Adaptation of the tropical hybrid Euphorbia × lomi Rauh to the exposure to the Mediterranean temperature extremes

Poysean (Euphorbia × lomi Rauh) has been introduced in the Mediterranean countries as an ornamental plant for indoor uses. When used outdoor, few information is available about its ability to withstand the Mediterranean temperature extremes. An experiment in an open stand was performed to evaluate poysean tolerance to the winter and summer temperatures of the thermo Mediterranean climate and its ornamental value for urban greening. Two genotypes of poysean (Nguen Muang, NM; and Soi Budsanin, SB) with similar bracts and flower colours were grown at either 2 or 3 plants per pot during 23 months. Number of flower racemes and leaves per plant and plant height were recorded monthly. Overall ornamental value of each pot was scored by means of a panel test (PT) performed by independent examiners. Score assignment was homogeneous between examiners. On average, NM showed a 36% lower number of flower racemes, but a 30% higher ornamental value than SB. During fall and beginning of the winter, NM showed a higher number of flower racemes per plant than SB. Increasing plant density from 2 to 3 plants per pot did not influence flower racemes and leaves per plant. From March to November of the second year, number of flower racemes in NM was similar to the first year, whereas SB flower production was markedly higher, which can be due to a genotypic difference to Mediterranean temperature tolerance. Correlation between number of flower racemes per pot and ornamental value was higher in SB than NM, which suggest that in NM flower abundance contribute less to the pot ornamental value. The present data suggest that poysean is able to withstand the Mediterranean temperature extremes and still produces flower racemes during winter, which indicate it as a suitable ornamental plant in outdoor applications.     

Improvement of flower color by means of leaf treatments in lily

Flower color, an important feature biologically and commercially, is based on four natural pigments – flavonoids, carotenoids, betalains and chlorophylls. Temperature, light, nutrition – as well as additions of sugar, salt, or metals to the conservation water – have an effect on pigmentation. We investigated the effects of K-sulphate and/or sucrose on flower color in leaf treatments applied 30–10 days before harvest to four Asiatic lily (Lilium × elegans Thunb.) cultivars during the winter and summer. Colors of tepals were evaluated by a portable spectrocolorimeter that calculates the standard CIE L*a*b* coordinates and the color differences (E). After leaf treatments during both seasons, cultivars with flowers with high red components (e.g. the purple ‘Fangio’ and the pink ‘Brindisi’) showed significant improvements in color quality. The orange-flowered ‘Tresor’ showed improvement only if K-sulphate and Mix (K-sulphate and sucrose) solution treatments were applied during the summer. The yellow-flowered ‘Menorca’ was not affected by treatments during either summer or winter forcing season. Especially in the winter, a significant reduction in flower abortion was observed for cut flowers of all cultivars. In summer only ‘Fangio’ and ‘Tresor’ showed a reduction in flower abortion. Also, flower size and longevity were improved by the leaf treatment. The results, obtained from a commercial nursery operation, demonstrate that lily growers can adopt a very simple and inexpensive treatment to improve important qualitative traits of their product.     

控制灌水对梨幼树枝条生长和成花的影响

以3年生梨幼树为试材,研究了4种不同灌水处理对梨幼树枝条生长和花芽形成的影响。结果表明,在冬季一次灌水(250m~3/亩)的基础上,减少土壤供水可有效地控制新梢长度和粗度,缓和树势,增加花芽数量。减少土壤供水可使幼树总生长量轻微下降,主干生长减弱,树冠长梢比例下降,中、短梢比例增加,单位主干横截面积上的花芽数明显增加。生长季节控制灌水,可节约灌水量、扩大灌溉面积、并能促使梨幼树早期结果。     

Promotion of Globularia sarcophylla flowering by Uniconazol,an inhibitor of gibberellin biosynthesis

