Articles
Evaluation of timing for spraying Metamitron or NAA plus BA for thinning ‘Brookfield Gala’ apple fruitlets
Article number
1177_33
Pages
229 – 234
Language
English
Abstract
In Chile, apple chemical thinning uses primarily carbaryl, which is expected to be banned in the future.
New thinning chemicals are needed.
During the 2013-14 season, two trials were conducted in a ‘Brookfield Gala’/Pajam 2 orchard.
Metamitron (Goltix CompactMR 90% WG, 450 g ai ha-1) or BA (Exilis®, 180 g ai ha-1) plus NAA (NAA 800®, 18 g ai ha-1) were evaluated at different timings beginning at 4 mm up to 28 mm fruit diameter at 3 to 8 day intervals.
Control treatments included, one without any spray and a sprayed control that included NAA at full bloom, carbaryl (Carbaryl 85 WP, 1368 g ai ha-1) at petal fall and BA (180 g ai ha-1) plus carbaryl (1368 g ai ha-1) at 12 mm fruit.
All sprays were done when no carbohydrate deficit was predicted by Malusim Model (Cornell University). Thinning was evaluated on two branches tree-1, fifty days after full bloom, as fruits per cluster (F/C). All treatments differed from the control (2.3 F/C). Metamitron treatments were more effective when applied between 8 and 16 mm fruit (1.0 F/C). NAA+BA treatments were more effective when applied right after petal fall (4 mm fruit; 1.3 F/C). After removing the effect of crop load, average fruit weight was increased with BA+NAA spray at 4 and 12 mm fruit.
All treatments of metamitron were different from the control.
New thinning chemicals are needed.
During the 2013-14 season, two trials were conducted in a ‘Brookfield Gala’/Pajam 2 orchard.
Metamitron (Goltix CompactMR 90% WG, 450 g ai ha-1) or BA (Exilis®, 180 g ai ha-1) plus NAA (NAA 800®, 18 g ai ha-1) were evaluated at different timings beginning at 4 mm up to 28 mm fruit diameter at 3 to 8 day intervals.
Control treatments included, one without any spray and a sprayed control that included NAA at full bloom, carbaryl (Carbaryl 85 WP, 1368 g ai ha-1) at petal fall and BA (180 g ai ha-1) plus carbaryl (1368 g ai ha-1) at 12 mm fruit.
All sprays were done when no carbohydrate deficit was predicted by Malusim Model (Cornell University). Thinning was evaluated on two branches tree-1, fifty days after full bloom, as fruits per cluster (F/C). All treatments differed from the control (2.3 F/C). Metamitron treatments were more effective when applied between 8 and 16 mm fruit (1.0 F/C). NAA+BA treatments were more effective when applied right after petal fall (4 mm fruit; 1.3 F/C). After removing the effect of crop load, average fruit weight was increased with BA+NAA spray at 4 and 12 mm fruit.
All treatments of metamitron were different from the control.
Publication
Authors
G. Reginato, C. Riquelme, T.L. Robinson
Keywords
chemical thinning, fruit size, crop load
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