Winter Wheat GPC Estimation Based on Leaf and Canopy Chlorophyll Parameters
SONG Xiao-yu1, 2, WANG Ji-hua2, 3, YANG Gui-jun1, 2, CUI Bei4, CHANG Hong1, 2
1. Beijing Research Center for Information Technology in Agriculture，Beijing 100097, China 2. Beijing Academy of Agriculture and Forestry Science，Beijing 100097, China 3. Beijing Research Center for Agri-food Testing and Farmland Monitoring，Beijing 100097, China 4. Institute of Remote Sensing and Digital Earth，Chinese Academy of Sciences，Beijing 100094, China
Abstract：The present study focused on the wheat harvest grain protein content (GPC) estimation based on wheat leaf and canopy chlorophyll parameters, SPAD and SFR, which were acquired by two hand-held instruments, SPAD and Multiplex 3. The wheat GPC estimate experiment was applied on a wheat field of the Scientific Observation and Experiment Field Station for Precision Agriculture at suburb of Beijing in 2012. The wheat leaf SPAD and canopy SFR value were measured in field for all 110 wheat sample points at five different wheat growth stages from April to June. The wheat plant sample for each point was then collected after the SPAD and SFR measurement and sent to lab for leaf nitrogen content (LNC) and canopy nitrogen density (CND) analysis. Analysis results showed that the correlation coefficients of wheat GPC with wheat CND were much higher than that from wheat tillering stage to early milking stage. They were similar at the wheat middle milking stage. While the wheat leaf SPAD value was highly correlated with wheat LNC at wheat tillering, heading and early milking stage. Wheat canopy chlorophyll parameters SFR were highly correlated with wheat CND at wheat tillering, jointing, heading and milking stage. It can be seen from the study that SFR is more sensitive to the wheat CND compared with wheat LNC. The analysis also indicated that leaf SPAD value at wheat tillering, heading and milking stage was highly correlated with wheat GPC and yield of grain protein (YGP). The wheat canopy parameters, SFR_G and SFR_R were significantly correlated with wheat GPC and YGP at wheat milking stage. Then the optimal GPC and YGP estimation model was established. The R2 of GPC estimation models established by SPAD and SFR_R are 0.426 and 0.497, and the standard errors of the estimate are 0.060% and 0.055%, respectively. The R2 of YGP estimation models established by SPAD and SFR_R are 0.366 and 0.386 and the standard errors of the estimate are 125.367 and 123.454 kg·ha-1, respectively. The study reveals that SPAD value is a good indicator of single plant activity while SFR_G and SFR_R are better indicators for the wheat group activity. Wheat leaf SPAD value and canopy chlorophyll fluorescence information SFR are all feasible and valuable for GPC estimation before wheat harvesting.
Key words：Winter wheat;Nitrogen content;Canopy nitrogen density;Grain protein content (GPC);SPAD;SFR
[1] HUANG Wen-jiang, ZHAO Chun-jiang, WANG Ji-hua, et al(黄文江，赵春江，王纪华，等). Transactions of the Chinese Society of Agricultural Engineering(农业工程学报), 2004, 20(6): 1. [2] FENG Wei, YAO Xia, TIAN Yong-chao, et al(冯 伟，姚 霞，田永超，等). Acta Agronomica Sinica(作物学报), 2007, 33(12): 1935. [3] Zhao Chunjiang, Liu Liangyun, Wang Jihua, et al. International Journal of Applied Earth Observation and Geoinformation, 2005, 7(1): 1. [4] Wang Z J, Wang J H, Liu L Y, et al. Field Crop Research, 2004, 90(2-3): 311. [5] WANG Ji-hua, HUANG Wen-jiang, ZHAO Chun-jiang, et al(王纪华，黄文江，赵春江，等). Journal of Remote Sensing(遥感学报), 2003, 7(4): 277. [6] ZHAO Ben, YAO Xia, TIAN Yong-chao, et al (赵 犇，姚 霞，田永超，等). Acta Ecologica Sinica(生态学报), 2013, 33(3): 916. [7] Arregui L M, Lasa B, Lafarga A, et al. European Journal of Agronomy, 2006, 24(2): 140. [8] TIAN Yong-chao, ZHU Yan, CAO Wei-xing, et al(田永超，朱 艳，曹卫星，等). Scientia Agricultura Sinica(中国农业科学). 2004, 37(6): 808. [9] GAO Fei, XIAO Jing, GU Yun-hong, et al(高 飞，肖 靖，谷运红，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2012, 32(5): 1350. [10] Krause G H, Weis E Annu. Rev. Plant Physiol. Plant Mol., 1991, 42: 313. [11] ZHANG Yong-jiang, LIU Liang-yun, WANG Ji-hua, et al(张永江，刘良云，王纪华，等). Optical Technique(光学技术), 2007, 33(1): 119. [12] YU Huan, YANG Gai-he, WANG Zhi-jie(鱼 欢，杨改河，王之杰). Plant Nutrition and Fertilizer Science(植物营养与肥料学报), 2010, 16(2): 266. [13] Gianquinto G, Orsini F, Sambo P, et al. Hort Technology, 2011, 21(3): 287. [14] Hazir M H M, Shariff A R M, Amiruddin M D. Industrial Crops and Products, 2012, 36(1): 466.
