scholarly journals Productivity of apricot cultivars of medium late and late maturity in the Belgrade area

2017 ◽  
Vol 62 (3) ◽  
pp. 241-249
Author(s):  
Dragan Milatovic ◽  
Dejan Djurovic ◽  
Gordan Zec

Characteristics of productivity and growth (yield per tree, trunk crosssectional area, yield efficiency and fruit weight) were studied in 30 apricot cultivars of medium late and late maturity in the Belgrade area during the six-year period (2009?2014). The cultivar ?Hungarian Best? was used as a control for comparison. The period of study was divided into initial bearing (trees aged three to four years) and full bearing (trees aged five to eight years). Significant differences in yield between cultivars and years were found. An average yield in the period of initial bearing ranged from 0.6 to 6.4 kg per tree, and in the period of full bearing from 4.5 to 18.4 kg per tree. Compared to the control cultivar, significantly higher yield was obtained in 11 cultivars. Adverse weather conditions resulted in a significant reduction in yield in two out of six years of study. Cumulative yield efficiency varied from 0.10 to 0.85 kg/cm2 and in 13 cultivars it was significantly higher compared to the control cultivar. Fruit weight ranged from 26.6 to 81.1 g. Compared to the control, fruit weight was significantly higher in nine cultivars, and significantly lower in ten cultivars. On the basis of high yield and large fruit size, introduced cultivars ?Roxana?, ?Mary de Cenad? and ?Silvercot? as well as domestic cultivars ?Novosadska Rodna?, ?NS-4? and ?NS-6? can be recommended for growing in the Belgrade area.

2019 ◽  
Vol 180 (3) ◽  
pp. 12-18
Author(s):  
K. G. Tkachenko ◽  
G. A. Firsov ◽  
L. F. Yandovka ◽  
A. V. Volchanskaya ◽  
N. E. Staroverov ◽  
...  

Pyrus zangezura Maleev (Rosaceae) is a rare species representing the native vegetation of Armenia (Southern Transcaucasus). It was first described in 1936. P. zangezura has been cultivated at the Peter the Great Botanical Garden of the Komarov Botanical Institute (St. Petersburg, Russia) since 1949, where it has reached the height of 8,0 m. For many years, it was in its vegetative state. The first flowering was observed in 2016 (the plant entered the reproductive state). The first progeny from seed was obtained in April 2019. Fruit size was assessed for P. zangezura plants in the dynamics of their development. The studied plants of P. zangezura in the environments of St. Petersburg have demonstrated a high fruiting potential – on average, 109 flowers per 1 m of a shoot. Observations have shown that not all ovules in the opened flowers of P. zangezura are fertilized and produce fruits and seeds. A significant part of the opened flowers, a few days after the onset of flowering, dry up and fall off. On average, 7 fruits are set on 1 m of the shoot in P. zangezura. The reasons for the low flower setting may be variable: impaired pollination processes and insufficient fertility of pollen, underdevelopment of the flower morphological structures, or lack of pollinating insects due to adverse weather conditions. An X-ray analysis of the seeds from the harvests of 2016, 2017 and 2018 showed that the number of plump and fully developed seeds (grades IV and V) in fruits has been growing year by year. As an ornamental plant, P. zangezura may adorn any botanical garden, but it is also promising for urban landscaping, for example, in St. Petersburg. Even in the vegetative state, its elongated lanceolate glossy leaves make it appreciably different from the common P. communis L., and it is especially ornamental during flowering and fruiting. It is as winter-hardy as the common pear-tree, demonstrates resistance to diseases and pests, and may be of importance for breeding programs aimed at the development of resistant cultivars for the Northwest of Russia.  


2019 ◽  
Vol 180 (2) ◽  
pp. 60-72
Author(s):  
O. A. Tikhonova

Background. High yield is one of the main requirements for modern black currant cultivars. It depends on many factors, but is always linked to self-fertility. Highly selffertile cultivars are of particular importance in areas with unfavorable weather conditions during flowering, because they are able to provide high yields even in single-cultivar plantings. In this regard, it is very important to study selffertility of cultivars in order to identify those with the highest level of this character for use in breeding and large-scale cultivation.Materials and methods. The study of selffertility was carried out at Pushkin and Pavlovsk Laboratories of VIR in 2014–2017. Fifty-seven black currant cultivars of different genetic and ecogeographic origin were the material of the research. The degree of self-fertility was measured by conventional techniques in 3 variants of pollination: 1) natural self-pollination; 2) artificial self-pollination; and 3) free pollination. Statistical data processing was performed using Microsoft Excel and the guidelines by B. A. Dospekhov.Results and conclusions. Highly self-fertile cultivars were identified, which may be recommended for breeders as sources of this trait: ‘Navlya’ (k-42228), ‘Dobrynya’ (k-42121), ‘Golubichka’ (k-32624), ‘Golosievsky velikan’ (k-44176), ‘Valentina’ (k-15631A), ‘Kozatskaya’ (k-44187), ‘Arapka’ (к-44175), ‘Kanakhama’ (k-44197) and ‘Fat’ (k-42509). High yield in the Northwest of Russia can be secured by cultivars that combine high self-fertility with large fruit size: ‘Valentina’ (k-15631A), ‘Vernisazh’ (k-43126), ‘Garmoniya’ (k-40677), ‘Dobrynya’ (k-42121), ‘Desertnaya Ogoltsovoy’(k-45670), ‘Joninai’ (k-43124), ‘Kanakhama’ (k-44197), ‘Karri (k-44172), ‘Mila’ (k-40673), ‘Sevchanka’(k-45551), ‘Sofievskaya’(k-43131), ‘Talisman’ (k-44183), ‘Yubileinaya Kopanya’ (k-44189), ‘Shalunya’(k-41988), and accession 2780-20-33 (k-15575A). It is shown that free pollination and artificial self-pollinationprovide a positive impact on the fruit setting level, fruit weight and seed productivity. Natural autogamy, on the contrary, tends to decrease the weight of berries and the number of seeds in them.


HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 995C-995
Author(s):  
Gabino Reginato ◽  
Terence Robinson ◽  
Victor Garcia de Cortazar

Several field experiments to assess the effect of tree size and crop load on fruit size and yield were conducted in a `Ross' cling peach orchard and in three nectarine orchards of different harvest seasons in Chile. Trees were randomly selected in each orchard and then hand-thinned at the beginning of pit hardening to a wide range of crop loads. The fraction of above-canopy photosynthetically active radiation intercepted by the canopy (PARi) was determined at harvest and all fruits were counted, weighted, and average fruit weight calculated. Cropload and yield were expressed in terms of fraction of PARi. Data on farm gate prices for export fruit of different sizes and export dates were obtained from a Chilean export company. For each orchard, the relationship between cropload and fruit size or cropload and yield efficiency was assessed by regression analysis. Fruit size distribution was calculated from adjusted fruit size assuming a normal fruit size distribution and valued according to shipment date and price. Using crop load as a covariate, fruit size adjusted for cropload was calculated for each nectarine orchard. Differences in adjusted fruit size and yield efficiency were detected among cultivars. Predicted crop value, normalized in terms of PARi intercepted, was calculated for all the cultivars. Large differences in predicted crop value were found for early, mid-season, and late-ripening nectarines. The early and late ripening cultivars showed the highest predicted crop value, especially at lower crop loads and larger fruit sizes. On the other hand, `Ross' cling peach showed its highest crop value at a medium crop load with high yield and relatively small fruit size. (Funded by FONDECYT grant 1930695.)


EDIS ◽  
2013 ◽  
Vol 2013 (7) ◽  
Author(s):  
Mongi Zekri ◽  
Tom Obreza

Citrus fruits remove large amounts of K compared to other nutrients. Potassium moves from leaves to fruit and seeds as they develop. Potassium is necessary for several basic physiological functions such as the formation of sugars and starch, synthesis of proteins, normal cell division and growth, and neutralization of organic acids. Potassium is important in fruit formation and enhances fruit size, flavor, and color. This nutrient also helps to reduce the influence that adverse weather conditions (such as drought, cold, and flooding) have on citrus trees. This 4-page fact sheet was written by Mongi Zekri and Tom Obreza and published by the UF Department of Soil and Water Science, July 2013. http://edis.ifas.ufl.edu/ss583


2021 ◽  
Vol 2 (1) ◽  
pp. 46-62
Author(s):  
Santiago Iglesias-Baniela ◽  
Juan Vinagre-Ríos ◽  
José M. Pérez-Canosa

It is a well-known fact that the 1989 Exxon Valdez disaster caused the escort towing of laden tankers in many coastal areas of the world to become compulsory. In order to implement a new type of escort towing, specially designed to be employed in very adverse weather conditions, considerable changes in the hull form of escort tugs had to be made to improve their stability and performance. Since traditional winch and ropes technologies were only effective in calm waters, tugs had to be fitted with new devices. These improvements allowed the remodeled tugs to counterbalance the strong forces generated by the maneuvers in open waters. The aim of this paper is to perform a comprehensive literature review of the new high-performance automatic dynamic winches. Furthermore, a thorough analysis of the best available technologies regarding towline, essential to properly exploit the new winches, will be carried out. Through this review, the way in which the escort towing industry has faced this technological challenge is shown.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1407
Author(s):  
Courtney A. Weber

Annual plasticulture production of strawberries promises superior weed control, fruit quality and yields. However, strawberry varieties adapted for perennial, matted-row production and local markets in cold climate regions have not been widely tested for adaptation to an annual production cycle. Productivity of seven short-day varieties developed for matted-row and/or annual production was examined in an annual plasticulture system in two consecutive trials in central NY (lat. 42.87° N, long. 76.99° W) harvested in 2013 and 2014. ‘Flavorfest’ demonstrated good performance in Trial 1 with high yield (390 g/plant) and large fruit size (13.9 g mean berry weight). ‘Jewel’ was shown to be well adapted to the annual plasticulture system with consistently high yields (330 and 390 g/plant) that equaled or surpassed other varieties and had moderate fruit size. ‘Chandler’ performed similarly to previous trials conducted in warmer regions with yield (340 g/plant) and fruit size (9.8 g mean berry weight) similar to ‘Jewel’. ‘Clancy’ yielded less but was consistent from year to year. The late season varieties Seneca and Ovation showed marked variability between years, possibly due to drastically different temperatures during flowering and fruit development in Trial 1 compared to Trial 2. High temperatures in Trial 1 likely caused higher early fruit yield, a compressed season and a precipitous decline in fruit size in the later season, thus reducing yield in the late season. Survival after a second dormant period was poor resulting in a small second harvest and reduced fruit size. Overall, the system demonstrated many of the expected benefits but may be more sensitive to weather conditions in the region. While many varieties developed for matted-row production may work well in an annual plasticulture system, not all varieties are equally adapted. Performance of each variety should be determined independently before large scale adoption by growers.


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