Globularia sarcophylla, originating from the Canary Islands, was recently introduced as a new cut flower in Israel. Two major problems have prevented its commercialization: the late-summer blooming and the low quality of its flowering shoots. In the present work we studied the factors affecting G. sarcophylla flowering. We found that long-day (LD) conditions slightly promote flowering but artificial photoperiodic illumination does not enable the manipulation of flowering time. On the other hand, treatment with the gibberellin (GA)-biosynthesis inhibitor, Uniconazol, had a dramatic promotive effect on flowering time. Application of Uniconazol in autumn or winter induced flowering in winter or early spring, respectively. The inhibitor did not advance flowering during the summer or in the phytotron under high temperatures. When plants were grown in the spring/summer under heavy shading, they did not flower unless they were treated with Uniconazol. Uniconazol treatment also improved flower quality by reducing the length of inflorescence pedicles. This effect was found in all seasons. Based on our results, we raise the hypothesis that Uniconazol treatment induces flowering by diverting assimilates to the apex. Inhibition of GA biosynthesis under conditions limiting photosynthetic activity reduces vegetative growth and increases the availability of assimilates to the apex, leading to flower initiation. However, under high irradiance and/or high temperatures, when the levels of assimilates are sufficient to induce natural flowering, the inhibitor has no further effect.     

The response of rose plants to evaporative cooling: Flower production and quality

The effect of evaporative cooling in a compartmentalized greenhouse on the flower production and quality of 4 rose cultivars was investigated during 2 cutting-seasons.Evaporative cooling reduced flower formation of all rose cultivars tested, regardless of their location in the greenhouse. This reduction was ascribed to the decrease in growth rate of rose shoots resulting in fewer flowering-flushes than in the uncooled control plants during the same time period.Flower quality, however, was significantly improved under evaporative-cooling conditions. This was apparent in an increase in weight of the entire flower as well as in unit of flower-stem length. Weight of the flowering-bud was less affected, and was increased during the autumn and spring seasons only. Anthocyanin content of flower petals was increased by evaporative cooling, especially during the summer.     

青花菜新品种浙青80的选育

青花菜浙青80是利用萝卜质(ogura)雄性不育系技术选育的杂交品种,适合夏种秋冬收,从移栽至收获80 d左右。株型中等,较直立,株高约70 cm,开展度约70 cm;叶色深绿,侧枝少;花球紧实、颜色绿,遇低温不发紫,花蕾匀细,花球表面不易满天星,球茎不易空心,商品性好,球径15 cm左右,单球质量570 g左右。于2018年通过浙江省农作物品种认定委员会认定。     

Rose flower production as related to plant architecture and carbohydrate content: Effect of harvesting method and plant type

Summary

The dependence between flowering cycles and woody stem parts of a rose crop was studied, with respect to plant architecture and carbohydrate content. Two harvesting methods (“control” versus “flush”) and two plant types (“control” versus “one stemmed”) were compared. Crop growth and partitioning of dry matter were studied as influenced by crop management during 18 months of culture. For a full-productive year, flush harvesting generally promoted bud break as compared with continuous harvesting but at the same time, also due to lower light interception, blind-shoot formation was enhanced and the individual flower weight reduced. Numbers of basal shoots were hardly related to flower production over a full cropping year. Flower production was much more sensitive to the number and diameter of branches at the height of cutting the flowers. The treatments did not affect carbohydrate allocation in the plant. Total carbohydrate storage was much too low to argue a clear role for the possible use of movement of carbohydrate reserves towards new growth. Maximum starch concentration was found at the beginning of summer and gradually dropped to a minimum in December and then increased again to a spring maximum. A cold treatment did increase the total non-structural carbohydrate (TNC) concentration but no positive influence on new basal-shoot formation was observed. No starch gradient was found in basal stem parts.     

Factors Controlling Flowering in Seed-Raised Freesia Plants

The effect of plant age, temperature and day-length on flower initiation and development in “ K. & M. Super ” freesias has been studied.

The flowering response decreased with increasing temperature and the critical temperature for flower initiation was found to be about 21°C. An interaction of plant age, temperature, and duration of treatment was present. Short days (9 hrs.) slightly stimulated flower initiation in“ Yellow K. & M. Super” but delayed it in “ Blue K. & M. Super” freesias. Short-day treatment in the open during the summer had no significant effect, whereas shading markedly hastened flowering.

Flowering could be initiated at an early stage, but older plants were more responsive, especially those of “Blue K. & M. Super”. Optimum temperatures for flower initiation were 12-15°C., applied for 6-9 weeks after the plants had formed about seven visible leaves.

