Production of high yielding red raspberry long canes in a Northern climate

Techniques for the production of raspberry long canes with high yield potential were studied on a research station and in two commercial nurseries in South Norway. Potted ‘Glen Ample’ plants were grown in the open and in polyethylene greenhouses during two seasons in order to optimize cultural practices. Dates of propagation and transfer to the production sites were varied. Following cold storage from December to early June, the canes were tipped (cut) at 160 cm height and grown in open plastic tunnels in the fruiting season for the evaluation of growth and yield performance. Remarkable berry yields of 1.5–3.8 kg per plant (cane) were regularly achieved. When grown in the open, later starts than June 1 (June 15 and July 1) successively reduced yields. On the other hand, an earlier start involves risks of growth cessation due to low spring temperature. When grown in greenhouses, high yields were still possible when plants were transferred from propagation conditions as late as July 1, although optimal yields of nearly 4 kg per plant were obtained with transfer on June 15. In a year with unusually high summer temperatures, the yields of canes produced in the open and in greenhouses did not vary significantly, whereas in the second year with normal summer temperatures, canes produced in greenhouses consistently out-yielded those produced in the open by about 1 kg per cane. Regression analyses revealed that high yields were associated with fruiting cane architecture traits such as cane height, number and length of laterals, and a low proportion of dormant buds. The single most important component was lateral length which alone accounted for 82% of the yield variation. Since lateral lengths increased from the shoot tip towards the base, cane heights in excess of 2 m are required for the attainment of top yields as the uppermost nodes with short and low-yielding laterals then can be eliminated by tipping.     

单株留芽量及结果母枝剪留长度对猕猴桃结果性能的影响

对栽植株行距3m×4m的美味猕猴桃秦美品种连续进行了3年试验,单株分别剪留250、300、350、400个芽处理后,平均单株新梢数、叶面积指数、落叶率与留芽数量呈正相关,叶幕下层的光强度、净光合率与留芽数量呈负相关;单株果枝数、果实数及单位面积产量均以留400芽处理最高,但平均单果重最小,88g以上的优质果产量最低。综合评价以单株剪留350个有效芽的效果最佳,优级果产量达到2102.7kg/666.7m2。结果母枝分别剪留7、12、17个有效芽处理后,平均每母枝的结果枝数、果实数、产量与留芽数量呈正相关,均以17芽处理最高,分别达到9.5个、30.4个和3.09kg,各处理间的单果重差异不显著。     

巨峰葡萄主梢和副梢坐果与内源激素的关系

巨峰葡萄副梢坐果率、有种子果粒率、果粒的平均种子数明显高于主梢。在小花发育过程中主梢的小花重、小花纵径、横径明显重于或大于副梢。主梢花的子房壁明显厚于副梢，子房壁的细胞层数也多于副梢，但子房壁的细胞大小两者之间没有差异。另外胚珠、珠心大小也没有差异。主梢小花中的IAA与细胞分裂素水平较高，ABA水平较低，副梢小花中的GA水平较高。开花前2～3周用高浓度的NAA与CPPU处理副梢小花则加重落花落果。由此可见，开花前小花中较高水平的IAA与细胞分裂素很可能是加快小花发育和引起落花落果的原因。     

Stockplant factors affecting root initiation in cuttings of Triplochiton scleroxylon K. Schum., an indigenous hardwood of west africa

The ability of auxin-treated T. scleroxylon cuttings to root was affected by the prior management of potted stockplants. In undecapitated single-stem stockplants more cuttings from upper rather than lower mainstem nodes rooted; a difference paralleled by leaf water potential immediately after severance, although there was also a positive relationship with internode length. The rooting percentage of mainstem cuttings from unpruned stockplants ranged from 15% to 43% whereas that of cuttings from the lateral shoots of pruned stockplants ranged from 40% to 83%. Considerably more cuttings rooted from stockplants which were severely pruned than from those where decapitation removed only the top node; there seemed to be an inverse relationship with the number of shoots per plant and the carbohydrate: nitrogen ratio. However, in tall pruned stock- plants, more cuttings from lower lateral (basal) than from upper (apical) shoots rooted, although the differences between cuttings from basal and apical lateral shoots were less when the stockplants’ mainstems were orientated at 45° or kept horizontal, instead of vertically. Adding NPK 16 weeks before harvesting cuttings from 10-node vertical stockplants increased the rooting ability of cuttings from basal shoots without affecting the rooting of those from apical shoots. More lateral shoot cuttings rooted when two, instead of one or four lateral shoots were allowed to develop per stockplant, this being associated with less cutting mortality than occurred in pruned stockplants. In stock- plants with two shoots, cuttings from basal lateral shoots rooted better than those from apical shoots, although without competition from basal shoots. The rooting of apical shoots was enhanced by application of a complete fertilizer. The presence of basal shoots reduced the rooting ability of apical shoots even with the fertilizer application. Many of the effects of lateral branch position on rooting may be related to light intensity, for greater rooting percentages occurred among cuttings from lower, more shaded, than from upper less shaded branches. This positional effect was eliminated when branches were uniformly illuminated.     

