scholarly journals Study of Density of Raspberry Fruits in View of Mechanized Harvesting

2021 ◽  
Vol 247 ◽  
pp. 01045
Author(s):  
Natalia Bogomolova ◽  
Svetlana Rezvyakova ◽  
Maxim Lupin

The paper discusses the possibility of combining large-fruits and density of raspberries as one of the main and decisive limiting indicators of the suitability of varieties for mechanized cultivation and further harvesting, as well as for long-term transportation to the consumer. The objects of research were 20 raspberry varieties and 15 elite forms from controlled crossings and populations from free pollination. The annual assessment of the density of raspberries was carried out at the collection and selection plots during the period of active fruiting (June-July-August) 2019-2020. From each variety sample, 10 berries were taken at full maturity. The berry crushing force was determined using the fruit test device. The climatic conditions of the study periods were rich in contrast, which indicates the instability of climatic factors of the summer growing season. This made it possible to fairly objectively evaluate the collection and breeding material in terms of the size and density of raspberries. Assessing the crushing force of collection and elite forms of raspberries made it possible to identify varieties having the increased fruit density. Rannyaya Zarya, Lyachka and Lazarevskaya have a relatively large (3.5-4.5 g) and dense berry with a crushing force of 7.6-8.4 N. The interesting elite forms are 9-58; 9-27; 9-20 with a berry mass of 3.8-4.0 g and a crushing force of 7.3-9.7-N. The crushing force of fruits of these elite forms during the study period was not lower than 5.0 N, but sometimes it was significantly influenced by soil and air moisture, which negatively affected the commercial qualities of berries.

Author(s):  
Laima TAPARAUSKIENĖ ◽  
Veronika LUKŠEVIČIŪTĖ

This study provides the analysis of drought conditions of vegetation period in 1982-2014 year in two Lithuanian regions: Kaunas and Telšiai. To identify drought conditions the Standardized Precipitation Index (SPI) was applied. SPI was calculated using the long-term precipitation record of 1982–2014 with in-situ meteorological data. Calculation step of SPI was taken 1 month considering only vegetation period (May, June, July, August, September). The purpose of investigation was to evaluate the humidity/aridity of vegetation period and find out the probability of droughts occurrence under Lithuanian climatic conditions. It was found out that according SPI results droughts occurred in 14.5 % of all months in Kaunas region and in 15.8 % in Telšiai region. Wet periods in Kaunas region occurred in 15.8 %, and in Telšiai region occurrence of wet periods was – 18.8 % from all evaluated months. According SPI evaluation near normal were 69.7 % of total months during period of investigation in Kaunas and respectively – 65.5 % in Telšiai. The probability for extremely dry period under Lithuania climatic conditions are pretty low – 3.0 % in middle Lithuania and 2.4 % in western part of Lithuania.


1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield


2021 ◽  
pp. 41-48
Author(s):  
Halina A. Kamyshenka

The results of a statistical assessment of the influence of changing weather and climatic conditions of the territory of Belarus on the productivity of the main winter cereal crops are presented in order to build computational models of productivity. The calculations were made with respect to the climatic component as a predictor, taking into account the deviations of air temperature and precipitation from the long-term climatic norm of months that have the most significant effect on the yield of the studied crops. For winter rye and wheat, adequate models of yield variability have been built. The research results are relevant for solving forecasting problems.


2021 ◽  
Vol 12 ◽  
Author(s):  
Domen Arnič ◽  
Jožica Gričar ◽  
Jernej Jevšenak ◽  
Gregor Božič ◽  
Georg von Arx ◽  
...  

European beech (Fagus sylvatica L.) adapts to local growing conditions to enhance its performance. In response to variations in climatic conditions, beech trees adjust leaf phenology, cambial phenology, and wood formation patterns, which result in different tree-ring widths (TRWs) and wood anatomy. Chronologies of tree ring width and vessel features [i.e., mean vessel area (MVA), vessel density (VD), and relative conductive area (RCTA)] were produced for the 1960–2016 period for three sites that differ in climatic regimes and spring leaf phenology (two early- and one late-flushing populations). These data were used to investigate long-term relationships between climatic conditions and anatomical features of four quarters of tree-rings at annual and intra-annual scales. In addition, we investigated how TRW and vessel features adjust in response to extreme weather events (i.e., summer drought). We found significant differences in TRW, VD, and RCTA among the selected sites. Precipitation and maximum temperature before and during the growing season were the most important climatic factors affecting TRW and vessel characteristics. We confirmed differences in climate-growth relationships between the selected sites, late flushing beech population at Idrija showing the least pronounced response to climate. MVA was the only vessel trait that showed no relationship with TRW or other vessel features. The relationship between MVA and climatic factors evaluated at intra-annual scale indicated that vessel area in the first quarter of tree-ring were mainly influenced by climatic conditions in the previous growing season, while vessel area in the second to fourth quarters of tree ring width was mainly influenced by maximum temperature and precipitation in the current growing season. When comparing wet and dry years, beech from all sites showed a similar response, with reduced TRW and changes in intra-annual variation in vessel area. Our findings suggest that changes in temperature and precipitation regimes as predicted by most climate change scenarios will affect tree-ring increments and wood structure in beech, yet the response between sites or populations may differ.


