Effects of chemical thinning with Armothin® on fruit set, yield and quality of Japanese plum (Prunus salicina Lindl.) cv. ‘Fortune’

The effects of the application of the chemical thinner Armothin® on fruit set, yield and quality of Japanese plum (Prunus salicina Lindl.) cv. ‘Fortune’ were studied during two seasons in Central Chile (34.56°S, 71.5°W). Trees were sprayed with Armothin® at 0.5%, 1% and 2% concentrations. All thinning treatments reduced the fruit set and fruitlet number (fruitlets/50 cm of branch). Armothin® at 2% conc. was the most aggressive treatment, drastically reducing the fruit set from 85.9% and 82.9% of the control and crop load to unprofitable levels during both seasons. Chemical thinning treatments at the two lowest concentrations (0.5 and 1%) did not significantly alter the crop load compared with the unsprayed control during both study seasons. Thinning costs were reduced (Armothin® 0.5%, 25.0% and 21.5% of the control treatment and Armothin® 1%, 24.6% and 24.1% of the control, during the first and second season, respectively). In general, chemical thinning increased the fruit size and total soluble solids content (TSS). Taking into account the effects on thinning, crop load, fruit quality and thinning costs, Armothin® 1% and Armothin® 0.5% are the most advantageous treatments in the case of this study

Effects of decreasing levels of n amendments on organic "granny smith" apple trees

Artículo de publicación ISIThe effect of decreasing levels of organic N-fertilization on fruit production, mineral composition and fruit quality was evaluated in organically cultivated "Granny Smith" apples trees. Treatments included the application of decreasing levels of N fertilization (100 kg N ha(-1), 75 kg N ha(-1), 50 kg N ha(-1) and 0 kg N ha(-1)) applied as fossilized red guano (50% of the total amount of N) and blood meal (50% of the total amount of N) to twelve years old Granny Smith apple trees. Yield was not affected by the treatments (yield ranged from 0.28 to 0.4 kg cm(-2) SCSA). Fruit mineral concentration and ratios were not affected by treatments. Fruits showed low Ca concentrations (2.8 to 3.3 mg Ca 100 g(-1) FW), high levels of K (118.6 to 130.1 mg K 100 g(-1) FW) and high values for K+Mg/Ca (> 12) and K/Ca (> 30) ratios. Mineral concentration on leaves was not affected by treatments (normal concentrations for macro and microelements). Bitter pit was only detected after 60 days of storage (100 kg N ha(-1) tree, 1.1 in a scale 1-4). Besides orchard nitrogen management, fruit mineral ratios and Ca foliar applications should be considered for managing fruit production and quality in organic apples