Monday, January 30, 2012

Reasons Why Vegetable Seeds Do Not Germinate

                               One lone carrot seedlings pops up.

There are several explanations why seeds don’t germinate once they are planted.  
 1. Insufficient soil moisture.  The seeds did not have enough moisture to germinate, or shortly after, there was insufficient water to continue their sprouting.
2. The top layer of soil is crusted thus preventing the seedlings from emerging. 
3. Incorrect planting depth.  
4. Heavy rains that will wash the seeds away.  
5. Seed are eaten by insects.  Or, in the case of larger seeds like corn, they may be eaten by birds or even domestic chickens.  
6.  Old seed. 
7. Damping off – this is a fungal disease which arises  when the fungus is present in the soil and conditions are suitable for its growth – mainly over watering.

The problem also occurs when seeds are started in pots or flats, and the potting soil is contaminated with the fungus.   Apply less water, keeping the soil moist not soaked and
use only a sterile potting mix and clean pots.  The second planting of this seed should not be in the same location, since the fungus is still there; plant in a new area.  Transplant vegetables that are well established and preferably from a different plant family, in the old location.

Friday, January 27, 2012

Why Squash Plants Produce Lots of Bloom But Little Fruit


 
 Squash, along with melons and cucumbers belong to the same plant family called cucurbits (cucurbitaceae). These vegetable plants bear two kinds of flowers on the same plant, male and female.  In order to produce fruit, the pollen from the male flower must be transferred to the female flower. Since the pollen of cucurbits is sticky, wind-blown pollination will not occur. Instead, insects do the major pollination work –honeybees being the main workers.  So, if bees aren’t frequenting your garden, for whatever reason, the fruit set on your squash, cucumbers and melons will be poor. 

Hand pollination, although a tedious chore, can be accomplished by transferring the pollen from the male flower to the female flower, often done with a small artist’s paintbrush.  Female flowers can easily be distinguished from the males by the presence of a miniature fruit at the base of the flower. 

Sometimes gardeners are concerned because none of the first blooms produce  fruit.  This is because the first flowers produced on the plants will be male. In time, female flowers are produced.  Also remember that cucumbers, melons and squash do not cross-pollinate; a cucumber will not cross with a melon; a squash will not cross with a cucumber, etc.  But within each species, cross pollination often occurs. A zucchini squash can pollinate a crookneck squash, and a Crenshaw melon can pollinate a Casaba melon.  Planting the seeds from these crosses will produce fruit that will be different from either parent.

Sunday, January 22, 2012

Spittlebugs


What causes the frothy substance on the stems of rosemary and basil? The froth is created by an insect called a spittlebug which is well hidden in the mass of frothy bubbles that it produces.  The bubbles act as protection from predators, moisture loss and temperature fluctuations.  Without the mass of spittle surrounding it, these insects would quickly dehydrate and die.
The spittlebug inserts its mouthpart like a hypodermic needle into the stem of the plant and sucks out the juices.   In many cases, spittlebugs do not cause serious damage, yet the plants are unsightly.  Ants, birds and spiders have been known to feed on these insects, but generally, they are not efficient enough to completely eliminate the infestation. The spittlebug and its froth can be removed from plants with a forceful stream of water from a garden hose. 

Friday, January 20, 2012

Why fruit trees don’t produce.


Since there are many factors involved in fruit production, there are also many reasons why fruit trees don’t produce.  Here are a few of the more common ones.
·        Rain- Too much rain during the bloom period can wash pollen away,  and a forceful rain along with wind can actually knock blossoms off.  Also, bees tend to fly less, or not at all, during heavy rains.
·        High heat and low humidity during bloom will hamper pollination.
·        Juvenility  - Sometimes it takes many years before a tree will produce fruit; mangosteen is a good example. However, new evidence indicates the size of the tree is more of a factor than age. In general, trees grown from seed take longer to produce fruit than those that are grafted, budded, or air layered. 
·        Pollinators – Some fruit trees require more than one tree or one variety in order to set more abundant fruit.  Examples are rambutan, macadamia, and avocados.
·        Some trees require insects to help in pollination, such as durian. 
·        Lychee and longan need a combination of low temperatures, 50 -59 degrees Fahrenheit, and a dry period (4-6 weeks) before bloom occurs.  Bloom for rambutan will be enhanced in response to drought.
·        The deciduous fruit trees, like peach, plum, nectarine, apple, etc., require cooler temperatures for good fruit production. This chilling requirement is the number of hours the tree needs to experience below 45 degrees F.  This requirement differs among species and varieties, ranging from a few hundred hours to over a thousand. 

