Mustard Biofumigation in a Vegetable Rotation System February 6, 2018 Mark Uchanski Horticulture, Specialty Crops http://nassgeodata.gmu.edu/CropScape/ Management strategies for Iris yellow spot virus (IYSV) using potassium Research: fertilizer in conventionally managed onions: higher K= more IYSV?
Onion thrips (Thrips tabaci) apsnet.org, bugwood.org 2016-2017: Observations: • Treatment 1: 250g muriate of potash/10’ • Treatment 2: 750g muriate of potash/10’ -ELISA results in 2016 suggested a • Treatment 3: 250g potassium sulfate/10’ P/IYS relationship. • Treatment 4: 750g potassium sulfate/10’ -But, IYS (visual) was very low • Control: no additional potassium in 2017, despite placement of symptomatic bulbs in the field. -ELISA results from 2017 forthcoming. Organic high tunnel tomato cluster Research: pruning impacts on size & quality
Biofumigation performance of four Brassica crops in a chile pepper rotation system
Rachel Rudolph, M.S. Department of Plant & Environmental Sciences Biofumigation • Biologically active (bioactive) cover crops, green manures¹ • Members of the Brassicaceae family¹ • Have been shown to increase soil organic matter (OM) and moderate soil pH² • Demonstrated suppression of soilborne pests and pathogens via the release of isothiocyanates (ITCs) from glucosinolates (GSLs)³
¹Kirkegaard et al., 1999; ²Collins et al., 2006; ³Kirkegaard and Sarwar, 1998 Biofumigation • ITCs are chemically similar to methylisothiocyanate (MITC), the breakdown product of fumigant metam sodium, the most widely used soil fumigant¹ • Can be used in an integrated system—conventional or organic • GSL concentrations and pathogen effects vary within Brassica species, cultivar, and region² • The ideal biofumigant crop should have/be: • High biomass production³--OM increase, pH moderation • High GSL content in the tissues³--pathogen suppression • Non-host for nematodes—particularly Southern root-knot (RKN)4
¹Cox, 2006; ²Kushad et al., 1999; ³Kirkegaard et al., 1999; 4Thomas , 1995 Objectives • To evaluate the biofumigation performance of three mustard cultivars (Brassica juncea ‘Caliente 61’, ‘Caliente 199’, ‘Pacific Gold’) and one broccoli cultivar (Brassica oleracea var. botrytis ‘Arcadia’) in the semi-arid climate of southern New Mexico. • To evaluate chile pepper crop performance in rotation with biofumigants. • To evaluate the growth and host suitability of the biofumigant crops in the presence of RKN (Meloidogyne incognita). Materials & Methods Planting/harvesting schedule 2011-2013
SPRING FALL Seed green chile pepper Seed biofumigants
WINTER SUMMER Incorporate Harvest chile peppers biofumigants Biofumigant research field Fabian Garcia Research Science Center October 2011