Acceleration of growth in tomato seedlings grown with growth retardant

Abstract

In vegetable growing, seedling is the foundation of a successful growing. Use of commercial seedlings have become more popular in recent years due to effective use of labour and land and economic concerns. It is aimed to produce small vigorous seedlings with sufficient roots and free of diseases and pests in the commercial seedling enterprises. Although certain cultural applications are used for production of small-sized seedlings, growth retarding chemicals are generally preferred due to their effective results. There are some concerns regarding on-going retarding effects of such chemicals under field conditions. In this study, it is aimed to remove the possible retarding effects provided by paclobutrazol in dosages of 0, 25, 50 and 100 ppm applied on tomato seeds in a short period of time by applying gibberellic acid (GA3) in dosages of 0, 50, and 100 ppm by spraying it on the leaves. In this study, the plant height (cm), stem diameter (mm) height to stem diameter ratio, number of blooming cluster and dry matter ratio of stem (%) were determined in the different stages of growth. Paclobutrazol ensured a height control of 26.45%-40.85% on the height of plants in the seedling period depending on the dosage, and this ratio varied by 19.51 to 45.86% under field conditions. It has been found out that effects of paclobutrazol diminished in time, and these effects were removed faster by GA3 applications. Paclobutrazol, as opposed to GA3, decreased the height to stem diameter ratio and induced formation of a stronger seedling. Paclobutrazol increased the number of blooming clusters, whereas GA3 had no significant observable effect on the number of blooming cluster. It has been concluded that 50 ppm paclobutrazol can be used for height control of the seedling in terms of growth and flowering, and 100 ppm GA3 should be applied for quality plant growth and to remove possible retarding effects.