Agro-physiological responses of Tepary bean to planting patterns and plant densities

Planting pattern and plant density are efficient management tools for maximizing crop yield by reducing soil surface evaporation and optimizing resource utilization such as light, nutrients, and water. A two-year (2017-18) field trial was conducted to determine the effects of plant density and planting pattern on some agro-physiological and biochemical traits of Tepary bean (Phaseolus acutifolius L.) at the Research Station of Islamic Azad University, Arak Branch, Iran. The experiment was performed as a split-plot arranged in a randomized complete block design with three replications. The treatments were two planting patterns (one-row and two-row plantations) and three plant densities (30, 40, and 50 plants per m2). The results showed that that one-row planting pattern and 40 plants per m2 improved seed yield by 75% and 65% compared to 30 and 50 plants per m2 in one-row planting pattern in the second year, respectively. The plant chlorophyll content increased by 20% with two-row plantation and medium plant density compared to high and low plant density in the first year. The highest accumulation of seed carbohydrates (38.26 mg. g-1 FW) was obtained with two-row cultivation and medium plant density in the second year. The relative seed water content significantly decreased with one-row plantation and low plant density compared to a two-row plantation and medium plant density. The least malondialdehyde and proline aggregation (3.2 and 225 µ mol. g-1 FW, respectively) was achieved with two-row plantation and medium plant density. Finally, a two-row planting pattern with medium-density cultivation is recommended to obtain optimal Tepary bean seed yield in the region.