不同水分处理下基于辐热积的温室番茄干物质生产及分配模型

Greenhouse tomato dry matter production and distribution model under condition of irrigation based on product of thermal effectiveness and photosynthesis active radiation

为了探讨干物质生产及分配模型在西北地区温室环境不同水分处理的使用性,以番茄为材料,于2013-2015年在陕西省杨凌区温室内进行亏水处理试验,设置全生育期充分灌水处理、仅苗期亏水50%处理、苗期开花期连续亏水50%和全部亏水50%共4种水分处理,通过2013-2014年温室试验分析不同水分处理条件下番茄茎、叶、果实和根系的动态变化,建立了基于番茄耗水量、地上部和根系分配指数、地上部各器官分配指数的番茄干物质生产及分配模型;利用2014-2015年试验数据对干物质生产及分配模型进行验证。结果表明,利用累积辐热积与干物质总量进行拟合得到的关系式,可以利用累积辐热积较为准确地模拟不同水分处理下番茄干物质总量。番茄干物质总量受累积辐热积和水分影响较大,而干物质总量在地上部、根系及地上部各器官的分配指数只随辐热积变化,不随灌水量发生显著的变化。运用番茄耗水量、累积辐热积、经验公式和经验系数得到的干物质生产及分配模型,通过该模型估算不同水分处理番茄茎、叶、果实和根系干物质的预测值和实测值拟合度较高,其绝对误差为0.24~9.46 g/株,均方根误差为0.35~10.01 g/株和决定系数为0.78~0.89,可以用该模型预测肥料充分条件下各水分处理温室番茄各器官的干物质生产及分配,为温室番茄不同水分条件下番茄生产提供理论依据。

To know the applicability of dry matter production and distribution model in greenhouse environment in northwest of China, we conducted a tomato deficit irrigation experiment in 2013-2015 in Yangling Shaanxi Province. Four treatments were set up including no deficit in whole growth period, deficit of 50% only in seedling stage, deficit of 50% both in seedling stage and flowering stage and deficit of 50% in whole growth period. We analyzed the dynamic changes of tomato stems, leaves, fruits and roots under different irrigation treatment in 2013-2014, and established a dry matter production and distribution model by using water consumption, aboveground and root distribution index, aboveground organ allocation index. Then the experimental data in 2014-2015 was used to validate the dry matter production and distribution. Total radiation, temperature, and water consumption of tomato under different treatments and dry matter weight of tomato including stems, leaves, fruits and roots in different growth stages were observed. Meteorological data was measured by artificial weather station, and water consumption was calculated based on water balance theory, and dry matter weight of each organ was measured by weighing method. The results showed that the total cumulative of thermal effectiveness and PAR （TEP） and water condition influenced tomato＇s dry matter most. For full irrigation treatment, dry matter increased rapidly in seedling stage and flowering stage. In mature stage the increase rate of dry matter reduced to the minimum level, and the total amount of dry matter increased to the maximum level. Water deficit in seedling stage would not significantly reduce the total amount of dry matter. Water deficit both in seedling stage and flowering stage would significantly reduce the total amount of dry matter in mature stage, and longer durations would result in larger reduction. The process of dry matter production under different water condition could be simulated by using total cumulative of TEP as an input variable in a dry matter production and distribution model. The dry matter allocation index of aboveground and root only changes with TEP while irrigation amount influenced it little. The aboveground index increased with TEE and reached minimum in establishment stage, i.e.0.79, reached maximum in mature stage, i.e.0.95. While the root index decreased with TEP, and reached maximum in establishment stage, i.e. 0.21, reached minimum in mature stage, i.e. 0.05. Before flowering, tomato only underwent vegetative growth, distribution indexes of stem and leaf were 0.24-0.26 and 0.74-0.76, respectively in establishment stage. Distribution indexes of stem and leaf became closer in later vegetative growth stage, and were 0.49-0.51 and 0.49-0.51 respectively in the end of seedling stage. The distribution index of fruit increased with TEP after flowering. A high precision could be attained when using this dry matter production and distribution model to calculate tomato＇s stem, leave, fruit and root dry matter under different water condition, and absolute errors were 0.24-9.46 g per plant, root mean square errors were 0.35-10.01 g per plant, and coefficients of determination were 0.78-0.89. This model could be used to simulate production and distribution of tomato＇s dry matter under different water condition when fertilizer supply was sufficient. This research provides useful information for greenhouse tomato production under different water conditions.