Ammonia thiosulfate in Japanese plum tree thinning

Abstract

In order to test the use of ammonia thiosulfate (ATS) in the chemical thinning of the Japanese plum tree, a field experiment was conducted throughout the 2015/2016 and 2016/2017 crop growing seasons at Ponta Grossa, PR, Brazil. The experimental design adopted herein was a randomized block design (RBD). During the 2015/2016 season, the trial was comprised of two accesses and six treatments, such as T1 (control); T2 (ATS 4%); T3 (ATS 5%); T4 (ATS 6%); T5 (ATS 7%) and T6 (manual thinning) with four replications. During the 2016/2017 season, solely one plum tree access was taken into account along with six treatments, such as T1 (control); T2 (ATS 6%); T3 (ATS 7%); T4 (ATS 8%); T5 (ATS 9%) and T6 (manual thinning) and four replications. The evaluations were performed seven days before the application of ATS and 30 days before harvest to establish the percentage of fruit drop. The following response variables were assessed: diameter (D), fresh mass (MF), firmness (N), soluble solids (SS), titratable acidity (AT), ratio, pH and plant production (PP). Experimental data were compared by means of the Tukey test at 5% probability. The concentration of 8 % ATS was efficient in the chemical thinning of the Japanese plum fruits, having a diameter and productivity similar to the manual thinning, evidencing that such a product was amenable to enhance commercial fruit quality.

Characterization of a Florida plum introduction (USA) in Southern Brazil

“…On a commercial scale, the average size of the fruits has a direct influence on the viability of an orchard, impacting productivity and profitability, as it can increase production per plant and the price negotiated for the largest size fruits on the market (HF BRASIL 2016). AYUB et al (2019) determined that the Japanese plum of the accessions G52, G7 and G53 did not exceed the value of 4.8 cm. Fruits of the cultivar Poli Rosa have an average diameter of 4.58 cm (MAnSOURI et al, 2010).…”