Influence of irrigation frequency and different combinations of the potting mixture on shoots and root growth of betel

Abstract

Betel is an export agriculture crop in Sri Lanka. In the traditional propagation method, orthotropic cuttings were taken from high yielding mother bushes. These healthy cutting can be planted directly in the field or planted in poly bags nurseries. A mixture of topsoil, cattle dung, coir dust and compost was used in equal portions. Usually, potting mixtures and irrigation frequencies are used unorganised by betel growers at a nursery in Sri Lanka. Therefore, this study was conducted using grower practices to determine the optimum level of irrigation frequency and to identify a lower cost potting mixture for obtaining the best quality nursery plants for planting. The research was conducted at Vairavapuliyankulam, Vavuniya district, during Yala season 2019. Orthotropic cuttings with three nodes were selected from a healthy and high yielding mother bush of Maneru variety, popular among betel varieties with high export quality. The experimental design was a Randomized Complete Block Design with twelve treatments and five replicates. Four types of the potting mixture were used with four different components at equal ratio (1:1:1:1), such as topsoil, sand, cattle dung, and coir dust for control (M1), topsoil, sand, cattle dung, paddy husk for (M2), topsoil, sand, cattle dung, and sawdust for (M3), topsoil, sand, compost and coir dust for (M4) were used. Irrigation was done on a daily basis (I1), at three-day intervals (I2) and at five-day intervals (I3). Data were collected at 3, 6 and 8 weeks after planting of cuttings in poly bags. The treatment combination of M1 and M4 with I1 was recorded for better growth performance compared to other treatments. At eight weeks after planting, treatment M1M1 was significantly showed the highest values (p- value) for shoot length (7.9 cm), fresh weight (102.7 mg), dry weights (15.4 mg), roots number (18 per plant), total root length (12 cm) dry weight (2 mg). This study revealed that coir dust used for the potting media could not be replaced by sawdust or paddy husk, but cattle dung can be replaced by using compost for the potting media. Daily irrigation gave better growth in the nursery plants compared to other irrigation intervals.