Spatial and temporal incidence of insect pests in farmers’ cabbage fields in Senegal

2017 ◽  
Vol 37 (04) ◽  
pp. 225-233 ◽  
Author(s):  
Babacar Labou ◽  
Thierry Brévault ◽  
Serigne Sylla ◽  
Mamadou Diatte ◽  
Dominique Bordat ◽  
...  
Keyword(s):  
Insect Pests ◽  
Tomato Fruit ◽  
Diamondback Moth ◽  
Temporal Distribution ◽  
Dry Season ◽  
Effect Of Temperature ◽  
Small Scale ◽  
Vegetable Production ◽  
Spatial And Temporal Distribution ◽  
The South

Abstract In Senegal, damage caused by insect pests is a major obstacle to seasonal stability and an increase in cabbage production. Little is known about the spatial and temporal distribution of cabbage pests, which makes the design of management recommendations to small-scale farmers challenging. The objectives of this study were to: (i) evaluate the status of insect pests observed in cabbage farmers’ fields; (ii) give information on the spatial and temporal distribution of key pests and (iii) assess the effect of temperature, insecticide applications, and host crop abundance on their incidence. A total of 116 cabbage fields were monitored for insect pests and related damage over four crop cycles, from October 2012 to May 2014, in the main vegetable producing area of Senegal (Niayes). The diamondback moth Plutella xylostella (L.) was by far the most important pest present in all the fields and with high levels of incidence (37.1% infested plants), particularly in the latter part of the dry season in the South of Niayes (50% infested plants). The cabbage webworm Hellula undalis (F.) was mainly observed in the early dry season in the south of Niayes, with an incidence of up to 12.5% infested plants. More surprising was the detection of the tomato fruit worm Helicoverpa armigera (Hübner), with damage of up to 9.4% of cabbage heads. The incidence of sucking pests such as whiteflies Bemisia tabaci (Gennadius), or aphids (including Lipaphis pseudobrassicae (Davis, 1914), Myzus persicae (Sulzer) or Brevicoryne brassicae (L.)) was generally low. The incidence of P. xylostella increased significantly with the number of insecticide applications, indicating that control deployed by growers was ineffective. The incidence of H. undalis did not depend on the number of insecticide applications, but significantly increased with host crop abundance and decreased with temperature. This study is a first step towards developing alternative pest management strategies in the framework of sustainable vegetable production systems.

Spatial and temporal distribution of genes involved in polyamine metabolism during tomato fruit development

2016 ◽  
Vol 100 ◽  
pp. 27-36 ◽  
Author(s):  
Georgios Tsaniklidis ◽  
Anastasios Kotsiras ◽  
Athanasios Tsafouros ◽  
Peter A. Roussos ◽  
Georgios Aivalakis ◽  
...  
Keyword(s):  
Fruit Development ◽  
Tomato Fruit ◽  
Temporal Distribution ◽  
Polyamine Metabolism ◽  
Spatial And Temporal Distribution

scholarly journals Comparative analysis of frequency of dry winds occurrence in Ukraine in the mid-20th century and at the beginning of the 21st century

2018 ◽  
pp. 57-63
Author(s):  
M. O. Slizhe
Keyword(s):  
Comparative Analysis ◽  
Large Scale ◽  
Crop Yields ◽  
Regional Climate ◽  
Temporal Distribution ◽  
Vegetation Period ◽  
Spatial And Temporal Distribution ◽  
Urgent Problem ◽  
The South ◽  
Summer Time

Dry winds in Ukraine present a dangerous phenomenon which can significantly impact on crop yields. The winds damage agricultural crops active development of which occurs in spring and summer time. Their impact can in a short time reduce or destroy further yield. Study of spatial and temporal distribution of the dry winds, their meteorological characteristics, dynamics of their development and circulation processes resulting in their formation in Ukraine is a very urgent problem because almost every year the dry winds and droughts occur at the time of vegetation period. The current research of spatial and temporal distribution of the dry winds and its meteorological characteristics on the territory of Ukraine under the conditions of changed climate is an urgent problem because this phenomenon occurs over almost every vegetation period. The paper describes the results of comparative analysis of average number of days witnessing the dry winds at 14 meteorological stations in Ukraine located in different agro-climatic zones for the periods of 1936-1964 and 1995-2015. The number of dry winds significantly increased at most of such stations located in different parts of Ukraine. Same as over previous periods, the greatest repetition of days with the dry winds occurred in the south and the south-east of the country where, according to the data from some meteostations, vegetation period may, on average, consist of up to 27 days when dry winds blow. The reason for such increase is explained, firstly, by change of the large-scale atmospheric circulation resulting in weakening of the heat and moisture inter-latitude exchange which in its turn causes change of the temperature and humidity regime in Ukraine and, secondly, by increase of frequency of synoptic processes accompanied by formation of arid phenomena on the territory of the country. These changes could be traced when observing the positive anomalies of average air temperature during recent decades. The negative anomalies of precipitation and change in their distribution contribute to the formation of conditions that increase frequency and intensity of droughts. The obtained results indicate that changes of the regional climate contributed to the increase of frequency and prevalence of the dry winds in Ukraine.

