Quantitative Effects of Planting Time on Vegetative Growth of Broccoli (Brassica Oleracea Var. Italica)

Abstract

This study was carried out in the research field of The Black Sea Agricultural Research Institute in Turkey from spring to winter, 1999. Cv. Platini, which is known as sprouting broccoli, was used in the study. Seedlings were raised in module seed trays. Planting procedure was repeated for the times, viz., 25 April (first, P1), 27 May (second, P2) and 27 June 1999 (third, P3). The aim of the study was to see a clear picture of the effects planting times (growing periods) on plant growth parameters, viz., leaf thickness (LT), leaf area (LA), total plant dry weight (TPDW), leaf weight ratio (LWR), stem weight ratio (SWR), root weight ratio (RWR), specific leaf area (SLA), leaf area ratio (LAR), net assimilation rate (NAR) and relative growth rate (RGR) and plant growth accordingly. The results showed that LWR decreased with time after planting while SWR increased with time. Generally, later planting times resulted in higher SWR and LWR while early planting times had higher RWR. Both LAR and SLA declined with ontogeny. Earlier planted plants had higher LAR and SLA. NAR and RGR were found to be lower with earlier plantings. LA and TPDW varied with planting times and ontogeny. Both LA and TPDW increased with time after planting and plants from earlier plantings had lower LA and TPDW values. LT was higher at later planting times and increased with time. Significant positive and negative relationships were also found between plant growth parameters.