Ratings of rooting systems (left) were best, good, and fair. Almost all types of vine wood yielded good root systems and resulted in vigorous plants. Propagating California wild grape James A. Robbins 0 David W. Burger Easy to start from cuttings, the vine is useful in landscape plantings California native plants are being used fluenced by such factors as date of collec- ing at that time, sap was flowing freely in increasingly in landscape and revegeta- tion, storage conditions, and type of cane the stems. The segments were transport- tion projects, but little information is wood. We conducted a study to investigate ed to Davis in an ice chest and stored in a available on how to propagate them. Cali- the effect of chemical pretreatment, cold room at 43°F (6°C) for three days. fornia wild grape, Vitis californica wood type, and rooting medium on the Before preparing and treating the cut- Benth., is one such plant that would be rooting of dormant hardwood cuttings of tings, we graded the stem wood into seven useful in the revegetation of steep slopes the California wild grape. classes according to stem diameter, stem and embankments. This vigorous, decidu- length, and type of wood (table 1). Al- ous, woody vine, which grows along though this grouping is artificial, these streams throughout the Coast Ranges, Rooting study categories correlated well with the posi- Central Valley, and Sierra Nevada foot- We collected propagation material in tion of wood on the original canes. Thin- hills, can cover large areas in a short mid-March 1985 from wild vines growing nest wood (grade A) would be associated time. Flowers produced in May and June, along the northern shore of Folsom Lake with the terminal part of the canes, thick- although not showy, are very fragrant, near Newcastle, California. Dormant est wood (grade G) with the older wood and the leaves, which resemble a typical canes of one- to two-year-old wood (6 to 10 closer to the base of the cane. We pre- grape leaf, offer a pleasing spectrum of yards long) taken from several plants pared the cuttings by making a fresh colors in the fall from lemon-yellow to were cut into stem segments 4 to 10 transverse cut above the uppermost node orange-pink and maroon. The vine lends inches long with two to four nodes per and a slant cut below the bottommost itself to training on an arbor, providing segment. Although no buds were expand- node. shade in the summer. Although relatively drought tolerant, the California wild grape benefits from moderate watering. A great deal of information exists on TABLE 1. Characteristics of wood grades used for preparing cuttings of the California wild grape the vegetative propagation of other grape Mean stem Mean stem species, but none is available on the Cali- Wood Bark Nodes/ segment segment fornia wild grape. Hardwood cuttings of grade type stem segment diam. length the European grape, Vitis vinifera, read- number mm cm ily form adventitious roots. Cuttings from A Smooth 2-4 4 12 0 Smooth 2-3 5 13 some American grape species and their C Pubescent 2-3 6 14 hybrids, however, often require special D Shredding 2-3 7 15 treatment to induce rooting. E Shredding 2 8 17 Other researchers have found that F Shredding 2 9 19 rooting of hardwood grape cuttings is in- G Shredding 2 10 21 CALIFORNIA AGRICULTURE, MAY-JUNE 1986 9 Treatments included two soil media rooting media in wooden flats. The flats ages. All wood grades except G had sub- and four pretreatment solutions. The two were misted with deionzed water (2% sec- stantially better rooting percentages media were peat:vermiculite (1:l by vol- onds every 2% minutes, dawn to dusk) in after the additional 33 days. ume) and very coarse sand. We used man- a mist bench with bottom heat of 77°F The rooting percentage after 57 days ganese sulfate (MnSO,) as one of the pre- (25°C). Greenhouse temperatures were appeared to be slightly better on the me- treatment solutions, because research in 75°F (24°C) (day) and 64°F (18°C) (night). dium grade woods (C, D, E, F), indicating the past had shown that it increased the On three dates, we removed cuttings a small gradient in rooting ability depend- rooting of several grape varieties. We and evaluated them for rooting percent- ing on the location between vine base and also tested two forms of the auxin IBA - age and quality of the root system. In apex from which cutting material was the acid and the potassium salt (K-IBA). judging quality, we considered both the collected. Auxin is the class of plant hormones most number and length of roots produced. Us- Based on the overall rating at all sam- often associated with increased rooting of ing a numerical value for each quality pling times, grade C wood is the best cuttings. A number of researchers have rating (best=3, good=2, fair=l) and the source for cutting material. Cuttings pre- investigated the effect of synthetic auxins number of cuttings in each category, we treated with deionized water for 24 hours on the rooting of grape varieties with calculated a general quality rating. Multi- had similar rooting percentages and over- variable results; some varieties have re- plying this value by the rooting percent- all ratings to those treated with manga- sponded favorably and others not at all. age yielded an overall cutting rating. Cut- nese sulfate. The four treatment solutions with the tings that had rooted were not returned to K-IBA was no better or worse as a peat:vermiculite medium were 10 mM the flats. chemical pretreatment for wild grape manganese sulfate, 0.8 mM indole-3-b~- than manganese sulfate or water. A 50 tyric acid (potassium salt, K-IBA), 1 mM Results percent ethanol solution of IBA was clear- indole-3-butyric acid (IBA), and deionized Our results indicate that California ly phytotoxic, killing all cuttings within 24 water. Cuttings rooted in sand were treat- wild grape is easy to propagate. Quality days of treatment. ed with 10 mM manganese sulfate. The root systems and high rooting percent- The rooting medium significantly af- solvent for all chemicals was deionized ages can be achieved with little effort. fected rooting percentages and the type of water, except for the IBA, which was dis- Of the cuttings treated with manga- root system produced (general rating). All solved in 50 percent ethanol. nese sulfate and rooted for 24 days in cuttings (grade C wood) in coarse sand After soaking the basal 2 inches of the peat:vermiculite, grades A, C, and G had rooted in 24 days, but only 60 percent of cuttings in the treatment solutions for 24 the highest rooting percentages (fig. 1). those in peat:vermiculite had rooted by hours, we rinsed them in deionized water, After an additional 33 days of rooting, this time (fig. 2). Although rooting was then inserted the basal 2% inches into the grades C and D gave the highest percent- faster in sand, the roots produced were finer and less numerous than those in peat:vermiculite. We obtained similar rooting results for the other wood grades evaluated. Therefore, if propagation bench space is not limited, a better root 100 100 system would be obtained by using peat: r vermiculite and allowing cuttings to root for at least 57 days. Conclusions Based on these results, we can make several recommendations for the vegeta- tive propagation of California wild grape: Cuttings should be collected in late winter or early spring (March, April) to avoid problems with bud dormancy. Ma- B terial collected for our experiments broke buds within days of being placed in the mist beds. It has been shown that, for sev- eral grape varieties, the time of season at which cuttings are made does not affect root formation but does affect bud break. Almost all types of vine wood will yield fairly good quality root systems and high rooting percentages. Chemical pretreatment does not ap- ABCDEFG Peat/vermiculite Sand pear to be required for good rooting when Wood grade Rooting medium cuttings are collected in late winter. 24 days 24days The rooting medium influences the 39 days 39 days type of root system and speed at which it 057 days 057 days is produced. Choice of rooting medium should be based on specific needs. James A. Robbins is Post-Graduate Researcher and David W.Burger is Assistant Professor, Department Fig. 1. Medium-gradewood had the highest Fig. 2. Rooting medium significantly affect- of Environmental Horticulture, University of Cali- fornia, Davis. This research was supported by a rooting percentages (A) and best overall ed rooting percentages (A) and type of root -erant for environmental research from The Pacific rating (B) after 57 days. system produced(overall rating, B) . Gas and Electric Company 10 CALIFORNIA AGRICULTURE, MAY-JUNE 1986 .