Ipomoea triloba
(three-lobe morning glory)

Genetic importance

• Related to

Human food and beverage

• Honey/honey flora

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Chemical, Cultural and Sanitary Methods

Coconuts
Research in the Philippines showed that I. triloba was controlled in coconut nurseries with the use of paraquat or by hand weeding at intervals of 1-2 months (Abad and Juan, 1981).

Maize
Field studies to evaluate different herbicides and herbicide combinations in the Philippines showed that pendimethalin alone failed to control I. triloba in maize cv. Pioneer 6181 (Jover et al., 1982). Madrid and Manimtim (1978a) found that atrazine provided good control of broad-leaved weeds, including I. triloba; however, oxyfluorfen provided good control for I. triloba but killed the maize.

Sugarcane and Sorghum
Research by the Hawaiian Sugar Planters' Association indicated that metsulfuron provided good control of I. triloba (Santo, 1989). In another Hawaiian study, conducted during the first 4-6 months of sugarcane growth until the canopy closed, atrazine was found to give excellent control of several broadleaved weeds, including I. triloba (Olney, 1971).

Field trials in sugarcane and sorghum in New South Wales and Queensland (Australia) during 1982-86, showed that I. triloba was moderately susceptible to fluroxypyr, but was controlled with a tank mixture of fluroxypyr and 2,4-D (Webb and Feez, 1987).

Hondrade (1981) found that pendimethalin was ineffective in controlling I. triloba in sugarcane.

In field trials in the Burdekin District of Queensland, 2,4-D and MCPA applied to sugarcane at hilling up gave good control of I. triloba, I. plebeia and I. purpurea, and provided an economical and reliable alternative to aerial spraying. The major Burdekin cane cultivars, Q96 and Q80, could be treated without risk of damage. 2,4-D was the least expensive of the treatments (on the basis of the cost of chemical). Extensive commercial spraying showed that 2,4,5,-T [superseded] could be used to maintain satisfactory weed control, but that higher rates were needed where Cucumis metuliferus or Passiflora subpeltata were also present (Anonymous, 1980).

Mungbeans and Soyabeans
In the Philippines, oxyfluorfen was effective in inhibiting the germination of I. triloba in mungbeans and soyabeans when applied 2 days after planting. Emergence of I. triloba was observed at lower rates, but the seedlings died 2 weeks after treatment (Fabro and Robles, 1982).

In another Philippine study, oxadiazon applied pre-emergence in soyabeans gave excellent control of I. triloba. In another trial, however, oxadiazon controlled I. triloba but severely injured the crop. Combination pre-emergence and post-emergence directed applications of bentazone also provided control (Madrid and Manimtim, 1978b).

Tomatoes and Cabbages
Rice straw, rice hulls and sawdust mulches reduced populations of I. triloba in tomatoes by 50% at 30 days after transplanting. However, the weed eventually penetrated the mulches and grew out of control. In transplanted cabbage, mulching also cut populations of I. triloba in half during the wet season of 1977 in the Philippines (Paller et al., 1979).

Miscellaneous
Pre-emergence application of bromacil was effective in controlling I. triloba in a variety of tropical crops in the Philippines (Mendoza, 1979). In another Philippine study, bentazone applied post-emergence or as a directed spray controlled I. triloba at the 2-3 leaf stage. However, yields were less than with hand weeding and weed control was not season long (Robles et al., 1979).

Biological Control

The phytophagous arthropods (and their natural enemies) in an agroecosystem in the warm region of central Tolima, Colombia were investigated from November 1976 until May 1979. This project found that Agrius cingulatus showed some promise for biological control of I. triloba. On several occasions, this sphingid completely defoliated the weed in soyabean crops without damaging the crop. Larvae placed on soyabean leaves in the laboratory died without feeding (Hallman, 1979).

Regulatory Control

I. triloba is listed as a Federal Noxious Weed in the USA. Introduction is permitted there only by permit from the Animal and Plant Health Inspection Service, USDA.

Preliminary studies indicate that a 0.35% solution of caustic soda (NaOH) in hot water at 92°C is sufficient to kill seeds of I. triloba that contaminate shipments of sesame (caustic soda is used to de-hull or decorticate raw sesame seeds). Preliminary studies also indicate that dry heat (hot air) temperatures of 130°C will kill seeds of I. triloba (R Westbrooks, Animal and Plant Health Inspection Service, USDA, North Carolina, USA, personal communication, 1995).

Regulatory strategies to prevent the world movement and further establishment of exotic pest plants such as I. triloba include foreign prevention (production of weed-free commodities for export to uninfested countries); exclusion (detection and mitigation of weed contaminants in imported products at ports of entry); detection, containments and eradication of incipient infestations, and cost-effective control of widespread species (Westbrooks, 1991).