Abnormal inflorescences in freesias, recognized by enlarged bracts and irregular spacing of the florets (so-called “gladiolus-like flowers”), appeared to result from incomplete flower initiation. In extreme cases flower stalks without any flowers were formed. In order to avoid such abnormal flowering it was important that the first floret in the inflorescence should have reached a certain stage (P₂) of development before low-temperature treatment was discontinued.     

茎用芥菜新品种1年2代繁育研究初报

为了探索福建省茎用芥菜1年2代繁育技术,选择6个茎用芥菜品种,分别进行冬春季正常繁育和夏秋季高山加代繁育的2代繁育试验,并对比各品种2代繁育的生育期、株高、株幅和种子产量。结果表明：所有参试茎用芥菜品种只要通过打破种子休眠、衔接好2代繁育的播种期都能完成1周年2代繁育,夏秋季高山加代繁育的全生育期比冬春季正常繁育平均缩短约50 d;冬春季繁育比夏秋季高山加代繁育株高增加31.2%～132.9%,株幅增加1.5%～21.8%,所有参试品种冬春季繁育的种子产量都极显著高于相应夏秋季高山加代繁育,种子产量增加17.8%～153.6%。     

Analysis of the Growth and Yield of Overwintered Onions

The growth of a number of onion cultivars sown on different dates during late summer in several years was assessed by regular sampling. The growth during the winter of five different winter-hardy cultivars was very similar, whereas that of Rijnsburger Bola, a cultivar normally sown in spring, was clearly slower. Sowing date was shown to affect final yield through its effect on overwintering size, which in turn influenced bulb size at harvest, the proportion of plants which bolted and the extent of winter losses. During the winter months the rate of leaf initiation appeared to be decreased to a lesser extent than the growth in dry weight, which itself was decreased less than growth in leaf area. The growth of the winter-hardy cultivars from all sowing dates and seasons was well summarized by a single linear relationship between the logarithm of plant dry weight and the accumulated day-degrees between 6° and 20°C from the day of seedling emergence. Using this relationship together with temperature records from past years it was possible to estimate the best average sowing date and the year-to-year variation in optimum sowing date. This approach may prove useful in predicting optimum sowing dates for other localities from past weather records.     

Stärkeeinlagerung in die Blütenorgane beim Apfel vom Beginn der Blütenknospendifferenzierung bis zur Aufblüte

Starch as an important reserve carbohydrate plays in deciduous fruit species an important role in frost resistance of the wood during winter as well as of flowers during spring frosts. Also during development of flowers the deposition of starch, e.g. in the conducting tissue of the style and in pollen grains is evident. This starch accumulation in the reproductive flower parts seems to be important for fertilization and thus fruit set. The investigations presented should contribute to elucidate the dynamic of starch accumulation in the different organs of a flower bud in apple, from the beginning of bud differentiation until anthesis. The sampled buds were sectioned after embedding in plastic material. Starch accumulation was determined by image analysis. In the four apple cultivars ‘Boskoop’, ‘Elstar’, ‘Golden Delicious’ and ‘Pinova’ starch deposition could be observed already shortly after beginning of flower bud differentiation in July/August in the calyx, corolla, anthers and ovary. Until autumn, starch content increased considerably, it showed during winter some fluctuations according to flower organ, and decreased again towards the flowering season, presumately by conversion to sucrose, as shown in the wood in relation to frost resistance. This decrease seems to be related to the energy demand which is needed for flower development, fertilization and early fruit development.     

