A comparison of the yield response of solin (cv. Linola 947) and flax (cvs. McGregor and Vimy) to application of nitrogen, phosphorus, and Provide (Penicillium bilaji)

Field studies were conducted at three locations over three years with Linum usitatissimum L. to determine whether the solin cultivar Linola 947 and the traditional oilseed flax cultivars McGregor and Vimy, differed in seed yield, straw yield and harvest index response to N and P fertilizer and the phosphorus-solubilizing fungus, Penicillium bilaji, marketed as "Provide". While cultivars differed in seed yield, straw yield and harvest index, the relative performance of the cultivars varied with site and year and did not relate to whether the cultivar was solin or traditional oilseed flax. The degree and pattern of response of straw yield and harvest index to N and/or P fertilization varied with year and location. Where significant differences occurred due to P or Provide management, seed yield and harvest index were lower and straw yield higher with application of Provide than with application of P fertilizer, indicating that Provide was less effective than P in enhancing seed yield of flax. Solin did not generally differ from traditional oilseed flax in the response of seed yield, straw yield and harvest index to fertilizer applications. Response of seed and straw yield to N and response of harvest index to P each differed among cultivars in only one-site year, while an N-by-P-by-cultivar interaction occurred in only one site-year for seed and straw yield. Considering the limited occurrence of cultivar-by-fertilizer interactions, fertilizer recommendations produced for traditional flax cultivars should also be applicable to solin cultivars. Key words: Seed yield, harvest index, cultivar

Viability of Penicillium bilaji and Colletotrichum gloeosporioides conidia from liquid cultures

The effect of water activity on Penicillium bilaji Chalabuda and Colletotrichum gloeosporioides f.sp. malvae conidia at 20 °C was examined. The optimal relative humidity for storage at 20 °C was found to be 12–34% for C. gloeosporioides spores and 100% for P. bilaji spores. Retention of viability by C. gloeosporioides spores was improved by drying the spores from a 20% sucrose solution. The data demonstrate the conditions required for adequate shelf stability for commercial, biological products for agricultural application, based on these two organisms. Key words: Penicillium bilaji, Collectotrichum gloeosporioides, water activity, germinability.

INCREASED YIELDS AND PHOSPHORUS UPTAKE BY WESTAR CANOLA (Brassica napus L.) INOCULATED WITH A PHOSPHATE-SOLUBILIZING ISOLATE OF Penicillium bilaji

Greenhouse and field experiments were conducted to evaluate the effect of inoculation with a phosphate-solubilizing isolate of Penicillium bilaji on the yield and phosphate uptake by canola (Brassica napus L.). Under greenhouse conditions, P. bilaji inoculation did not affect canola pod or straw dry matter production, but did increase straw and pod P concentrations resulting from increased P uptake over uninoculated treatments. Addition of P at 20 mg kg−1 soil as Florida rock phosphate plus inoculation with P. bilaji resulted in P uptake by canola nearly equivalent to that resulting from the addition of monoammonium phosphate (MAP) alone at the same rate of P. Addition of Florida rock phosphate alone had much less effect on plant P uptake. Addition of P. bilaji generally increased dry matter yields and P uptake by canola in two field sites. Penicillium bilaji appears to be able to increase the uptake of P from sources unavailable for plant uptake; P uptake by control plants inoculated with P. bilaji absorbed as much P as that absorbed by uninoculated plants receiving MAP. Key words: Penicillium bilaji, Brassica napus, fertilizer efficiency, rock phosphate, monoammonium phosphate

EFFECT OF Penicillium bilaji ON THE SOLUBILITY AND UPTAKE OF P AND MICRONUTRIENTS FROM SOIL BY WHEAT

Penicillium bilaji has previously been shown to increase wheat growth and P uptake by solubilizing phosphates under soil conditions. Laboratory experiments were conducted to determine if P. bilaji was able to solubilize inorganic compounds of copper, iron and zinc. Greenhouse and field experiments were also conducted to determine if P. bilaji had an effect on uptake of copper, iron and zinc by wheat. Under pure culture conditions, P. bilaji was able to solubilize cuprous and cupric oxide, cupric carbonate and zinc metal and, to a lesser extent, ferrous and ferric oxides and pyrite. The soil studies showed increased wheat dry matter production and seed and P yields in response to P. bilaji inoculation, which was related to increased incidence of P-solubilizing fungi in the wheat rhizospheres. Penicillium-inoculated plants contained greater quantities of Cu and Zn under greenhouse conditions and more Cu and Fe under field conditions than treatments not receiving Penicillium inoculum. Cu and Fe concentrations in the plants, in most cases, were not affected; however, Zn concentrations were increased by P. bilaji under greenhouse conditions. It was concluded that P. bilaji is able to cause solubilization of relatively insoluble forms of Cu, Fe and Zn. It did not directly affect the uptake of Fe and Cu by wheat in the soils used in these experiments, but may increase the uptake of Zn by plants. Key words: Penicillium bilaji, rock phosphate, copper, zinc, iron, wheat