Effects Of Different Irrigation Amount On Yield, Quality And Aroma Of Fragrant Rice

Water is the most important factor affecting rice production.Lack or absence of water will lead to rice production loss or death.In order to select the best irrigation method which can increase the yield and increase the fragrance of fragrant rice,it provides some theoretical basis and technical guidance for high yield and high quality cultivation of fragrant rice.In this study,a pot experiment was carried out on the experimental farm of south China agricultural university in the late season of 2018,using the conventional fragrant rice variety ivory xiangzhan and he xiangzhan 2 as the experimental material.Different irrigation methods were started after the planting of fragrant rice to regain its green color.CK irrigation was set as routine irrigation,and W1 as dry-wet alternating irrigation.In the whole growth period after the regeneration of rice,when the soil water potential reached-15 kpa,the irrigation depth of 2～3 marks cycled successively.W2 for mild dry irrigation,after full panicle when soil water potential reach 15 kpa,water deep 2 ～ 3 ㎝,W3 for natural hydrating irrigation,under the condition of using natural rainwater irrigation,when rice to withering state(roughly50 kpa ～-70 kpa),water deep 2 ～ 3 ㎝,W4 for severely dry irrigation,after full panicle when soil water potential to achieve-30 kpa,water deep 2 ～ 3 ㎝,irrigation and W5 nature,only in the whole growth period of rice root after the use of rainwater for irrigation.As to research in different irrigation modes of scented rice photosynthetic characteristics,production quality,brown rice aroma(2-AP)content of scented rice,brown rice,leaves,leaf sheaths related synthetase,such as: late in full panicle proline dehydrogenase,pyrroline-5-carboxylic acid synthetase,ornithine aminotransferase activity,such as proline,pyrroline-5-carboxylic acid,such as 1-pyrroline precursor substance content,the influence of the main results were as follows:(1)under W1 treatment,the yields of ivory-flavoring and mei-flavoring2 were increased by 8.23% and 0.05%,respectively;under W2 treatment,the yields of ivory-flavoring and mei-flavoring2 were increased by 11.24% and 6.99%,respectively;W3 decreased by 24.32% and 27.07%,respectively;W4 decreased by 17.57% and17.61%,respectively.This may be because moderate water control is conducive to the absorption of water and fertilizer by rice roots,thus promoting the growth of rice,while excessive water stress reduces SPAD value,leaf area index,photosynthesis and material accumulation,leading to reduced yield of rice.(2)the W1 treatment can make the ivory incense(mei xiang(2,2-AP content of brown rice aroma increased by 27.18% and 25.85%,W2 processing can be increased by 3.03% and 36.42% respectively,the W3 treatment increased by 15.48% and 7.57%respectively,W4 treatment increased to 3.86% and 18.42% respectively,based on the relevant material of forming scented rice aroma and enzyme test results can be found,is not only affecting the formation of aroma 2-AP rice specific areas and specific precursor substances or enzymes,but a process of comprehensive effect.(3)W1 treatment improved the water use efficiency of ivory-flavorant zhan,meixiangzhan 2 by 19.58% and 16.99% respectively,while W2 treatment improved the water use efficiency by 16.63% and 21.88% respectively.In addition to rainfall,W3 treatment can significantly improve its water use efficiency,but its yield and quality decrease sharply,which cannot achieve the effect of high yield and high quality cultivation.W4 treatment improved the water efficiency by-3.33% and 5.35%,respectively.The possible reasons for the decrease in wue are,first,the decrease in yield due to water stress,and seer lcond,the need for more water to replenish the soil when it is irrigated after excessive soil watoss.