Effect of Planting Arrangement on Forage Yield, Protein Content and Some Morpho-Physiological Characteristics of Forage Amaranth

Increasing yield in field crops requires identification of appropriate management practices including suitable planting arrangement. A field experiment was carried out to determine the effect of planting arrangement on forage yield, protein content and some phsio-morphological traits of forage amaranth at Gorgan agriculture research station, Gorgan, Iran, in 2017-2018 growing seasons. The experimental design was factorial arrangements in randomized complete block design with three replications. The first factor was the row spacing at three levels (30, 45 and 60 centimeter), and the second factor was inter plant spacing at six levels (5, 10, 15, 20, 25 and 30 centimeter). The results showed that the effect of inter plant spacing and the interaction effects of row spacing × inter plant spacing were significant on all studied traits. The effect of row spacing on all traits, except leaf to stem ratio, was significant. Considering the significant interaction effects, slicing of interaction effects was performed to determine the best inter plant spacing for each row spacing. In suitable combinations; 30 × 5, 30 × 10, 45 × 10 and 60 × 5 centimeters planting arrangement, higher protein yield and dry forage yield of 896-956 Kg.ha-1 and 7.7-8.05 ton.ha-1 were obtained, respectively. In summary, for achieving higher forage yield, if the row spacing is 30 cm the inter plant spacing should be 5-10 centimeters (plant density 66.6 and 33.3 plant m-2, respectively). Given the row spacing is 45 and 60 cm, then the inter plant spacing should be five centimeters (plant density 44.4 and 33.3 plant m-2, respectively). The results of this experiment showed that the appropriate planting arrangements for amaranth in Gorgan environmental conditions are 30 × 5, 30 × 10, 45 × 10 and 60 × 5 centimeter.