Murdannia nudiflora
(doveweed)

M. nudiflora is classified as one of the world's worst weeds by Holm et al. (1977), infesting no less than 16 crops in 23 countries. It is a major weed species in rice and other crops (Moody, 1989), and is a moderately invasive weed species both in agricultural crops and non-agricultural areas in South and South-east Asia (Waterhouse, 1993). Its special ability to root easily at the nodes, propagating clonally through cut stems and dispersal during tillage and land preparation make this weed difficult to control. This trait coupled with its ability to adapt and survive a wide ecological window of soil types, pH, moisture availability and soil drainage makes M. nudiflora a weed to watch for potential spread into new areas in near future, and a species under the 'alert list' by the Invasive Species Specialist Group. Oliveira Pellegrini et al. (2016) recognize M. nudiflora as one of two Murdannia species invasive in the Neotropics.

M. nudiflora is native to tropical and subtropical Asia, from China to India, Malaysia, Indonesia and the Philippines (Govaerts, 2017; USDA-ARS, 2017). It has now spread to other tropical and sub-tropical parts of Africa, Asia, Oceania, Central, North and South America, and the West Indies, where it is invading both the agricultural and non-agricultural areas (Holm et al., 1977; Acevedo-Rodríguez and Strong, 2012; Govaerts, 2017; USDA-NRCS, 2017; PIER, 2017; USDA-ARS, 2017). In the New World it is found between the southeastern USA and Argentina (Oliveira Pellegrini et al., 2016).

While USDA-ARS (2017) lists M. nudiflora as native in Japan, Nakamura (2015) suggests that it is a new record for Japan when found newly naturalized in northern Kyushu.

The relatively free or unrestricted movement of plants or plant parts within each country in Asia, Africa or Latin America makes it possible that both seeds and vegetative parts of M. nudiflora can be transported or dispersed to different parts of those countries where the weed is prevalent, unhindered, principally through its use as animal fodder. Sharing of agricultural implements, especially those tillage and harvesting implements among farmers either through the hire-for-service by private individuals or cooperatives may also help to disperse the propagules from one locality to another.

M. nudiflora can be found naturalized across the tropics and subtropics on derelict or abandoned land, roadsides, and often in moist, waterlogged places being almost sub-aquatic, along the banks of irrigation canals, ditches and dikes, in rice paddies and in other lowland crops, field borders and wet pasturelands. In Brazil, it is found in disturbed vegetation, roadsides and near rice crops (Oliveira Pellegrini et al., 2016). In temperate regions, it is widespread in moist, often waterlogged, arable and non-arable lands in open places (Atkinson, 2017; PIER, 2017). Within its native distribution range, M. nudiflora also grows as a weed on wet and waterlogged places, grasslands, and damp prairies at elevations up to 1500 m (Flora of China Editorial Committee, 2017; India Biodiversity Portal, 2017).  

M. nudiflora is a principal weed of peanuts, lowland and upland rice, tea, and maize in Indonesia, Philippines and Sri Lanka (Soerdarsan et al., 1974; Baki and Md Khir, 1983; Soerjani et al., 1987; Pancho and Obien, 1995). It is a weed of rice in the eastern plains of Colombia (Bastidas-Lopez, 1996; Plaza and Forero, 1998), bananas, citrus, sugarcane, vegetables, rice, maize and coffee in Mexico (Holm et al., 1977), pineapples in Hawaii, Indonesia, South Africa, Malaysia and the Philippines (Holm et al., 1977; Pancho and Obien, 1995; Baki et al., 1997), and taro in Fiji and Hawaii (Holm et al., 1977). Galinato et al. (1999) reported widespread occurrence of the weed in teak, tea, oil palm, chincona, cotton and coffee plantations, and in arable lands. In the United States, it has historically been a problematic weed in turfgrass systems, but it has become increasingly more common in North Carolina in cotton (Gossypium hirsutum) and soyabean (Glycine max) plantations (Wilson et al., 2006).

Genetics

The chromosome number reported for M. nudiflora is 2n = 20 (Renugadevi and Sampathkumar, 1986).

