Question

1. I want to verify the difference of c/n ratio in each part of the plant between before treatment(leaf wounding) and after treatment using SPSS. Should I use covariance analysis to control the value of before treatment? If so, how can I use it ( I only have these data.). If not, what method should I use?

2. Why did C/N ratios differ more when new leaves were damaged compare with mature leaves? (Plz give me references)

		Before treatment			After treatment
		Average	standard deviation	N	Average	standard deviation	N
Sun	Mature leaf	10.56	1.05	10.00	17.00	3.07	9.00
	New leaf	9.68	1.85	9.00	19.69	3.07	8.00
	control	10.79	1.42	9.00	18.97	5.33	8.00
Shade	Mature leaf	10.29	1.01	7.00	20.63	3.77	9.00
	New leaf	8.66	0.45	10.00	20.50	2.11	9.00
	control	10.32	2.18	10.00	20.52	3.65	10.00

Answer 1

Answer:

1:

Yes, this method is suitable for this test.

Analysis of covariance contains mix the variance analysis technique and regression by introduction the nominal and continuous charitable(measurement) In the single model.

In the random experiment precise on can be increased by this method.

This method is applied before the treatment and it is used where we want to compare the relationship of regression at the various level of the charitable of treatment.

This method is suitable for medical, research and ecological research.

2:

C/N ratio differs more when new leaves were damaged compare with mature leaves because of decreased carbon level in the new damaged leaves in comparison to the others.

Hence, difference in the comparison of ratio occurs.

Reference:

Masclaux-Daubresse, Céline, et al. “Nitrogen Uptake, Assimilation and Remobilization in Plants: Challenges for Sustainable and Productive Agriculture.” Annals of Botany, vol. 105, no. 7, 2010, pp. 1141–1157., doi:10.1093/aob/mcq028.