James A. LaMondia

Integrated management of strawberry pests by rotation and intercropping

Abstract ‘Saia’ oats ( Avena strigosa ) and ‘Triple S’ sorgho-sudangrass ( Sorghum bicolor x S. sudanense ) were investigated as rotation crops and as interplanted companion crops the following year for their individual and combined effects on strawberry root pathogens, weed species composition and density, weevil and white grub densities in soil, rhizosphere microbial populations, nutrient content of crowns, and strawberry yield. Treatments were compared with ‘Garry’ oats ( Avena sativa ) or continuous ‘Honeoye’ strawberries at two sites in Connecticut. Lesion nematode ( Pratylenchus penetrans ) recovery was greater from Garry oats than for strawberry, Saia oats or sorgho-sudangrass. Bait root infection by Rhizoctonia fragariae was highest for strawberry. Weed density was inversely related to rotation crop density. White grub larvae were most common in strawberry. Rotation crop did not affect isolation of Rhizoctonia or Pythium in 1996 or 1997. Weed growth in plots in 1996 was suppressed after sorgho-sudangrass in 1995, but not in 1997. Intercropping was similar to herbicide application, but only when the intercrop was present. Rotation crop did not affect pathogen recovery from roots of 2-year old strawberry crowns. Numbers of European chafer larvae were greatest in Saia oats, which may have been attractive to gravid females. Japanese and Asiatic garden beetle populations were positively correlated with soil organic matter. Rhizosphere populations of fluorescent pseudomonads were unaffected by treatment. Fruit yield (1997) was greatest in plots previously planted to Garry or Saia oats and least after sorgho-sudangrass, possibly due to phytotoxic properties of residues. Production of rotation crops such as sorgho-sudangrass or Saia oats may suppress pathogen densities, weeds, and white grub densities prior to planting strawberries but may also adversely affect strawberry growth and yield.

Evolution of Fungi and Update on Ethnomycology

In the last 20 years, studies on the early evolution of fungi have made significant developments with the assistance of molecular clock dating methods and new fossil evidence. The origin of fungi probably dates back over 800 million years ago. The evolution of major fungal phyla is also reviewed. New archaeological discoveries and new analytic technologies developed in the last four decades enable us to date the artifacts related to using fungi from preliterate periods of human beings. At present, utilization of fungi by humans can be traced back to prehistorical periods. The production of alcoholic drinks and fermented foods and usage of medicinal microfungi in human history are discussed and updated.

Interactions of Microfungi and Plant-Parasitic Nematodes

Plant-parasitic nematodes and microfungi inhabit many of the same ecological habitats and interact in almost every conceivable way. Nematodes can feed on fungi, and conversely fungi can use nematodes as a food source. Fungi have been widely studied as biological controls of plant-parasitic nematodes. Fungi can attract or repel nematodes, and nematodes and fungi can interact to either directly or indirectly increase or even decrease plant disease. Nematodes can also feed on fungi and act as biological controls of plant disease. Plant-parasitic nematodes likely obtained the cell wall-degrading enzymes necessary to successfully feed on plants from fungi through horizontal gene transfer. Finally, plant-parasitic nematodes can interact with fungal pathogens or even nonpathogenic or weakly pathogenic fungi to increase plant disease.