Monday, October 8, 2018

Composting Produces Good Organic Matter

By following some simple rules you can speed up the processing time and produce good compost in one to two months. Some ‘experts’ can even turn a pile of garden waste into nice compost in as little as 14 days.  Here are the essentials:

A. Proper moisture and air (oxygen) content - Compost works best if the moisture content of the materials is about 50%. That’s not easy to measure, but it has been estimated to be about the moisture content of a wrung-out sponge.  If the material is too dry, decomposition will stop; if too wet, oxygen becomes limited, decomposition slows, and foul odors will be produced.

B. Proper carbon/nitrogen ration - For effective composting, the raw materials must have a proper carbon/nitrogen ratio – set at about 30:1.  Since this cannot be easily measured, experience has shown that mixing equal volumes of green and brown plant material will give this ratio. The 'greens' are fresh, moist materials like grass clippings, weeds, manures and kitchen scraps. The 'browns' are dry materials such as twigs, wood chips, straw, saw dust and paper.  If a pile of twigs are thrown to the side, they will eventually decompose. But when leaves (greens) are combined with the twigs (browns) in the proper ratios, the organic matter will decompose more quickly.    

Mixing the greens with the browns is not only good for obtaining the proper ratio, but also helps to maintain a good oxygen level.  Grass clippings alone (shredded paper too) tend to mat and exclude oxygen.  Adding twigs helps to open the pile allowing a better movement of air.   

C. Proper size of material - Soft, succulent plant tissue does not need to be chopped into small pieces because it will decompose rapidly.  However, the harder to decompose woody materials will compost best if pieces are ½ to 1 ½ inches in size: the smaller the pieces the quicker the decomposition.

D. Proper pile size - The size of the compost pile is important.  The minimal size is 3 cubic feet (3x3x3). Maximum size would be around 5x5 and as long as you want it.

E. Proper turning - Turning the pile is not required, but will certainly speed up the process; turn any time from every day to every10 days. Turning helps ensure proper air circulation along with good moisture and heat distribution. 

Finally, here’s how to know when the composting process is finished: when the majority of the pile has become dark, loose, crumbly and sweet smelling.  Also, the original ingredients will not be recognizable with the exception of a few pieces of tough woody material. Composting is a good way to reuse our natural resources, recycle nutrients and add good organic matter back into the soil. 

Wednesday, September 5, 2018

Pineapples - Easily Propagated

Can the top of the pineapple fruit be cut off and planted in order to produce a new plant? The answer is YES! There are many variations on how to propagate pineapple. The drier the environment, the more precise the instructions need to be followed. In Hawaii, especially in high rainfall areas, propagating pineapple is relatively easy. 

The simplest method is to cut off the top of the pineapple, called the crown, as you normally would do when cutting the fruit. Let the top sit in a shaded, dry area for 2-7 days. Before planting, remove the dried fruity portion and some of the lower leaves exposing  ½ -1 inch of the stem. Letting the crown sit for several days will seal the wound and make it less susceptible to rot. When planting, keep in mind that the mature plant can grow to 3-4 feet in diameter and height. Mature plants also have a tendency to fall over, thus planting several together, they will give each other support.

Alternatively, the stem can be placed in a shallow glass of water. Be careful to place only the stem and not the leaves in the water.  After a short time, roots will form; it is then ready to be planted outside.  

Thursday, August 16, 2018

The Corn Earworm

The corn earworm is one of the most destructive insect pests of corn in the world. But here in Hawaii it is not quite as destructive thanks to CTAHR (University of Hawaii College of Tropical Agriculture and Human Resources) plant breeders. Hawaii-bred corn varieties are more resistant to the earworm due to their thicker and tighter husks, thus limiting the number of larvae that can gain entry to the ear. This allows growers to simply cut off the tips of the ears to remove any damage that may have occurred.

Most of the eggs of the corn earworm are laid on the young silks soon after the silks have emerged. Young larvae crawl down the silk to feed on the kernels, soft cobs and the silk itself.  Luckily they also eat each other, keeping populations low.

Corn planted early in the year is not as seriously affected as is late corn because population densities increase as the season progresses. Early plantings will have minimal damage; later in the year one or two worms may appear in the tops of each ear of corn.

To help control the pest, between plantings destroy the crop residue or haul it off to the compost bin. This eliminates places that would harbor the pest. Several natural enemies are present in Hawaii and, in general, they keep the corn earworm at tolerable levels. In most cases, control is simply a matter of cutting off damaged ends of corn at harvest.

For those gardeners who are plagued with the corn earworm, here are some chemical recommendations from the University of California IPM program:
  • Spinosad -  must be applied on silks within 3 days after first silks appear and at 3-day intervals until silks turn brown.
  • Bacillus thuringiensis (Bt) - may be dusted on silks every 3 days after 5 to 10% silk formation for partial control.
  • Applying a few drops of mineral oil with a medicine dropper to silks just inside each ear 3 to 5 days after silks first appear may be effective.