Annual rye (Secale cereale) and Gliocladium virens inoculated composted chicken manure as weed control options in horticultural crop production
Abstract
This research investigated the potential of using an allelopathic cover crop for weed control and composted chicken manure (CCM) for fertilization in vegetable cropping systems. In addition, the potential of CCM as a substrate for growth and delivery of Gliocladium virens, a potential mycoherbicide, was determined. The first set of experiments tested the use of a rye cover crop and CCM as management inputs in fresh market tomato and snap bean production. Rye was fall planted, overwintered, killed in the spring, and left on the soil surface as a mulch. Rye was compared to bare ground for weed control. Rye provided acceptable weed control in both crops for five weeks in all years of testing while bare ground treatments required weed removal within three weeks of crop planting. Rye did not provide season long weed control, however, it did reduce by one postemergence application the amount of herbicide required to prevent weed competition from reducing crop yields. Crop maturity was delayed seven to ten days in rye compared to bare ground treatments due to cooler soil temperatures under rye mulch, however, total yields in rye were similar to bare ground treatments. Fertilization with CCM resulted in equal to improved yields compared to ammonium nitrate. The research discussed below contributed to the mycoherbicide literature by demonstrating the following: composted chicken manure can serve as a substrate for G. virens growth and field delivery. G. virens and its phytotoxin, viridiol, inhibited weed seed germination and root elongation. Viridiol inhibited root elongation in plants at ($\mu$M) with the (ID$\sb{50}\rbrack$ for foxtail and pigweed being 56.3 and 1.3 $\mu$M, respectively. Actively growing G. virens was shown to control weeds over a wider pH range than did viridiol alone. G. virens inoculated CCM was an effective mycoherbicide reducing weed emergence and growth in greenhouse, field soil experiments by 77 and 68%, respectively, eight weeks after soil incorporation compared to bare soil with no weed control. This work with CCM and G. virens provided the foundation necessary to conduct field work to investigate the weed control potential of G. virens inoculated CCM in vegetable production systems.
Degree
Ph.D.
Advisors
Weller, Purdue University.
Subject Area
Agronomy
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