Cracked Mangoes

The cause of cracking in mangoes is the same whether it’s mangoes, oranges or tomatoes. The majority of cracks are caused by irregular periods of dry and wet weather.  Abundant rain alternating with dry spells will produce stages of slow growth followed by rapid growth, resulting in cracked fruit.  In addition, a fungus or bacteria may invade these cracks and cause the fruit to rot.  The weather is beyond our control, but if irrigation is involved, an even supply of moisture throughout the growing season will help eliminate cracking in fruit. Also, anthracnose fungal disease, common on mangoes, can cause deep cracking in certain varieties which are especially susceptible to this disease. The florigon mango variety is rated ‘moderately resistant to anthracnose.’

Invader in the Lawn

A small-leafed, weed with purple flowers is spreading over my lawn. It has nasty stickers and a long tap root.  Sensitive plant is one name of this weed; sleeping (or sleepy) grass is another.  The name comes from the fact that the leaves close when they are touched. In Hawaiian it is called pua hilahila. This invader commonly grows in well drained soils that have been disturbed such as lawns, orchards, pastures and roadsides.  It does not grow under forest canopies.  It is a real scourge as it crowds out other plants and grows up into taller ones.  It appears from sea level to about 4,000 ft. in elevation. The sensitive plant can also be a fire hazard in dry terrain.  Control Physical:  Hand weeding is obviously difficult due to thorns and a strong, woody root.  In pasture land, it can be controlled by intensive grazing where cattle will kick the pua hilahila out of the way to get at the grass beneath.  Chemical: The sensitive plant can be controlled with the herbicides Roundup and Garlon. Roundup will also damage or kill your lawn. In lawns, herbicides containing the active ingredient 2,4D (Crossbow, Trimec Southern) are fairly effective and should not damage the lawn.  Damage can occur to carpetgrass when Trimec Southern is applied. Locally it has been observed that no damage occurs when applying Garlon to many of our lawns. When in doubt, spray a small portion of the lawn and wait for 2 weeks to see if any damage occurs.  If plants are disturbed before spraying, the leaves will fold up and the herbicide will be ineffective. For further information go to the following website: http://www.ctahr.hawaii.edu/invweed/WeedsHI/W_Mimosa_pudica.pdf

The Citrus Tree Switch : Sweet to Sour

Have you ever purchased an orange tree, harvested sweet oranges for many years, only to have a crop of sour fruit the next?  All commercially sold citrus trees are budded. A budded tree is like a grafted tree, except a single bud is used instead of a graft which is a few inches of stem containing several buds.  When you look at the trunk of a citrus tree, you should be able to observe a slight to obvious bulge. This is where the original budding took place; it is called the bud-union. Everything above that bulge or bud-union grew from that bud and is the variety of tree you purchased; everything below is of the original rootstock seedling. Sometimes shoots originating from below the bud-union will grow up into the tree. These are typically covered with large thorns. If the shoots not pruned out, they will continue to grow, branch and eventually form a good part of the tree. Rootstock branches are usually more vigorous and will eventually blossom and produce fruit. This fruit is different from the variety you originally purchased, and most often is quite sour. These branches must be cut out so the original budded variety can repopulate the tree and produce sweet fruit.