候设备以监测温度与太阳辐射强度。篱壁形整枝的可溶性固形物含量（°Brix）为9.64，Y形整枝为9.59，二者无统计学显著性差异。但多数果实理化指标均表现为篱壁形整枝更优：果实单果重（g）分别为97.56与90.44；果肉出肉率（g）分别为92.42与85.70；果肉硬度（Kg·cm–2）分别为4.27与3.50；可滴定酸度（以柠檬酸计，g·100 ml–1）分别为0.76与0.71；固酸比分别为12.79与13.58（对应篱壁形整枝与Y形整枝）。采收期时，Y形整枝的太阳辐射透过率与日最高温度均高于篱壁形整枝。本试验结果表明，篱壁形整枝系统可作为巴西桃种植户的备选方案，在不降低产量的前提下生产出品质更优的果品。