Citrus Harvest Time Sticker Weeds in the Yard

William Hogan  |  11/22/2011 8:29:07 PM

Citrus Harvest Time

Citrus fruit (Satsuma, sweet oranges, lemons, grapefruit, etc.) are the most popular fruit trees grown in home orchards in our area. They have the advantage of having relatively low maintenance, as fruit trees go. They are not, however, problem free; 2011 was no exception to that rule.

We have experienced over two years of much drier than normal weather conditions. Last spring, when the citrus trees were blooming, there was adequate soil moisture to allow for a good bloom and fruit set of the fertilized blooms. We had several outbreaks of cool or cold weather in late spring. Many of these trees lost blooms to the cold weather. It doesn’t have to reach freezing temperatures for a Satsuma bloom to die. There was a great amount of variation of fruit set from tree to tree due to the cool periods in spring. Not all citrus trees bloom at exactly the same time and not all blooms on a tree form at the same time. Those that have very few fruit this fall probably had susceptible blooms when the temperatures dropped last spring.

Many trees have plenty of citrus fruit, but it is small in size. This is most probably attributable to the prolonged drought this summer. If there was adequate warmth and soil moisture in the spring, the tree set a good crop of fruit. Without sufficient rain this summer, this fruit did not reach a maximum size. The fruit will still have good quality, it just won’t be as large as you desire. Many irrigated their citrus trees through the drought. This was an excellent practice. It probably didn’t contribute to large fruit, but it allowed the fruit present to survive. Irrigation also kept the citrus tree healthy for another and hopefully a better year.

Black or sooty mold is a condition on some citrus fruit every year. It was probably present all summer long, but wasn’t noticed until time for harvest drew near. The sooty mold is a by-product of an insect problem. Aphids, white flies and scale insects feed on plants by sucking juice from their tissues. These are very small insects and not easily detected at a quick glance. They are usually present in extremely large numbers. The waste of these insects is high in sugars from the plant juice. Sooty mold will grow on this sugary waste and produce the black material. The sooty mold is not very harmful to the plant or its fruit. The insects that cause it can be very harmful. Control the white flies, aphids and scale insects and the sooty mold will cease to be present. An application of an ultra-fine oil emulsion spray will smother the insects. This application should have been made in the spring and early summer before the population of pests reached its peak. They have already done their damage by now. Applying an oil emulsion spray now will not be most effective timing. Remember to make these applications next spring after the citrus tree has completed its bloom period. If you had these insects this year, you will have them again next year. Make yourself a note to perform this chore next spring after the blooms fall. A second application of ultra-fine oil emulsion spray should be made about fourteen days after the first. This should take care of any surviving insects. For now, wash the fruit to remove the sooty residue.

Some have asked why their fruit is not sweet. There could be several reasons, but it is probably because it is not ripe yet. Just because a citrus fruit is the desired color, doesn’t mean that the sugars have reached their peak. The proper amount of time for maturity and cool fall weather are needed for citrus to reach their peak quality. Certain citrus fruit such as grapefruit do not normally reach peak sweetness until the end of December. If freezing temperatures don’t destroy the fruit, they tend to become sweeter the longer they stay on the tree. Be patient.

Bird pecking and scratching is present on many citrus fruit every fall. I have no solution for this condition. Black birds like to scratch citrus fruit all summer to get the oils and preen their feathers. We have plenty of black birds all year long. These scratches are only “skin deep”, they don’t enter the fruit or juice. Scratched citrus fruit may not be very appealing to look at, but after the peel is removed it is the same as the unblemished fruit.

Sticker Weeds in the Yard

There are a lot of little plants that grow in our lawns. Some have a tendency to stick our bare feet in the spring. The problem with most is that by the time they develop the stickers, it is too late to control them. The number one culprit is a plant known as “lawn bur weed”. Others include bur clover and a stinging nettle known locally as “fire grass” or “burning grass.”

One or more applications of post emergence herbicide during the winter months will often kill these plants while they are immature. Killed at this stage, they never develop the stickers or thorns. December through February most summer lawns are completely dormant. An application of a labeled herbicide at this time will not harm the lawn grass. It will also be more effective on the young sticker weeds. Continue to check your lawn regularly throughout the late winter. Control the weed before it becomes a problem.

Post emergence herbicides containing 2, 4-D and other broadleaf weed killers work best on sticker weeds that have emerged. Apply to young weeds from now through early March. Best activity occurs if the temperature is over 60 degrees F. Always use only herbicides that are labeled for use on your species of grass. Always read the label and follow all directions and restrictions when using any pesticide. Also give some consideration to maintaining good soil fertility in the lawn. A healthy, well fertilized lawn will have fewer sticker weeds, clovers and other weeds. Proper applications of nitrogen fertilizers in the spring and early summer will make the lawn more competitive with both cool and warm season weeds.

Rate This Article:

Have a question or comment about the information on this page?

Innovate . Educate . Improve Lives

The LSU AgCenter and the LSU College of Agriculture

Top