Nematoxins of Microbial Origin: Their Identification, Characterization and Development as Bio-Nematicides III. Exploitation of Bacterial Isolates for Nematode Management Kumar Anil, Walia R.K.*, Kapoor Ashima Department of Nematology, CCS Haryana Agricultural University, Hisar-125 004, India *Corresponding author, E-mail: raman261156@gmail.com
Online published on 29 August, 2017. Abstract In preliminary green-house trials, four bacterial isolates viz., Providencia rettgeri (isolate nos. 78, 123), Vibrio sp. (84) and Pseudomonas putida (113) resulted in initial gall reduction by Meloidogyne javanica on tomato; P. putida was the best in enhancing fresh weight of plants. Seed treatment of okra with all the bacterial isolates did not result in significant improvement of plant growth as well as nematode suppression. Nursery soil treatment with bacterial cultures recorded enhanced seedling germination of tomato, more transplantable seedlings and reduction in root galling; P. putida was most effective. Based on the green house results, P. putida was selected for field tests. In the first trial conducted in a M. javanica sick field (Pi 3 J2 per g soil), observations were recorded up to nursery stage only. Visible differences in tomato seedling health were noticeable in P. putida treated beds; reduction in root galling by M. javanica was recorded up to 50% and it was comparable with carbofuran @ 2 kg a.i. per ha. In another field trial on brinjal, P. putida (@1 lt culture per m2), carbofuran (@ 2 kg a.i. per ha) or Pasteuria penetrans (@1 x 104 spores per g soil) were applied alone or in combinations (half doses) to the nursery beds infected with M incognita (Pi 1.2 J2 per g soil). Seedlings in nursery plots treated P. putida, whether alone or in combination were very healthy with broader leaves and maximum seedling fresh weight was recorded in the treatment receiving combined application of P. putida + P. penetrans, followed by P. putida alone which was statistically at par. Number of galls at nursery stage was also least with P. putida in combination with P. penetrans or carbofuran. All the treatments increased the brinjal fruit yield. Maximum increase (66%) over check was recorded in P. putida + P. penetrans, followed by P. putida + carbofuran, which resulted in 59% increase in yield. Significant reduction in final J2 population was caused by the same treatment combination. Top Keywords Bacteria, Biocontrol, Plant parasitic nematodes, Providencia rettgeri, Pseudomonas putida, Vibrio sp, Pasteuria penetrans. Top |