An evaluation of pepperbean intercropping using different plant populations and bean cultivars

One of the advantages of intercropping has been the increase in yield over the monocultures. Intercrop yield can be improved by selecting for compatible cultivars and by efficient spacing arrangements of the component crops. A field experiment was conducted in the 1990 growing season to compare two spacing arrangements for the pepper/bean intercrop, to observe the effects of three bean cultivars on the system, and to examine whether there is any interaction between cropping system and bean cultivar. Three bean cultivars (Frenchie, Earliserve, and E-Z Pick), differing in their morphology and time to maturity, and one pepper cultivar (Hybrid Bell Boy) were used in the study. In the intercrop, the beans were sown at 50% of the optimum bean monocrop density while the peppers were planted at 100% or 50% of the optimum pepper monocrop density, resulting in 50:50 and 100:50 pepper/bean intercrop treatments. The experiment was repeated the following growing season with the addition of light transmission measurements, an $ sp{15}$N experiment to test for the possibility of nitrogen transfer, and the addition of three monocrop treatments (one for each cultivar) with the same intra-row spacing as in the intercrops. Beans were generally the dominant crop for both years. When compared to the optimum monocrops on a per plant basis, intercropping increased bean yields by 52% and 31% and decreased pepper yields by 49% and 21% in 1990 and 1991, respectively. The LER (Land Equivalent Ratio) ranged from 0.96 to 1.23 in 1990 and from 1.09 to 1.42 in 1991, with the 100:50 intercrops usually having the higher values. Frenchie and E-Z Pick were best suited for intercropping in 1990 and 1991, respectively. The overall increase in yields in intercropping was probably due to the larger bean intra-row spacing and the greater utilization of light, water and nutrients, as well as the increased population pressure in the 100:50 intercrop. Bean cultivars generally performed the same relative