Optimal sowing time and planting density for selected field grown cut Antirrhinum and Matthiola

Abstract

A field study was conducted on selected cultivars of Antirrhinum majus L. and Matthiola incana L. at University of Agriculture, Faisalabad, Pakistan, to determine the best planting time and density to develop optimal planting protocols to grow these species as cut flowers in the sub-tropics. Antirrhinum and Matthiola seeds were sown five times at 15 or 16 d intervals on 15 Sept., 01 Oct., 15 Oct., 01 Nov. or 15 Nov. In a separate study, the optimum planting density was determined by transplanting seedlings at 15 × 15, 15 × 22.5, 22.5 × 22.5, 22.5 × 30 or 30 × 30 cm apart. For planting time, both species demonstrated shorter crop time with delayed sowings, but delayed sowing reduced stem quality. Cultivars of both species sown on 15 Sept. had the tallest plant height, 104.2 and 58.6 cm for Antirrhinum and Matthiola, respectively, along with the greatest number of leaves (176.7 and 28.9), leaf area (13.7 and 35.0 cm2), number of florets (32.8 and 14.8), floret diameter (41.3 and 47.3 mm), raceme length (27.2 and 14.6 cm) and stem diameter 14.8 and 9.9 mm for Antirrhinum and Matthiola, respectively, compared to those sown on 15 Nov. Moreover, vase life of stems of both species decreased (4.0 d for Antirrhinum and 5.5 d for Matthiola) with delayed sowing time. Among all tested cultivars of Antirrhinum, ‘Admiral White’ flowered the earliest, ‘Potomac Orange’ and ‘Potomac Yellow’ flowered mid season, and ‘Potomac Rose’ and ‘Potomac White’ took longest to produce flowers, while all Matthiola cultivars produced flowers at similar times for each sowing date. Antirrhinum and Matthiola planted at 30 × 30 cm spacing had greatest number of leaves (198.1 and 31.4 for Antirrhinum and Matthiola, respectively), leaf area (14.3 and 40.1 cm2), number of florets (32.4 and 15.4), floret diameter (36.1 and 47.7 mm), raceme length (26.2 cm of Antirrhinum only) and stem diameter (14.1 and 14.7 mm for Antirrhinum and Matthiola, respectively) compared to those planted at 15 cm × 15 cm. In summary, for extending harvest season, Antirrhinum cultivars may be sown at same time, but Matthiola cultivars should be grown using staggered sowing times. Antirrhinum and Matthiola cultivars may be sown on 15th September to 1st October and transplanted at 22.5 × 22.5 cm spacing for best cut stem quality.