The Effect of Planting Arrangement, Phosphorus and Nitrogen on Physiological Traits and Guar Yield (Cyamopsis tetragonoloba L.)

Abstract

Background: The guar, known as Cyamopsis tetragonoloba L., is an annual, summer plant of the legume family and importance of guar as a food, industrial and medicinal product is new in the cultivation pattern. Methods: This combined experiment was conducted as factorial based on a randomized complete block design with three replications during two consecutive years (2020-2021) under the climatic conditions of Jiroft area (Kerman province, Iran) in the farm of research center and agricultural and natural resources education. Three levels of Nitrogen (20, 60 and 100 kg pure nitrogen per hectare) from a source of urea and phosphorus fertilizer at two levels (zero and 75 kg P2O5 source per hectare) and a source of monopotassium phosphate fertilizer and three levels of planting row spacing (30, 45 and 60 cm) equivalent to 47, 31 and 24 plants per square meter, plant density was taken into account. Result: The highest chlorophyll a (2.69 mg/fresh weight), chlorophyll b (1.97 mg/fresh weight) and carotenoid (2.64 mg/fresh weight) was measured for guar in treatment N3P2D3 under application nitrogen 100 kg/ha-1 + phosphorus 75 kg/ha-1 + planting row distance 60 cm, while the lowest chlorophyll a (1.85 mg/fresh weight), chlorophyll b (1.25 mg/fresh weight) and carotenoid (1.72 mg/fresh weight)was observed in treatment N1P1D1 under nitrogen 20 kg/ha-1 + phosphorus zero kg/ha-1 + planting row distance 30 cm.