2021 ◽  
Vol 51 (1) ◽  
pp. 25-32
Author(s):  
A. A. Malyuga ◽  
N. S. Chulikova

Long-term studies (2014–2019) of the population dynamics of the fungus Rhizoctonia solani Küch. were carried out in the soil on the Purple Majesty, Vitelotte and Fioletovy potato varieties and preceding crops (potatoes, oats and tendergreen). The study was carried out in Novosibirsk region in the soil and climatic conditions typical of the forest-steppe zone of Western Siberia. To study the peculiarities of R. solani fungus population dynamics in potato plantations, soil samples were taken from under the plants during the entire growing season. The accumulation of rhizoctonia propagules in the soil was determined using the method of multiple soil pellets. The difference in the amount and rate of accumulation of the fungus R. solani on different varieties, as well as the influence of previous crops on this process, was established. Two peaks of the fungus accumulation were observed on the Purple Majesty variety: the first (48.7 propagules/100 g of soil) – during the full germination period, the second (57.2 propagules/100 g of soil) – at the end of the crop maturation phase. One peak was observed in the population dynamics of the fungus on Vitelotte and Fioletovy varieties, at the end of the ripening period (59.0 and 49.1 propagules/100 g soil, respectively). The smallest amount of R. solani fungus in the soil on average during the growing season was noted on the Fioletovy variety – 33.3 propagules/100 g of soil. In the Purple Majesty and Vitelotte varieties, this figure was 41.5 and 40.4 propagules/100 g of soil, respectively. When potato variety Agata was cultivated as monoculture, there was a rapid and significant accumulation of the fungus R. solani in the soil (from 34.6 to 126.8 propagules/100 g of soil). When this variety was cultivated following tendergreen or oats, the amount of the pathogen varied to a lesser extent (25.1–52.2 and 19.8–41.0 propagules/100 g of soil, respectively). No sharp increases in the number of propagative structures of the phytopathogen in the soil were noted.


Agriculture ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 197 ◽  
Author(s):  
Befekadu Chemere ◽  
Jiyung Kim ◽  
Baehun Lee ◽  
Moonju Kim ◽  
Byongwan Kim ◽  
...  

Despite the gradual increase in livestock feed demands, the supply faces enormous challenges due to extreme climatic conditions. As the presence of these climatic condition has the potential to affect the yield of sorghum-sudangrass hybrid (SSH), understanding the yield variation in relation to the climatic conditions provides the ability to come up with proper mitigation strategies. This study was designed to detect the effect of climatic factors on the long-term dry matter yield (DMY) trend of SSH using time series analysis in the Republic of Korea. The collected data consisted of DMY, seeding-harvesting dates, the location where the cultivation took place, cultivars, and climatic factors related to cultivation of SSH. Based on the assumption of normality, the final data set (n = 420) was generated after outliers had been removed using Box-plot analysis. To evaluate the seasonality of DMY, an augmented Dickey Fuller (ADF) test and a correlogram of Autocorrelation Function (ACF) were used. Prior to detecting the effect of climatic factors on the DMY trend, the Autoregressive Integrated Moving Average (ARIMA) model was fitted to non-seasonal DMY series, and ARIMA (2, 1, 1) was found to be the optimal model to describe the long-term DMY trend of SSH. ARIMA with climatic factors (ARIMAX) detected significance (p < 0.05) of Seeding-Harvesting Precipitation Amount (SHPA) and Seeding-Harvesting Accumulated Temperature (SHAMT) on DMY trend. This does not mean that the average temperature and duration of exposure to sunshine do not affect the growth and development of SSH. The result underlines the impact of the precipitation model as a major factor for the seasonality of long-term DMY of SSH in the Republic of Korea.


