I think you should use the highest quantity of data that you can obtain, speacially if you want to make some inferences. It is important to notice that your data should be at the nearest of your study area.
I would suggest scaling down your research objectives to 2-3 parameters of climate change variability (specific to the crop of interest). Once you determine that, you can mine your data and see what it shows. Some indicators might be salient than others.
If the region I want to assess has 2 regional climate data. How do I aggregate two regional climatic data. I assume that crop data is only available as an aggregate data not a regional data.
Hi Dear, You have to decide which factor you want to study. For studies on climate change a long time good climatological data is required. Yes of course, one must use reliable data for studies. Thanks