brown rot – Lee Reich

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Fruit, Again, With Nod To Michael Jackson

August 16, 2017/0 Comments/in Fruit, Gardening, Planning, Pruning/by Lee Reich

Blackcaps Redux, This Season

I took a cue from Michael Jackson today when pruning my black raspberry (a.k.a. blackcap) plants. Not that I had to prune them today, or even this time of year. But I couldn’t stand looking at the tangled mass of thorny canes. And, more importantly, the tangled mass would make harvest, slated to begin in a couple of weeks or so, a bloody nightmare.

(Most blackcaps bear only once a year, in early summer, so tidiness would be the main reason to prune conventional blackcaps now. Pruning would also let remaining canes bathe in more light and air, reducing the threat of diseases. My blackcap plants, though, are the two varieties — Niwot and Ohio’s Treasure — that bear twice a year; hence, my pruning now to make picking the soon-to-ripen second crop less intimidating.)

All blackcaps have perennial roots and biennial canes. Typically, the canes just grow their first year, flower and fruit their second year, then die. Niwot and Ohio’s Treasure differ in bearing on both one-year-old canes and on new canes. I picked the early summer crop from canes that grew last year. And now my mouth is watering as I look forward to the late summer crop, which will be borne on canes that just started growing this season.
Pruned blackcaps
Pruning is straightforward. I started by lopping right to ground level all the canes that bore the early summer crop; they’re dying anyway. Step two is reducing the number of new canes, selectively keeping the fattest and healthiest-looking ones, and lopping all others to ground level. Even then, I reduce their number to the best six of them. That’s it. Easy, as long as the thorns are avoided.

My blackcaps are in a row, three feet apart. An iron pipe sunk into the ground next to each plant provides support for each plant’s clump of stems. With pruning finished, I tied a piece of rope to the pipe and then around the clump of stems, a gloved hand cozying the thorny stems into position while my ungloved hand tied the rope, à la Michael Jackson. Tying blackcap with gloved hand

Rotten Plums

I wish that pruning was all that my plum trees needed. With this being such a good year for fruits generally, I was very hopeful for a good crop. And they looked fine up until a week ago, when the fruit started ripening — and rotting.

Brown rot is the culprit, mostly the handiwork of the fungus Monolinia fruticola. Characteristic powdery, gray masses of spores form on the surfaces of rotting fruits, which eventually dry to become “mummies.” Brown rot is not new to me; I’ve experienced it on peaches, nectarines, and plums in the past. It also attacks apricots, cherries, and other “stone fruits” (Prunus genus). Typically, a plant bears well for a couple of years while the fungi are building up, and then full-fledged, annual attacks begin. Brown rot

The usual recommendation to hold the fungus at bay is, first, to remove sources of inoculum by cleaning up all infected fruit in summer and mummies in winter, and pruning away dead, infected twigs. That’s quite a job on a big plum tree.

I sprayed my trees with sulfur many times this past spring. Sulfur is an organically approved fungicide, used by gardeners and farmers for thousands of years, that is effective against brown rot. But only for a few days. Hence my repeated sprays, evidently not repeated enough.

The easiest approach would be for me to grow brown rot resistant varieties.

Plumquest Begins

So now I am embarking on a plumquest, my search for plums that taste good and are resistant to brown rot. Resistant genes must lurk somewhere — actually right in my yard, on the wild plums. They hardly ever show fuzzy grayness; they also don’t taste very good.

I now remember a pertinent page I photocopied many years ago. Shuffling through piles of papers on my desk, I come across the page, from a scientific-looking paper, entitled “Range of known genetic traits in Plum cultivars.” That’s a start, and the list on the page includes one of my favorite plums, the Green Gage, also known as Reine Claude Verte, as resistant. Shiro, which I grow with some success, is only listed as “tolerant.”

My next queststep is on the web, bringing me to a publication entitled “The Cultivated Native Plums and Cherries,” authored by Liberty Hyde Bailey in 1892. I immediately ordered a reprint to make it easier to sort through the many varieties and their gustatory and pest potentials.

Once suitable varieties are identified, the next queststep is to locate trees or, more likely, stems for grafting, to bring here to the farmden. I will report on my plumquest as events unfold.