scholarly journals Spatial and temporal distribution of foot and mouth disease outbreaks in Amhara region of Ethiopia in the period 1999 to 2016

2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Endris Aman ◽  
Wassie Molla ◽  
Zeleke Gebreegizabher ◽  
Wudu Temesgen Jemberu
Keyword(s):  
Temporal Distribution ◽  
Foot And Mouth Disease ◽  
Dry Season ◽  
Mouth Disease ◽  
Spatial And Temporal Distribution ◽  
Amhara Region ◽  
Term Trend ◽  
Foot And Mouth ◽  
Long Term Trend

Abstract Background Foot and mouth disease (FMD) is an economically important trans-boundary viral disease of cloven-hoofed animals. It is caused by FMD virus, which belongs to the genus Aphthovirus and family Picornaviridae. FMD is a well-established endemic disease in Ethiopia since it was first detected in 1957. This retrospective study was carried out to identify the spatial and temporal distribution of FMD outbreaks in Amhara region of Ethiopia using 18 years (January 1999–December 2016) reported outbreak data. Results A total of 636 FMD outbreaks were reported in Amhara region of Ethiopia between 1999 and 2016 with an average and median of 35 and 13 outbreaks per year respectively. In this period, FMD was reported at least once in 58.5% of the districts (n = 79) and in all administrative zones of the region (n = 10). The average district level incidence of FMD outbreaks was 4.68 per 18 years (0.26 per district year). It recurs in a district as epidemic, on average in 5.86 years period. The incidence differed between administrative zones, being the lowest in East Gojjam and highest in North Shewa. The occurrence of FMD outbreaks was found to be seasonal with peak outbreaks in March and a low in August. The long-term trend of FMD outbreaks indicates a slight, but statistically significant (p < 0.001) decrease over the study period. Conclusion FMD occurred in all zones of the region and showed statistically significant decrease in the long-term trend. Numbers of outbreaks were relatively higher during dry season. The spatial and temporal distribution identified in this study should be considered in controlling the disease. As unregulated and frequent animal movements are the likely causes of high outbreak occurrence during the dry season, animal movement regulations should be considered for the long-term control of FMD.

scholarly journals SPATIAL AND TEMPORAL DISTRIBUTION OF THE CLOUD HEIGHT AND CLOUD THICKNESS OVER CHINA AND THE ADJACENT AREAS BASED ON CALIOP

2019 ◽  
Vol XLII-3/W9 ◽  
pp. 15-22
Author(s):  
X. Feng ◽  
H. K. Cai ◽  
B. W. Wang ◽  
X. M. Li ◽  
L. Zhang
Keyword(s):  
Regional Differences ◽  
Temporal Distribution ◽  
The Tibetan Plateau ◽  
Spatial And Temporal Distribution ◽  
The South ◽  
The North ◽  
Cloud Height ◽  
The Mean ◽  
Cloud Thickness ◽  
The Western Pacific

Abstract. Based on CALIOP data, spatial and temporal distribution of cloud height and thickness over China as well as the adjacent areas have been analysed in this paper. The results show significant regional differences. The heights of clouds that lie to the south of 27.6°N are greater than those to the north of 27.6°N. The highest and thickest clouds are located above the Bay of Bengal and the Western Pacific, while the lowest values distribute in the northwest of the Tibetan Plateau and Sichuan Basin. The clouds ranging from 0.3 km to 0.6 km thickness account for a large proportion of total clouds. And the probability of occurrence of clouds decreases as cloud thickness increases. Overall, within the area under study, the thick clouds are higher than the thin clouds. Besides, low and thin clouds occur more frequently than high and thick clouds. As for their seasonal variation, the height of clouds peaks in summer. In addition, the mean of cloud thickness to the south of 27.6°N is 2.4 km thicker in summer than in any other season.

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