International apple & pear research – Aug/Sep 2018
Snippets of the latest apple and pear research from all around the world covering nursery and breeding; production; robotics; pests and diseases; post-harvest; and consumer interest.
Nursery and breeding
Black spot resistant apples
Belarus: Four new apple cultivars resistant to black spot with medium vigour, very precocious and high regular yields have been released and there are further new cultivars currently being assessed. See New results of apple breeding program in Belarus.
Scab resistance trade-off
Slovenia: Eight black spot resistant apple cultivars were compared with ‘Golden Delicious’ and they were found to be more susceptible to spring frost and some extremely prone to powdery mildew. See Characteristics of scab resistant apple cultivars.
Initial productivity in focus
Serbia: Knip nursery trees had a higher yield in the first fruit season to budded trees although subsequent yield and fruit quality was identical. See The influence of planting material type on initial productivity and fruit quality in apple cultivars.
Genetic diversity of Malus
India: Thirty-two Malus species, including 12 wild Himalayan apple cultivars, were evaluated for genetic diversity and potential new useful rootstocks have been identified. See Morphological and biochemical diversity among the Malus species including indigenous Himalayan wild apples.
Production
Temperature holds key
Tibet: Data from four growing regions for Golden Delicious revealed that high quality fruit production is related to cool mean annual temperature. See Quality evaluation of ‘Golden Delicious’ apple from different ecological regions in Tibet and its response to meteorological factors.
Training systems for Conference pears
Spain: Out of five training systems, Axis 2 was identified as the most suitable for early cropping of Conference pears as it had intermediate establishment costs and was productive. See Yield and profitability of ‘conference’ pear in five training systems in North East of Spain.
Increasing polyamines
China: Polyamines increase with branch bending (90-110°) causing an increase in flower bud numbers which can also be stimulated by polyamine sprays rather than bending. See Effect of branch bending angle on contents of endogenous polyamines in shoot terminals of apple tree.
Red blush improved
Australia: A single pre-harvest spray application of l-phenylalanine improves red blush development of Cripps Pink apples. See Pre-harvest spray application of phenylpropanoids influences accumulation of anthocyanin and flavonoids in ‘Cripps Pink’ apple skin.
Shade for fruit thinning
Germany: Shading of Gala apple trees (90 per cent for 77 daylight hours in May) as a form of fruit thinning almost completely eliminated fruit from the trees by harvest. See Effect of non-chemical crop load regulation on apple fruit quality, assessed by the DA-meter.
Shoot growth from axillary buds
China: The application of 6-BA stimulates natural production of cytokinin biosynthesis in apple trees promoting shoot growth from axillary buds. See Identification and expression analysis of the IPT and CKX gene families during axillary bud outgrowth in apple (Malus domestica Borkh.).
Leaf analysis accuracy
Turkey: With appropriate reference data, accurate foliar analysis of apple trees for tree nutritional needs can be carried out from two weeks after full bloom for all elements except iron and copper. See: Interpretation of leaf analysis performed in early vegetation in apple orchards.
Macronutrient absorption
Spain: Calcium is absorbed and accumulated in apples during early fruit development while the other macronutrients are absorbed later in fruit development. See Macronutrient accumulation dynamics in apple fruits.
Chemicals’ effect on efficiency
India: The foliar application of solubor, biozyme and triacontanol to apple trees overcomes the influence of climate change and improves cropping efficiency. See Influence of solubor, biozyme and triacontanol on leaf and fruit nutrient content of apple cv. RED DELICIOUS.
Robotics
Robotic harvester
USA: An experimental robotic apple harvester successfully picked 127 of 150 apples attempted with an average of 6 seconds per fruit. See Design, integration, and field evaluation of a robotic apple harvester.
Finding hidden apples
China: A simple method of detecting apples hidden behind other apples or branches with 93 per cent accuracy has been developed to aid in robotic harvesting of apples. See Location of occluded apples based on gradient Hough transform.
