OCCURRENCE OF MELOIDOGYNE JAVANICA PARASITING ROOTS AND NODULES OF PEANUTS IN PARAGUAY

III. FITOSSANIDADE

NOTA

OCCURRENCE OF MELOIDOGYNE JAVANICA PARASITING ROOTS AND NODULES OF PEANUTS IN PARAGUAY(¹)

RUBENS RODOLFO AlBUQUERQUE LORDELLO(²), ANA INES LUCENA LORDELLO(³) and IGNÁCIO JOSÉ DE GODOY(⁴)

ABSTRACT

The root-knot nematode Meloidogyne javanica (Treub, 1885) Chitwood, 1949, was identified in roots, nodules and shells of peanut plants (Arachis hypogaea L.), cv. Florman-INTA, collected from a field in Menno colony, Chaco Central region of Paraguay. Infected plants were observed in patches, showing wilting and drying of vegetative parts. Peanut had been grown ininterruptly for many years in the same area and patches had already been observed in the preceding year in cv. Starr. Nematodes collected from roots in this field reproduced on tomato cultivar rutgers and peanut cultivar florunner and produced egg-masses on roots, nodules and shells of cultivar Florman. This is the first report on M. javanica parasiting peanut in Paraguay.

Index terms: root-knot nematode, Meloidogyne javanica, peanut, Arachis hypogaea, occurrence, damage, host, nodules, shells.

RESUMO

OCORRÊNCIA DE MELOIDOGYNE JAVANICA PARASITANDO RAÍZES E NÓDULOS DE AMENDOIM NO PARAGUAI

Em lavoura de amendoim (Arachis hypogaea L.) cv. Florman (INTA), na colônia Menno, região do Chaco Central do Paraguai, reboleiras até de 3 m de diâmetro apresentavam plantas com murcha e secamento da parte vegetativa. Com este quadro, procedeu-se à coleta de raízes para exame que revelou o parasitismo do nematóide das galhas Meloidogyne javanica (Treub, 1885) Chitwood, 1949. A infestação das raízes era abundante, incluindo vagens e nódulos. O amendoim vinha sendo plantado ininterruptamente na área por muitos anos. Plantas de amendoim dos cultivares Florman e Florunner e tomateiros cv. Rutgers foram submetidas à inoculação de 10.000 ovos por vaso, os quais foram extraídos de raízes do cv. Florman, procedentes do Paraguai. Os vasos foram cheios com areia fina tratada com brometo de metila e mantidos em casa de vegetação até serem avaliados. O nematóide se reproduziu no tomateiro e no cv. Florunner e reinfestou o cv. Florman, gerando massas de ovos em raízes, nódulos e vagens. Este é o primeiro relato do parasitismo de M. javanica em amendoim no Paraguai.

Termos de indexação: nematóide de galhas, Meloidogyne javanica, amendoim, Arachis hypogaea, ocorrência, danos, hospedeiro, nódulos, vagens.

Peanut (Arachis hypogaea L.) is listed among the more ancient known host of root-knot nematode Meloidogyne arenaria (Neal, 1889). It is referred as "peanut root-knot nematode", since it was described from specimens collected in peanut roots and it is frequently found parasiting it. This species, along with M. hapla, is responsible for severe losses to growers in United States production regions. M. arenaria race 1 was reported parasiting shells and stems of peanuts (Taylor & Sasser, 1978).

The peanut was listed as resistant to M. javanica and other species of genus Meloidogyne by Sasser (1954), while looking for hosts to distinguish their species. However, along the years, a few occurrences of peanut parasitism by M. javanica have been reported from Zimbabwe (Martin, 1956), Georgia, USA (Minton et al., 1969) and São Paulo, Brazil (Lordello & Gerin, 1981).

Wilting and dried plants of peanut cultivar Florman (INTA), distributed in patches of nearly 3 meters of diameter, were observed near maturity in commercial fields of the Menno agricultural area, located at the Chaco Central region of Paraguay (Figure 1A). Whole plant samples were collected and examined, showing heavily galled roots, from which the root-knot nematode Meloidogyne javanica (Treub, 1885) Chitwood, 1949 was identified by morphological characters of females and males (Figure 1B).

Figure 1.
A: Peanut field of cv. Florman (INTA) in Paraguay showing patches caused by Meloidogyne javanica. B: Root system and nodules of peanut cv. Florman (INTA) parasited by M. javanica.

The peanut cv. Florman and cv. Florunner and tomato cv. Rutgers were inoculated with 10.000 eggs per pot. The inoculum was obtained from peanut cv. Florman roots collected on the infested field. The pots were filled with sterilized fine sand and kept under greenhouse conditions for assessing reproduction. The nematode reproduced on tomato and cv. Florunner, reinfected cv. Florman, producing egg-masses on roots, nodules and shells.

Peanuts are grown as a cash crop in Chaco Central and no crop rotation is made. Historical data on the infested field indicate that peanuts had been grown ininterruptly in the same location for many years. Symptoms similar to what is reported herein were also observed in the previous year on peanut cultivar Starr. This is the first report on M. javanica parasiting peanut in Paraguay.

⁽²) Seção de Nematologia, Instituto Agronômico (IAC), Caixa Postal 28, 13001-970 Campinas (SP), Brasil. Fellow of CNPq.

⁽³) Seção de Nematologia, EMBRAPA/IAC, Caixa Postal 28, 13001-970 Campinas (SP), Brasil.

⁽⁴) Seção de Genética, IAC. Fellow of CNPq.

• LORDELLO, A.I.L. & GERIN, M. Nematóide javanęs parasitando raízes e nódulos de amendoim. Revista de Agricultura, Piracicaba, 56(4):278, 1981.
• MARTIN, G.C. The common root-knot nematode and crop rotation. The Rhodesian Farmer, Onwards, 13:1-20, 1956.
• MINTON, N.A.; McGILL, J.F. & GOLDEN, A.M. Meloidogyne javanica attacks peanuts in Georgia. Plant Disease Reporter, St. Paul, 53:668, 1969.
• SASSER, J.N. Identification and host-parasite relationships of certain root-knot nematodes (Meloidogyne spp.). College Park, Maryland Agricultural Experiment Station. 1954. 31p. (Technical Bulletin, A-77)
• TAYLOR, A.L. & SASSER, J.N. Biology, identification and control of root-knot nematodes. International Meloidogyne Project, Raleigh, North Carolina State University Graphics, 1978. 111p.

⁽¹) Presented in XIX Congress Paulista of Phytopathology, realized at Campinas (SP), Brasil, from 5-8/February/1996. Received for publication in May 25

) Presented in XIX Congress Paulista of Phytopathology, realized at Campinas (SP), Brasil, from 5-8/February/1996. Received for publication in May 25^th, 1996 and accepted in February 28^th, 1997.

Publication Dates

• Publication in this collection
  16 June 1999
• Date of issue
  1997

History

• Received
  25 May 1996
• Accepted
  28 Feb 1997