1) 3N, 5P

2) 5N, 3P

3) 0N, 5P

4) 5N, 0P

And two controls were used one positive and one negative:

5) 5N, 5P

6) 0N, 0P

The dependent variable was the resultant yield.

Six blocks were used and so 6 replicates. With 6 treatments overall, including the two controls. The design is a randomised complete block design (RCBD).

The Mutalau research station was the trial site.

 | Source | df
| Blocks | 6-1=5
| Treatment | 6-1=5
     Factor N= 3-1=2
     Factor P= 3-1=2
Interaction NP=4
| Residual | 35-5-9= 21
| Total | 36-1=35

Y is the individual observation when treatment factor ₓ (Nitrogen) is at either 0, 3 or 5 , and when the treatment factor ₐ (Phosphorus) is at either 0, 3 or 5, within block ₑ, which is either in 1, 2, 3, 4, 5 or 6.

μ is the overall mean

βₑ is the blocking effect,

αₓ is the treatment factor effect of Nitrogen

τₐ is the treatment factor effect of phosphorous

(ατ) ₓₐ is the interaction effect of nitrogen and phosphorous at the combination level of ₓₐ.

εₐₑₓ is the residual effect

H₀: there is no interaction between the treatment factors

H₁: there is an interaction between the treatment factors

 

If there is not sufficient evidence to reject the null hypothesis, the main effect hypothesis will be:

For δ (nitrogen)

H₀: the means are all the same

H₁: the means are not all the same

 

For τ (Phosphorus)

H₀: the means are all the same

H₁: the means are not all the same

all tests will be conducted at a significance level of 5%, or α = 0.05