PGS Events

Postgraduate Events

Farm Visits

With the growing season in full swing we are starting to visit project participant farms to see how the Physalis plants perform in different environments and any challenges that may come with growing Physalis. This past Tuesday we visited a plot of Physalis plans in Danby NY. The first thing we noticed was the size of the plant. Unlike our plants that are tall and lanky in pots in the greenhouse, these plants remained small and we observed much more lateral growth. This was particularly interesting as we had started these plants in the greenhouse at BTI, where some of their growing cohort still remains, so we could clearly see the differences the growing environment had caused. In addition, we also observed some pest damage. The three-lined potato beetle was found in egg form as well as larvae. We have found that it is best to pinch off the eggs and larvae, and that within due time the plant will recover.

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Project Update: Physalis Pest Alert!

Hello Physalis Growers, It has come to our attention that the insect known as three-lined potato beetle (Lema daturaphila) has been infesting Physalis plants this season (pictured below). They are known to prefer Physalis over potato. According to the University of New Hampshire Extension the beetles lay eggs usually on the underside of the leaf and the larvae hatch in late June or July. Once hatched, these larvae resemble slugs. Below is a picture of Physalis plant material covered in the insect larvae. This plant material came from Danby, NY. To control the infestation of these insects you can pick them off of the plants. If the plant is too overrun with the insects you may have to resort to a pesticide to rid the plant of the pest. If you choose this option please record the type of pesticide used. As part of the project, we are interested in any information pertaining to pests, in particular if pests prefer one type of Physalis versus another. As you continue in to the growing season please keep your eyes peeled, and record any useful information on your survey sheet. Happy Growing  ...

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Biology Minute: Differentiating Between Groundcherry and Goldenberry

In the earliest stages of growth, groundcherries and goldenberries appear quite similar, however as they develop the difference between them becomes apparent. From plant architecture to fruit taste, these two species have differentiated themselves over the course of their evolution. Goldenberry (P. peruviana) originated in the Andes Mountains of South America and presently grows wild around the world in temperate and tropical regions where it is considered a perennial. The plant has a woody stem and produces fruits surrounded by a husk that remain on the plant as the fruit matures. When the fruit is ripe, it is harvested directly from the plant. The fruit itself is sweet and tangy and is similar in size to a quarter Groundcherry (P. pruinosa) is believed to be native to parts of Mexico and Central America. The species first became prominent in the Northeastern United States when it was widely grown by the Pennsylvania Dutch in the early 1800s. Although the species grows in northern regions of the United States, it does not tolerate freezing temperatures and is therefore grown as an annual. Like the goldenberry, groundcherry fruits are enveloped by a husk and must be removed...

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Nutritional Properties of Physalis Fruit

In addition to their unique appearance and sweet taste, groundcherries and goldenberries are considered a healthy fruit. As your fruit start to ripen keep in mind the nutritional profile that is being developed. Some of the nutritional benefits reported in literature are as follows: Good Source of vitamins A, B, and C Similar level of vitamin C to oranges, more Vitamin C than apple 42% of fatty acids in fruit are linoleic acid Rich in antioxidants   The first fruits are just starting to develop on my plants that I started at the end of March. Hopefully you all will begin to see fruit soon!  

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Physalis Transplanting

On Tuesday of this week we transplanted our Physalis seedlings from market packs to individual 4-inch pots, and moved them from the growth chamber to the greenhouse. They will stay in the greenhouse for the next few weeks until they go to their new homes where they will need to be hardened off before being grown outside. Hardening off is necessary for Physalis to reduce the shock of a new environment. To harden the plants off, start them off in an area of the garden that has shade or filter light, then gradually over the course of one week expose them to more sunlight. As long as there is no frost in the forecast it is okay to leave them out overnight. Happy...

