Relationships between climatic factors and flower and boll production in Egyptian cotton (Gossypium barbadense)     

Z. M. Sawan  L. I. Hanna  Gh. A. Gad El Karim  W. L McCuistion 《Journal of Arid Environments》2002,52(4):499

Fruiting of cotton plant is determined and influenced by cultivar, climatic conditions, management practices and pests. An understanding of the flowering and boll retention patterns of cotton cultivars can contribute to more efficient and economical crop management. The objective of this investigation was to study the effect of various climatic factors on flower and boll production of Egyptian cotton. This could be used in formulating advanced predictions of the effect of certain climatic conditions on the production of Egyptian cotton. Two uniform field trials, using cotton Gossypium barbadense cv. Giza 75 were carried out in 1992 and 1993 at the Agricultural Research Station, Agricultural Research Center, Ministry of Agriculture, Giza, Egypt, to investigate the relationships between climatic factors, flower and boll production. Climatic factors included maximum and minimum air temperatures along with their difference, evaporation, surface soil temperature (grass temperature or green cover temperature) at 0600 and 1800 h°C⁻¹, sunshine duration, maximum and minimum humidity and wind speed. The effects of climatic factors on flower and boll production were quantified in the absence of water and nutritional deficits and damage effects of insects. Results obtained indicate that evaporation, sunshine duration, humidity, surface soil temperature at 1800 h, and maximum air temperature, were the important climatic factors that significantly affect flower and boll production of Egyptian cotton. Consequently, applying appropriate specific cultural practices that minimize the deleterious effect of these factors will lead to an improvement in cotton yield.  相似文献   

Egyptian cotton (Gossypium barbadense) flower and boll production as affected by climatic factors and soil moisture status     

Zakaria M. Sawan  Louis I. Hanna  Willis L. McCuistion  Richard J. Foote 《Theoretical and Applied Climatology》2010,99(1-2):217-227

The information on impact of climatic factors on cotton production is not generally available, or at least not available in the required form. Understanding this impact may help physiologists determine a possible control of the flowering mechanism in the cotton plant. Two field trials were conducted to investigate the relationships between climatic factors, soil moisture status, and flower and boll production of Gossypium barbadense. The climatic factors considered were daily maximum air temperature (°C), minimum air temperature (°C), maximum–minimum temperature (diurnal temperature range) (°C), sunshine duration (h day^?1), maximum relative humidity (%), minimum relative humidity (%), and wind speed (m s^?1). Minimum relative humidity and sunshine duration were the most significant climatic factors affecting flower and boll retention and production. Temperature appeared to be less important in the reproduction growth stage of cotton in Egypt than minimum relative humidity and sunshine duration. The soil moisture status showed low and insignificant correlation to flower and boll production. High minimum relative humidity, short period of sunshine duration, and low temperatures enhanced flower and boll formation.  相似文献   

Influence of Diverse Urban Pressures on Water Characteristics in a Small Eastern Mediterranean Watershed     

Maatouk  E.  Samrani  A. El  Sawan  R.  Salameh  R. Bou Ghosn  Kazpard  V.  Matar  Z. 《Aquatic Geochemistry》2022,28(2):111-133

This work focuses on the characterization of a typical coastal karst watershed by addressing its physico-chemical parameters. The concentrations of the main ions clearly indicate the dominance of Ca²⁺ and HCO₃^? with a carbonate weathering rate equivalent to 230t/Km²/year; that is a typical weathering of karst watersheds. The spatio-temporal variability of dissolved organic matter (DOM) is also assessed in the watershed. Many samples were collected under different hydrological conditions from three representative sites. The evolution of OM composition along an urbanization gradient from upstream to downstream Kadisha watershed reveals the very strong impact of urban discharges on the receiving waters. Substantial differences in DOC results are highlighted in relation to the urban or natural origin of the DOM. Upstream OM flux is quantified and compared to downstream OM flux showing that, during the low flow period, the downstream flux is 29 times higher than the upstream. Also, a large fraction of non-humic substances, including hydrophilic organic matter HPI, is detected in the downstream section impacted by urban discharges. The higher values of SUVA noticed for DOM at upstream compared to downstream, reflects the low aromaticity and non-humic character of DOM in downstream. These outcomes show the impact of the Tripoli urban discharges on the quality and quantity of OM in the receiving waters downstream of the Kadisha catchment. This is typical at low water period when the dilution factor of urban discharges in the receiving waters is the least.

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Response of flower and boll development to climatic factors in Egyptian cotton (Gossypium barbadense)   总被引：1，自引：0，他引：1  

Zakaria M. Sawan 《Climatic change》2009,97(3-4):553-591

Fruiting of cotton plant is determined and influenced by cultivars, climatic conditions, management practices and pests. An understanding of the flowering and boll retention patterns of cotton cultivars can contribute to more efficient and economical crop management. The objective of this investigation was to study the effect of various climatic factors on flower and boll production, and also, the nature of its effects prevailing prior and subsequent to either flowering or boll setting on flower and boll production and retention in Egyptian cotton. This could be used in formulating advanced prediction of the effect of certain climatic conditions on the production of Egyptian cotton. Also, the study focused on four equal periods during the development of flower and bolls stage to study the response of these characters to climatic factors during these periods and to determine the most representative period corresponding to the overall crop pattern. Further, the study predicting effects of climatic factors during convenient intervals (in days) on cotton flower and boll production compared with daily observations to find the optimum interval. Evaporation, sunshine duration, humidity, surface soil temperature at 1800 h, and maximum air temperature, are the important climatic factors that significantly affects flower and boll production. Evaporation; minimum humidity and sunshine duration were the most effective climatic factors during preceding and succeeding periods on boll production and retention. There was a negative correlation between flower and boll production and either evaporation or sunshine duration, while that correlation with minimum humidity was positive. The fourth quarter period of the production stage was the most appropriate and usable time to collect data for determining efficient prediction equations for cotton production. Evaporation, humidity and temperature were the principal climatic factors that governed cotton flower and boll production during the fourth quarter. The five day interval was found to be adequately and sensibly related to yield parameters than other intervals and was closest to the daily observations. Evaporation was found to be the most important climatic variable affecting flower and boll production, followed by humidity. An accurate weather forecast 5–7 days in advance would provide an opportunity to avoid adverse effects of climatic factors on cotton production through utilizing proper cultural practices which would limit and control their negative effects.  相似文献