2016 ◽  
Vol 107 (1) ◽  
pp. 137 ◽  
Author(s):  
Salim LEBBAL ◽  
Malik LAAMARI

Citrus fruits represent one of the most important fruit productions worldwide. However, they suffer from a numerous constraints. Aphids are among the causes of the decline in the production of citrus. In this study, the diversity of citrus aphids and their seasonal occurrence were explored on orange and mandarin, during 2012 and 2013, in an orchard located in Skikda province (Algeria). In total, six different aphid species were found during two years. The most common species was <em>Aphis spiraecola </em>Patch, 1914.  Climatic conditions had an important role in the infestation level by aphids. There were changes of aphid dynamics between the two years of the investigation. No aphids was recorded in six months in 2012 (January, June, July, August, September and December) and in three months in 2013 (January, February and August).  Besides, the number of identified aphid species increased from two to five. On the other hand, the orange trees seemed to be the most infested host species.


2007 ◽  
Vol 37 (10) ◽  
pp. 1915-1923 ◽  
Author(s):  
F. Campelo ◽  
E. Gutiérrez ◽  
M. Ribas ◽  
C. Nabais ◽  
H. Freitas

The influence of climatic factors on tree-ring width and the formation of double rings was studied in Quercus ilex L. growing in a coppice stand left unmanaged for 22 years. Ten trees were felled and discs were taken every 30 cm from bole and dominant branches. Dendrometer bands were installed on 10 nearby trees and the data recorded were used to confirm the accuracy of our tree-ring identification. They were also used to relate the seasonal radial growth pattern to double-ring formation. Double rings were frequent and occurred consistently along the stem. Two types of double rings could be recognized according to their width: type I, with the extra growth band accounting for approximately 50% of the tree ring; and type II, with a narrow extra growth band. Type I double rings were formed when approximately 1/2 of the growing-season precipitation occurred during the second growth period of the season and after the summer drought. Type II double rings occurred when approximately 1/3 of the precipitation in the growing season occurred after the summer drought. The formation of double rings was triggered by rainfall in summer and the extra growth-band width was related to summer and autumn environmental conditions. Double rings in Q. ilex can potentially be used in dendroclimatological studies, as they are formed in response to climatic conditions within the growing season.


Author(s):  
Rаside B. Sharipova ◽  

The article summarizes the results of changes in climate conditions: the average annual air temperature for 1961-2018 in the Ulyanovsk region increased by 1.8°C, the most significant increase in temperature was observed in the last twenty-five-year period of time, in the winter pe-riod. There is a tendency to increase both average and seasonal values. When analyzing the time values of the dynamics of the average monthly precipitation amounts, it was found that: the min-imum amount of precipitation falls in the winter months, in June – July they are maximum. There is a clear trend of their growth in September, in the winter months: December, January, February, March. A steady decline in precipitation is observed in June, July, August, and November.


2020 ◽  
Vol 222 ◽  
pp. 05001
Author(s):  
A.A. Vasiliev ◽  
L.V. Ufimtseva ◽  
N.V. Glaz ◽  
D.Yu. Nokhrin

During the observation period, the annual air temperature increased: in Yekaterinburg (1832-2018) by 3,1°C, in Zlatoust (1881-2018) by 2,2°C, in Kurgan (1894-2018) by 2,2°C and in Shadrinsk (1894-2018) by 2,1°C. The analogical climate change was noted for the period 1966-2018. The strongest warming is observed in winter (by 2,3-3,0°C), the weakest warming is observed in spring (by 0,8-1,7°C). We noted an increase the annual amount of precipitation in Ivdel (by 68,2 mm), Shadrinsk (by 50,9 mm) and Krasnoufimsk (by 43,6 mm). Also marked an increase the amount of precipitation during the growing season in Ivdel (by 43,9 mm), Shadrinsk (by 42,8 mm) and Krasnoufimsk (by 26,8 mm). The annual amount of precipitation increased in Chelyabinsk and Yekaterinburg, but the amount of precipitation during the growing season decreased in Kurgan. Favorable changes in the agro-climatic conditions of growing season were noted in Shadrinsk and Zlatoust. Unfavorable changes in hydrothermal coefficient for cultivated plants were noted in Chelyabinsk, Kurgan, Troitsk, Yekaterinburg and Bredy. Identified the need to introduce an irrigation system for cultivated plants of the southern districts (Chelyabinsk region).


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