Context :

Aims : Recent work has shown that major mergers of disc galaxies can only account for \sim 20 % of the growth of the galaxy red sequence between z = 1 and z = 0 .
Our goal here is to provide merger frequencies that encompass both major and minor mergers , derived from close pair statistics .
We aim to show that reliable close pair statistics can be derived from galaxy catalogues with mixed spectroscopic and photometric redshifts .

Methods : We use B - band luminosity- and mass-limited samples from a Spitzer /IRAC-selected catalogue of GOODS-S. We present a new methodology for computing the number of close companions , N _ { \mathrm { c } } , when spectroscopic redshift information is partial .
The methodology extends the one used in spectroscopic surveys to make use of photometric redshift information .
We select as close companions those galaxies separated by 6 h ^ { -1 } kpc < r _ { p } < 21 h ^ { -1 } kpc in the sky plane and with a difference \Delta v \leq 500 km s ^ { -1 } in redshift space .

Results : We provide N _ { \mathrm { c } } for four different B - band-selected samples .
It increases with luminosity , in good agreement with previous estimations from spectroscopic surveys .
The evolution of N _ { \mathrm { c } } with redshift is faster in more luminous samples .
We provide N _ { \mathrm { c } } of M _ { \star } \geq 10 ^ { 10 } M _ { \odot } galaxies , finding that the number including minor companions ( N _ { c } ^ { m } , mass ratio \mu \geq 1 / 10 ) is roughly two times the number of major companions alone ( N _ { c } ^ { M } , mass ratio \mu \geq 1 / 3 ) in the range 0.2 \leq z < 1.1 .
We compare the major merger rate derived by close pairs with the one computed by morphological criteria , finding that both approaches provide similar merger rates for field galaxies when the progenitor bias is taken into account .
Finally , we estimate that the total ( major+minor ) merger rate is \sim 1.7 times the major merger rate .

Conclusions : Only 30 % to 50 % of the M _ { \star } \geq 10 ^ { 10 } M _ { \odot } early-type ( E/S0/Sa ) galaxies that appear between z = 1 and z = 0 may have undergone a major or a minor merger .
Half of the red sequence growth since z = 1 is therefore unrelated to mergers .