Physiology and Phenology

Flowers open only for a few hours, and then wilt. The weed produces 500-2,200 seeds per plant, and there are 1,000 seeds/g. In India, it has been recorded flowering and fruiting from September to November (India Biodiversity Portal, 2017).  In China, its flowers and set fruits from June to October (Flora of China Editorial Committee, 2017). In Central America, flowers and fruits are produced from July to January (Davidse et al., 1994).

Reproductive Biology

Although M. nudiflora reproduces through seed and vegetative propagation, the time- and environment-mediated loss of seed viability limits population increase by sexual means. Flowers open only for a few hours, and then wilt. An unpublished study recorded that a single plant of M. nudiflora produced less than 100 seeds per plant in 3.5 months of its growth cycle (M Azmi, MARDI Food and Industrial Crops Research Centre, Penang, Malaysia, personal communication, 2003).

Arguably, the species has to rely on vegetative propagation to ensure a continuous population increase, and there is a need to obtain essential plant resources through roots produced at the stolon nodes. Seeds and stolon parts are dispersed principally via wind and water, and through human activities such as agriculture. The weed is hydrochorous: the mode of propagation and dispersal is through seeds and stolon fragments. The plant roots easily at the nodes of the creeping stolons, and will do so when cut or broken, especially during cultivation and tillage operations. In fact these stem cuttings may survive for several days to several weeks on the soil surface before eventually taking root, notably under moist or waterlogged conditions.

Longevity

In tropical and subtropical areas, M. nudiflora is mostly a perennial plant, whereas it becomes an annual in temperate regions (Atkinson, 2014). Under suitable condition (e.g. high humidity or irrigation), it behaves as a fast-growing herb (Atkinson, 2014).

Activity Patterns

Less than 60% of the seeds produced remained viable after 6 months under ambient temperature of 23°C (night) and 35°C (day). Seed viability was less than 15% when buried in moist paddy soil for 6 months, underlying high percentages of seed decay when exposed to the soil environment. No seeds were viable a year after production, irrespective of whether they were exposed to the soil environment or kept under the ambient temperature stated above (M Azmi, MARDI Food and Industrial Crops Research Centre, Penang, Malaysia, personal communication, 2003).  Greenhouse and laboratory experiments have showed that germination in this species was higher at alternating day/night temperatures of 35/25°C (95%) than at 30/20°C (72%), and no germination occurred at 25/15°C. Light strongly influenced germination (95%) and dark completely inhibited germination (Wilson et al., 2006; Ahmed et al., 2015).

Environmental Requirements

M. nudiflora prevails under a wide range of environmental conditions with varying soil types, pH, moisture conditions, nutrient status, high light exposure or shade, and competition with crops and other plants. These crops include rubber, oil palm, cocoa, coffee and groundnuts, which are generally planted in well-drained soils, in either lowland or higher altitudes, and the weed occurs under varying degrees of shade. In non-crop situations, the weed can tolerate soil pH ranging from <4.0 (peat soil) (Masayu, 1995; Baki et al., 1997) to >7.0 (calcareous soils). In rice or on the banks of irrigation canals and drains, rivers, etc., populations of M. nudiflora prevail under wet or waterlogged conditions where soil pH is often low (acidic). It appears tolerant to a wide range of conditions, either in open situations or in rather deeply shaded sites, and at low altitude or at altitudes of 1800 m or higher.

Associations

M. nudiflora as a component of weed flora, together with other weed species prevailing on arable peat, and lowland irrigated and non-irrigated rice in Malaysia (Baki et al., 1997), displayed an aggregated pattern of spatial distribution based on Lloyd's mean crowding, Lloyd's patchiness or variance-to-mean ratio dispersion indices. Negative associations were observed between Boerhavia diffusa and several weed species, one of which was M. nudiflora in highly disturbed sites in Uttar Pradesh, India (Pandey and Shukla, 2001).

Bastidas-Lopez (1996) cited the prevalence of phytophagous insects as natural enemies on weeds, including M. nudiflora, in the eastern plain of Colombia. M. nudiflora is also a host of nematodes such as Pratylenchus pratensis and Meloidogyne arenaria (Valdez, 1968), the fungus Pythium arrhenomanes (Sideris, 1931), and the viruses Cucumber mosaic virus (Anon, 1960), Southern celery mosaic virus (King, 1966), Tomato mosaic virus and Clover yellow-vein virus (Baker and Zettler, 1988). M. nudiflora is an ovipositional host of the plant hopper Nisia carolinensis that is common in rice field habitats, and is a host of the hairy caterpillar Diacrisia obliquais also noted as feeding on aerial parts of the plant, mostly leaves and stems, in West Bengal, India but is not specific to this genus (Satpathi, 1999). The weed is also a host to rice sheath blight caused by Rhizoctonia solani [Thanatephorus cucumeris] (Galinato et al., 1999).