ROT AND FLOWERS

August 11, 2016/0 Comments/in Flowers, Fruit, Gardening, Pests, Planning/by Lee Reich

Brown Rot Strikes Again

   The plan was for me to be now sinking my teeth into the soft, juicy, rich flesh of my Oullins golden gage plums. The tenuous start this past spring, with a freak late freeze that sent temperatures plummeting into the low teens, had me worried. The trees shook off the cold and, when warmer weather returned, burst into snowballs of white blossoms. Tiny fruitlets that followed those blossoms have swelled to the bountiful crop now dangling from the branches.
   The plan has been foiled — by brown rot disease. Almost every plum, just as its skin starts to shade towards ripeness, becomes spotted with fuzzy, gray droplets that, with good weather (good for the fungus, that is), soon covers the fruit. Brown rotted plum fruit
   Brown rot was not unexpected, and a counterattack was planned. All through spring, before blossoms even unfolded, I doused the plant with insecticide and fungicide sprays. Insecticides help control brown rot by preventing insects, most notably plum curculios, from laying eggs in the developing fruitlets. Even if the egg-laying itself doesn’t cause the fruit to drop, holes left behind provide easy entrance for the brown rot fungus.
   Perhaps I was too lenient, using relatively benign (to us humans, that is), organically approved sprays. ‘Surround’, a commercial formulation of kaolin clay for the insects. And sulfur, a naturally occurring mineral, for the brown rot fungus. Brown rot mummy
   That’s not all. Gathering up infected fruits cuts back the number of new disease spores that waft among the branches looking for new fruits to infect. In fall and winter, those infected fruits are easily recognized as blackened, dry “mummies.” They lose their dryness and come to life, fungal life, with spring’s warmth and moisture. I’ll gather them up also. I’m hoping my ducks develop a taste for the fresh, dropped, rotten fruit; so far, they seem to be picky eaters.
   My late winter pruning of the trees should also have helped reduce brown rot disease. Removing enough stems and limbs to allow those that remain to bathe in light and breezes allows for quicker drying from dew or rain.

The Disease Triangle

    Three conditions must be satisfied for any disease, whether in animals or plants, to take hold: inoculum must be present, the host must be susceptible, and the conditions must be suitable for disease development. Check, check, check for my Oulin plum (a susceptible host plant) getting brown rot here in the Hudson Valley, throughout most of the humid eastern U.S., in fact. We have plenty of wild and cultivated plums and related plants here to provide brown rot inoculum from infected fruits, and the weather is usually just about perfect (for the disease, that is).
   But Oullin isn’t the only great-tasting plum. How about a less susceptible host variety? Fungi are picky eaters, and varieties of plants vary in their susceptibility to specific diseases.(Unfortunately, most gage-type plums, which are heart-shaped, with greenish flesh, are very susceptible to brown rot.) Infected plums on tree
   My plum trees are grafted to multiple varieties. The variety Shiro also finds a home on the tree grafted to Oullin. This year, and in years past, Shiro seems to be somewhat resistant to this disease. And I see that Cummins Nursery has a variety called Jam Session that also is resistant. This past spring I also planted the varieties Alderman and Superior, which are American hybrids with some alleged resistance.
   As consolation, plums are, at least, less susceptible to this scourge than are peaches and apricots.

Flowers to the Rescue?

    I’m planning and planting for flowers for next season and for years to come, with perennials.
   I could, of course, just purchase some potted plants to plug into the ground now or next spring. I could buy seeds and sow them next spring. Instead of those two options, I’m sowing seeds now, a time when, admittedly, there’s not that frenzied urge to plant seeds as in spring. Black-eyed Susan Purple coneflower
   One packet of seeds can — should — result in oodles of plants, plenty to plant and to give away. Sown now, the seeds should grow into plants that will be large enough to weather autumn, then winter’s, cold. Plants should also be large enough to flower next year. Their experience of cold, known as vernalization, will further coax them on to flower. Spring sown perennial flower seeds often don’t flower their first season, no matter what their size, because they have yet to be vernalized. Liatris
   I’m sowing purple coneflower (Echinacea), black-eyed-susan (Rudbeckia), and blazing star (Liatris). They’re all in the daisy family, a family known not only for its good looks but also for providing nectar to attract and help support beneficial insects. If I plant enough, perhaps the increased number of beneficial insects will significantly decrease the number of plum curculios and other plum fruit insects resulting in, because of less insect scarring of fruit, significantly less brown rot of my plums.
   It’s a stretch but the flowers, anyway, are very pretty.

SUNNY DAYS & YOGA, BUT TOMATOES?

