Evaluation of Potato and Pinto bean Intercropping

To evaluate beneficial effect of intercropping based on replacement and additive methods to sustainable agriculture, two experiments were conducted at the Agricultural Research Station of University of Tabriz in 2005 and 2006, to study the effect of intercropping potato and pinto bean by using these two methods. The experiments carried out using randomized complete block design with three replications and 16 treatments. The treatments, consisted of: eight treatments of replacement intercropping with 2:1 and 3:1 proportions of potato and pinto bean (with densities of 4.7 and 5.3 plants m-2 for potato and 45 and 55 plants m-2 for pinto bean), four treatments of additive intercropping (with densities of 4.7 and 5.3 plants m-2 for potato and 5.3 and 10.6 plants m-2 for pinto bean), two sole croppings of potato (4.7 and 5.3 plants m-2) and two sole croppings of pinto bean (45 and 55 plants m-2). Maximum tuber yield per plant, tuber yield of potato per unit area, tuber size, mean tuber weight, number of leaves and branches per plant were obtained from replacement intercropping treatments. Maximum grain yield of pinto bean per unit area was obtained from the replacement intercropping treatments; Maximum grain yield per plant, number of pods per plant, number of leaves and branches, plant height, dates of emergence, flowering, poding and ripening were obtained from the additive intercropping treatments. To evaluate the beneficial effect of intercropping, land equivalent ratio (LER) was more than one, and the maximum amounts for two years (1.25 and 1.27, respectively) belonged to replacement intercropping of 1:2 treatment (66% potato with 5.3 plants per m2 34%pinto bean with 55 plants per m2). This treatment, therefore, can be recommended to be the best intercropping pattern for sustainable agriculture.