BURQA, WEST BANK — Olive tree by olive tree, Palestinian farmers and Jewish settlers are competing over the rocky hills of the West Bank, planting more of the gnarled evergreens to strengthen their hold on the land. Now in harvest season, the battle gets rough, with orchards robbed, vandalized and burned.

This year, the stakes have been raised: Palestinians have planted double the number of trees as in past seasons, and Jewish settlers have responded by boosting their own olive production.

The olive tree has long been a symbol of the Palestinians' attachment to their homeland, its mystique enhanced by settlers' annual efforts to disrupt the harvest. In a more literal sense, a tree helps protect a claim, since possession is often determined by who works a piece of land — and not always who owns it.

"We plant so they won't come and grab it," said Palestinian farmer Ghassan Seif, 48, on his lands close to the West Bank village of Burqa, referring to hardline Jewish settlers who live nearby.

He stood among olives that his extended family had just picked during the annual October harvest season. Nearby, women in headscarves took a break, sipping sage-infused tea under an olive tree. Children smeared with dirt from the dusty fields ran about.

Just 10 miles (16 kilometers) away in an olive orchard, Israeli settler Erez Ben-Saadon echoed his Palestinian neighbor's motives.

"Before Arabs take over the lands, we farm them," said Ben-Saadon, 36, fingering the smooth leaves of the young saplings he is growing. Ben-Saadon is hired by Jewish settlers to work fallow lands surrounding their hilltop communities.

The olive competition is part of the long-standing struggle for the West Bank, which Israel occupied during the 1967 Mideast war. The United States is trying to broker peace negotiations that would give Palestinians an independent state including most, if not all of the territory. But neither side is waiting idly for a deal.

Israeli military officials can seize farmland if it has lain fallow for three to 10 years. The military has grabbed some 240,000 acres this way since the 1980s, mostly handing them over to Jews to build settlements, according to Peace Now, an anti-settlement watchdog group.

Partly in response, Palestinians are planting more. They planted around 200,000 olive saplings annually for the past three years, double the average of previous years, said agricultural official Nabil Saleh. The Palestinian Authority, the semi-autonomous government in the West Bank, is also subsidizing saplings to boost planting rates to 300,000 trees a year, he said.

They are focusing on planting their fallow plots, particularly ones close to Jewish settlements where the most intense land struggles take place, said Palestinian negotiator Nabil Shaath.

"It is the land that settlers want to dominate, to occupy," he said as he plucked olives near the Jewish settlement of Psagot.

Olives are the Palestinian crop of choice for more than sentimental reasons. They grow easily and need little maintenance, so farmers need not linger in fields around settlements where they are sometimes at risk of being attacked. The trees survive on winter rains, a key source of water in an otherwise drought-ridden territory.

Olive oil now sells locally for about $7 a liter, or about $25 a gallon, making it an important cash crop. And for the some 70,000 families who grow the estimated 10 million Palestinian olive trees — most of them rural poor — it's a food staple.

Jewish settlers have planted 20,000 new saplings this year, up from a few thousand last year, said Yehuda Shimon, a legal adviser to settlers. Jewish settlers already farm some 100,000 trees, Shimon said.

Devout Jewish farmers draw inspiration from biblical verses that command them to work the land.

"We feel we are going to be here forever and ever," Ben-Saadon said.

Ben-Saadon walked through the valley of Shiloh — mentioned in the Old Testament as a resting place for the Holy Tabernacle on its way to Jerusalem — showing off olive trees engineered to bear more fruit. He said the olives are part of a wider project involving vineyards for wine and organic apples.

Palestinians and activists groups accuse settlers of using vandalism and arson to push back Palestinian orchards.

Rights groups documented over 40 attacks against Palestinian-owned trees this harvest season, including 20 chopped down overnight Saturday near the Jewish settlement of Eli, not far from where Ben-Saadon farms.