Apple and Pear Cultivars for Organic Production in a Cool Climate

Only early ripening cultivars of apples and pears may be grown successfully in the short and rather cool growth season of the fruit producing areas of Norway. Due to a combination of high yield, good fruit quality and scab resistance, the Swedish cultivar ‘Aroma’ is recommended as major cultivar for organic apple production today. ’Philip’ is recommended as cultivar for organic pear production. During 5 years 21 apple cultivars and 15 pear cultivars have been tested in organic orchards in comparison with ‘Aroma’ and ‘Philip’. Several cultivars in the trial are promising for use in organic production

Comparison of Short-grain Rice Cultivars Grown in Japan and the United States

Although short-grain rice accounts for less than 2% of U.S. rice production, the demand for short-grain rice is expected to increase because of the increasing popularity of sushi and sake. The objective of this study was to compare the physical, chemical and textural properties of short-grain rice cultivars grown in Japan and in the U.S. Seven short-grain rice cultivars from the 2016 crop year were collected, including five cultivars (Hatsushimo, Kinuhikari, Koshihikari, Nanatsuboshi, and Yumepirika) grown and purchased in grocery stores in Japan, one (RU9601099) grown in Arkansas, and one (CH-202) grown in California. The rice cultivars were characterized for kernel dimensions, color, chemical composition, amylopectin fine structure, and gelatinization, pasting and textural properties. RU9601099 had a smaller kernel width and a greater whiteness (L*) value than the other cultivars. Japanese cultivars were comparable in protein content, while RU9601099 had the greatest and CH-202 had the lowest protein content. RU9601099, CH-202 and Kinuhikari shared a similar value of average amylopectin chain length and gelatinization temperatures and enthalpy, which were significantly greater than the other cultivars. Kinuhikari and RU9601099 displayed greater peak and trough viscosities, whereas Hatsushimo and Nanatsuboshi had lower peak and breakdown viscosities. When cooked, the Japanese cultivars exhibited significantly greater hardness than the U.S. cultivars. Based on Ward’s cluster analysis considering all data, CH-202 shared similar properties with Kinuhikari, and RU9601099 was distinctively different from the other cultivars in most properties. The information obtained from this study will help future cultivar development and marketing of existing short-grain rice cultivars in the U.S

Oriental lily hybrids engineered to resist aphid attack

Establishing in vitro bulb scale cultures of lily cultivars followed by callusing and regeneration after gene transfer was found to be not very successful in our hands, except for ‘Snow Queen’. Identifying a more generally applicable system to generate callus with the ability to regenerate and amenable to Agrobacterium-mediated gene transfer was the goal of the research described here. Callus was induced on style and filament explants of 26 cultivars of lily. The cultivars were chosen from the hybrid groups longiflorum, asiatics and orientals of the genus Lilium but also interspecific hybrids were represented. Most cultivars were diploids but some were of triploid level and one was tetraploid. In general once callus was induced, it could relatively easily be maintained and propagated for further use. Regeneration was observed on both callus types from all cultivars tested with an efficiency ranging from 40 to 100%. Gene transfer as demonstrated by positive reporter gene uidA activity was found in all cultivars tested. Transgenic plants could be obtained in the first series of transformations and the applicability of a marker-free system was proven in lily. The protocol can now be used for the introduction of genes aiming at conferring resistance to aphids

Suitability of peach and nectarine cultivars for organic production under pannonic climate conditions in Austria

The suitability of nectarine and peach cultivars for organic production was examined in a field experiment in the experimental orchard of the institute in Vienna. Therefore, fifteen cultivars including Redhaven as standard cultivar were planted in 2003 and cultivated organically. Characteristics of the cultivars, such as blossom, growth, yield and susceptibility to frost damage and diseases (Taphrina deformans and Monilinia ssp.) were examined. Furthermore, fruit quality characteristics were checked in the laboratory. The results of growth, yield, susceptibility to damages and diseases and fruit quality showed significant differences among the cultivars. ‘Redhaven’, ‘Sweethaven’, ‘Redcal’, ‘Benedikte’ and ‘Mireille’ can be recommended for organic production regarding the results of susceptibility of peach diseases. ‘Red Robin’, ‘Royal Glory’ and “Nectared 6’ can partly be recommended. ‘Weingartenpfirsich Eibesthal’, ‘Sunglo’, ‘Diamond Princess’, Early Devil’ and ‘Royal Gem’ seem to be unsuitable for commercial organic production

