Dry Beans

Dry Bean—Diseases

Howard F. Schwartz, Gary D. Franc & Bob Harveson

Introduction

Pathogens that cause diseases in beans are subdivided into four classes: bacteria, fungi, nematodes, and viruses. Fungi produce spores that germinate and infect the plant. Some fungi can survive for long periods in soil via specialized resting spores. Bacteria are single celled organisms that enter plants through wounded tissue or plant breathing pores (stomates). Bacteria are often seed-borne and typically survive in soil only in association with crop debris. Nematodes are small worm-like animals that move throughout the soil and feed on plant roots or leaves. Viruses are very small infectious particles moved from plant to plant by insects, mechanically by foliage contact between plants or cultivation equipment, or in infested seed.

This section focuses on disease problems known to occur in our bean production region. Common diseases and management priorities are summarized in this section. The strategies that are most critical for effective and economical disease control are highlighted in Table XIII-1. Consult your local extension educator and industry representatives for current management recommendations for specific varieties grown in your area.

Commonly employed disease management strategies include control of volunteer beans, tillage to remove previous crop debris and alleviate stresses such as soil compaction, best management practices such as moderate fertility applications based upon soil testing and protection of groundwater sources, selection of adapted varieties suitable to the region, and timely application of appropriate pesticides when economically justified.

Table XIII-1. Priorities of management strategies for selected bean diseases.

Volunteer    Crop      Variety     Good    Planting                 Practice                            Pesticide                                                                                               Control  Rotatation Selection    Seed     Date      Tillage Irrigation Fertilization        Schedule
Fungal Diseases
Root	L	H	M	L	H	H	M	M	M
Fusarium Wilt	L	H	H	L	H	H	M	M	M
White Mol	L	H	H	L	M	M	H	H	M
Rust	H	H	H	L	H	L	M	M	H
Anth/ALS^2	H	H	H	H	M	L	M	M	H
Bacterial & Viral Diseases
Bacteria	H	H	M	H	M	L	M	M	H
Viruses	M	M	H	H	L	L	L	L	L

¹Pythium, Rhizoctonia and Fusarium. ²Anth = Anthracnose; ALS = Angular Leaf Spot.
H = High, M = Moderate and L = Low Priority Disease Management Practice

Categories:  Dry beans, Diseases, Introduction

Date: 04/01/2007