# A Low-Cost Sensorized Vehicle for In-Field Crop Phenotyping
## 3 Field Acquisition and Results  
To test the prototype ability of the phenomobile system with respect to real field conditions, a measure of the spectral properties of plants was performed on _i._ tomato plants of the F1 hybrid Elisir (Olter Sementi) and _ii._ durum wheat sown by parcels.  
The tomato experiment was conducted on eighteen plants at the 4-5 th true leaf stage of the F1 hybrid Elisir (Olter Sementi) that were transplanted in three rows (six plants per row), considered replicates. To favor a visual inspection of the plants, 200 cm was left between the rows and 50 cm between the plants along the row. The initial indeterminate growth of the plants required the use of supports. Lateral shoots were removed at weekly intervals during the plant growth. The transplantation occurred between the 11 th and 20 th days of May 2021 in the experimental field of the CREA Research Center for Engineering and Agro-Food Processing, Monterotondo, Italy (42\({}^{\circ}\)N 05\({}^{\prime}\)56.86\({}^{\prime\prime}\), 12\({}^{\circ}\)E 37\({}^{\prime\prime}\)26.23\({}^{\prime\prime}\)). For at least three years, the soil was fertilized with cow manure and no chemicals were used to control pathogens or pests. The plants were drip irrigated with lines placed near the plants. The water supply was scheduled according to the Integrated Production Regulations for tomato processing [17]. The durum wheat experiment was carried out on the CREA experimental farm in Montelibretti (42\({}^{\circ}\)07\({}^{\prime}\)47.71\({}^{\prime\prime}\) N, 12\({}^{\circ}\)38\({}^{\prime}\)31.01\({}^{\prime\prime}\) E, Rome, Italy) on 8 June 2022, at the pre-harvesting phase. The field flow over includes the tests of the national durum wheat and soft wheat network [18]. The plants were arranged in a randomized block design of 10 \(\times\) 2 m\({}^{2}\) plots with a sowing density of 350 seeds/m\({}^{2}\) for durum wheat. The block design for both the durum and soft wheat s was framed by edges of barley plots. A total of 10 durum wheat parcels were analyzed. The test was carried out onto a part of a varieties collection planted to perform fertilization and plant protection screening and characterization.  
The phenomobile prototype system was used to acquire the multispectral signal of the plants. Figure 15 shows the output of the nine sensors. Using these data, the NDVI and GDVI indexes were calculated from Equations (2) and (3). These are shown in Figure 16, together with the RGB images obtained by combining the signal of sensors S1, S2, and S3.  
Generally, these reflectance indices derived from spectral vegetation measurements are widely exploited in experimental field research and breeding programs, as they enable the noninvasive estimation of the biomass, nitrogen content, and photosynthetic status of plants to provide interventions as needed. In addition, specific bands in the NIR region are of particular interest for large-scale plant phenotyping, as they allow estimating tissue water content and thus programming the differentiated responses of genotypes to drought.  
Figure 15: Output of the 9 sensors of the MAIA spectral camera on tomato plants (**A**), durum wheat (**B**).  
The phenomobile can be used for research and development purposes and is especially suitable for crop plots given its lateral measures ranges as reported above.