New apple thining agents and their combination evaluated on cultivar Gala

• Published in: Sodobno kmetijstvo (Slovenia) Vol. 34; no. 4
• Main Authors: Stopar, M. (Agricultural Inst. of Slovenia, Ljubljana (Slovenia)), Zadravec, P. (Sadjarski center Gacnik, Pesnica pri Mariboru (Slovenia))
• Format: Magazine Article
• Language: Slovenian
• Published: 2001
• Subjects: APPLES; CALIDAD; DEFRUITING; FRUITS; FRUTAS; MALUS PUMILA; MANZANA; POMME; QUALITE; QUALITY; SUPPRESSION DE FRUITS; SUPRESION DE FRUTOS
• ISSN: 0350-1655

Three years old apple trees 'Gala'/M9 were thinned with new thinning compounds and their combinations. ATS 0.5%, ATS 1%, BA 50 ppm, BA 100 ppm or ethephon 150 ppm did not thin experimental trees which showed a light fruit set and so the control did not differ from sprayed trees in view of harvest fruit load and fruit quality. NAA 10 ppm applied alone thinned weakly and not too much. The combination spraying of ATS 0.5% and later with BA 50 ppm, or ethephon 150 ppm and later with BA 50 ppm did not thin too much either. In the case of ATS 0.5% application combined with NAA 10 ppm later spraying, or ethephon 150 ppm in combination with NAA 10 ppm after that, a too strong thinning was observed, so the total yield and the yield of bigger fruits was diminished too. A similar too strong 'Gala' fruitlets abscission happened when NAA 10 ppm and BA 50 ppm were sprayed as tank mix. Ethephon 150 ppm applied alone or in combination with BA 50 ppm inhibited the fruit growth to the extent, that the average fruit weight at harvest was lower when yield remained unchanged.