Tuesday, June 4, 2019

Heirloom Seeds and Hybrid Seeds

Note:
 In this article, we are not speaking about genetically modified organisms (GMO'S).  A GMO  is a plant, animal, microorganism or other organism whose genetic makeup has been modified using genetic engineering, i.e. gene modification, recombinant DNA methods (also called gene splicing) or transgenic technology.


A hybrid is defined as a plant that results from the cross between two plants of differing genetic characteristics, i.e., two species, subspecies, cultivars, varieties, etc. Some crosses may occur naturally, but most hybridizing is deliberately done by man in order to produce a plant with improved characteristics such as disease resistance, greater vigor and uniformity. Hybrids generally have higher yields and better exterior quality.   
  
Today, hybrid seed is prevalent both in agriculture, as well as home gardening, and is a major contributor to the rise in agricultural output in the last 50 years.  The commercial hybrid market actually began back in the 1920’s, when the first hybrid corn was produced.

The disadvantage of using hybrid seeds is that the resulting seed cannot be used at the end of the season for next year’s crop. The seed taken from a hybrid will either be sterile or produce plants that are not true to the mother plant, i.e., not true to type. Thus it becomes necessary to purchase new hybrid seeds each year. 

On the other hand, heirloom seeds are from open-pollinated varieties. This means that plants grown from these seeds will be identical to their parent.  In addition, their genes have not been subjected to modern breeding techniques and manipulation. Note: All heirloom varieties are open-pollinated but not all open-pollinated varieties are heirlooms.

Heirloom seeds can be saved from year to year and planted for the next crop. Although they may have some built-in hardiness, heirlooms generally do not possess disease resistance, vigor and uniformity that hybrids do.

One of the main advantages attributed to heirlooms is their excellent flavor.  In hybridization programs, plant breeders sacrifice flavor in preference to other attributes such as disease resistance and higher yields. 


Friday, May 17, 2019

Basil - a Great Aromatic Herb


Basil is a member of the mint family and is one of the world’s most popular herbs.   In colder climates it is generally grown as an annual, but in Hawai`i   can be grown as a perennial.  After flowering, when seeds have matured, basils will stop producing new leaves.  To ensure continued growth, cut off any flower buds that begin to form. Be sure to cut the branch rather than just the tips, otherwise, new flower buds will quickly appear.  By pruning basil often (every 3-4 weeks), plans remain vigorous with many harvests throughout the season. 

Sweet basil is the variety most widely grown on the Islands, but there is also Thai basil, lemon basil, cinnamon basil and royal basil.  Basil prefers a sunny location with a well-drained soil.  Typically, the best time to harvest basil is in the morning when the essential oils are strongest. However, University of Michigan researchers have found that harvesting basil in the evening between 6 and 10 p.m. increases its shelf life.

This aromatic herb can be used in soups, stews, and rice dishes, and with fish, chicken, and other meat. It can also be a key ingredient in cheeses, vinegars, oils, jellies and teas.  Even basil's flowers are edible and can be candied or added to salads and other dishes. For optimum flavor, add fresh basil in the last few minutes of cooking; the dried spice just doesn’t have the same robust flavor as the fresh.

Cooks often notice that fresh basil will quickly turn black.  This is due to oxidation of some elements in the leaves. To prevent this blackening and insure the best flavor, add basil to salads and other cold dishes soon after cutting. 


Pests – Basil is often grown with few or no pests.  But some of the more common problems encountered are thrips, leafhoppers, whitefly, spittlebug, scale and leafminers.  Insect pests that would be causing chewing damage to the leaves include the Chinese rose beetle, beet armyworm, a pinkwinged grasshopper and flea beetles.  If you see worms (caterpillars), pick them off, or you can spray the plant with an insecticide with the active ingredient, Bacillus Thuringiensis (Dipel, Javelin). Bt is an organic, bacterial preparation which will control the caterpillar but is harmless to humans.  


Tuesday, April 23, 2019

Hapuu, the Hawaiian Tree Fern, vs. the Australian Tree Fern



                                                        
The Hawaiian tree fern is native to most of the Hawaiian Islands. Although once common, hapu’u stands have been reduced due to a large number of ferns being harvested for orchid media and landscape use. The last remaining large stands of native hapu’u are found on the Big Island.

The Hawaiian hapu’u  are very slow growing; the young ones grow at about 3.5 inches per year while the older plants grow even more slowly, eventually growing to  15-20 feet tall.  The unfurled fronds are covered with silky, red-brown wool-like fibers called pulu.  In the past, pulu was used for stuffing pillows and mattresses and for dressing wounds.




The Hawaiian tree ferns are relatively easy to grow. They grow best in well drained slightly acid soils and partial shade; they will tolerate full sun in cloudy upland areas. They need a steady supply of water and occasional light applications of a complete, slow release fertilizer. Old and injured fronds should be pruned. It is illegal to ship tree ferns or products from the ferns internationally. 


 The Australian tree fern, Cyathea cooperi, is considered invasive in the State of Hawaii due to aggressively out competing native plants in the forest understory. As a threat to  Hawaiian forests, this fern eventually displaces the native ferns, including the slower growing Hawaiian tree fern, or hapu’u.  


Although invasive, the Australian tree fern is being sold in Hawaii at many commercial plant nurseries. This fern grows to 40 feet tall and tolerates full sun in cool wet areas. The spores are spread by wind and can travel over 7 miles from the parent plant.

 The best diagnostic characteristic to distinguish between the Australian tree fern and the native hapu'u is the hairs on the leaf stems. With the  hapu’u, the hairs are either fine and reddish-brown for hapu'u pulu (Cibotium glaucum) or fine and black for hapu'u i'i (C. menziesii). The hairs on the Australian tree fern are broad and white.
     



                                                Cibotium menziessi

  Photos: Native Plants Hawaii, University of Hawaii