MISSISSIPPI STATE -- Most of the state's crops need more water, but vegetable producing counties in southeast Mississippi are among the driest.

"Even the vegetable crops with irrigation are struggling. The systems just aren't set up to meet this much demand," said David Nagel, horticulture specialist with Mississippi State University's Extension Service.

The horticulturist said most systems are set up to deliver about 1 inch of drip irrigation per week. Watermelons are in their highest water-demand period and need 2 ´ (two and one-half) inches per week.

"That will mean vines will only produce one or two melons instead of three or four because there isn't enough water to support the third and fourth melons," Nagel said. "Since the first two melons are the largest anyway, it will mean a 25 percent yield loss instead of a 50 percent loss."

Fewer melons also will mean a shorter harvest season and higher production costs.

"Basically, watermelon growers are going to experience production costs up, yields down and prices level with last year," Nagel said.

Greene County Extension agricultural agent Mark Gillie said almost anything that is not irrigated will have a 75 percent yield loss.

"Most of the county has only received about a fourth of an inch of rain in the last two months, and it was dry even before that," Gillie said. "Even incidental showers aren't happening."

Gillie said corn has been the most drastically hit.

"Corn is literally falling down in the fields. Only about 10 percent of it is irrigated," he said. "Normally, corn is more mature and the stalk is fully formed before this kind of drought stress hits."

A vegetable problem related to weather but probably not the drought is tomato spotted-wilt virus which impacts tomatoes and peppers.

David Ingram, Extension plant pathology specialist in Raymond, said the virus began showing up six or seven years ago. Transmitted by thrips, the virus has a wide range of plant hosts outside the garden.

"Recent mild winters have done very little to reduce insect populations," Ingram said. "As tomatoes begin flowering, thrips move from weeds to gardens. Once infected, plants will not yield much marketable fruit."

Ingram said greenhouse tomato growers may lose 20 to 25 percent of their plants to this disease this year. Field tomato growers may have 10 to 15 percent infected. Growers need to watch their crop closely and respond quickly with insecticide treatments.

"The best method of control will be resistant varieties which will be available in the next couple of years," Ingram said. "Mississippi has several test plots around the state to evaluate newly developed varieties."