M. nudiflora is similar to Murdannia spirata (L.) G. Brückn., although the latter species has very shortly pedunculate inflorescences, persistent floral bracts, 3 fertile stamens, and non-congested fruits with more than 6 seeds per fruit (Soerjani et al., 1987). Occasionally M. nudiflora is mistakenly identified as Commelina diffusa (Everaarts, 1981), despite quite distinct morphological differences between them, the former with narrow leaf blades and yellowish petals in the flowers as opposed to wide size leaf blades, and bright blue petals in the latter species. M. nudiflora was treated together with the closely-related species Commelina benghalensis and C. diffusa by Holm et al. (1977) though easily separated morphologically. 

Oliveira Pellegrini et al. (2016) say that M. nudiflora can be easily identified by its "caduceus bracteoles, single terminal cincinni, two fertile stamens and four staminodes, and capsules with 2-seeded locules".

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.

Cultural Control

Burning of straw, stubble and weeds after harvesting rice, maize or vegetables prior to tillage operations and replanting/sowing of new crops are a common practice in Indonesia, Malaysia, Thailand, Vietnam and elsewhere. Where M. nudiflora does manage to survive, the populations are much reduced or controllable in the following season. Grazing by animals may help reduce weed populations, either in post-harvest in rice, maize, vegetables, or within plantation crops (rubber, oil palm, cocoa). Exploitation by animals (grazing, used as poultices and harvested animal fodder), or man (eaten as palatable vegetable in Indonesia and India) also reduces the effects of the weed though does not eliminate it (Burkill, 1935; Holm et al., 1977; Soerjani et al., 1987).

Mechanical Control

Farmers in Indonesia, the Philippines and elsewhere control M. nudiflora manually by hand weeding, hoeing or cutting with machete (Wilson, 1981; Soerjani et al., 1987; Pancho and Obien, 1995).

Chemical Control

Wilson (1981) reported that bentazone applied as an early post-emergence herbicide either singularly or in mixtures was particularly effective in controlling M. nudiflora and other species of the family Commelinaceae. Also, metribuzin applied as pre-emergence alone or in mixtures gave satisfactory control in many countries. The efficacy of triazines and 2,4-D against the weed were variable, although these herbicides were moderately effective when applied in mixtures. Good control of the weed can be achieved with 2,4-D or MCPA applied 20-30 days after emergence (Galinato et al., 1999).

In tea plantations in Indonesia, glyphosate was effective as a broad-spectrum herbicide, controlling several weed species including M. nudiflora (Soerdasan et al., 1974). However, other studies have shown that even when glyphosate is a broad-spectrum herbicide for control of annual grasses and broad-leaved weed species, M. nudiflora and other members of the Commelinaceae are tolerant and thus not adequately controlled by glyphosate (Wilson et al., 2006; Atkinson, 2014). Atkinson et al. (2017) found that M. nudiflora in turfgrass was tolerant to glyphosate, but that two applications of 2,4-D + MCPP + dicamba + carfentrazone or thiencarbazone + foramsulfuron + halosulfuron provided ∼80% control 6 weeks after initial treatment. In Brazil, Volf et al. (2017) found that only atrazine gave efficient control in soyabean, and that glyphosate gave poor control even mixed with imazethapyr. Yu and McCullough (2016) found that M. nudiflora was less tolerant to atrazine than to simazine.

Biological Control

There is no published information available on the biological control of M. nudiflora.

Integrated Control

There is no available information on research and practices pertaining to the integrated control of M. nudiflora per se in the field. However, tillage operation, stubble or straw burning after harvest, animal grazing, and chemical, mechanical, and manual weeding, employed alone, or in sequence to each other are being practised by farmers to control weeds and in cases where M. nudiflora is incidentally prevalent.

08/05/17 Updated by:

Julissa Rojas-Sandoval, Department of Botany-Smithsonian NMNH, Washington DC, USA