I want to know how analyze growth data taken from two section of the same greenhouse with different temperature levels and humidity levels. 3 different varieties used as the treatments. What could be the suitable experimental design.
Taking into account the context of the main question, a first approach regarding a suitable experimental design could be a completely randomized one with two factors. The first factor includes two levels, each corresponding to each plot and the second factor includes three levels, each corresponding to each studied variety. This design could be applied for each measured variable concerning growth and yield data. A first step of statistical analysis is analysis of variance for the aforementioned design.
For analyzing such problems, you may need to read, arithmetic and geometric series as well as their means. http://www.mathcentre.ac.uk/resources/uploaded/mc-ty-apgp-2009-1.pdf