Broccoli Rotation and Residue Amendment: A Sustainable Management Option for Soil-borne Diseases of Strawberry

Abstract

Continuous strawberry monocropping increases the prevalence of soil-borne diseases caused by plant parasitic nematodes and fungi. This study was undertaken to verify the effects of broccoli rotation and residue amendment on the population of plant parasitic and free-living nematodes; to evaluate their effectiveness against major soil-borne fungal diseases of strawberry and to assess the profitability of the potential technology. Four rotation treatments were evaluated namely, Strawberry-strawberry (untreated); Broccoli-strawberry; Broccoli-broccoli-strawberry; and Strawberry-strawberry (The soil was applied with thiophanate methyl). The treatments were laid out using the Randomized Complete Block Design with four replications. Although not significant, broccoli-broccoli-strawberry and broccoli-strawberry rotations reduced the population of lesion nematodes (Pratylenchus penetrans) and foliar nematodes (Aphelenchoides fragariae) in the soil, roots and leaves, respectively. The same treatments increased the number of free-living nematodes in the soil which are necessary in the decomposition of organic materials. Significant reduction in root necrosis and disease severity of fungal diseases was noted in the above treatments resulting in significant increase in strawberry yield. The highest return on cash expense (ROCE) was obtained from broccoli-broccoli-strawberry, followed by broccoli-strawberry with 238.61% and 143.75 %, respectively and lower on two croppings of strawberry drenched with fungicide (43.79%) and the lowest on untreated strawberry monocropping having only 21.84%.