Monday, January 16, 2012

The Pineapple Flower


Most people do not notice the flowers of a pineapple plant, but nevertheless, pineapple plants have flowers, too.  During bloom, the stem of the pineapple elongates and enlarges to put forth a head of small purple or red flowers. The resulting pineapple fruit that develops from these blooms is not one fruit at all. In reality, each pineapple flower forms its own small fruit, but they fuse together to make one single pineapple. The inner fibrous core is actually the stem. A pineapple fruit can be up to 12 inches long and weigh 1 to 12 pounds.

Friday, January 13, 2012

Spiders: Friend or Foe?



Spiders are beneficial creatures and are the best bio-control agents known.  They should be tolerated as much as possible since they feed on large quantities of insects such as aphids, ants, thrips and termites. 

Most people would rather not have a house full of cobwebs. But spiders capture and consume many household pests including flies and once in a while, a centipede. Spiders are actually classified as arachnids and not insects; spiders have eight legs, insects have six.
There are over 3,000 species of spiders in the U.S., and only a small number of these are dangerous to people; very few are equipped with mouth parts that can actually pierce the human skin. 


For people who won’t tolerate spiders, here’s what to do.
·        The easiest and safest way to rid your house of spiders and their webs is to vacuum rather than spray.  The dust inside the vacuum bags will quickly suffocate any spiders you catch. If you’re willing to share the house with a few spiders, you can periodically vacuum up the webs that are eyesores and leave the spiders to continue their job of controlling the household pests.
·        If you can catch a spider in a jar, take and release him outside where he can continue working.  You might try caulking cracks and installing screens to prevents more spiders from coming inside.

Monday, January 9, 2012

Propagating Pineapple


Can the top of the pineapple fruit be cut off and planted in order to produce a new plant?   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 would normally do when cutting the fruit.  Let this sit in a shaded, dry area for 2-7 days.  Then, plant it in your garden, keeping the leaves above ground.  Leaving the crown on the counter for several days will dry it out a bit, making it less susceptible to rot.  When you plant it, keep in mind that the mature plant can grow to 3-4 feet in diameter and in height.  Mature plants also have a tendency to fall over, so by planting several together, they will give each other support.
Some variations include removing the fruity portion of the crown, then pulling off  the bottom layer of leaves, exposing  ½ -1 inch of stem that will be planted in the ground.  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.  

Friday, January 6, 2012

Insect Signs and Symptoms


In order to successfully combat insects, and other pests, the correct identification must be made.  Often we can see the actual pest that is chewing on our favorite flowers.  But many times all that is seen is the damage - the sign that someone or something was there.  The following is a list of pest symptoms or signs with the corresponding probable cause.
·        Chewed leaves or blossoms  -  caterpillars, beetles, sawflies, snails, slugs.
·        Tunneling in the leaf – leafminers.  This insect actually feeds on leaf tissue as it meanders between the upper and lower layers of the leaf.
·        Stippled, bleached or yellowed leaves – leafhoppers, aphids, lace bugs, phyllids, mites
·        Distortion (twisting, cupping, swelling) of plant parts – thrips, aphids, eriophyid mites, bud mites, psyllids, gallmakers, true bugs.
·        Dieback of plant parts – borers, scales, tip miners, twig borers.
·        Presence of excrement – lace bugs, plant bugs, thrips, caterpillars.
·        Sooty mold – aphids, soft scales, whiteflies.
·        Froth – spittlebugs.
·        Cast skins – aphids.
·        Waxy, white material – aphids, mealybugs, adelgids, whiteflies.
·        Pitch tubes – pitch moths, clear winged moths, boring insects.

Monday, January 2, 2012

Unsuspected Causes of Plant Damage

A variety of plant diseases may lurk in the garden, but the odds are against it. Many professionals in the horticultural field estimate between 80 and 90% of all problems occurring in the garden are abiotic or non-infectious.  In other words, 10 to 20% of the problems are actually caused by some organism, some living creature – a rat, a bug, a fungus, a virus.  The rest of the problems are caused by too much or too little of an important environmental component that supports plant growth. Some examples are nutrient deficiencies OR excesses, a lack of water OR over watering, along with pesticide toxicities, air pollution, sunburn, frost and wind. So, when problems arise in the garden, investigate these noninfectious causes.