The Effect of Planting Date and Different Amounts of Nitrogen and Phosphorus Chemical Fertilizers on Biochemical Traits and Seed Yield of Lallemantia (Lallemantia iberica)

This study investigated the effects of planting date and nitrogen-phosphorus fertilizer levels on the physiological, morphological, and biochemical traits of Lallemantia iberica (Balango) at a medicinal plant farm in Azna County, Lorestan Province, Iran. The experiment utilized a two-factor factorial design within a randomized complete block design (RCBD) with three replications. The factors included two planting dates (Autumn: November 1; Spring: March 1) and three fertilizer levels (Control: no fertilizer; 50%: 50 kg ha-1; 100%: 100 kg ha-1). Key findings from the variance analysis revealed that the interaction between planting date and fertilizer levels significantly influenced protein and nitrogen yield, total carbohydrate content, mucilage percentage, thousand-grain weight, and seed yield at the 1% probability level. Phosphorus yield was affected by planting date at the 5% level and by fertilizer amount at the 1% level. Spring planting with full fertilizer (100 kg ha-1) resulted in the highest grain nitrogen yield (1.92%), mucilage percentage (7.66%), and thousand-grain weight (2 g). Autumn planting with half fertilizer (50 kg ha-1) achieved the highest grain protein content (9.85%), total carbohydrate content (80.18 ppm), and seed yield (1065.06 kg ha-1). Autumn planting with full fertilizer led to the highest grain phosphorus content (7.07 ppm). The interaction between autumn planting and half-fertilizer also produced a high mucilage percentage (7.4%) and thousand-grain weight (1.97 g). Generally, it is recommended to apply 50% of the fertilizer during the autumn planting season to optimize the cultivation of the Balango plant in the desired area, as it balances yield and biochemical quality while conserving resources. This study provides valuable insights for optimizing cultivation practices to enhance the productivity and quality of this medicinal plant.