Combined Application of Rhizosphere Bacteria with Endophytic Bacteria Suppresses Root Diseases and Increases Productivity of Black Pepper (Piper nigrum L.)

Abstract

Black pepper (Piper nigrum L.) is one of the most important crops and global demand continues to increase, giving it a high export value. However, black pepper cultivation has been seriously affected by a number of pathogenic diseases. Among them, “quick wilt” caused by Phytophthora sp., “slow decline” caused by Fusarium sp., and root-knot nematode Meloidogyne sp. have a serious negative effect on black pepper growth and productivity. There have been different chemical and biological methods applied to control these diseases, but their effectiveness has been limited. The aim of this research was to evaluate different combinations of rhizosphere bacteria and endophytic bacteria isolated from black pepper farms in the Central Highland of Vietnam for their ability to suppress pathogens and promote black pepper growth and yield. Formula 6, containing the strains Bacillus velezensis KN12, Bacillus amyloliquefaciens DL1, Bacillus velezensis DS29, Bacillus subtilis BH15, Bacillus subtilis V1.21 and Bacillus cereus CS30 exhibited the largest effect against Phytophthora and Fusarium in the soil and in the roots of black pepper. These bio-products also increased chlorophyll a and b contents, which led to a 1.5-fold increase of the photosynthetic intensity than the control formula and a 4.5% increase in the peppercorn yield (3.45 vs. 3.30 tons per hectare for the control). Our results suggest that the application of rhizosphere and endophytic bacteria is a promising method for disease control and growth-promotion of black pepper.

Two plant-associated Bacillus velezensis strains selected after genome analysis, metabolite profiling, and with proved biocontrol potential, were enhancing harvest yield of coffee and black pepper in large field trials

“…The parameters for measuring the plant growth promoting effect on pathogen-infested coffee and black pepper plants were: height, plant canopy diameter, number of shoot branches, and the leaf chlorophyll content index (SPAD values, measured with the Chlorophyll Meter SPAD502Plus, Konica Minolta). The assays were performed as described by Nguyen et al (2021).…”

“…In addition, also the black pepper cultivation has been seriously affected by a number of diseases (Santos et al, 2023). Among them, the "quick wilt" or "quick death" disease caused by the root-knot nematode Meloidogyne spp, and the oomycete Phytophthora palmivora has a serious negative effect on black pepper growth and productivity (Nguyen et al, 2021). Widespread application of disease management strategies, based on chemically synthesized fungicides and nematicides, such as carbamate and organophosphorous, were found worldwide associated with increasing resistance of the target pathogens (Stukenbrock and Gurr, 2023).…”

Emerging strategy for eco-friendly management of black pepper root-knot nematodes

“…EK7 reduced more than 64 % and 55 % of nematode populations in roots and rhizome soil, respectively, and showed good plant growth-promoting effects. For searching the potential use of beneficial microbes, several bacterial strains were examined under field conditions to explore their nematode-killing and plant growth-promoting effects on the black pepper trees in the fields in the Central Highlands of Viet Nam [19,36] B. cereus CS30 also demonstrated a high inhibitory activity against some harmful fungi in soil and root of black pepper [36].…”

“…For searching the potential use of beneficial microbes, several bacterial strains were examined under field conditions to explore their nematode-killing and plant growth-promoting effects on the black pepper trees in the fields in the Central Highlands of Viet Nam [19,36] B. cereus CS30 also demonstrated a high inhibitory activity against some harmful fungi in soil and root of black pepper [36]. Some fungal strains were also isolated from the soil samples in Gia Lai and Dak Lak provinces, Viet Nam, for testing the ability to trap nematodes and their impact on black pepper plants through invitro analysis, under greenhouse and field conditions [37].…”

Health Benefits and Risks of Consuming Spices on the Example of Black Pepper and Cinnamon

“…Such alternative cultivation methods include, for example, the combined use of Rhizosphere bacteria with endophytic bacteria, which inhibits root diseases and increases the productivity of black pepper. Organic cultivation, on the other hand, provides pepper without pesticide and herbicide residues [ 14 , 15 , 16 ]. Additional factors affecting the quality of pepper are climate change and economic and social factors.…”