Doubt if any, since the crop rotation makes it rather senseless to develop such a data set

Here is some of them:

https://datadryad.org/stash/

https://dataverse.harvard.edu/dataverse/ODjAR

https://catalogue.ceda.ac.uk/uuid/211ce60ba1cf4336b189b1e15859088d

See this paper:

Leaf Spectral Reflectance of Maize Seedlings and Its Relationship to Cold Tolerance

I mean open datasets, not articles. According to your research, the following can be said: corn belongs to C-4 plants according to the type of carbon metabolism, so the reaction to stress in the change in reflectivity is worse expressed than in wheat or barley. Due to the fact that you use linear indexes, therefore, you do not get the obvious result. Try additionally recording CIF fluorescence.

Thanks so much

I am busy with other projects right now. I tray all possible wavelength and if you look to the heatmap you will find that in Fig.7.

Here are superbly organized, exemplary data sets !!!

"Laboratory, field, mast-borne and airborne spectral reflectance measurements of boreal landscape during spring" https://zenodo.org/communities/boreal_reflectances/?page=1&size=20 Such data sets allow you to check and compare different research methods and find the best !!!

Preprint A New Model of “Color” Vision for Remote Sensing

New open plant and crop remote sensing dataset

the EcoSIS spectral library (ecosis.org)