Biocidal Potential of Livestock and Plant-Derived Organic Amendments on Plant-Destructive Nematodes associated with Rice (Oryzae sativa L.) in Makurdi, Nigeria

Field trials were conducted at the Teaching and Research Station of Joseph Sarwuan Tarka University, Makurdi in 2021 and 2022 to determine the impact of some livestock and plant-based organic manures on the population dynamics of plant-parasitic nematodes (PPNs) associated with rice fields. Treatments comprised six organic amendments [cattle dung (CD), chicken litter (CL), goat dung (GD), neem leaf powder (NLP), moringa leaf powder (MLP), eucalyptus leaf powder (ELP), all applied at the rate of 5 t/ha], furadan 10 G (as check applied at the rate of 1 kg ai/ha) and an untreated plot (control). The experiments were laid-out in a Randomized Complete Block Design (RCBD) with three replications. A total of Ten PPNs were recovered from the field trials and included Meloidogyne incognita., Pratylenchus zeae, Helicotylenchus multicinctus, Tylenchus sp. Xiphinema index, Hirschmaniella oryzaea, Trichodorus sp, Criconemoides sp., Hoplolaimus clarissmus and Rotylenchus sp. Results showed that of the six organic amendments evaluated in the study, NLP consistently suppressed populations of Criconemoides sp., Helicotylenchus multicinctus. Hirschmaniella oryzaea, Hoplolaimus clarissimus, Pratylenchus zaea, Trichodorus sp., Tylenchus sp. and Meloidogyne incognita the most during the two-year field trials. Although plots treated with CD, CL, ELP, GD and MLP reduced total populations of PPNs, again use of NLP suppressed the total population PPNs associated with rice by 74.8% and 68.3%. Chicken litter ranked second after NLP in terms of efficacy of plant-parasitic nematode control, decreasing total number of plant-parasitic nematodes associated with rice by 67.1% and 57.1% in 2021 and 2022, respectively. The current study concluded that Neem leaf powder and Chicken litter applied at the rate of 5 t/ha reduced the population of PPNs associated with rice and has proven to be effective against PPNs and therefore recommended for used in nematode management in rice fields.