| The objectives of this experiment, completing the fourth cycle of a five-year study, were to: 1) Determine the success of strip-till peanut in North Florida, planted in double-cropping systems with winter crops [wheat, rye, oat, lupine, vetch and crimson clover]; 2) Determine peanut response to cropping systems and rotation with summer crops [peanut, corn and cotton]; and 3) Determine pest problems in 24 double-cropping and summer crop rotations.
Winter crops were planted Nov. 20, 2003 at the Plant Research and Education Center in Citra, Fla., and harvested for forage in late March 2004. Georgia Green peanut was strip-tilled in 30” rows at harvest, following each winter crop, and in rotation with peanut, corn and cotton planted in 2003. Corn and cotton were planted in similar rotations to maintain the double-cropping systems and summer crop rotations.
The experiment was repeated six times, with 24 combinations of double cropping and summer crop rotations. Insecticides and fungicides were regularly used to control pests and diseases.
Quality data was measured from sub-samples of pods in January and February, and disease ratings about 10 days prior to peanut harvest. Nematode incidence was determined via soil samples, while dayflower infestation and the percentage of weeds in ground cover were measured at harvest.
In 2004, as in preceding years, strip-till peanut proved successful. Acceptable yields followed all six winter crop plantings, with no interaction between summer and winter crops. The highest-yielding winter crop rotation was oat/peanut, while peanut/corn and continuous peanut produced the highest summer crop yields.
There were no differences among the peanut double-cropping systems or summer crop rotations for leaf spot, and double-cropping winter crop systems with peanut were not significantly different for Tomato Spotted Wilt (TSW). However, TSW was about ¼ higher for peanut/corn than other summer crop rotations.
Continuous peanut rotations produced the lowest percentage of weeds to ground cover over the four years, followed closely by peanut/corn. There was a high correlation between weed ground cover and dayflower, and it appeared weeds had more impact on yield than either disease measured.
Root-knot nematodes were highest on peanut in winter crop rotations following oat and in summer crops with peanut and corn, which means the systems with the highest pod yield also had the highest incidence of Tomato Spotted Wilt Virus (TSWV) and root-knot nematodes. This could be because the higher yield peanut produced more roots, which could support more nematodes.
The 2004 study indicated the need to test more weed control options in cotton to prevent weed carryover to peanut. The study area was heavily infested with dayflower, one of the hardest weeds to control, but the researchers improved their ability to do so with combinations of herbicides under strip-till management. They also found that continuous peanut is the rotation best suited for dayflower control.
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