The record cold has a
chilling effect on residents, as well as
on many crop and plants

By Mary Adamski
Star-Bulletin

Enough of the chilly-weather complaints. It's time to make friends with a mango tree owner.

This winter's record-setting cold spell has a positive side: It brings the promise of spectacular mango and lychee crops.

But for most of the plant-growing business, the below-normal winter weather may have a chilling economic effect. Experts say it will affect the growing cycles of everything from commercial pineapple and papaya plantations, to vegetable-patch entrepreneurs, to backyard lei flower raisers.

National Weather Service records show the overnight low temperature was below the average for most nights so far this year.

It dipped into the 50s several nights. The Wahiawa gauge hit a record-setting 48 degrees on Feb. 1. It was 53 degrees at Honolulu Airport on Jan. 31 and in Makaha on Feb. 2, matching previous record lows.

Even Hawaii's predictably warm daytime temperatures have fallen short of the average high-70s mark for this time of the year. On Jan. 17, 75 degrees was as hot as it got at Honolulu Airport.

"Some crops benefit from the cold temperature, such as lychee and mango," said Randy Hamasaki, Windward agent with the University of Hawaii Cooperative Extension Service.

On the other hand, a combination of cool nights, lack of rainfall and previous wind damage slowed banana production, according to the Hawaii Agricultural Statistics Service.

"Coolness can cause what they call 'choke throat' in bananas: The growing shoot stops growing," said Hamasaki. "It can affect vegetable crops in different ways. For example, with corn, if you plant it in cold soil, it can affect the kind of start it gets.

"As far as production in just about any agriculture business, it will be the drought that affects crops more than the cold weather," said Hamasaki, echoing what other agriculture experts had to say. "Oahu is not as bad as some islands because a lot of the crops are irrigated. There's an added advantage: As long as irrigation water is used, there is less disease."

Fruit

Long-term low temperatures can even set the carefully orchestrated commercial pineapple crop awry.

"They spray a compound to get a field to flower at the same time, so when the fruit matures, it all can be harvested at the same time," said Robert Paull, plant physiologist with the University of Hawaii College of Tropical Agriculture and Human Resources. "The low night temperatures can lead to precocious flowering: The big plants flower sooner without being forced with chemicals."

"There is a measurable slowing in production in bananas and papayas," Paull said.

"In papaya they also may run into problems with pest infestation. They are more susceptible to infestation. Cool weather may also make the fruit more liable to show injury, such as scalding on the skin or lumps in the flesh" during the warm-water dipping treatment that kills fruit flies and renders the fruit transportable.

Flower crops

Paull said cool weather slows development of flower crops such as dendrobiums and anthuriums, which means not as many available as anticipated on the market.

"But it will be a great year for lychee," Paull said. "Cool weather initiates flowering. If you look around town, you will see flowering in lychee and mangoes."

County extension agent Mel Wong, who specializes in landscaping plants, said: "I don't think it will make much difference, to tell the truth. We expect cooler nights at this time of the year.

"An orange may turn more orange; it turns below 55 degrees. That's why here they tend to stay yellowish-green," Wong said.

The diminished rainfall isn't good for most crops, but it's a plus for the mango crop. "The lack of moisture keeps disease down," said Richard Criley, who does research on plant flowering at the College of Tropical Agriculture.

"As for the cold, lei flower people will probably experience the effects quite soon. On a cool night, pikake just doesn't open, the buds tend to be smaller, and the crop isn't as big," Criley said. "People who do have gardens and look to find things coming at the regular time will see a delay."

Potted azaleas and Easter lilies are deliberately chilled in mainland nurseries before they are sold here because it stimulates the flowering, he said.

Local gardeners who have kept those azaleas don't always see much of a blooming season, but "they will see good flowering of azaleas this spring. It's a good year for simultaneous blooming," Criley said. "The same is true for camellias in higher elevations."

"Some farmers have actually found this favorable weather," said Don Martin of the state Department of Agriculture statistics branch. "When it is dry and cool, there is less problem with disease and insects.

The ag outlook

"Agriculture has all the problems other businesses do, but it is unique in the way weather is a big factor," Martin said. "Farmers deal with it every day. It can be the factor that decides whether you will stay in business or not."

Martin said he doesn't expect a diminishing in fruit and vegetable crops because of the cold. "It's not unusual to have lower temperatures this time of year."

The diminished rainfall is the more important weather change and the one that concerns professional growers, Martin said. "At the moment it is not a crisis, but if we don't get some rain, it can get really serious really fast."