NAIROBI, May 26 (Xinhua) -- Kenyan crop and livestock farmers are grappling with a myriad of diseases resulting from adverse weather conditions brought about by the rains.

It has been raining in the East African nation since March and Kenya's Meteorological Department has said the heavy rains would go on until next month, adding more pressure on farming.

Crop farmers are grappling mainly with blight and bacterial wilt. The diseases have attacked coffee, tomatoes, onions and potatoes pushing up the cost of production for farmers.

Even as they save on irrigation water, the farmers have to invest heavily in pesticides to fight the diseases and others to avoid losses.

The two diseases are a huge threat to the crops because they lead to 100 percent loss if not checked.

"I have grown tomatoes on half-acre. Last month when it was raining heavily, the crop was attacked by blight and I had to spray consistently to save it because it had started fruiting," Joseph Gitau, who grows the crop in Juja, told Xinhua recently.

The farmer who works as an auditor in Nairobi said eradicating the crop became difficult because the rain washed away the chemicals.

"I am not going to harvest much this season because the rains destroyed some fruits and some flowers also aborted. This is a bad season for me," he said.

The blight has attacked coffee in main production areas in central Kenya threatening the cash crop that is exported in markets in Europe, Asia and the Middle East.

Farmers in Nyeri, Murang'a and Kiambu are currently grappling with the disease, which they say is attacking their crop for the first time in years.

"It is the first time I am seeing it since I started farming coffee 10 years ago. We have been asked to use certain chemicals to save the crop," said Moses Karanja, a coffee farmer.

The disease, according to farmers in central Kenya, was prevalent in other areas including Nakuru and Trans Nzoia. However, excess rainfall in the area led to its emergence.

"This is new disease in the region. I am calling it new because it is the first time it is being heard of in Nyeri," said Karanja.

Caroline Wandia, an agronomist in Nyeri, said bacterial blight in coffee is normally favored by cool, wet weather.

"Normally, lesions appear on leaves with water soaked margins when the infection begins. The leaves eventually dry up and roll inwards as they turn brown," she said.

She added that the same symptoms are observed with tomatoes, onions and potatoes when attacked by blight.

"The brown, dried leaves normally do not shed but remain attached to the plant. Sometimes the leaves appear like they have been scorched by fire," she said.

For livestock farmers, the rainy season comes along with coccidiosis, pneumonia and Rift Valley Fever, among others. Coccidiosis affects mainly chicken, pigs, sheep and goats.

On the other hand, sheep and goats and even chickens are prone to pneumonia, with a number of farmers recording deaths.

"I lost my five goat kids last week to pneumonia. They were rained on and after two days, they developed the disease. It was too late when the vet arrived," said Jackson Mutisya, a farmer in Kangundo, on the outskirts of Nairobi.

Several cases of the deadly Rift Valley Fever have been reported in the East African nation. The disease affects cattle, sheep and goats and also humans.

The government on Saturday last week issued an alert on the disease, citing possible outbreak due to the rains. Mosquitos spread the Rift Valley Fever virus, and with the rains, the insects multiply faster.

Veterinary services director Obadiah Njagi and medical services director Jackson Kioko said in statement that the weather conditions are ideal for mosquito breeding and increase the risk of Rift Valley Fever outbreak in Wajir, Garissa, Tana River, Malindi, Kwale, Laikipia and Kajiado.

The major outbreak in Kenya was reported in 2006/2007 following prolonged rain. At least 160 people died and the livestock sector lost about 40 million dollars, according to official figures.