Flower emasculation accelerates ovule degeneration and reduces fruit set in sweet cherry

Flower emasculation is commonly used to make flowers unattractive to pollinating insects and to carry out controlled pollinations. In sweet cherry, we have observed recurrent low fruit set after flower emasculation and compatible pollination without apparent causes. This led us to evaluate its effect on the progress of the reproductive phase and on fruit set in this species. Flower emasculation reduced by more than a half the fruit set obtained in crosses made during two consecutive years. This effect could be traced back to the first week after anthesis where weight increase of pistils from emasculated flowers was smaller and ovule degeneration was accelerated compared to pistils from non-emasculated flowers. Pollen tubes, which behaved similarly at the stigma-style level in emasculated and non-emasculated flowers, lost their directionality in the area close to the degenerated ovule in the ovary. While flower emasculation is valid to evaluate pollen tube performance in the style and to determine incompatibility relationships, the lower fruit set registered after emasculation alerts on its use in fruit set experiments and breeding programs.     

Differential effect of cultivar and harvest date on nectarine colour,quality and consumer acceptance

The influence of nectarine cultivar and the harvest date on fruit colour, fruit size, fruit quality parameters, and consumer acceptance were assessed. The analyses were carried on cultivars with different fruit taste (acidity and sweetness), from 5-years-old trees at the IRTA-Experimental Station of Lleida (Spain). The six cultivars were grouped in three pairs in which each had a similar commercial harvest date. Each pair comprised by a non-acid cultivar and an acid cultivar, except the pair of ‘Big Top^®’ and ‘Mesembrine^®’, which included two non-acid cultivars. The nectarines were harvested at 8 days intervals on five harvest dates, three of which were before the commercial harvest date, one at commercial harvest and another 1 week after commercial harvest.     

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.     

Investigation of the fertilization biology of some sweet cherry cultivars grown in the Central Northern Anatolian Region of Turkey

The experiments were carried out between 2003 and 2005 in the Province of Amasya. The first objective of the study was to determine the best pollinizer for the cultivar ‘0900 Ziraat’ which is the most popular sweet cherry cultivar (Prunus avium L.) in Turkey. The ‘0900 Ziraat’ was used as a female parent and ‘Türko?lu’, ‘Köro?lu’, ‘Kargayüre?i’, ‘Hac? Ali’, ‘Starks Gold’ and ‘Geçkiraz’ were used as pollinizer cultivars. In 2003, for the hand cross pollination combinations, fruit set was between 31.25% and 42.80%. In 2004, fruit set was reduced by spring frost and was between 9.69% and 15.24%. Additionally, the blooming periods of the experimental cultivars, fruit set of open pollination and hand self pollination were examined. The fruit set ratios of all tested cultivars under open pollination conditions varied between 26.73% and 53.49% in 2003 and 4.38% and 38.35% in 2004. ‘Geçkiraz’ had the highest fruit set owing to its late flowering date. For open pollination, fruit set values of ‘0900 Ziraat’ were lower than hand cross pollination with other cultivars in 2003 when the results of both treatments are compared. On the contrary, fruit set was higher than hand cross pollination in 2004. In the present study, pollen germination values varied greatly among year, cultivar and sucrose concentration. Viability percentages were generally high, not less than 66%. According to phenological observations, partial or complete overlapping of the flowering period of ‘0900 Ziraat’ and its possible pollinizer cultivars were observed in 2003 and 2005. But in 2004, the flowering period overlapped for only ‘0900 Ziraat’ and ‘Geçkiraz’ cultivars. When blooming times are taken into consideration, ‘Geçkiraz’ was found to be the best pollinizer cultivar.     

Physico-chemical changes during growth of persimmon fruits in the East Mediterranean climate region

Physico-chemical changes were monitored during growth of pollination variant non-astringent ‘Harbiye’ persimmon fruits (Diospyros kaki L.) grown at low or high altitude of the East Mediterranean Region of Turkey for two growing seasons (2001–2002 and 2002–2003). Fruit growth in diameter followed a typical double sigmoid curve, consisting of two rapid growth stages, stage I and stage III, separated by a period of slow growth (stage II) at both altitudes. The durations of stages I, II and III were 105–119, 21–35 and 21–42 days, respectively, at low and high altitude. ‘Harbiye’ persimmons showed significant decreases in soluble tannin concentration and total carotenoid content during stage I. At the end of stage I, ‘Harbiye’ persimmons became non-astringent. Stage II was characterized with slow growth, the beginning of acid degradation and a significant increase in total sugars, especially in the sucrose component. At end of stage II, the fruit began to turn yellow-orange, indicating the occurrence of colour break. The greatest increase in total soluble solids (TSS) content occurred in the final month before harvest during stage III when pronounced changes in skin colour and softening of fruits were observed. The 175 and 168 days after full bloom (DAFB) at low and high altitudes, respectively, are appropriate timing for harvest of the ‘Harbiye’ persimmon fruits in the East Mediterranean region. At these stages, ‘Harbiye’ persimmon fruits reached the best quality for consumers.     

