Garden Guy: Be careful when spraying

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Overly zealous spraying of Roundup hit the lower branches of my lemon tree with fruit on it. Days later, I discovered fruit turned yellow before its natural time. My question is, is it still safe to use or should I just trim all the affected branches and fruit? Thank you — Pat

Overly zealous spraying of Roundup hit the lower branches of my lemon tree with fruit on it. Days later, I discovered fruit turned yellow before its natural time. My question is, is it still safe to use or should I just trim all the affected branches and fruit? Thank you — Pat

All of the fruit present on the tree, no matter what size, should be picked and thrown away. Concerning the vegetative growth, wait approximately a month or two to see how much damage, or how much dieback occurs, then prune appropriately. Prune well into the healthy tissue.

In the next vegetative flush cycle, you might notice some of the new growth will appear feather-like, that is, individual leaves will look longer than normal, as if they were stretched. This symptom is caused by certain herbicides. Eventually, the tree will recover and produce normal appearing leaves.

Roundup can be absorbed by citrus leaves and taken into the system of the tree. Spray drift landing on mature bark does not seem to cause tree damage. Spray drift, however, contacting young bark, especially with a greenish coloration, will cause damage.

Be careful when spraying. Do not spray under windy conditions.

My cherry tomatoes are fully fruiting. When I went to harvest my tomatoes today, the majority of them had split and the seeds were spilling out. I’m not sure if this is because of overripeness, as I have not harvested in a few days because of rain, or if all the rain caused the tomatoes to swell and split. Do you know if either is a factor or if it is something else? — C.C., Hilo

The rain can take the blame for this problem.

Cracks and splitting occur during periods of heavy rainfall, especially following a dry spell. The typical symptoms are cracks on the top of the fruit in concentric circles around the stem and cracks radiating down the fruit from the stem end (these downward cracks are sometimes blamed on high temperatures and too much sunlight).

Ripe fruit might actually burst open, spilling out the seeds, since its skin is weaker than the skin of unripened fruit. The cure would be to remove ripe fruit immediately after a rain to prevent the cracking. If the tomatoes are grown in a drier climate where irrigation is necessary, water should be applied so the plant receives an even supply of moisture throughout its growing season, thus preventing alternating stages of fast and slow fruit growth.

Cracking alone is not that bad because the fruit can still be eaten. This open wound, however, will often allow for the entry of secondary disease organisms, such as fungi and bacteria, causing the fruit to rot.

The following varieties are considered resistant to cracking:

• Lisa King.

• Jet Set.

• Heinz 1350 and 1439.

• Mountain Spring 286.

Rats?? Rats!

Are you wondering if you have rats on your property? Do you suspect you might?

Check out the new CTAHR publication, “Rat-Feeding Injury to Plants in Hawaii.” This publication discusses the different species of rats on the Big Island, their signs and control, cultural and chemical. Check out the photos of rat damaged fruit to determine if rats are on your property.

Go to www.ctahr.hawaii.edu/oc/freepubs/pdf/MP-7.pdf to access the publication and a wide range of photos.

Upcoming class

“General Care of Backyard Citrus and Avocado Trees” is the name of a class I am teaching from 9:30 a.m.-12:30 p.m. Saturday on the University of Hawaii at Hilo campus.

There are still seats available.

Call the UH-Hilo College of Continuing Education and Customer Service at 974-7664 for reservations.

There is a fee.

Hilo resident Nick Sakovich is a professor emeritus of the University of California. He has worked in the field of agriculture for 30 years. Email your questions to Sakovich at askthegarden guy@earthlink.net. You also can visit his website at www.gardenguyhawaii.com.