Standardisation of top working in nutmeg (Myristica fragrans Houtt.)

Abstract

The present investigations on “Standardisation of top working in nutmeg (Myristica fragrans Houtt.)” were conducted at the Department of plantation Crops and spices, College of Horticulture, Vellanikkara, Thrissur during 1991-1993. For the purpose of the study nutmeg trees available at state seed Farm, Mannuthy and farmers’ field at Mannuthy and Ettumuna in Thrissur district as well as Neduvannur in Ernakulam district were utilized. The presence of two type of buds on the bud stick could be distinguished by the bud scare at the inner side of the bark for the viable buds and absence of scar and browning in the non- viable buds. Among the difference methods tried, in situ budding on hard trunk proved to be most successful. Forkert method with bud selected from brown bud wood with fallen leaves and the buds inserted by leaving space on all the four sides gave maximum success. In order to achieve a quicker bud burst stumping the plants two months after budding was most effective. Budding on hard trunk could be done with maximum success in three year old plants and July was found to be the best season. Trials on topping of male trees indicated that heading back the tree above the first tier during August was found to be the best with regard to sprout production and reducing the time for sprouting. Forkert budding on new sprouts gave only initial success which failed to sprout even with physical and chemical treatments. Grafting on new sprouts showed least response among the method tried. Successful graft union was obtained during March with scion shoots having mature leaf and full green stem and stock having two months growth. The anatomical studies revealed low callus development and sparse differentiation of vascular tissues in the bud shield, presence of necrotic tissues hindering the formation of callus and the lack of union between old and new callus as the probable reasons for bud failure.