54 MASS. EXPERIMENT STATION BULLETIN 436 



Material Amount per Percentage of Cuttings Rooted 



Square Foot In 9 Weeks In 20 Weeks 



Untreated 92 



Formaldehyde 2.5 cc. 88 93 



Potassium permanganate 7 grams 86 95 



Fermate 28 grams 6 70 



Spergon 14 grams 12 50 



Rooting was quicker and better with the formaldehyde and potassium per- 

 manganate treatments than in the untreated medium. Fermate and Spergon 

 prevented rot, but had a decidedly retarding effect on rooting. Apparently, when 

 propagating media are to be used again, the preferred treatment is either formalde- 

 hyde or potassium permanganate. 



In a comparison of the root-promoting substances, Hormodin No. 2 and 

 Hormodin No. 3, in used sand treated with formaldehyde 2.5 cc. per square foot 

 or with potassium permanganate 7 grams per square foot, better and quicker 

 rooting was obtained with Hormodin No. 2. In the formaldehyde-treated sand 

 Hormodin No. 2 gave 96 percent rooted in 10 weeks, against 80 percent for No. 3. 

 In the sand treated with potassium permanganate, the percentage rooting in 10 

 weeks was 96 for Hormodin No. ? against 86 for No. 3. 



Control of Weeds in the Nursery by Chemical Sprays. (C. J. Gilgut, Waltham.) 

 During the past season, Savasol No. 5, one of the oils which has found such a 

 definite place in the commercial growing of carrots and parsnips, was investi- 

 gated for control of weeds in the nursery. Nearly all the common weeds were 

 quickly killed, especially when they were small. A few, notably ragweed {Am- 

 brosia artemesiifolia L.), wild chamomile (Matricaria suaveoletis (Pursh) Buche- 

 nau), and fleabane {Erigeron canadensis L.), all of which are in the family Compos- 

 itae, were highly resistant to the oil and both young and old plants usually sur- 

 vived even thorough soakings. 



Applications of undiluted oil were made with a 4-gallon sprayer equipped 

 with a Skinner greenhouse irrigation nozzle, ST 50, which gives a flat fan-shaped 

 spray. A flat spray is better than a cone-shaped for it wets the weeds better 

 and is more easily controlled so that less oil gets on the nursery plants. The 

 spray was directed at the weeds, and in the case of tall nursery plants the lower 

 foliage of these plants was also wet. With the smaller nursery stock, it was neces- 

 sary to wet the entire plant in order to wet the weeds. 



On hemlock there was no injury to the older leaves, and slight injury to the 

 soft, tender new needles but not enough to retard growth. Arbor vitae was like- 

 wise highly resistant, and young plants 12-15 inches tall showed only slight 

 yellowing of foliage. Norway spruce and Colorado blue spruce, as well as white 

 pine and Scotch pine, showed little or no injury. The most tolerant of all the 

 evergreens tested was Junipenis virginiana glauca, which showed only a slight 

 yellowing of some of the needles and no bark injury when sprayed much more 

 heavily than is needed to kill weeds. 



On Taxus spp. the spray injured the leaves and caused considerable defoliation 

 as well as some bark injury, and it definitely is not safe on this group of plants. 

 In general, on broad-leaf plants, evergreen and deciduous, there was considerable 

 injury to the leaves, and to the bark in many cases if wet to any extent. 



Although most of the narrow-leaf evergreens are highly tolerant to Savasol 

 No. 5; as with other chemical sprays, caution should be used that too much 

 spray does not get onto the plants. A careful operator, using a flat fan-shaped 

 spray, can kill weeds close to the plants in a nursery row quickly and efficiently 

 with a minimum of injury to the stock. 



