Saturday, June 23, 2012

Green Garden Looper

A common pest of the garden is the green garden looper (Chyssodeixis eriosoma). It feeds on a variety of plants including vegetables crops such as basil, cabbage, Chinese pea, corn, eggplant, green beans, lettuce and sweet potato. This pest also infests ornamentals like orchids, ti and other tropical foliage. As the name implies, the looper's movement is distinguished by the typical "looping" fashion. 

The looper’s chewing damage can leave a typical window-like appearance.  This is accomplished by the young caterpillars that consume only one side of the leaf. As the caterpillars mature, they chew holes through the leaves and on the margins.  Some caterpillars will also feed on flowers and fruits.  The larvae are green; the older ones have faint white stripes running the length of their bodies.

The adult moth, with a 1 1/2 inch wingspan, is usually seen flying at dusk. During the day they rest inside flowers, on vegetation, or on walls. The adult feeds on flower nectar and honeydew.

Several parasites are present in Hawaii, as well as other parts of the world and contribute to controlling the populations of the green garden looper. For immediate control, gardeners can spray with Bt (Bacillus thuringiensis). It is a bacterial powder (sold as Dipel, Gnatrol, Thuricide and others) which is an effective organic pesticide specific to caterpillars, fungus gnat and mosquito larvae; it is not harmful to humans.
Bt produces a toxin that causes the affected caterpillar to stop feeding within hours of ingestion. In addition, Bt rapidly degrades in sunlight. For best results, applications should be made in the late afternoon. Most caterpillars feed after dusk anyway. 
Entrust (Spinosad) is another product which can be used against the garden looper and has a low toxicity.

Tuesday, June 19, 2012

Benefits of Houseplants

A few, well-placed houseplants can transform a dull room into an attractive, warm environment. Plants add character, charm and beauty to a dwelling. But they do much more.  Indoor plants can clean the air and enhance creativity. Currently many hospitals encourage visitors to bring in plants. More than a cheerful greeting, plants provide oxygen to patients and cleanse the air.

The good news about these living air cleaners comes from a classic study by NASA. They found that plants can take airborne chemicals that are toxic and convert them into an energy source for the plant. The studies reported that houseplants were able to remove up to 87 % of air toxins in 24 hours. They can eliminate a variety of toxic air emissions including formaldehyde (found in particleboard, fire retardants, natural gas and cigarette smoke), benzene (found in inks and paints), trichloroethytene (found in paints and varnishes), and carbon monoxide, xylene and ammonia. The above chemicals and other nasty pollutants can also be found in carpeting and cleansers. Using a variety of indoor plants will purge many toxins from the home.

How many plants are needed to keep a home clean?  Recommendations vary from one or two good-sized plants per room to 15 to 18 plants for a 1,800 square foot house.  The point is the more house plants, the better it is.  However, having this many plants in a home could potentially produce lots of mold from the moist soil and decaying organic matter. It’s crucial not to over-water plants. Placing a layer of small gravel over the topsoil may help to minimize the mold.

Other studies have shown that indoor plants can reduce fatigue, coughs, sore throats and other cold-related illnesses by more than 30 percent, partially by increasing humidity levels and decreasing dust. Note: this study was done at the University of Agriculture in Norway which has a very dry climate.

Indoor plants are good for businesses, too. When a manufacturing company integrated living plants into its office, company administrators noticed enhanced creativity and increased productivity in their employees.

Keep in mind, some houseplants are poisonous and should be handled with care, or not at all, especially if there are small children in the home. Some of the common, poisonous, indoor plants include dieffenbachia (dumb cane) and philodendrons. These plants contain oxalate crystals. Chewing a leaf or stem may cause mild to severe swelling and burning of the mouth, tongue and throat along with choking. If the skin is exposed to the plant’s sap, where the abrasive oxalate crystals are found, an uncomfortable skin rash can develop with burning, redness and itching.  

Friday, June 15, 2012

What’s Crawling in the Compost Pile?

There is truly an abundance of living creatures that inhabit compost piles.  They range from slugs, centipedes and beetles to tiny microorganisms like fungi and bacteria; some can be seen but most cannot.  Some of the giant inhabitants may be toads and rats.

 The insect population of compost piles will include ants, beetles, cockroaches, centipedes, earwigs, millipedes, sowbugs, springtails and termites as well as flies laying their eggs.  Some insects like earwigs and sowbugs feed on the organic matter; springtails and some beetles like fungi to eat, as do ants; termites, of course, eat wood, and cockroaches like decaying wood.

Spiders and tiny mites are eight legged creatures classified as arachnids rather than insects.  Spiders feed on other insects while mites feed on many things including decomposing plant material, nematodes and fly larvae.

    Nematode on plant root

Some nematodes are garden pests, infesting ornamentals and edibles.  But many are helpful and thrive in compost piles.  They feed on decaying matter, bacteria, protozoa, fungal spores and other nematodes.  Earthworms are especially beneficial.  They help breakdown the organic matter, make N-P-K (nitrogen-phosphorous-potassium) available to the plants and help till the soil.  

Tuesday, June 12, 2012

Seeds in Pineapples?

                                               A Young Pineapple in Bloom

It is possible to find seeds in a pineapple, especially in South America, where pineapples are native and growing naturally.  Commercially grown pineapples have no seeds due to the hybridization that has been conducted over many years.          
Consequently, lacking pollination, commercial pineapples are propagated asexually, not from seed.

Pineapples are self-sterile, meaning they cannot produce seeds if they pollinate themselves (self-pollination). To produce seeds, pineapples must be cross-pollinated.  All of the pineapples in one commercial field are genetically the same, so if pollen is transferred from one plant to another, it is still self-pollination. Cultivated pineapples could potentially produce seed if they were cross-pollinated – using pollen from another genetic source. 

When growing pineapple in the backyard, it is possible for pollination to take place between two different genetic types. Consequently, there is the potential for producing seeds. Luckily, the pineapple fruit itself will development even though no seeds develop. This is called parthenocarpy, the development of fruits without seeds. Some of our most popular fruits are seedless such as bananas and navel oranges.

Friday, June 8, 2012

When to Pick Taro

In determining when to pick taro, also known as kalo, some publications simply tell us to harvest when the corm reaches the desired size. A corm is a swollen underground plant stem that serves as a storage organ similar to a bulb.  Since the corm is underground and cannot be seen, here are some above ground signs that indicate harvest is near. 
First, it is helpful to know that dry land or upland taro is ready in 8-10 months after planting the flooded taro or wetland in about 12-15 months. Time of maturity varies with location, varieties, soil fertility, and water availability.  As maturity approaches, the height of the plant declines and the leaf petioles (stems) become shorter, usually to less than 2 ft.  This is accompanied by a general yellowing of the leaves. In wetland taro, because of the abundant water supply, the root system remains active and thus these signs are less distinct.  In addition, the main corm will begin to protrude from the soil surface. 

Harvesting leaves can be done at any time during the growth of the taro. Only the young leaves should be harvested, perhaps 1 or 2 at a time. A continual harvesting of many leaves will hamper the development of the taro corm.