光皮类厚皮甜瓜新品种‘翠雪5号’的选育

‘翠雪5号’是以‘145M’为母本、‘86W’为父本杂新而成的中晚熟厚皮甜瓜新品种。该品种植株生长势中等,叶片中大,节间较短。果实发育期43 d左右;果实椭圆形,单果质量1.2 kg左右;果皮为乳白色,光皮;果肉质地松至松脆,果肉白色,肉厚约3.5 cm,果实中心可溶性固形物含量15%以上。田间表现较抗白粉病,对蔓枯病耐性强,对霜霉病抗性弱。适合浙江省及其他适宜地区的春季、越夏和秋季的保护地栽培。2013年12月通过浙江省非主要农作物品种审定委员会审定。     

Effects of water deficit on olive trees cv. Chemlali under field conditions in arid region in Tunisia

Water scarcity in the Mediterranean basin in addition to the extension of irrigated lands is one of the main factors limiting agricultural development. The need for supplementary irrigation of the Chemlali olive cultivar (Olea europaea L.) during summer and autumn periods was investigated. Leaf water content, gas exchange parameters, fruit development and yield in rain-fed and in irrigated plants have been monitored in 12-year-old olive trees grown under environmental conditions in semi arid regions characterized by high temperatures and high light intensity. Trees were subjected to three irrigation treatments, T0, T1 and T2 corresponding respectively to 0, 33 and 66% of crop evapotranspiration (ET_c) by a drip irrigation system. The water deficit during the summer (from June to August) led to the decrease of soil moisture, leaf water content and gas exchange parameters. Irrigated trees showed the same slow activity in the three summer months as the rain-fed trees. For all treatments, net CO₂ assimilation, stomatal conductance and transpiration rates were markedly decreased by environmental conditions (high air temperature and high light intensity) during the summer period. At the partial active growth phase of the Chemlali olive cultivar (September–November), a significant re-increase in all parameters was observed. However, net photosynthesis and stomatal conductance of control plants (T0) were, respectively, 57 and 40% lower than those of plants conducted under milder water contribution (T1). The decrease of physiological activity in irrigated plants during hot and dry (summer time) and cold (winter) seasons was a clear evidence that water supply during such periods will be without a great benefit for photosynthetic activity, and thus growth, if applied under critical conditions inducing the rest phase of the plant. The non-statistically significant slight differences as well in photosynthetic performances activities (Pn, Gs and E rates), as in olive production between the two irrigated treatments will not cover the expenses of water loss when applying irrigation at 66% of ET_c especially in arid region characterized by scant and irregular rainfall. On the light of these results, we can conclude that the irrigation of this species during the vegetative growth phase (in spring and autumn), and stopping it during the olive rest phase (in summer and winter) could be recommended at least under the experimental conditions of this study; and that the contribution of 600 mm of water per year (33% of ET_c) can respond to the needs of the Chemlali olive cultivar in a semi arid region without impairing photosynthetic activity and olive production.     

Leaf production and growth in Begonia × hiemalis under long and short days

Plants of Begonia × hiemalis cultivar ‘Rieger's Schwabenland Red’ were grown in summer and winter under both long and short days, and the rates of leaf appearance and leaf growth were measured at regular intervals. Leaves appearing during short days showed a progressive decrease in size at maturity, but leaves growing actively at the time of transfer from long to short days were almost unaffected by the change in environment. The rate of leaf appearance in long days was similar in winter and summer, but decreased rapidly after transfer to short days. The response to short days was greater in winter than in summer.The implications of these growth responses for the commercial grower are discussed.     

Characteristics of Dormancy of June-Bearing Strawberry(Fragaria Xananassa Duch. cv. Elsanta)

Abstract

The development of Fragaria xananassa Duch. cv. Elsanta was analyzed during summer and fall in order to define the sequence of growth alteration and dormancy with regard to inflorescence initiation. The leaf growth as well as the initiation of the inflorescence buds were followed in the fall by conditions imposed in a climate chamber, with plants then being transfered to conditions favorable for growth. Results pointed to clear changes in leaf growth characteristics over the late summer-early fall (September-October) period while the leaf emergence rate remained constant up to mid-October when it stopped. The first sign of inflorescence initiation started in early October, and the differentiation of the terminal flower reached the stamen initiation stage within 2 weeks. From early November, the terminal flower had initiated the carpel primordia and no further differentiation was detected later on. The plant growth potential, expressed by the size, at full growth, of the leaf or inflorescence axis emerging from the terminal bud, decreased progressively from early September and reached a minimum between October and November. By mid-December, the growth capacity of the plant was restored to a situation similar to that described for early September.     

