Crop rotation effects on Cyperus rotundus and C. esculentus population dynamics in southern California vegetable production

Abstract

Summary Control options for Cyperus rotundus and Cyperus esculentus (purple and yellow nutsedge) were evaluated within three cropping systems in the low desert of southern California: (1) standard vegetable crop rotation (weed‐free, uncontrolled nutsedge and cultivation) with spring cantaloupe (Cucumis melo) – summer fallow – winter broccoli (Brassica oleracea), (2) cover crop rotation (halosulfuron and smother crop) with spring wheat (Triticum aestivum)/corn (Zea mays) – summer sudangrass (Sorghum sudanense) – Winter Fallow, (3) rotation with solarization (non‐solarization and solarization) with spring wheat – summer fallow/solarization – winter broccoli. After two growing seasons, broccoli was planted without Cyperus control, to study the effect on yield. Cyperus rotundus tubers increased from 0.66 tubers per m2 to 1260 tubers per m2 in the uncontrolled treatment over two seasons. Cultivation during the growing season reduced C. rotundus tubers by 93% compared with the uncontrolled plots. Cover crop rotation did not reduce the number of C. rotundus tubers significantly, despite the dense sudangrass canopy shading the soil during most of the summer. Cyperus rotundus was effectively controlled by the solarization treatment. All methods controlled C. esculentus, especially when there were no crops growing in the summer. When broccoli was grown after two years of various management strategies, the cultivation treatment showed a 44% yield reduction compared with the weed‐free control, while the solarization treatment increased broccoli yield by 64% compared with the non‐solarization treatment. Rotations that included sudangrass had low broccoli yield when either C. rotundus or C. esculentus were present.

Robust Methods for Measurement of Leaf-Cover Area and Biomass from Image Data

“…Its rapid spatial development and LCA expansion motivated modeling its spatial growth (Wang et al 2008).…”

Allelopathic Effects of Bidens pilosa L. var. radiata Sch. Bip. on the Tuber Sprouting and Seedling Growth of Cyperus rotundus L.

“…In addition, it was also found that the CR plant density was higher in both cover plant species in the presence of opaque plastic sheet treatment as compared to that in the absence of the opaque plastic sheet. Although soils covered with the plastic sheet was observed to elevate the temperature in the air space (between the sheet and soil surface) and the upper soil [51], it was found that no negative effect on the tuber reproduction unless the upper soil temperature was elevated up to 45 • C and persisted for more than 7 h per day [52]. Moreover, studies indicated that phenolic compounds released from apple residues decreased with the elevating soil temperature [53].…”

Estimation of base temperature for Sorghum halepense rhizome sprouting

“…Although mechanical and physical methods (i.e. solarization) have been reported as effective control measures for other spring‐emerging perennial weeds (Wang et al. , 2008), S. halepense management is still largely based on herbicide application.…”