Drive vs. harmful vine stepped up

The Department of Lands and Natural Resources has combined efforts with the Integrated Pest Management Program of the Northern Marianas College-CREES to stop the spread of the noxious Scarlet Gourd.

Scarlet gourd has reportedly started destroying some of the islands’ most coveted assets that include trees and melons. The scarlet gourd, Coccinia grandis, is a very aggressive alien invasive vine that was illegally imported into the CNMI 10 years ago.

It presents natural resource and agriculture crop protection managers with two big problems: 1) it climbs up any structure or tree, and covers it with dense vines and foliage, choking out and killing all plant life under it. 2) The fruits are a very good wild host for the melon fly, Bactrocera cucurbitae, the number one agricultural pest of cucumbers, melons, squashes, gourds and pumpkins.

DLNR and the NMC-CREES Integrated Pest Management program is calling for the public’s participation in locating, identifying, and mapping all known locations of the invasive alien vine, the scarlet gourd.

This is especially important for Rota and Tinian, where the infestations of the weed vine are still limited, unlike the situation in Saipan, where whole neighborhoods are covered with the heavy vine.

The scarlet gourd has a two-inch white flower and a small cucumber-like fruit that has red pulp on the inside and turns bright red, or scarlet, when ripe.

The USDA Animal and Plant Health Inspection Service’s named the Scarlet Gourd a noxious and prohibited species and should not be allowed through the inspection points.

The vine is often mistaken as an ornamental plant, but in reality has become one of the CNMI’s ornamental enemies. This vine can be multiplied easily from a cutting of stem or root. What makes it more dangerous is that the vine can escape cultivation, when birds eat the fruits and seeds and spread them all over the CNMI.

The vines change the colorful landscapes into a dull shroud of waxy green leaves. The scarlet gourd grows fast and high, even covering the tall kapok trees.

The IPM teams fear that even the islands’ coveted and beautiful flame trees are in danger, cause the vines have no mercy. The trees, shrubs, and other plants under this canopy die, leaving the ground devoid of other vegetation, reducing the flora and biodiversity to almost zero.

Native trees, plants, and shrubs die, removing food for wildlife and humans alike. Medicinal plants that once grew in the understory of our forests are now dead under the blanket of scarlet gourd vines.

Secondly, the scarlet gourd’s cucumber-like fruits are a very good alternate wild host for the melon fly, which is the major crop pest for cucumbers, squashes, gourds, and melons.

Third, the heavy vine poses some significant risk of damage to utility lines, which it easily reaches and covers.

The scarlet gourd is not easily killed. It has tuberous underground roots, which spread out over an area. If the above ground vines are cut or sprayed with a herbicide, the underground roots will sprout again, producing new plants.

The public is asked to help slow down the spread of the vine by doing the following things:

• Cut all stems of the scarlet gourd vine on your property or any land that you manage;

• Spray all cut stems with the herbicide Roundup, which will slow down the future growth of the stem and vine, but not kill it;

• Bag and burn all the fruits (don’t eat them, because the seed will not be destroyed) and vines and stems and any roots that you dig up;

• Help support retailers who are willing to import Garlon for control, since it is not yet available here, due to lack of demand.

• Do NOT spread the seeds or transport cuttings of the vine to other places, especially to the other islands in the CNMI.

This combination of mechanical and chemical control is currently being used in Hawaii to control patches of the vine, which is called “Ivy gourd” there.