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Biology Minute: Fruit Ripening

The fruit ripening process is a crucial stage of fruit development, as it results in an edible and more attractive fruit for consumption. Fruits that ripen as a result of a sharp increase in respiration and ethylene production are classified as climacteric fruit, and continue to ripen once picked. Physalis peruviana and Physalis pruinosa are both climacteric fruits, with one study (Trinchero et al. 1998) recording a 45-fold increase of ethylene in peruviana during the ripening stage. As a result of this influx of phytohormone (ethylene), responses such as fruit softening and color changes are observed. Due to the ethylene sensitivity climacteric fruits exhibit, once ripening occurs the fruit must soon be consumed to avoid quality degradation. To avoid this issue, many climacteric fruits are harvested unripe, and then later treated with ethylene when ready for consumption. A common example of this practice is with bananas. Physalis are unique in that they have a husk, which has been shown to reduce ethylene production, however once the husk is removed, the rate of respiration and ethylene production increases. Therefore, large exporters of Physalis will ship the fruit with the...

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Physalis Fossils

How old is the genus Physalis? Check out the article below to read about tomatillo fossils discovered early last year in Patagonia, Argentina. This discovery marks the earliest findings of the Solanaceae family to date. South American fossil tomatillos show nightshades evolved earlier than thought | Penn State University Delicate fossil remains of tomatillos found in Patagonia, Argentina, show that this branch of the economically important family that also includes potatoes, peppers, tobacco, petunias and tomatoes existed 52 million years ago, long before the dates previously ascribed to these species, according to an international team of scientists.

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Physalis Germination

It’s been 11 days since we planted our Physalis seeds here at BTI, and as of yesterday we are starting to see the first signs of germination. This is right on track as we expect Physalis seeds to take anywhere from 7-14 days to germinate (and maybe even longer!). It is too soon to estimate our germination rate, but from what we are seeing it appears to be promising. In a few weeks the seedlings should be ready for transplanting into bigger containers. We have also heard from some of our project participants that they have had successful germination! Vanessa, who has been growing hers on the windowsill of her office since March 6th, has already had successful germination and some noticeable growth. The next few weeks should be full of new growth and development. Although your seeds may have seemed slow to germinate, once they start growing they will grow quickly, with development times differing based on growing conditions. For reference I have included a picture of an eight-week old pruinosa plant grown under optimal conditions.

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Biology Minute: The Berry Husk

A distinguishing property of groundcherries and glodenberries is the calyx (or husk) that covers the fruit. The calyx collectively refers to the sepals that surround the flower, that protect the bud and support the petals. As the flower matures into fruit the calyx surrounds the berry, creating a protective shield that can help deter pests. This mechanism also plays a role in elongating the shelf of the berry. Husked berries may last 5-7 days whereas berries still encased can last a month or longer. An extensive study conducted by Olivares-Tenorio et al 2017 evaluated the factors that determined shelf-life based on consumer preference. One of their main findings was that fruit with the husk significantly outperformed fruit without husks, and that the limiting factor in husked fruit performance was mold presence. Fruits that no longer had their husks experienced rapid fungus growth after 10 days whereas unhusked fruits saw little to no difference in fungus presence. See More...

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Project Update: Seed Sowing

It’s been an exciting week here at BTI! On Tuesday, with the help of volunteers, we planted 120 Physalis seeds to kick off the growing season for the first year of this project. The plants grown from these seeds will be distributed to citizen scientist volunteers who will record their observations as they grow their plants. Additionally, some plants will be distributed to local public gardens where they will be on display for the general public. We planted the seeds in small 4-pack pots using a potting soil designed for plant propagation. Each seed was planted in a 1/4 inch indentation into the soil and then loosely covered back up. Germination time for these seeds can be expected to be about two weeks. Once planted, the seeds are transferred to a growth chamber where they will remain until they germinate and grow big enough to be transplanted. Before we know it, they will be ready to be distributed to our volunteers! If you would like to be kept updated on this project and receive informational posts about Physalis, please subscribe to our blog by filling out the form at the bottom of the page. To check out our other posts see the button below.   See More...

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Biology Minute: A Perfect Flower

The flowers of pruinosa and peruviana are perfect, meaning that they have both male and female reproductive parts. The male parts are the stamens whereas the female part is the carpel. Each flower will contain both of these reproductive organs allowing them to self-pollinate as well as outcross. See More...

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Biology Minute: Sympodial Growth

Physalis plants exhibit what is known as sympodial growth. With this type of growth pattern plants grow laterally as the result of the termination of the apical meristem. When the apical meristem is terminated a physalis flower will grow in it’s place. From this point forward the growth of the plant is now continued by the lateral meristems. See More...

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