Fruiting position,mineral concentration and incidence of physiological pitting in ‘Hayward’ kiwifruit

Summary

‘Hayward’ kiwifruit (Actinidia deliciosa (A. Chev) C. F. Liang et A. R. Ferguson) were sampled to identify populations of fruit with differing fruit mineral concentrations and levels of the storage-related disorder physiological pitting. Fruit were taken from different shoot types at different locations within vines. Fruit from short shoots near the tips of canes, in an area of the vine with low leaf:fruit ratios, had low fruit calcium concentrations and more pitting. In contrast, fruit from long shoots and with high leaf:fruit ratios near the base of canes, had high concentrations of calcium and less pitting. At the more distal positions along canes in an area of the vine with low leaf:fruit ratios, increasing leaf:fruit ratios on individual fruiting shoots led to higher inflow of calcium to the fruit. No such relationship was found when fruit were sampled from shoots near the base of canes, an area of the vine with relatively high leaf:fruit ratios. Inconsistent relationships were found between fruit soluble solids concentrations and calcium, probably due to different mobility of calcium and carbohydrates within the vines. Fruiting position and the associated leaf area are a source of variability in mineral concentrations of fruit, and by consequence, in the incidence of physiological pitting in ‘Hayward’ kiwifruit, and should be considered when developing sampling techniques.     

Cane and bud number effect on yield components of non-irrigated grapes cv. ‘Yaghooti’

An experiment was conducted with non-irrigated vines (Vitis vinifera), in which the number of buds per cane and the number of canes per vine were varied. With increasing canes per plant the percentage bud-burst decreased. Cluster number and total yield increased with increasing the number of buds per vine. Cluster weight and sugar content decreased when vines were overloaded. Yield was positively correlated with cluster number and negatively correlated with sugar content. The position of the pruning-cut affected the percentage bud-burst only near the cut.     

Cane Morphology and Anatomy Influence Freezing Tolerance in Vitis vinifera Cabernet franc

In 2014 and 2015, Ohio vineyards were exposed to multiple freeze events of –20 °C or lower, resulting in vine dieback, i.e., complete damage of above ground parts in Vitis vinifera. Grapevines that sustained dieback were rehabilitated for trunk replacement by training 1-year-old shoots with two distinct morphologies, based on internode diameter of large (L) and normal (N). This study evaluated the impact of cane morphology (L and N) in V. vinifera Cabernet franc on freezing tolerance (FT) of bud, phloem, and xylem tissues in relation to their respective anatomical structures and carbohydrate concentrations. Compared to N canes (7–9-mm diameter), L canes (10–15 mm) in Cabernet franc were considered vigorous and had the following morphological characteristics: long and heavy, with long and wide internode, and presence of numerous laterals. Furthermore, cane anatomy was also different with L canes having a significantly higher number of vascular transport units, xylem vessels, and phloem fibers than those in N canes. Freezing tolerance of buds and phloem was also different between the two cane types, with L canes being more cold sensitive than N canes, especially during fall acclimation and late-winter deacclimation. Sugar concentrations, however, were not different between L and N canes. These results suggest that cane morphology and anatomy play a significant role in affecting FT and the large and abundant anatomical structures of phloem and xylem contributed to the reduced FT of these tissues. In all practicality, this study suggests the best cultural practice for trunk replacement, and vine recovery should include the removal of the undesirable vigorous and cold sensitive canes during pruning.     

Phenology of strawberry guava (Psidium cattleianum) in ReÂunion Island

Summary

The phenology of wild stands of strawberry guava (Psidium cattleianum Sabine) was studied at 100, 480 and 720.m over 2 years in ReÂunion Island. The shoots bore flower buds at the basal nodes, and vegetative buds at the apical nodes. Trees produced vegetative growth from September to December, flowers from November to January and fruit from February to June. Shoot growth was earlier at 100 and 720.m the first year, but were synchronized in the second year. Flowering and fruiting were also earlier at 100.m. The intervals between shoot emergence and flowering, and flowering and fruit maturity were strongly related to temperature, with base temperatures of 5.58C and 2.68C, and heat units requirements of 675 and 2,5528C.d, respectively. The number of shoots, flowers and fruit per branch varied across sites and years, unrelated to temperature. However, production was significantly higher at 720.m. Production was much lower after a hurricane. Flowering (y) was related to shoot production per branch (x) (log(y)=111.33.log(x); r².=.0.78), whereas the fruit set rate was highly variable between trees (26±100%). The number of fruits per branch (1±6) was possibly related to poor shoot growth or fruit set, but unrelated to the timing of the phenological events. It is expected that commercial orchards would be more productive than feral stands.     

Flower production in Gerbera: I. Correlations between shoot,leaf and flower formation in seedlings

Flower production of seedling plants of Gerbera was shown to be positively correlated with the number of lateral shoots and with the number of leaves per flower. The most productive plants were those which formed 2–5 lateral shoots during the first year and had a $\text{leaf}\text{flower}$ ratio of 2–4. The number of lateral shoots at the moment the first flower bud became visible was strongly correlated with the number of lateral shoots after 1 year.There was a positive correlation between the number of lateral shoots and total number of leaves, but hardly at all between total leaf number and flower production, as the $\text{leaf}\text{flower}$ ratio increased with the number of lateral shoots.     

留果节位对哈密瓜果实品质及产量的影响

为了探讨不同留果节位对哈密瓜果实生育期、产量及品质的影响,以华蜜0526、华蜜1001、雪里红这3个品种为试验材料,分别在低节位(8~10节)和高节位(13~15节)留果,采取吊蔓栽培,单蔓单果整枝方式进行试验。结果表明:不同留果节位对试验品种采收期有一定的影响,留果节位高成熟晚,高节位比低节位延迟4~5 d;3个试验品种高节位果实的果肉厚度、中心糖度均高于低节位,且单果质量和产量也均显著高于低节位哈密瓜;所以,实际生产中选择留果节位时,可以根据不同品种成熟采收时间以及产量高低来综合考量,还可以根据需求合理分配,错峰上市。