PENICILLIUM-BILAJI AND PHOSPHORUS FERTILIZATION EFFECTS ON THE GROWTH, DEVELOPMENT, YIELD AND COMMON ROOT-ROT SEVERITY OF SPRING WHEAT

A strain of Penicillium bilaji Chalabuda (PB) has recently been commer cially released as a seed inoculant to increase phosphorus (P) uptake by wheat (Triticum aestivum L.). The purpose of this study was to comp are the effects of drill applied P (15 kg P ha-1) with PB seed inocula tion on early growth, development, P uptake, and grain yield of 'Stoa' spring wheat at four sites in North Dakota. Fertilization with P cons istently enhanced early season growth, main stem development, tillerin g and P uptake. Seed inoculation with PB had little or no effect on th ese traits. Phosphorus fertilization tended to increase common root ro t severity (CRR, incited by Cochliobolus sativus (Ito & Kurib) Drechs. ), while PB inoculation had no effect. Grain yields were significantly increased by P fertilization at one location. Inoculation with PB als o increased grain yield at this location. The reason why PB inoculatio n increased yield at this location is not evident, as plant growth and P uptake were not enhanced earlier in the season. Averaged across all four sites, PB inoculation increased wheat yields 66 kg ha-1, which i s similar to averaged yield responses reported from the Prairie Provin ces of Canada.