August 21, 2015/5 Comments/in Fruit, Gardening, Pests, Vegetables/by Lee Reich

Springtown Farmden Health Spa

In the past, I have written of rei-king and sie-thing as two of the many healthful exercises offered here at Springtown Farmden Health Spa. We now have a new offering at the spa: garden yoga or, more catchy, gardoga or yōgdening. I like the last one best.
Yōgdening grew out of my respect for the soil, my desire to maintain and foster a healthy balance of life below ground. A healthy population of bacteria, fungi, worms, actinomycetes and other below-ground dwellers translates to healthy plants above ground. Those beneficial creatures need to breathe, which is why most gardeners and farmers till their soil. To aerate it.

Yogdening, for health and weedlessness

   But tilling a soil also burns up valuable organic matter. This organic matter feeds soil organisms and, in turn, plants, makes nutrients already in the ground more accessible to plants, helps hold moisture for plants, and helps aerate the soil.
   I avoid the need to till my soil for aeration by almost never walking, rolling a wheel barrow, or allowing any other traffic where plants are growing. Plants in fields and forest grow well despite never being tilled except what earthworms and other small animals manage to do. (No small amount: Charles Darwin computed that earthworms completely turn over the upper six inches of a pasture soil every 10 to 20 years — in England, at least.)
   Getting back to yōgdening . . . Weeds are making inroads into certain parts of my gardens. Not my vegetable gardens, the 3-foot-wide plant beds of which I keep well weeded with my feet firmly planted in the 18-inch-wide paths bordering the beds. But the only way I can reach into some other planted areas, a bed of various flowers sprawling beneath some Asian pear espaliers, for example, is by stepping into them. To minimize foot traffic, after stepping into a planted area, I try to keep my foot anchored in place, from which I pull every weed I can reach.
   As you might imagine, reaching every weed possible with feet planted in one place calls for all sorts of contortions and stretches forwards, backwards, and sideways involving my legs, trunk, shoulders, arms, and neck. My guess is that after a half-hour of weeding, I’ve run through a close approximation of Utthia Trikonāsana (Triangle Pose), Vīrabhadrāsana (Warrior Pose), and Uttānāsana (Standing Forward Fold Pose), to name a few classic yoga poses — and cleared away weeds!
   Weeding (or, perhaps, I should write “we-ding,” another spa offering) is especially satisfying this time of year. Dry weather has slowed sprouting of new weeds so cleared areas remain clear.

Brown Rot Not (Too Much)

Dry weather is also good for fruit ripening. That is, ripening rather than rotting. As sweetness develops in ripening fruits, they become more susceptible to rotting. Fungi, like humans, can make quicker use of simple sugars than more complex carbohydrates, such as a are found in unripe fruits. Fruits with thin skins are especially susceptible to attack from fungi.
For a variety of reasons, known and unknown, this has been a good year for plums. In past years, late frosts in spring have snuffed out blossoms or plum curculio has caused many, if not all, plumlets to rain to the ground. This year, blossom buds were unscathed from winter cold or spring frosts, curculios were kept at bay by my spraying Surround, a commercial product that is nothing more than kaolin clay.

Shiro plum

Current dry weather should also limit plums’ other nemesis: brown rot, a fungal disease that turns ripening fruit gray and fuzzy and then, at the end of the season, into dark brown, shriveled mummies. (Of course, beautiful clear days are often followed by clear nights during which water, in the form of dew, condenses on fruits and leaves.) The mummies hang from the branches, along with cankers on branches, spread spores and infection the following year. Fallen mummies are also a source of the following season’s infection.
   Brown rot gets to work early in the season, around blossom time, and then later in the season, as fruits are ripening, which is now, for my Shiro plums. Early in the season, I added sulfur, a naturally mined mineral whose use as a fungicide goes back to the ancient Greeks, to the mix when I was spraying Surround.
   Supplementing that spraying was cleaning up hanging and fallen mummies at the end of the season, and promoting drying of branches and fruits with pruning and thinning out of excess fruits.
   The upshot is that some brown rot is showing up on ripening plums. But not all of them. And those that have been spared are delectable. Even the birds think so. Their peckings, unfortunately, like wounds inflicted by plum curculios, increase fruits’ susceptibility to brown rot.

Tomatoes, Where Are You?

    Tomatoes are growing like gangbusters, here and in other gardens I’ve seen locally. And the fruits are likewise growing very plump.
   But the scene is not as rosy as it should be, literally, because too many of the tomatoes are still green. Again, other local gardens mimic my experience. How are your tomatoes doing this year?
   Day after day of bright sunny, weather and moderate temperatures should have promoted ripening. Then again, day after day of rainy weather last month might have retarded it. At any rate, in gardening and farming, you can’t go wrong blaming the weather.