Response Of Winter Wheat And Barley To Date Of Planting And Fall Fertilization PDF Download

Two winter wheat (Triticum aestivum L. em Thell) and two winter barley (Hordeum vulgare L. em Thell) cultivars were grown with and without straw mulch utilizing six different planting dates. Soil temperature was recorded continuously at seeding depth from planting date through March of the crop year. A series of thermocouples connected to a point recorder were used for the soil temperature measurements. Soil temperature data were condensed through the use of a computer to obtain monthly averages for fallow treatments (bare and straw mulch) and diurnal variations. Plant growth in terms of days to emergence and days to tillering was noted for each planting date and related to the average soil temperature. Soil temperature differences between the bare and mulch (2400 kg/ha wheat straw) fallow treatments were small. Slightly higher soil temperatures were recorded in the mulched plots but the differences had no significant effects on emergence and tillering. Average soil temperatures decreased gradually at each subjecent planting date but differences in the time interval between planting, emergence and tillering for the first four dates were slight. When considering the first four dates of planting the time interval between planting and emergence ranged from 9 to 11 days, while between emergence to tillering time interval ranged from 17 to 29 days. For the fifth and sixth planting date the interval between planting and emergence and emergence and tillering increased sharply ranging between 14 and 20 days and 51 and 125 days, respectively. These increases in time intervals between plant growth stages corresponded with relatively rapid decreases in average soil temperatures during the same period. Significantly lower grain yields were observed for the early (14 August) and late (1 November) planting dates when compared to the other four planting dates. The early planting date produced excessive vegetative growth and many tillers early in the season and may have used much of the stored moisture in the soil in the fall. There was also severe lodging in these plots. The first two planting dates also showed heavy infestation of barley yellow dwarf virus. The plants from the late planting lacked sufficient growth to efficiently use the moisture that was available. Within the second to fifth planting dates all four cultivars exhibited a differential response in yield and for some agronomic traits indicating distinctly different types of adaptation. Higher yields were noted for the barley cultivars, Hudson and Schuyler, at the second and third planting dates while the yield levels of the wheat cultivars, McDermid and Moro, were higher at the fourth and fifth planting dates. Differential responses in plants per square meter and tillers per plant at the same planting dates showed opposite trends, e., as the former increased the latter decreased. Neither of these two traits appeared to contribute to grain yield. The fallow treatments, bare and straw mulch had no significant effect on grain yield in the cultivars studied. However, a significantly higher 1000 kernel weight was observed with the straw mulch treatment. Number of plants per square meter was significantly higher under bare fallow than under mulch fallow treatment. All cultivars showed differential response to fallow systems in tillers per plant but not in yield and other agronomic traits. McDermid and Hudson responded to the mulch fallow while Moro had good response to the bare fallow in tillers per plant. Schuyler responded almost the same to the both mulch and bare systems in tillers per plant.