Assessment of the susceptibility to pests and diseases of 36 apple cultivars in four low-input organic orchards in France

One of the keystones of the organic orchard is the cultivar choice as one element of pest and disease control. However, few exhaustive data sets concerning the cultivar susceptibility to pests and diseases are available for growers. In order to identify cultivars adapted to organic production methods, the susceptibility to scab, aphids and powdery mildew and the agronomic properties of 36 cultivars were assessed in four French sites under different pedo-climatic conditions. Different levels of susceptibility to scab were observed for 23 scab Vf-resistant and 13 other cultivars. In the North of France where Vf resistance is overcome, the Vf cultivars displayed different levels of scab severity. A high variability in the susceptibility to aphids was observed whereas susceptibility to powdery mildew varied less. The analysis of susceptibility properties, yield and fruit quality, fruit storability and tree behaviour permitted to identify a set of interesting cultivars according to the site

Sensory quality of scab-resistant apple cultivars

Twenty-two scab-resistant apple cultivars were harvested in autumn 1999 and evaluated for sensory quality the following October, November and December. Multivariate analysis was effective in describing the comblex relationships and variabillity among the numerous attributes used to characterise apple quality. Crispness, mealiness, skin toughness, apple flavour, sweetness, unripe flavour and overripe flavour were informative attributes describing the variation in the sensory quality. Texture attributes, apple flavour and overripe flavour were affected by storage. Extended storage resulted in an increase in mealiness and overripe flavour and a decrease in crispness, juiciness and apple flavour. Many potential scab-resistant cultivars were suitable for consumption in October: 'Dayton', 'Primicia', 'Retina' and 'Realka'; in November: 'Merlijn', 'Saturn', 'Initial', 'Realka', 'Rajka' and 'Rubinola'; and in December: 'Otava', 'Ecolette', 'Rejka', 'Rubinola', 'Delorina', 'Initial' and 'Resista' and 'Topaz'. This study gives a sensory sharacterisation of scab-resistant cultivars as an indicator of suitability for commercial growing and marketing of low-input apple cultivars

Leaf stripe resistance of spring barley cultivars

Results of six years of screening trials clearly indicate that effective resistance against barley leaf stripe is available, also in modern cultivars. Among the spring barley cultivars that are currently most widely grown in Denmark, Cabaret, Troon, Sebastian, Justina and Brazil appear most resistant, but only Brazil combines a favourable resistance performance (= low mean and standard deviation of environment-adjusted leaf stripe incidence) with a high number of observations (= years of testing). However, the cultivars appearing most resistant over the years are relatively old ones such as Vada, Alabama, Odin and particularly Scarlett, which has been resistant in all years in which it was tested. Amongst the new cultivars, Marigold, Native and SW Immer appear to have the most promising resistance properties so far. However, they have only been tested in two years of which only one had reasonably high infection levels. The results furthermore indicate huge year-to-year variation in infection levels, presumably due to variation in environmental conditions related to leaf stripe infection

Effect of Cultivar on Chlorophyll Meter and Canopy Reflectance Measurements in Cucumber

Optical sensors can be used to assess crop N status to assist with N fertilizer management. Differences between cultivars may affect optical sensor measurement. Cultivar effects on measurements made with the SPAD-502 (Soil Plant Analysis Development) meter and the MC-100 (Chlorophyll Concentration Meter), and of several vegetation indices measured with the Crop Circle ACS470 canopy reflectance sensor, were assessed. A cucumber (Cucumis sativus L.) crop was grown in a greenhouse, with three cultivars. Each cultivar received three N treatments, of increasing N concentration, being deficient (N1), sufficient (N2) and excessive (N3). There were significant differences between cultivars in the measurements made with both chlorophyll meters, particularly when N supply was sufficient and excessive (N2 and N3 treatments, respectively). There were no consistent differences between cultivars in vegetation indices. Optical sensor measurements were strongly linearly related to leaf N content in each of the three cultivars. The lack of a consistent effect of cultivar on the relationship with leaf N content suggests that a unique equation to estimate leaf N content from vegetation indices can be applied to all three cultivars. Results of chlorophyll meter measurements suggest that care should be taken when using sufficiency values, determined for a particular cultiva