| Nowadays lacking of water resources is the important problem, water-saving cultivation became the hot issues, Camellia oleifera as the economic tree species which have high economic and ecological benefits, Hunan as a leading producer of Camellia oleifera often have seasonal drought, phenomenon "July dry fruit, August dry oil" is more serious which impact the high and stable yield of Camellia oleifera. In this paper used the Camellia oleifera Xiang lin69clones which widely grown in hunan province as the research object, through pot experiment and tree test, etc, used the method of weighing method, the stem flow meter method, set different moisture stress, studied clones water consumption during drought spell, Revealed the differential water requirement rule in different period and water physiological and ecological basis of high and stable high quality yield, and provide theoretical guidance for water-saving irrigation.Main research results as follow:â‘ Analysis the Camellia oleifera soil moisture characteristic in this regions, Found that the areas have soil and water loss, cause the differences of Soil particle composition in different position and corresponding changes of soil moisture characteristic value, lend to the soil water characteristic value at downhill position is better than the uphill position, the correlation between moisture characteristic value and effective water content are:field capacity> capillary porosity> saturation moisture content>soil bulk density>capillary water holding capacity>Physical clay; there are different degree of deficit of growth of available water in May, July, August, September, especially in July and September, Moisture deficit ullage are respectively17.39mm and22.64mm.â‘¡Through pot experiment studying the Nursery stock water consumption, the results show that the daily change of Nursery stock water is almost in a certain appearance of unimodal curve, and has good ecology synchronization with the sun radiation, water consumption reduced with soil water dropping; Water consumption in different months is August> September> October, and in different weather is sunny > cloudy> overcast; Under different gradient of moisture, the seedling photosynthetic rate is in a certain appearance of bimodal curve, with the loss of the soil moisture content the seedling photosynthetic rate reduced; the correlation order between transpiration rate and environmental factors is stomatal conductance, solar radiation, air relative humidity, air temperature, and establishes the optimization model of transpiration rate and environment factors.â‘¢Transpiration and photosynthesis of8years Camellia oleifera clone were observed with the Li-6400, results show that the transpiration rate is an unimodal curve, appeared low in the morning and evening, and high at noon; transpiration rate in August> September> October; net photosynthetic rate in October> September> August. Using sap flow meter method for a year observation of Camellia oleifera clone, the results show that the liquid flow rate, high peak in August, long duration and low peak in October, short duration, moderate on September; and under different weather, the flow rate in sunny day> cloudy> overcast; Liquid flow rate has maximum correlation with solar radiation and temperature, relative humidity, wind speed correlation come second, minimum relevance with soil moisture content; and an optimized model of environmental factors between flow rate has been developed. The most good soil moisture content is80%-100%.â‘£analyzed the growth rhythm of camellia fruit in drought spell, found that the first stage is the period before august, size and weight increase fast, accumulating organic matter for oil transformation, the second stage is the period after the late september, it is the peak of oil transformation. |
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