Influence of field burning and soil treatments on growth of wheat after Kentucky bluegrass, and effect of Rhizoctonia cerealis on bluegrass emergence and growth

Abstract

Studies were conducted to assess the importance of soil-borne pathogens as impediments to the production of direct-drilled wheat following Kentucky bluegrass in rotation. Bluegrass sods were collected as cores from commercial seed fields in October (after open-field burning) and in December and March (after exposure to normal freezing and thawing), treated with glyphosate after a 2-to 3-week period of green-up in the glasshouse, and then planted to wheat 21 days later. Wheat seedlings in the 3-to 4-leaf stage were stunted and spindly in either burned or nonburned sods collected in October, but grew significantly better in burned than nonburned sods collected in December and March. Fumigation (methyl bromide), simulated tillage, and application of metalaxyl as a drench, singly or as combined treatments, improved the growth of wheat in nonburned sods. Growth of wheat in nontreated burned sods collected after frost had penetrated the upper portions was equivalent to that in fumigated sods. Experimental freezing at ¹20ЊC for up to 96 h, of burned and nonburned sods collected in October, followed by thawing also improved the growth of wheat subsequently sown directly into these sods. The stunted and spindly seedlings had roots girdled and severed by lesions typical of Rhizoctonia root rot. Isolates of Rhizoctonia cerealis were recovered from these roots and caused poor seedling emergence and stunted root and shoot growth of both wheat and bluegrass. The results suggest that both R. cerealis and Pythium spp. are potentially important soil-borne pathogens of wheat when following Kentucky bluegrass in rotation and that burning done routinely to improve the yield of bluegrass seed can also reduce the potential for damage caused by Rhizoctonia and Pythium root rots of wheat seeded directly into bluegrass sod.

United States Department of Agriculture—Agricultural Research Service research on alternatives to methyl bromide: pre‐plant and post‐harvest

“…Soil disturbance entailed excavation to a depth of 0.5 m in the fall prior to planting and spreading the soil over the adjacent ground. This resulted in soil exposure to repeated freeze/thaw cycles, an event that can limit the survival and activity of certain soil‐borne pathogens, including Rhizoctonia solani Kühn 69. Trees were also established in the old orchard aisle, rather than tree row, which subjected newly established trees to an environment possessing a reduced disease potential.…”

“… a After the wheat cultivation treatment, soil was infested with oat‐bran inoculum69, 70 of R solani AG 5 isolate 5–103 at a rate of 1 g kg −1 . …”

Grassland fires may favor native over introduced plants by reducing pathogen loads

“…Litter can also influence plant water relations (Wardle et al 2002), which may indirectly affect attack rates and the soil microbial (Zhang et al 2005). While the effects of fire on pathogens can sometimes be positive, as noted above, fire has been used in the grass seed industry since at least 1948 to control pathogens in fields because it reduces stubble and there is almost always an initial reduction in damage by numerous pathogens and some insects and nematodes (Hardison 1976, Johnston et al 1996, Smiley et al 1996, Mazzola et al 1997, Young et al 1999. While the effects of fire on pathogens can sometimes be positive, as noted above, fire has been used in the grass seed industry since at least 1948 to control pathogens in fields because it reduces stubble and there is almost always an initial reduction in damage by numerous pathogens and some insects and nematodes (Hardison 1976, Johnston et al 1996, Smiley et al 1996, Mazzola et al 1997, Young et al 1999.…”

“…Burned litter can increase the nutrient status of hosts (Ehrenreich and Aikman 1963), which can increase infection rates (Han et al 2008). While the effects of fire on pathogens can sometimes be positive, as noted above, fire has been used in the grass seed industry since at least 1948 to control pathogens in fields because it reduces stubble and there is almost always an initial reduction in damage by numerous pathogens and some insects and nematodes (Hardison 1976, Johnston et al 1996, Smiley et al 1996, Mazzola et al 1997, Young et al 1999.…”

Effects of air pollution on respiratory parameters during the wheat-residue burning in Patiala

“…Crop residue burning has been a part of agriculture for many years because it is the cheapest, least time-consuming and least laborious method to use the land for further farming [4]. Due to open crop residue burning, ambient air quality is reduced by the emission of a large amount of toxic matter and gases [5,6].…”