Experimental Study On The Best Model Of Spatio-temporal Deficit Controlled Irrigation Of Hot Pepper

Based on the water-saving technical principle and ABA theory, a new irrigation with high potentialities method of saving water named spatio-temporal deficit controlled irrigation is proposed, which uses full irrigation, both root-zone deficit irrigation and alternate partial root-zone deficit irrigation during the whole growing period of hot pepper. The experiment was carried out in the greenhouse of Hohai Univerisity from March to September in 2006. Effects of spatio-temporal deficit controlled irrigation on hot pepper were studied in this article based on the analysis of the soil water temporal and spatial variation, physiological control and stomata response, water use characteristic, yield, product quality and water use efficiency. The main results are:(1) Water consumption in flourishing issue was more than bloom-fruit issue, since the plant in seedling stage was little, meanwhile the temperature was very low and day water consumption was the minimum compared to the three other stages. It is concluded that the treatments which increased irrigation water in flourishing issue or bloom-fruit issue are reasonable through the analysis of water consumption of every growing period of hot pepper.(2) In seedling stage, the irrigation water quantity had different degree of inhibitive effect on the growth indexes such as plant height, leaf number and area. Meanwhile, the inhibition to growth index of the alternate partial root-zone irrigation was larger than both root-zone deficit irrigation while the effect on growth index of irrigation method was not apparent. The relationship of hot pepper height and leaf number with water control time exhibits the twice polynomial function characteristics. As water control continued, the height, leaf number and area grew slowly and compensation effect happened after rewatering.(3)Spatio-temporal deficit controlled irrigation also had different degree of inhibitive effect on photosynthesis(Pn), transpiration rate(Tr) and so on. Water control of hot pepper reduced 'luxury' transpiration without much reduction in photosynthesis rate and increased water use efficiency. The dependent relationship between Tr and conductance reached significant level while there are many factors influenced Pn and water using efficiency with no obvious relationships shown. The daytime change of Pn exhibited unsymmetry double peaks characteristics, the highest, the lowest and the second highest peak appeared at 11:00, 13:00 and 16:00 respectively, the phenomenon of "lunch break" in the daytime change of Pn was observed. The highest peak of full irrigation treatment happened ahead, the value of which was bigger than the water control treatment. The daytime changes of Tr and conductance both had the only peak, the highest peak appeared at 12:00. The chlorophyll fluorescence were sensitive to hot pepper water control, which had close relation to measure...