Pests and diseases
Biological control for mildew
Pakistan: The biological control material, Taegro (Bacillus subtilis), provides equivalent protective control of powdery mildew on apple trees as chemical methods and also has some curative action. See Comparative efficacy of bio control agent Bacillus subtilis and fungicides against powdery mildew of apple.
Black spot control
France: The use of acibenzolar-S-methyl, an inducer of plant defences, in combination with a light integrated pest management program effectively controlled black spot in an apple orchard. See When a plant resistance inducer leaves the lab for the field: integrating ASM into routine apple protection practices.
Flower strips for pest predation
France: The incorporation of flower strips into an apple orchard encourages pest predators improving biological control of pests in the orchard. See Impact of agroecological infrastructures on the dynamics of Dysaphis plantaginea (Hemiptera: Aphididae) and its natural enemies in apple orchards in northwestern France.
Soil sampling for pest control
Brazil: Sampling of soil below fallen fruit has identified an Oscheius nematode which is pathogenic to insect pests of apple and may be developed for biological control applications. See Isolation of entomopathogenic nematodes in an apple orchard in Southern Brazil and its virulence to Anastrepha fraterculus (Diptera: Tephritidae) larvae, under laboratory conditions.
Post-harvest
Addressing grey mould
China: Postharvest dipping of apples in Salicylic acid induces synthesis and accumulation of phenolic compounds and defence enzymes which enhance fruit resistance to subsequent grey mould infection. See Induced resistance of postharvest apples to Botrytis cinerea induced by salicylic acid treatment.
Thyme oil activates resistance
Italy: Postharvest dipping of apples in Thyme oil activates pathogen resistance genes which enhance fruit resistance to subsequent grey mould infection. See Thyme and savory essential oil efficacy and induction of resistance against Botrytis cinerea through priming of defense responses in apple.
Wind speeds in storage
Germany: A new device has been developed for measuring wind speed between apples within a bulk bin in a cold room to optimise layout for heat removal from the fruit. See Measuring device for air speed in macroporous media and its application inside apple storage bins.
Measuring phenolic concentrations
Belgium: NIR of fresh apples can be used to measure fruit phenolic concentrations as well as dry matter content. See Use of NIR spectroscopy on fresh apples to determine the phenolic compounds and dry matter content in peel and flesh.
Waxing Bartlett pears
India: Waxing of Bartlett pears reduces weight loss, microbial spoilage, respiration rate and fruit softening during marketing. See Effect of starlight fruit conserve wax emulsion and CFB packaging on storage quality of pear.
Bruise size imaging
China: A new imaging method of determining bruise size on apples using Random Forest models and 675 and 960 nm wavebands improves bruise estimation over current methods. See Pixel based bruise region extraction of apple using Vis-NIR hyperspectral imaging.
Melatonin application
China: Melatonin application to pears inhibits ethylene production resulting in a lower rate of fruit softening. See Melatonin limited ethylene production, softening and reduced physiology disorder in pear (Pyrus communis L.) fruit during senescence.
Treatment for blue mould
Brazil: Potassium phosphite dipping of apple fruit is effective against subsequent blue mould infection while three other treatments were not effective. See Alternative treatments for postharvest control of blue mold in ‘Fuji’ apples.
Consumer interest
Apple’s health benefits
Romania: Apples are a source of polyphenols, vitamins B and C, calcium, potassium phosphorus, and fibre, which reduce the risk of developing tumours, hypertension, diabetes, heart disease and brain aging. see Apples and derivated beverages, benefits for health.
European market insights
Poland: The European market for fresh apples has traditionally been driven by price, but today’s market has become more dynamic and consumers are more fastidious. See Winter prices for summer products on the example of apples in Spain, Poland and Latvia.
Consumer preferences
China: Consumer sensory studies have found a preference for freshly squeezed apple juice with sour-sweet flavour, golden yellow colour, moderate clarity and green apple aroma. See Relatively high acidity is an important breeding objective for fresh juice-specific apple cultivars.
