Effects of mycorrhiza biofertilizer and additive intercropping with peanut on growth, bulb formation, N and P contents of several varieties of shallot

Application of mycorrhiza biofertilizer to rice intercropped with soybean could increase growth and yield of rice. This study aimed to examine the effects of mycorrhiza biofertilizer application and intercropping with peanut relay-planted between double-rows of shallot on growth, N and P content, and harvest bulb number of several shallot varieties. The experiment was designed according to Split Split-Plot Design, testing three treatment factors, i.e. intercropping with peanut as the main plots (I0= without, I1= with intercropping), application of mycorrhiza biofertilizer as the sub-plots (M0= without, M1= with mycorrhiza application), and shallot varieties as the sub-sub-plots (V1= Bima Brebes, V2= Ketamonca, V3= Super Phillip). Results indicated that among the three treatment factors, mycorrhiza biofertilizer showed the most significant effects whereas intercropping did not show any significant effects. However, there were two-way interaction effects on some variables, and three-way interaction effect on harvest bulb number, with the highest average (12.8 bulb/clump) was on intercropped “Ketamonca” supplied with mycorrhiza biofertilizer whereas the lowest average (8.7 bulb/clump) was on monocropped “Bima Brebes” without mycorrhiza biofertilizer. Leaf N and P contents were also highest on peanut-intercropped shallot plants supplied with mycorrhiza biofertilizer, indicating the environmentally-friendly nature of using these treatments in increasing shallot productivity.