Effects of sowing date, placement of seed, vegetation suppression, slugs, and insects upon establishment of no‐till alfalfa in orchardgrass sod†

Abstract

AbstractFour treatments designed to affect some environmental factors during germination and establishment of alfalfa were: two sowing dates (March and May) to produce differences in temperature, light and soil moisture; two sowing methods (notill drill and hand sowing) for creating different degrees of soil‐seed contact; mowing and banded and broadcast sprays of glyphosate to produce varying degrees of plant competition; and methiocarb bait combined with carbofuran granules vs. no pesticide to establish different levels of invertebrate feeding.Alfalfa dry matter (DM) production was affected very little by sowing date in two identical experiments. It was unaffacted by sowing method in experiment 1 (1983) but was significantly higher when alfalfa was sown with a drill in the second trial (1984). Highest alfalfa DM yields were achieved when competition was suppressed by broadcast spraying rather than bands, but details of effect differed in the two experiments.Pesticide treatments yielded more alfalfa DM in the year of establishment. Slugs, Deroceras leave (Müller) and D. reticulatum (Müller), and the potato leafhopper, Empoasca fabae (Harris), were among the potential pest species controlled and may have been partly responsible for the observed effects.