The effects of N fertilization in the northeastern states on percent protein in soft winter wheat (Triticum aestivum L.) need to be evaluated in relation to time and rate of application and variety as a basis for developing practices that achieve the desired range in wheat protein. Fall and spring applications of different N rates to ‘Blueboy’ and ‘Redcoat’ varieties of soft winter wheat were compared at five locations on limestone-derived Pennsylvania soils. Average protein contents were increased from 10.!)% with no N applied to 14.3% with N fertilizer. The optimum rate of N for maximum grain yield often resulted in higher protein content than is considered desirable in grain used for pastry making. Under comparable conditions, the average protein contents of Redcoat and Blueboy wheats, respectively, were 13.3 and 11.8%. Spring application consistently gave higher protein contents than fall application, although the average difference was small (0.6%). Yields of protein were higher for Blueboy than for Redcoat, despite higher percent protein in the latter, because grain yields of Blueboy were substantially greater than yields of Redcoat. The importance of soil N as a source of N in these experiments was illustrated by the significant correlation that existed between relative N mineralization rates of soils from zero-N plots and corresponding protein yields.

Because of different climatical conditions during the growing season from those of reported experiments in literature and the relatively few data about annual cropped winter-grown wheat (Triticum aestivum L.) yield response to depth of tillage and to incorporation of previously broadcasted P-fertilizer, a 2-year field trial was conducted to evaluate the effects of three tillage depths, 10, 20, and 40 cm; and three P-fertilizer rates on grain yields and dry matter production. The three P-fertilizer rates were: no P-fertilizer, 12 kg P/ha per 10 cm depth of tilled soil, and a flat 60 kg P/ha rate. The field trial had a randomized split plot design with four replications and was simultaneously conducted on two soils of different texture. Grain yields, dry matter production, and P-uptake over 2 years were not influenced by depths of tillage. Initial development of wheat plants was better on shallow tilled soil. Added P-fertilizer markedly increased grain yields, dry matter production, and P-uptake. P-fertilizer rates based on volume of tilled soil were as effective as the flat P-fertilizer rate. Dry matter production response to P-fertilizer was influenced by soil texture, indicating limiting P-availability with decreasing clay content of soil. From the data obtained it can be concluded that increasing depth of tillage has no significant effect on annual cropped winter-grown wheat yields and secondly that there is no need to incorporate P-fertilizer deeper than the top soil layer of 10 cm. Therefore, if plowing a wheat stubble becomes necessary, P-fertilizer rate can be based on the P-availability of the sampled top soil layer after plowing and adjusted to the depth of the planned seedbed preparation to keep P-availability at the recommended level for wheat growing.

Samples of hard red winter wheat were fumigated with (i) methyl bromide (2 lb/1000 ft3, 24 h), (ii) 0,0-dimethyl 0-(2,2-dichlorovinyl) phosphate (20 ppm, 1 wk), (iii) ethylene dichloride: carbon tetrachloride (75:25 w/w) (3 gal/1000 bushels, 12 h) and (iv) chloropicrin (2 lb/1000 bushels, 48 h), aerated and stored in metal containers at 0°C for 2 wk before inoculation with Aspergillus flavus (4 strains), Asp. parasiticus (2 strains)m Asp. ochraceus and Penicillium viridicatum. Half the fumigated and nonfumigated wheats were sterilized by autoclaving at about 25% moisture before inoculation. Of the 8 fungal strains used, 6 were affected by (i), 5 by (ii), 4 by (iii) and 1 by (iv). Asp. parasiticus and Asp. flavus strains produced aflatoxin and Asp. ochraceus and P. viridicatum produced ochratoxin. Yields of aflatoxin were higher on sterilized than unsterilized wheat. Ochratoxin production was little affected by sterilization. Fumigation both increased and decreased aflatoxin and ochratoxin production, depending on the fungal strain with which the wheat had been inoculated.

The source of wheat (Triticum aestivum L.) seed may affect crop growth and yield. Within a genotype, seed that has a higher protein content and/or is larger will produce more vigorous seedlings and sometimes higher yields. Spring and winter wheat seed collected from five cultivar trials grown at several different locations were used to determine the relative effect of genotype and environment on seed protein and seed size, and these factors were related to the dry weight of seedling shoots (vigor). Both environment and genotype affected the protein content of the seed. Regardless of genotype or environment, seedling vigor was consistently related to seed protein. Seedling vigor was also related to seed size, but when seed size was eliminated as a factor by using uniformly sized seed, the seed protein content and vigor relationships were significant.

Ethrel (2-chloroethyl phosphonic acid) has significant effects on growth and development of corn (Zea mays L.) and soybeans (Glycine max (L.) Merrill) and has been suggested as a potential male gametocide for the production of hybrid wheat. The purpose of this study was tofurther elucidate the response of winter wheat (Triticum aestivum L. em Thell.) and spring oats (Avena sativa L.) to foliar applications of Ethrel. Ethrel was foliarly sprayed on the winter wheat variety ‘Knox 62’ at 0.28, 0.56, 1.12, and 2.24 kg/ha when plants were in the late tillering, early boot, late boot, and heading stages. The magnitude of effects was closely related to rate and stage of application. Rates of 0.28 or 0.56 kg/ha applied at early and late boot stages of development effectively reduced height and lodging and in several cases accounted for significant increases in yield. Higher rates (1.12 or 2.24 kg/ha) reduced height and lodging but usually decreased yields when applied at the boot stages of growth. The 1.12 and 2.24 kg rates applied at heading stage did not decreas~ yield but were less effective in reducing height and lodging. Higher yields in the Ethrel-treated plots were generally associated with somewhat heavier seeds. Although we did not bag spikes or observe pollen from treated plants, the excellent seedset we obtained indicated that either the Ethrel treatments did not cause significant male sterility, or if they did, it was completely obscured by cross fertilization. Clearly female fertility was not impaired to any great extent by the Ethrel treatments. Our results with the same rates and stages of application for two oat varieties suggested that Ethrel has little potential for use on spring oats. Beneficial effects, such as reduced height and lodging, were accompanied by reduced yields. Even the lowest rate of application (0.28 kg/ha) applied at the late boot stage of growth caused a 40% reduction in grain yield. Reduced yields were accompanied by severe blasting of florets. Although the applications made at heading stage did not reduce yields, they were not very effective in reducing height or lodging.

