根据光温对作物叶面积的影响,提出了辐热积(product of the rma leffectiveness and PAR,TEP)的概念。根据试验资料构建了利用辐热积模拟番茄(Lycopersicon esculentum Mill)叶面积动态的数学模型,并将其与已有的光合作用和干物质生产模拟模型相结合,构建了温室番茄干物质生产动态模型。利用不同品种、基质和地点的试验资料对模型进行了检验。结果表明,与传统的比叶面积法和有效积温法相比,辐热积法显著提高了温室番茄叶面积的预测精度,提高了光合作用和干物质生产的模拟精度。辐热积法对番茄叶面积的预测结果与1:1直线之间的决定系数R2和统计回归标准误差RMSE分别为0.9743和0.0515m2·株-1,对植株总干物质量的预测结果与1:1直线之间的R2和RMSE分别为0.9360和522.7104kg·ha-1;采用辐热积法对植株总干物质量的预测精度比有效积温法和比叶面积法分别提高56%和72%。
根据试验资料及温室番茄(Lycopersicon esculentum)作物的生长特性,构建了基于分配指数(Parti-tioning index,PI)和收获指数(Harvest index,HI)与辐热积(Product of thermal effectiveness and PAR,TEP)关系的番茄干物质分配和产量预测的数学模型,并利用不同品种、基质和地点的试验资料对模型进行检验.模型对番茄地上部分干重、根系干重、茎干重、叶片干重和果干重的预测结果与1∶1直线之间的决定系数(Coefficient of determination,R2)分别为0·95、0·57、0·82、0·79和0·93;统计回归标准误差(Root meansquared error,RMSE)分别为647·0、78·1、279·0、496·9和381·8kg·hm-2;对产量的预测结果与1∶1直线之间的R2和RMSE分别为0·88和5828·5kg·hm-2;不仅预测精度较高,且参数少、用户易于获取,为温室番茄模型应用于温室番茄生产的优化管理奠定了基础.
Greenhouse canopy transpiration not only has effects on greenhouse air temperature and humidity, but also is important for determining the set-point of fertigation. In this study, Penman-Monteith equation was used to calculate the greenhouse cucumber canopy transpiration under summer climate condition. The effects of greenhouse environmental factors on canopy transpiration were analyzed based on the measurements of greenhouse microclimate factors and canopy transpiration. The results showed that Penman-Monteith equation was reliable and robust in estimating greenhouse cucumber canopy transpiration under summer climate condition. Greenhouse cucumber canopy transpiration rate increased linearly with the increase of net radiation and water vapor pressure deficit (VPD) above the canopy. But the maximum value of the canopy transpiration rate occurred at the same time as that of VPD whereas about two hours later than that of net radiation. Based on the results, it was concluded that in addition to radiation, air humidity should also be considered when determine the set-point of fertigation.
LUO Wei-hong, WANG Xiao-han, DING Wei-min, CHEN Yu-qing and DAI Jian-feng(Key Laboratory of Crop Growth Regulation , Ministry of Agriculture/Nanjing Agricultural University ,Nanjing 210095, P.R.China)
根据光温对菊花品质的影响,通过不同定植期和不同品种试验,建立了以生理辐热积(physiological product of thermaleffectiveness and PAR,PTEP)为尺度的温室标准切花菊品质预测模型,并用独立的试验数据对模型进行检验.结果表明:模型对温室标准切花菊的展叶数、单株叶面积、株高、茎粗、节间长和花径的模拟值与实测值的符合度较好,模拟值与实测值基于1∶1线的决定系数(R2)和预测相对误差(RSE)分别为0.99、0.98、0.98、0.92、0.87、0.88和5.5%、6.5%、5.9%、4.1%、11.2%、12.4%.表明该品质预测模型预测精度高、实用性强,可为温室标准切花菊生产中的光温调控提供理论依据和决策支持.
