New York State IPM Program

Seed Selection for Resistance to Insects and Diseases

Today’s post is authored by  Jaime Cummings, NYS IPM Field Crops and Livestock

Whether planting a home garden or a one hundred acre soybean field, it’s important to consider all the pest, weed and disease issues that may occur during the growing season.  We have many tools in the IPM toolkit to help us manage these issues, including crop rotation, hand weeding, reliance on natural predators, and use of exclusion barriers, insect traps and pesticides.  But one of the most important cultural practices everyone should consider as a first line of defense against pests and diseases is genetic resistance in the varieties you select to grow.

Selective breeding, or genetic modification, for improved harvests has been occurring since the beginning of agriculture, and all modern crops have been modified in some way from their wild ancestor plants.  Think about corn, also known as maize, as one familiar example.  All modern corn was derived from the ancestral grass called teosinte through selective breeding by our ancestors (Figure 1).  Many advancements in breeding methods and technologies have developed in recent decades, but the goal is the same:  To develop elite varieties that are well-adapted to specific regions with resistance to common diseases and pests to achieve high yields.  We now have a wide range of corn varieties and hybrids with different maturities, different colored and sized kernels, and different levels of resistance to a wide variety of pests and diseases (Figure 2).  Some modern corn hybrids even have specific traits or genes that enable them to tolerate certain herbicides or to ward off some insect pests.  All these breeding advancements have resulted in improved yields and decreased pesticide use.  And there are many other disease resistance genes that have been discovered and integrated into many corn varieties.  These too have significantly reduced farmers’ reliance on pesticides for managing diseases and the harmful mycotoxins produced by some pathogenic fungi.

Figure 1. 

Teosinte is the wild plant that all modern corn originated from 8,700 years ago.  (Image from National Geographic)

Figure 2. 

Diversity in corn varieties developed through selective breeding efforts.  (Image from USDA)

Corn is just one example among all the crops we grow with options for genetic resistance to numerous pests and diseases.  We have similar opportunities when selecting varieties for our fruits, vegetables and grains (Figures 3 and 4).  Choose wisely and consider the advantages of selecting varieties with resistance.  Many insects and diseases plague our crops that are challenging to manage, with or without the natural or synthetic pesticides used in organic or non-organic agricultural systems.  To improve your chances of success in minimizing losses, consider all the strategies of integrated pest management, starting with the seeds you select to plant.

Figure 3. 

Tomato varieties that are susceptible (left) and resistant (right) to late blight.  (Image from Cornell University, Martha Mutschler)

Figure 4.

Soybean varieties that are susceptible (left) and resistant (right) to aphids.  (Image from University of Minnesota)

Whether developed through traditional selective breeding methods or high-tech genetic engineering, all of our crops have been modified from their original form to provide us with improved feed, fiber and fuel yields.  When selecting varieties to plant in your garden or on your farm, take advantage of these breeding advancements, and consider choosing varieties with resistance to the pests and diseases that are commonly problematic in your area.  You’ll be glad you did when you have fewer bugs chomping on your crops and fewer losses to those unsightly molds and mildews.

 

Jaime Cummings

Jaime Cummings

Field Crops and Livestock IPM Coordinator

524 Bradfield Hall, Cornell University, Ithaca NY, 14853
Jaime works with growers, dairy and livestock producers, extension educators, research faculty and staff and industry counterparts to promote the adoption of IPM practices for insect, disease and weed management for all field crops and livestock. Her work includes research and educational outreach throughout New York State.

 

Author: Debra E. Marvin

Community IPM Program Assistant for Schools, Daycare and Horticulture. New York State Integrated Pest Management Program, Cornell University, New York State Agricultural Experiment Station, 630 W. North Street, Geneva, NY 14456 Email: dem35@cornell.edu

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