The semi-dwarf, stiff-strawed soft winter wheat variety ‘Bineboy’ (Triticum aestivum L.) was released in 1965 by the North Carolina State University Agricultural Experiment Station. Presumably, its greater straw strength would allow producers to use higher rates of nitrogen without as much risk of lodging. Information was needed, however, on the nitrogen requirements of this new type of wheat and the most beneficial time for these applications. Field experiments were conducted on two soil types (Davidson clay loam and Lynchburg fine sandy loam) for 2 years to determine the response of Bluehoy wheat to nitrogen rates of 56, 112, 168, and 224 kg/ha applied at seeding in October or partly in October at seeding (56 kg/ha) and partly in February as.topdressing rates of 56, 112, and 168 kg/ha. Applying all the nitrogen at seeding on the Davidson clay loam was just as effective for high grain yields and high test weight as the split applications. The 112 kg/ha applied in October (seeding) on this soil type was sufficient for maximum yields. Grain yields were lower on the Lynchburg fine sandy loam soil for October applications than for February applications at nitrogen rates of 112 and 168 kg/ha. No difference in yield was obtained for the two dates at the highest rate of nitrogen (224 kg/ha). Test weights were significantly lower both years when the nitrogen was applied in February on the Lynchburg fine sandy loam as compared to the same total rate applied at seeding. A similar trend was also found for the February nitrogen applications on the Davidson clay loam. This study shows that Blueboy wheat producers can apply all of the nitrogen fertilizer to clay loams and fine sandy loam soils at the time of seeding rather than splitting the application into a small amount at seeding followed by a topdressing in February. A higher level of nitrogen fertilization will be required, however, to offset possible losses from leaching on soils with a sandy surface texture. On these soils producers must weigh the cost of using a higher nitrogen rate at seeding against the possibility of producing a lower-quality wheat and the cost of an extra trip over the field in February when fields may be wet.

In 1970–71, five N-rate field experiments were conducted with fall-seeded soft red winter wheat (Triticum aestivum, L.) on limestone-derived soils in Pennsylvania. Varieties ‘Blueboy’ and ‘Redcoat’ were compared at two locations. At three locations, only Blueboy was grown. Redcoat is widely grown in Pennsylvania, but Blueboy was only recently introduced. The relative nitrogen requirements of these varieties, therefore, was essentially unknown when these studies were begun. Fall and spring applications of 0, 34, 67, 101, 135, and 168 kg/ha of N as ammonium sulfate were compared at each location. The nitrogen content of grain plus straw associated with maximum attainable yield of dry matter was similar among locations and varieties, the mean percent N and its standard deviation being 1.38 ± 0.06%. Yields of grain invariably were depressed when nitrogen in grain plus straw exceeded the mean value of 1.22 ± 0.06% (S.D.). The latter value is considered to represent the internal N requirement of the wheat associated with optimum production of grain, and it corresponds to the percent N in grain plus straw associated with 95 to 98% of total dry matter production. Recovery of fertilizer N was significantly greater for spring than for fall applications, although differences were small (means were 56 and 48%, respectively, for all locations). Yields of Blueboy were substantially greater than those of Redcoat at locations where these varieties were compared. Interactions of rate and time of N application on yields of grain and dry matter and N yields were not significant. Total uptake of N required per unit of wheat grain for maximum attainable yield is almost twice that required for corn.

Fertilizer N applied at ever-increasing rates sometimes accumulates in the soil. The practice of fertilizing grain straw with N to stimulate decomposition is questionable, but decomposition of straw immobilizes N that must be compensated for in fertilizing the succeeding crop. Too much N decreases the sucrose content of sugarbeets and decreases sucrose recovery. Experiments were conducted to determine the relative value of early and late straw applications, plowing with N applied in the fall or spring, and the amount of N needed to compensate for straw applications in obtaining optimum beet and sucrose yields with maximum quality. Sugarbeets (Beta vulgaris L.) were grown following winter wheat (Triticum aestivum L., var. ‘Nugaines’) in 1970 and I971 on a Pormeuf silt loam soil near Kimberly, Idaho. Straw was applied to the beet plots at rates of 6.7, and 13.4 metric tons/ha, and the plots were plowed either in early September or mid-November. Nitrogen was applied at 67 kg N/ha in the fall and at 67 and 134 kg N/ha in the spring. The treatments were arranged in a split-split plot design with 4 replications. Control plots were used with all experiments. N fertilization increased beet, top, and sucrose yields, as well as amino N, Na, K concentrations, and impurity index. It decreased the sucrose percentages of the beets. Straw applications decreased beet, top, and sucrose yields, Na and amino N concentrations, and impurity index, but they did not influence K content of the beets. Early plowing increased sucrose percentage and yield and decreased Na, K, and impurity index. Interactions between straw applications and plowing dates were significant for sugarbeet and beet top yields. Approximately 7.5 kg N fertilizer per metric ton of straw were required to compensate for the deleterious effects of the straw.