Increasing Flower Number in Single-Truss Tomatoes

Flower number in the first truss (inflorescence) of glasshouse tomatoes was increased by growing the seedlings at low temperatures shortly after pricking off. The optimal timing for this treatment varied by only a few days over most of the year. The longest chilling duration (14 days) was most effective, possibly because of variability between plants. In summer flower number could be doubled, but in winter only 30% to 40% increases were obtained. Chilling delayed anthesis by up to ten days, the delay being proportional to the duration of chilling.

Day/night temperatures of either 10°/10° C. or 16°/4° C. during chilling had similar effects on flowering, and resulted in similar delays to growth and anthesis.

The mechanism by which chilling may increase flower number and the distinctions between this process and vernalization are discussed.     

Bitter Rot of Apples: II. Seasonal Variations in The Development and Sporulation of Cankers of Gloeosporium SPP. Inoculated into Apple Branches

Two-year-old potted trees of Cox’s Orange Pippin, Laxton’s Superb and Worcester Pearmain were grown in controlled environment chambers at Long Ashton during 1960 and 1961, and subjected to four types of winter temperatures : 1, a long, cold winter ; 2, a severe autumn and mild spring ; 3, a mild autumn and severe spring ; 4, a short, mild winter ; 5, natural winter.

The order of bud break was treatment 2 followed by 4, then I and lastly 3. The time of bud break was more strongly influenced by the date of winter chilling than by its intensity, but the intensity influenced the temperature at which bud break became possible. On I-year-old wood the number of leafy rosettes developing increased with the length of the chilling period.

Because of limitation of space and the consequent small number of trees used, no firm conclusions could be drawn, but flower bud production and rate of spur development from bud break to full bloom appeared to be favoured by a mild autumn. An early and severe autumn apparently increased flower bud abscission at green cluster, but no effect of treatments could be determined in the final yields of fruit.     

西葫芦新品种京葫12号的选育

京葫12号是以02-1-5-3-10-6-5为母本、以03-3-10-9-8-2-16为父本配制而成的中早熟西葫芦一代杂种。植株生长势强,雌花多,成瓜率高。商品瓜圆柱形,瓜长22~24 cm,横径6～7 cm,瓜皮浅绿色覆细网纹,光泽度好,品质佳,商品性好。冬日光温室种植每667 m²产量可达12 000 kg左右,中抗ZYMV、WMV和白粉病,对银叶病的抗性比对照碧玉强。适宜北方冬季日光温室、秋延后大棚,南方秋冬季露地种植,现已在北京、山东、甘肃、广东、广西、四川等地推广种植。     

Florogenesis of the Mediterranean geophyte Narcissus tazetta and temperature requirements for flower initiation and differentiation

Plant florogenesis is determined by the interaction between the genetics of the individual plant and environmental factors. Flower initiation and development of many studied plant species require low temperatures. However, some geophytes form flowers within the bulb during the summer quiescence period and do not require low temperatures for florogenesis. Narcissus tazetta was employed to study, in detail, the stages of flower development during the summer period, with special emphasis on the effect of temperature on inflorescence initiation. The sequence of morphological processes occurring during floral initiation and development was observed by SEM. During 3 years, the bulbs were subjected to different storage temperatures during the summer, and records were taken of the percentage of apical meristems that shifted from vegetative to reproductive development. Flowering and inflorescence quality were recorded after planting. It was concluded that, under natural conditions, the temperature increase in June, during the growth of the mother plant, leads to the transition of the apical meristem to the reproductive stage. Floral initiation and reproductive development in N. tazetta is promoted by high temperatures with an optimum of 25 °C. Sub- and supra-optimal temperatures (20 and 30 °C) delayed differentiation, while lower temperatures (12 °C) inhibited florogenesis completely.     

桂花新品种‘天香台阁’

 ‘天香台阁’桂花品种, 花部器官独特, 花中藏叶, 花中有花, 呈台阁现象; 花冠裂片大而厚, 花径1. 0～2. 5 cm , 最大可达3 cm; 花色随季节呈周期性变化, 呈乳白、淡黄、金黄色; 花香优于四季桂类其他品种; 终年开花, 可明显区别于四季桂品种群的其它已知品种。