Low-input management practices for container Ericaceous nursery crops

Project Overview

Project Type: Partnership
Funds awarded in 2008: $9,985.00
Projected End Date: 12/31/2010
Region: Northeast
State: New Jersey
Project Leader:
Gladis Zinati
Rutgers, The State University
Dr. John Dighton
Rutgers Universuty

Annual Reports


  • Additional Plants: ornamentals


  • Crop Production: biological inoculants
  • Pest Management: biological control, prevention
  • Production Systems: general crop production
  • Soil Management: soil microbiology

    Proposal abstract:

    Nursery production ranked first among agricultural commodities in New Jersey in the last seven years. Azalea and rhododendrons are considered the most requested among commonly produced nursery crops by landscapers and home owners. Such plants are considered sensitive to high fertilizer and irrigation rates, root diseases, and high rates of chlorinated water. Nursery growers constantly look for ways to produce high quality and low-input container-grown nursery plants with a minimum impact on the environment. The integration of naturally-occurring mycorrhizal fungi proved to increase plant growth and minimize nutrient runoff. Recently, commercial ericoid mycorrhizal inoculum became available and nursery growers are interested in learning about the feasibility of using various sources of mycorrhizal fungi at low fertilizer rates and influence of recycled chlorinated irrigation on production of ericaceous plants. We propose a one-year project to conduct a comparative study in collaboration with two nursery operators. The tests will be conducted in south Jersey and replicated at the Rutgers research center at Cream Ridge, NJ. In a randomized complete block design with four replications, two azalea cultivars or two rhododendron cultivars will be amended with six treatments: 1) naturally-occurring mycorrhizal fungi with a full rate of fertilizer, 2) naturally-occurring mycorrhizal fungi with a half rate of fertilizer, 3) commercially-available mycorrhizal fungi with a full fertilizer rate, 4) commercially-available mycorrhizal fungi with a half rate of fertilizer, 5) no mycorrhizal fungi amendment at a full fertilizer rate, and 6) no mycorrhizal fungi amendment at a half fertilizer rate. Plants will be assessed for horticultural properties, nutrient content, mycorrhize fungal colonization, and tolerance of treated plants to root rot when infected by Phytophthora cinnamomi using chlorinated recycled water and well water.

    Project objectives from proposal:

    The objectives of this study are to assess: a) plant growth, top and root biomass before and after overwintering, b) plant nutrient content, c) extent of root colonization by mycorrhizal fungi from commercially available and natural sources (both before and after overwintering) both in root rot infected and non-infected plants, d) root and crown rot incidence and severity, e) impact of chlorination on mycorrhizal colonization, and f) the economic feasibility of using the proposed sources in producing high quality plants.

    It is important to assess the impact of commercially-available ericoid mycorrhizal inoculum and naturally-occurring inoculum on plant growth and its quality, the combined benefit from using mycorrhizal fungi and fertilizer rates below industry standards, and the tolerance of plants to disease caused by the water mold pathogen Phytophthora cinnamomi.

    We hope to develop a feasible, cost effective, and environmentally friendly low-input production system for ericaceous plants.

    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.