Effect of Transplanting Petunia Plugs at Different Stages of Development

Abstract

<jats:p>Petunia seeds of `White Cascade', `Red Flash', and `Red Madness' were sown in 406 plug trays on the same date. The first transplanting occurred when the plants could be removed from the cells without root damage. Subsequent transplanting occurred for four weeks. The first transplanting of `White Cascade' flowered two weeks earlier than the second while the third transplanting was one week behind the second. `Red Flash' flowered two weeks earlier for the first transplanting. There was no effect on time to flower for the `Red Madness'. The highest fresh and dry weights corresponded to the earliest flowering transplants. Optimum growth and development for most petunia cultivars was obtained with the earliest transplanting without root damage.</jats:p>

Nutrient concentrations and root substrate formulations influence the performance of seedling grafts of tomato

“…The treatments of the highest seedling growth of rootstock 'J3B strong' in fresh weight were 4.0× in PM+PL and 1.0× in PM+VM medium (Table 1) and the electrical conductances of the two treatments were 0.79 and 1.35 dS m -1 , respectively, 31 d after sowing (Table 2). These results indicate that the optimum range of EC recommended by Koranski (1990) for the seedling growth of floral crops in stages 3 and 4 are suitable for the seedling growth of 'J3B strong' before grafting. Similar results were obtained in the growth of scion 'Sunmyung', as shown in Table 1.…”

“…This requires the addition of pre-planting fertilizers during the formulation of rooting media. The level of pre-planting fertilizers incorporated into root media during the formulation for plug seedling growth can be found in a number of previous studies (Argo, 1998;Koranski, 1990;Handreck, 1996;Nelson et al, 1996;Styer and Koranski, 1997). However, most of the previous studies are related to floral crops and limited research results to grafted plug seedlings of fruit vegetables are available in the optimum pre-planting fertilizer levels of root media.…”

“…Almost all of the commercial root media sold in the U.S. and European countries for raising plug seedlings contain pre-planting fertilizers (Argo, 1988;Nelson, 2003). The recommended optimum level of salt concentrations in terms of EC for seedling growth is in the range between 0.5 to 1.0 dS m -1 (Koranski, 1990;Nelson et al, 1996;Styer and Koranski, 1997) when EC is measured by the saturation extraction method (Warncke, 1988). Styer and Koranski (1997) described the optimum concentrations of mineral elements in the soil solution of root media for plug seedling growth of floral crops.…”

“…Styer and Koranski (1997) described the optimum concentrations of mineral elements in the soil solution of root media for plug seedling growth of floral crops. Based on their reports, the optimum nutrient concentrations are 40 to 60 for NO 3 -N, 5 to 8 for P, 50 to 100 for K, 60 to 120 for Ca, and 30 to 60 mg L -1 for Mg. Koranski (1990) also recommended that salt concentration (EC) for raising plug seedlings should be included in the range between 0.75 to 1.2 dS m -1 in plug stages 1 and 2. The optimum concentrations of individual mineral elements recommended by him for these stages are 40 to 75 for N, 10 to 15 for P, 30 to 50 for K, 50 to 75 for Ca, and 25 to 35 mg L -1 for Mg.…”

“…He also recommended the EC level and nutrient concentrations for stages 3 and 4. The optimum ranges recommended by Koranski (1990) for plug stage 3 and 4 of general floral crops are 1.0 to 1.5 dS m -1 in EC, 60 to 100 for NO 3 -N, 10 to 15 for P, 50 to 80 for K, and 80 to 120 mg L -1 for Ca.…”