No abstract

No abstract

No abstract

IntercroppingA gronomy J our n al • Volu me 10 0 , I s sue 4 • 2 0 0 8 ABSTRACT Th e increasing cost of nitrogen fertilizer and the need for a N source for low-input and organic farmers have led to the increased exploration of legume cover crops as an alternative to N fertilization. Reliable cropping strategies are needed to enhance legume cover crop use as a N source. Interseeding legume cover crops into corn (Zea mays L.) can aff ect corn yield and cover crop dry matter. Th is study, conducted at the Kellogg Biological Station in Hickory Corners, MI, from 2002 to 2005, evaluated (i) the impact of interseeded cover crops on corn yield at various corn densities (37,500 to 75,000 plants ha −1 ) and (ii) the eff ect of corn density on cover crop dry matter (DM) when corn was interseeded with red clover (Trifolium pratense L.) or chickling vetch (Lathyrus sativus L., var. AC Greenfi x). Interseeded cover crops did not aff ect corn yield at any corn density. Interseeded cover crop DM decreased as corn density increased. Th e subsequent spring, red clover DM was similar regardless of previous corn density; AC Greenfi x did not regrow. Interseeded cover crops produced less DM than monoculture cover crops. Cover crops can be interseeded into corn densities up to 75,000 plants ha −1 without corn yield reduction and still produce substantial DM the subsequent spring. Interseeding corn with red clover could be used in low-input farming systems to reduce N fertilizer costs, especially in developing countries and in organic farming systems. ).Abbreviations: CMNF, conventional management, corn seeded into plowed wheat stubble with N fertilizer applied; DM, dry matter; KBS, Kellogg Biological Station; PRIA, corn seeded into plowed red clover, no N fertilizer, interseeded with AC Greenfi x; PRIR, corn seeded into plowed red clover; no N fertilizer, interseeded with red clover; PRNI, corn seeded into plowed red clover, no N fertilizer, not interseeded with cover crop.

Fumigated dry common beans (Phaseolus vulgaris L.) that were artificially infested with Acanthoscelides obtectus Say, and others that were not artificially infested, were stored in hermetic triple-layer PICS (Lela Agro, Kano, Nigeria) or woven polypropylene (PP) bags for 6 mo at ambient laboratory temperature conditions of 22.6 ± 1.9°C and 60.1 ± 4.3% relative humidity. In an additional trial, beans contained in PP bags were treated with Actellic Super dust before introducing A. obtectus. Moisture content, number of live adult A. obtectus, seed damage, weight loss, and seed germination were determined at monthly intervals. At 6 mo, beans stored in PICS bags retained higher moisture than those stored in PP bags, but in all treatments the moisture level remained below that recommended for safe storage of beans. In the PICS bags, proliferation of A. obtectus did not proceed and at 6 mo, beans stored in these bags did not have insect-inflicted seed damage or weight loss. In contrast, seed damage and weight loss in PP bags exceeded economic threshold after 1 mo in the absence of Actellic Super dust (Syngenta Crop protection AG, Basle, Switzerland), and after 2 mo in the presence of it. Germination of beans stored in PP bags decreased greatly whereas the beans stored in PICS bags did not show reduced germination. Chemical free storage of common beans in PICS bags protects them against damage by A. obtectus.