Menu

How Does Irrigation Influence the Presence and Severity of Diseases?

Michigan vegetable and fruit growers can use irrigation systems to fulfill crop water requirements while minimizing the risk of yield loss associated with drought conditions. However, growers should consider the quality, amount and timing of the irrigation that specific crops require at various growth stages.

Sources of irrigation water can harbor plant pathogens. In general, surface water such as rivers, creeks and ponds have a higher likelihood to be contaminated with plant pathogens when compared with water from sealed wells.

Watermolds such Pythium and Phytophthora species can be found in open sources of water and may be capable of causing plant disease. These two types of waterborne pathogens have spores (seeds of the pathogen) that are capable of swimming in water. In fact, at least 26 and 17 different species of Pythium and Phytophthora, respectively, have been documented in irrigation water globally according to “Plant Pathogens in Irrigation Water: Challenges and Opportunities.” These pathogens are well known to cause symptoms like damping off, such as in soybean damping off; foliar blights; and rots of different tissues like roots, crown and fruits (photos below).

Some plant pathogens can survive in the soil and can also be associated with cull piles of discarded and diseased produce. Surface water can be contaminated by runoff from contaminated fields according to “Characterization of Phytophthora capsici from Michigan Surface Irrigation Water.” By choosing a clean source of water, the risk of introducing plant pathogens carried by the irrigation water to your production fields is decreased.

Water not only plays a role in dispersing waterborne pathogens, but can provide the moisture that favors the infection and disease development of airborne pathogens. In order for disease to occur, a susceptible host, virulent pathogen and favorable environmental conditions are needed. Irrigation provides moisture and leaf wetness so that if spores of the pathogen have landed on a host plant, an irrigation event allows the infection process to begin. As the disease progresses, overhead irrigation can splash disperse pathogens from infected plants to nearby healthy plants, allowing the epidemic to continue to develop in the field.

To summarize, the key factors to consider when using irrigation water include:

  • Quality. Use clean sources of water; well water is best.
  • Amount. Pathogens are favored by water so do not apply more than what is needed by the crop for its growth stage.
  • Timing. Consider current and forecasted environmental conditions and use irrigation scheduling tools.

Source: Michigan State University Extension

Recent News

Stretch Limited Hay Supplies
12/12/2019

Although growing conditions for hay production were favorable throughout much of North Dakota this year, challenges associated with harvest and transport have left many livestock producers facing a shortage of hay. North Dakota State University Extension agents from across the state have reported that 10% to 30% of this year’s forage crop is unavailable (that […]

USMCA on Course for Ratification in 2020
12/11/2019

Natalie Andrews, William Mauldin and Anthony Harrup reported yesterday at The Wall Street Journal Online that, “A new U.S. trade deal with Mexico and Canada gained backing from House Democrats, setting the agreement on course for likely ratification by Congress in 2020 and marking a victory for President Trump after months of negotiations to modify it. “Mr. Trump ran for office in 2016 […]

Soybean Price Prospects Moving into 2020
12/10/2019

The two major drivers of uncertainty impacting soybean prices in 2019 appear set to carry over into 2020.  The status of trade negotiations with China continues to move soybean markets despite numerous fits and starts in the process. Another USDA estimate of the 2019 soybean crop comes out in January.  Without supportive information on either […]

Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now