Evaluation of rootstocks for the Cyprus local lemon variety ‘Lapithkiotiki’

The effect of various rootstocks on yield, yield efficiency, tree size and fruit quality of the local lemon variety ‘Lapithkiotiki’ (Citrus limon (L.) Burm. F.) was studied under Cyprus conditions. Total cumulative yield over 13 years of production was the highest on rough lemon (C. jambhiri Lush) followed by that on Volkameriana (C. volkameriana Ten. & Pasq.), Yuma Ponderosa lemon (C. limon (L.) Burm. F.), sour orange (C. aurantium L.), Citrus macrophylla Wester, Morton citrange (C. sinensis cv. Washington navel × Poncirus trifoliata (L.) Raf.), Yuma citrange, Rangpur lime (C. limonia Obs.), Palestine sweet lime (C. limettioides Tan.), C-32 citrange and Citremon 1449 (C. limon × P. trifoliata), although no statistically significant differences were found between sour orange, the commercial rootstock used in Cyprus, and the other above mentioned rootstocks. Next in order as regards to total cumulative yield was Cleopatra mandarin (C. reticulata Blanko.) followed by Carrizo citrange, with statistically significant differences compared with sour orange. Trees on Citrumelo CPB-4475 (C. paradisi Macf. × P. trifoliata) and C-35 citrange died 3–4 years after grafting. Canopy volume was the lowest for trees on Cleopatra mandarin and Carrizo citrange. Yield efficiency A, expressed as total cumulative yield per trunk cross-sectional area, was the highest on C. macrophylla and lowest on Carrizo citrange. Rootstock significantly affected fruit size and weight, rind thickness, juice content, brix, total acids and brix:acid ratio. The results of the present study reveal that the most promising rootstocks that may replace sour orange for the local lemon variety ‘Lapithkiotiki’ under Cyprus conditions are Volkameriana, Yuma Ponderosa lemon, C. macrophylla and Citremon 1449.     

不同果袋对新西兰红梨品质的影响

选择5种不同类型的果袋对新西兰红梨果实进行套袋处理,研究了套袋对果实品质的影响.结果表明:套袋改善新西兰红梨果实外观品质,单果质量增加,果面光亮、洁净、着色好、果点变小且不明显;但套袋也会使新西兰红梨果实的可滳定酸有所降低,不同类型果袋使果实硬度、可溶性固形物含量、可溶性总糖含量、Vc含量降低或提高.在5种果袋类型中,编号为D-2和D-4果袋处理的果实综合品质最佳.     

套袋栽培对红富士苹果果实品质的影响

以采自甘肃省3个苹果产区的长富2号果实为材料,通过对采收期的果实品质及果实内含物含量的测定与比较,以及贮藏期品质的测定与观察,研究了套袋栽培对红富士苹果果实品质的影响.结果表明:套袋可导致红富士苹果果实的单果重、果肉硬度、可溶性固形物含量等品质指标的测定值下降;套袋后,果实水分含量略有增加,而有机酸、可溶性总糖有所损失,糖酸比略有下降,维生素C、全钙及硼的损失比较严重.套袋与否不影响果实贮藏期品质变化的基本趋势,但套袋果在贮藏期间更易失水,口感与风味都不及对照;因此认为套袋栽培不利红富士苹果果实的品质发育和采后贮藏.     

贮藏温度对藤牧1号苹果果实保鲜效果影响研究

以藤牧1号苹果果实为试材,研究了贮藏温度对果实酶活性及理化性状的影响。结果表明:20℃和5℃温度条件下果实纤维素酶、PG、LOX、淀粉酶活性变化均表现前期逐渐增加,出现峰值后逐渐下降的变化趋势。20℃条件贮藏的果实不但纤维素酶、PG、LOX、淀粉酶活性始终高于5℃条件的果实,酶活性峰值出现时间也较早。果实贮藏期间,果肉原果胶含量逐渐降低,可溶性果胶含量逐渐增加,纤维素含量逐渐下降。20℃条件贮藏的果实的纤维素和果胶物质的含量变化率均高于5℃条件贮藏的果实。随着果实中纤维素和果胶物质的变化,果实逐渐软化,果肉硬度降低,失重率增加,品质下降。