Rosa x fortuniana is famously resistant to nematodes. I was wondering whether the resistance was inherited from Banksiae, Laevigata or both. I found this. I assume that “Rosa laevigata Michx. anemoides” is ‘anemonoides’ = ‘Anemone’ or ‘Ramona’.
Pratylenchus (Nematoda: Pratylenchidae): Diagnosis, Biology, Pathogenicity and Management, p. 384 (2007)
By Pablo Castillo, Nicola Vovlas
In Rosa spp., Coolen and Hendrickx (1972b) identified slight resistance to P. penetrans in one (R. eglanteria) out of 13 common commercial rose rootstocks in Belgium, showing that Rosa dumetorum Thuill., Rosa canina L. and Rosa multiflora Thunb. Ex Murr. were hosts, in descending order of host suitability, for P. penetrans under field conditions. Similarly, Santo and Lear (1976) showed that Rosa noisettiana Thory cv. Manetti rootstock was a good host of P. vulnus whereas R. multiflora was less suitable and Ohkawa and Saigusa (1981) found that Rosa chinensis Jacq. cv. Major and R. multiflora cv. 60-5 proved to be efficient hosts for P. vulnus and P. penetrans. Subsequently, R. multiflora cv. Ludiek was found to he resistant to P. vulnus (Schneider et al., 1995). Peng and Moens (2002a) detected partial resistance to P. penetrans in R. virginiana P. Mill. which supported significantly lower multiplication of the nematode than the control R. corymbifera cv. Laxa. Finally, Peng et al. (2003) screened 131 Rosa accessions and whilst the majority of accessions supported the multiplication of P. penetrans, resistance of R. multiflora cv. K1 and R. virginiana to P. penetrans was confirmed and Rosa laevigata Michx. anemoides supported a significantly low nematode population.
I haven’t heard a lot about nematodes in roses in the North where I’m at and have the impression that Florida is particularly favorable to them and was the reason R. x fortuniana was used. Is that accurate? Do others throughout the South face nematode issues on roses?
On a side note, from my understanding part of the reason some of the ADR trial sites use marigolds between trials is to reduce/kill nematodes along with possibly problematic microbes. Marigolds supposed to exude some chemicals that negatively impact other organisms. It was interesting to see a field of tall marigolds where the Hannover ADR trial was going to be planted the following year.
No nematode issues in my yard here in middle GA (I do purchase some roses on fortuniana for the vigor it imparts). I work at a USDA research facility and we have some peach rootstocks developed specifically for nematode resistance - I’m guessing it becomes an issue over time in commercial peach orchards.
Stephen
It really is amazing what sort of substances plants can secrete through their roots. These may alter the chemistry of the soil, allowing phosphates to be extracted from alkaline soil, or to protect root tips against aluminum poisoning in acid soil. Then there are various substances that attract beneficial fungi, and foster the growth of companion plants. http://bulbnrose.x10.mx/Minerals/DakoraExudates2002.html
There is much to be learned about this subject, especially as to the inheritance of the various types of exudations. For example, what happens when we hybridize species with widely different habitats? If one species is native to alkaline soil, it may have a specialized ability to suck up phosphates. If we mate it with an acid-loving species, we should expect some interesting segregation in the F2 and later generations beyond mere flower color and growth habit.
Karl
Cloudehill: A Year in the Garden pp 53-54 (2010)
Jeremy Francis Rosa x fortuniana as rootstock in Western Australia
I came to know the nurseryman quite well and after a time he accorded me the special privilege of telling me how he propagated his plants. After much experimentation, West Australian nurserymen have found roses do well in Perth’s deep sand only when budded onto Rosa fortuniana rootstock. In fact, an understanding was reached by these nurserymen that roses must be put onto this rootstock in WA. This, I should point out, is exactly the reverse to just about everywhere else where roses are expected to do best in clay. It happens, though, R. fortuniana has roots adapted to delving into sand and plants grafted onto this stock in Perth are some of the finest to be seen. Unfortunately, I was told, budding onto fortuniana is no easy matter. Perversely, the buds will not take unless the task is performed during hot weather, in fact, very hot weather. On warm days when the temperature is in the low 30s, the take is barely passable; on high 30s days perhaps acceptable. However, budding onto fortuniana during a heat wave, when temperatures are in the 40s, or even better, the high 40s, results in the cultivar buds clamping to root stock stems with barnacle-like tenacity. R. fortuniana’s growth habit also bore consideration. In my friend’s field, fortuniana root stock protruded from the ground as a bare stem to around 30 centimetres, then branched sideways into a mass of twigs armed with long razor-sharp prickles. Plants in each row were spaced 4 centimetres apart with a 1.2-metre gap between rows; lateral growth formed a continuous, briar-patch-like canopy. My friend was on his belly below this for most of each day and, with his head twisted sideways and one ear brushing the ground, with luck there was lust sufficient wriggle room to make each ‘T’ incision, slip a cultivar bud into the cut, bind the wound and snake along to the next plant. Naturally, if air temperature was in the 40s, the ground temperature was hotter, enough to blister bare flesh not already slashed and bloody from those re-curved (backward facing), exquisitely sharp prickles. However, I must say his roses grew magnificently.
Fortuniana’s heat DEMAND is what I have experienced. In Encino (extreme heat, extreme fire danger), it rooted quickly and easily and everything I put on it took. In Santa Maria (cool, damp, with very short periods of “heat” into the mid to high eighties and very brief, infrequent ventures to the low triple digits) Fortuniana REFUSES to root and buds inserted into its bark REFUSE to take, the whole plant turning black from both tops and bottoms. I’ve given up on even attempting it here. Banksiae, however, roots well and appears to be accepting buds. They’re still too new to know for sure. Both stocks “rebloom” here, also, with scattered flowers much of the year. Our soil is remarkably sandy, so Fortuniana should be splendid here, just not for propagation.
Dr. Van Fleet (1902) reported that, “Perle des Jardins, budded on an established plant of the Cherokee rose, Rosa laevigata, is giving splendid blooms of almost exhibition quality, in a cold, damp house where five years’ effort with potted Perles on own roots and Manetti only resulted in a chance ‘bullhead’ once or twice a year. Further trials will be made with teas and hybrid teas on this stock.”
He did not mention any difficulties or offer suggestions for budding on laevigata.
Apparently the species loves heat, and blooms more profusely after a good baking (according the Sydney Hockridge, late of Redlands, CA). And yet its roots encourage Teas and such to bloom in “a cold, damp house.”