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In the past, chemical thinning dominated in fruit orchards. This paper for the special issue outlines alternatives to chemical thinning for crop load management (CLM) and its effect on fruit size, firmness, sugar, starch, and weight, indicating ripeness and fruit quality, yield, and alternate bearing. A total of 450 apple trees (Malus domestica Borkh., cv. 'Roter Boskoop'; six years old) on M9 rootstock were used at the Klein-Altendorf experimental station (50° N) of the University of Bonn, Germany. As the first alternatives, trees were mechanically blossom-thinned at the balloon stage (BBCH 59) with a rotor speed of 320 rpm or 380 rpm at 5 km/h tractor speed or were chemically thinned at the full bloom stage (BBCH 65) with ammonium thiosulfate (ATS), ethephon (ETH), and/or 6-benzyladenine (BA) at 10–12 mm fruit size (BBCH 71) after applying ATS/ETH. Flower clusters and/or cluster leaves (source) were manually removed to determine the optimum sink-source ratio to achieve different ratios of fruitlets (sink) relative to the leaves (source) at fruit set (BBCH 67–69). Un-thinned, adjacent trees served as the control. The majority of CLM methods improved fruit size and weight. Removing cluster leaves at fruit set increased fruit size and weight of the remaining fruit, which has not been observed before. The most effective treatment for fruit size and weight and return bloom was the 75% flower cluster and complete cluster leaf removal. Removal of more than 50% of flower clusters successfully improved return bloom, indicative of alternate bearing. The mechanical blossom thinning had a positive effect on fruit size and weight with a return bloom similar to that of removal of 50% flower clusters. [ABSTRACT FROM AUTHOR]

(1) Background: With ca. 10 million tons of annual production worldwide, the plum (Prunus ssp.) ranks as a major fruit crop and can suffer from small fruit size, premature fruit drop and alternate bearing, which are addressed in this paper using a range of crop load management (CLM) tools. (2) Methods: Sixty 10-year-old European plum cv. "Ortenauer" trees on dwarfing St. Julien INRA GF 655/2 rootstock (slender spindle; 4.25 = 2.80 m) in a commercial orchard near Bonn (50°N), Germany, were thinned in 2 years and flower intensity assessed in the following year. Thinning was performed either mechanically (type Bonn/Baum) or chemically, with ATS (ammonium thiosulfate) or ethephon (Flordimex), or by a combination of mechanical and chemical methods, to improve fruit quality and the proportion of Class 1 fruit. Adjacent un-thinned trees served as controls. (3) Results: Natural fruit drop in June was reduced from 290 fruits per tree in the un-thinned controls to 265 fruits after ATS blossom treatment, and to 148 fruits after mechanical thinning at 380 rpm at a 5 km/h tractor speed at full bloom. The un-thinned control trees developed a large number of small, undersized fruits. The yield of Class 1 fruits increased per tree from 47% in the un-thinned controls, up to 69% after crop load management. Sugar content and fruit firmness were unaffected. (4) Conclusions: The study has shown that fruit quality (i.e., fruit size) and financial returns could be improved by either mechanical (380 rpm at 5 km/h) or chemical thinning, or a combination of both. [ABSTRACT FROM AUTHOR]

Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. 'Schneiders späte Knorpelkirsche' trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. 'Schneiders späte Knorpelkirsche' cherries at Bonn exhibited a chilling requirement of 68.6 ± 5.7 chill portions (or 1,375 ± 178 chilling hours or 1,410 ± 238 Utah chill units) and a heat requirement of 3,473 ± 1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package ('chillR') and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. 'Payne') at Davis, California. [ABSTRACT FROM AUTHOR]

Carbon footprint studies of locally produced and consumed wine are missing. The objective of the present study was to identify management strategies and carbon reduction potentials for a sustainable wine production based on the carbon footprint and the water footprint of locally grown grapes and wine locally produced and consumed. Two wineries (A and B) were investigated, both of which grow the same white (Riesling) and the same red grape (Pinot Noir/Spätburgunder) on the same rootstock in the Rhine river valley of Germany. The study was based on PAS 2050-1 (BSI) and comprised 99% primary data derived from historical farm records. System boundaries ranged from planting of the grapevines to eventual disposal of a typical 0.75 L glass bottle, which served as the functional unit (FU). The product carbon footprint (PCF) was 1.91 ± 0.3 kg CO 2 eq/bottle (A) or 1.69 ± 0.3 (B) kg CO 2 eq/bottle of white wine and 1.86 ± 0.3 kg CO 2 eq/bottle of red wine for both wineries. These results were attributed to the consumer behaviour (22–30%), followed by the use and production of glass bottles (20–27%). Grapevine cultivation amounted to 0.3–0.4 kg CO 2 eq/bottle; grape processing caused ca. 0.05–0.06 kg CO 2 eq/bottle, packaging 0.5–0.6 kg CO 2 eq/bottle, distribution 0.2–0.4 kg CO 2 eq/bottle, while use and disposal of the glass bottles emitted 0.5–0.6 kg CO 2 eq/bottle. The plant protection chemicals caused only ca. 1.4% and organic fertilizer ca. 2.8% of the product carbon footprint (PCF). Red and white wine appeared commensurate in their PCF within 3–8% in both vineyards. The water footprint was ca. 5.7 ± 0.6 (A) and 2.1 ± 0.4 (B) L blue water/bottle for both red and white wine. The results are discussed with higher carbon footprint values for wine from overseas. We have identified the following reduction potentials such as the following management strategies: a) reduction of fossil fuels for gas heating of the premises and for farm vehicles, b) the use of lightweight glass bottles and c) alternative means of transport for the consumer purchase at the winery when using a private vehicle. Image 1 • Product carbon footprint ranged from 1.84 to 1.95 kg CO2eq/red or white wine bottle. • Plant protection amounted to 1.5 % (of PCF) and (organic) fertiliser to 3%. • Individual management strategies are suggested for both vineyards and wines – in winery B could save 10% of PCF. • Overall, management strategies include consumer shopping and light-weight glass bottles. [ABSTRACT FROM AUTHOR]

The commonly known alternate bearing, i.e. year-to-year change of large and small yields of fruit tree crops worldwide, is often induced by abiotic stress such as late frost, which will eliminate flowers or fruitlets. This study presents an alternative form, biotic biennial bearing, i.e. change of large and small yields of the same trees within the same tree row in the same year. Three methods were developed or modified for the analysis of the number of flower clusters and yield of 2086 apple (Malus domestica Borkh.) cv. 'Elstar' trees. The first method, i.e., based on intersect between yield in year x and year x+1 and flower clusters in year x, yielded 91-106 flower clusters, whereas the second method, i.e., mean yield in year x and year x+1, resulted in a range of 72-133 flower clusters, or 9.6kg/tree necessary for sustainable cultivation of apple cv. 'Elstar'. The third 'biennial bearing index' (BBI), was calculated in three ways as the ratio of differences in tree yields to cumulative tree yield, for individual trees (rather than orchard average) to demonstrate the tree-to-tree alternation. A scheme for the possible underlying regulatory mechanisms was developed, which includes potential elicitors such as light deprivation and subsequent lack of flower initiation, are discussed as a possible result of polar basipetal GA7 transport, cytokinin level in the xylem and phloem and down-regulation of the gene expression of the flowering gene. Suggested countermeasures included early chemical or mechanical thinning., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)