Friday, November 18, 2016

Unity College Dartmouth Greenhouse Week 3

Week 3: 11/7/16-11/10/16; ~86 hours left

This past week  has been tough for me to function with my typical enthusiasm and focus due to the election and  resulting aftermath.  I feel as though protecting the environment that we have left has just got much harder.

To distract from politics I have been focusing on tending to the basic needs of the plants (ie fertilizing, pruning, repotting) and the general upkeep of the greenhouse itself (ie clean drains, sweeping or squeegeeing the floors).  During the week I would often survey the different rooms to look for tasks that needed doing. I focused specifically on the Subtropical Room and the Cacti Room to trim and dead head the ferns and other 'leggy' plants or repot the xerophytes that were overgrow.

Rabbit's Foot Fern (
Davallia fejeensis) in the Sub-tropical Room, a large section of the subtropical plants are ferns and primitive plants (ie mosses, liverworts, clubmosses).

To keep track of the species we keep in the greenhouse we keep inventory lists. There are two separate lists one for the orchid and the general plant species. W
e have a large variety of orchids and most are housed separately.  The lists are organized by family and then species and includes their location, their potting information (ie size, re-potting dates, division dates, quantity).  Every time we re-pot or divide a plant we have to update their information in the inventory list. Normally this is done by hand on a printed copy that is then updated digitally.

The illustration class this past week was probably what helped me get through the day on Wednesday.  The lesson was to show the incremental steps involved with layering the watercolor to give the desired effect.  They also discussed the inclusion of fractals and Fibonacci's Sequence into botanical illustration and other precision based art forms.  They mentioned the NH artist, Maxfield Parrish as a prime example of precision and composition.  He apparently used surprisingly complex equations to create his art pieces whether they be murals or children's book illustrations.

A water lily called Blue Pigmy (Nymphaea colorata) that is native to eastern Africa. Its blooms only last one day so I was lucky to take pictures when I did!

A large percentage of the research done in the research section of the greenhouse is with transgenic rice.  Some of the professors are working on a way to prevent the ability of the rice to absorb heavy metals.  Accumulation of those metals lead to negative health effects.  To test the content of that rice, they have to harvest each generation of the rice seeds and pick the they want for the new generations.

In those experiments they must have a 'zero pest policy'. Any biological contaminations would potential change the outcomes.  The particular issue that the researchers had was with aphids attacking the young rice plants.  If the aphids are not removed completely they will prevent the rice seeds from forming.  This would halt the entire experiment as they need to be able to test those seeds.  To deal with this, we at the greenhouse use pesticides as a sterile environment must be maintained.

When using pesticides you are suppose to use multiple modes of action so as to not let the target species develop a resistance. Multiple modes of actions just refers to the different ways the chemicals are applied and/or effect the target.  One pesticide that was a possibility was Pyrethrum TR (aerosol spray).  It is derived from chrysanthemums.  For the chemical to work it must have physical contacted with the insect's cuticle.  I don't know the specifics but it effects the sodium channels in neurons, killing the insects.  Another pesticide with a different mode of action was Preclude. It is an insect growth regulator which means it prevents the insect from fully maturating to a sexually active adult.  This pesticide is not practical for dealing with aphids as it does not kill the young and aphids have a very flexible life cycle that allows them to reproduce at multiple stages.  The final type of pesticide we discussed was a systematic insecticide called Marathon II.  It is absorbed through the roots and transmitted throughout the plant.  When the insects feed on the plants it kills them.  The pesticides last for a couple weeks.

On Thursday, our order of bio-control species finally came in:

#1: Steinernema feltiae (Predatory Nematodes): These are the same nematodes that I used in the research lab to inoculate the mustard relative.  They requires lukewarm water to become active.

#2: Cryptolaemus montrouzieri ("Crypts"): They came as adult beetle. Hopefully they will mate and then lay their eggs on the plants with high populations of mealybugs.

#3&4: Predatory Mites- Neoseiulus californicus (left); Stratiolaelops scimitus (right): They will be let out on certain plants to consume the larval stages of the thrips and fungus gnat.

#5: Chrysopidae (Lacewing):  The eggs are attached to little paper sheets which will be hung on the plants.  The larvae which are voracious predators are supposed to hatch and then start consuming what ever pest species it can get its mandibles on.

#6: Eretmocerus spp. (Parasitic Wasp): This wasp could only be sent as a pupal stage rather then an egg as the larval stage is parasitic. They will parasitize aphids turning them into something like a mummy.  This lasts until the larva is ready to burrow out and begin metamorphosis, starting the process over again.

#7: Amblyseius cucumeris (Another Predatory Mite): I had to replace the old packets with the new ones on the plants in all the rooms except the Cold Orchid Room.  The temperature is to cold for them.  We can also compost the old bags without going through a complex process, which is nice.

Here are some pictures of the Welwichia (I know that some of you were asking for them). Unfortunately they do not show just how impressive the fronds are:

Have a great weekend!!

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