Propagation of some grape rootstocks in enriched organic media and their subsequent graft success

Abstract

Three experiments were carried out at Indian Institute of Horticultural Research (IIHR), Hessaraghatta, Bangalore–89 during the year 2006-07 to study the effect of various substrates and microbial combinations on rooting and graft success of grapevine rootstocks. The experiments consisted of three grapevine rootstocks viz., Dogridge, St.George and 1613 and three substrates namely plant sap, humic acid, vermiwash and a control and seven microbial combinations (M1: Glomus mosseae + Trichoderma harzianum, M2: Glomus mosseae + Bacillus subtilis, M3: Glomus mosseae + Pseudomonas fluorescens, M4: Glomus mosseae + Trichoderma harzianum + Bacillus subtilis, M5: Glomus mosseae + Trichoderma harzianum + Bacillus subtilis + Pseudomonas fluorescens, M6: IBA and M7: control). Among the substrates used, humic acid significantly influenced almost all the root and shoot parameters in hardwood grapevine cuttings of the three rootstocks. Next best treatments were vermiwash and plant sap. Among various microbial combinations tried, treatment M5 was the most effective for almost all the root and shoot parameters studied as compared to control. Other microbial combinations (M1, M2, M3 and M4) gave similar results as IBA treatment. Among different grape rootstocks tested, the root development was significantly superior in 1613, while St. George rootstock showed the best shoot development. Early budbreak was recorded in the cuttings treated with plant sap which was on par with the cuttings treated with vermiwash. Among the different microbial combinations M2, M3 and M5 gave early budbreak as compared to control. The percentage of graft success and root colonization was significantly increased by humic acid, whereas other substrate treatments were not significant. The percent graft success was significantly increased by M4 and M5, while the percentage of root colonization was significantly increased by all the microbial combinations (M1, M2, M3, M4 and M5). The rootstock 1613 gave the highest percent graft success, while St. George showed the highest percentage of root colonization 13