By Gram Slattery and Kanishka Singh

WASHINGTON, Sept 23 (Reuters) - Donald Trump said on

Monday he would slap a 200% tariff on John Deere's ( DE )

imports into the United States if the company moved production

to Mexico as planned, comments that hit the agricultural

equipment manufacturer's share price.

Earlier this year, John Deere ( DE ) announced that it was

laying off hundreds of employees in the Midwest and increasing

its production capacity in Mexico, a decision that upset workers

and some political leaders.

"As you know, they've announced a few days ago that they are

going to move a lot of their manufacturing business to Mexico,"

Trump said at an event held in western Pennsylvania. "I am just

notifying John Deere ( DE ) right now that if you do that, we are

putting a 200% tariff on everything that you want to sell into

the United States."

The Republican presidential candidate has frequently said he

would slap automakers that move their production to Mexico with

a 200% tariff, but this appears to be the first time he has

extended that threat to an agricultural equipment company.

Shares in John Deere ( DE ) fell more than 1.5% in after-hours

trade on Monday after closing up 0.75%. A representative for the

company did not respond to a request for comment.

Trump has made erecting extensive tariffs the central

element of his economic plan should he beat Vice President

Kamala Harris, the Democratic nominee, in the Nov. 5 election.

The strategy is designed to protect American jobs from foreign

competition, but economists warn his measures will boost

inflation.

Speaking to a gathering of farmers in a rural area outside

of Pittsburgh, Trump also said he would press Chinese President

Xi Jinping to honor a deal to purchase $50 billion of U.S.

agricultural goods.

During the so-called "Phase 1" trade deal inked between

China and the United States during Trump's 2017 to 2021 term,

the U.S. agreed to cut some tariffs on Chinese goods in exchange

for pledges to purchase more American agricultural products,

energy and manufactured goods. At the time, Trump said China

would buy $50 billion in U.S. agricultural products, though

Chinese purchases fell well short of that figure.

"Probably my first call - I'm going to call President Xi -

I'm going to say you have to honor the deal you made. We made

the deal, you buy $50 billion worth of American farm products,

and I guarantee you, he will buy it, 100% he will buy it," Trump

said.

Farmers and industrial workers are a crucial part of Trump's

coalition, and turning out these constituencies will be

important if he is to beat Harris. That is especially true in

Pennsylvania, where polls consistently show a razor-thin race.