While every growing season has its challenges, it appears that each season’s challenges are straying further from the historical norms. With weather extremes, changes in frost dates and periods of too hot, too cold, too dry or too wet conditions becoming as frequent as periods of “normal” patterns, growers may be fighting new pests and diseases or having to cope with multiple issues within a short span of time.
Preventing problems is going to be a wiser option than trying to control damage once it’s already happened. It might be tempting to prophylactically use chemicals to prevent any possible concerns, as the “typical” growing season has become all but atypical for many regions. A more effective approach is to build a strong basis of plant health, allowing crops to ward off diseases and pests using their own resilience.
John Kempf, regenerative farmer and owner of Advancing Eco Agriculture, explored the role of trace minerals in plant disease resistance in a recent webinar. Trace minerals play a role in keeping plants healthy, and their proper management requires an understanding of “some of the diseases that you can provide resistance to when you manage these trace minerals well,” Kempf said.
There are seven essential beneficial trace minerals that can generate resistance to disease by enhancing plant health: boron, cobalt, copper, iron, manganese, molybdenum and zinc. Although molybdenum and cobalt are not always measured, they need to be, and soil or sap analysis can do so.
“With what we understand about these trace minerals, and the impact they have upon yield and quality…they’re equally as important and have as significant an impact on overall crop development as any of the other trace minerals on this list,” Kempf said of molybdenum and cobalt.
There are also a growing number of other elements considered beneficial to plant development and growth. Silver, nickel and iodine are a few of those.
Here are some of the trace minerals, and the concerns and diseases that proper nutrient management can help prevent:
Boron increases sugar translocation and is important in crop maturity, Kempf said. Boron can help the crop move sugar into the seed or fruit just prior to harvest, resulting in substantial yield gains. Boron also increases calcium absorption from soil and calcium transport within the plant itself. Getting calcium into the fruit can be challenging as calcium movement slows down in the summer. Boron will push the calcium into the fruit, preventing physiological disorders. Boron will increase resistance to some viruses and verticillium and fusarium fungi.
Cobalt suppresses ethylene and can slow ripening and delay senescence. This can play a role in crop harvesting. Cobalt can push a crop, such as green beans, to begin sizing a third set, while delaying maturity of the first set, allowing mechanical harvest of first, second and third sets simultaneously. Adequate level of cobalt in a plant’s root tip increases branching.
Elasticity is the magic generated by copper. This reduces splitting and cracking of fruits, and also reduces lodging in corn or small grains. Copper provides stems with flexibility, allowing plants to bend in the wind. Brassica leaf petioles that do not bend indicate a lack of copper. Copper provides resistance to bacterial canker, speck and spot, and to a variety of wilts across a wide crop range. It provides resistance to early and late blight, white rot, mosaic virus and more. “We’re using copper to produce inherent resistance within the plant,” Kempf stated.
Iron increases the efficiency of photosynthesis, keeping plants healthier. Iron is required to assemble chlorophyll, Kempf explained. Dark green, lush plants are indicative of enough iron.
This is required for potassium absorption and movement, and is essential in water hydrolysis, which is the first step in photosynthesis. Downy mildew, bacterial speck, verticillium, phytophthora and anthracnose are some of the diseases which adequate manganese can help to prevent.
This element is essential in the enzymatic pathways. It is required for the conversion of nitrates into amino acids. It also deactivates plant viruses by attacking their protein coats.
Zinc is essential to leaf growth and size as well as uniformity. Petiole uniformity, where the leaf joins the stem, is a sign of adequate zinc levels. Zinc increases resilience to a variety of diseases, and can reduce aflatoxins in grains.
Growers can choose to use organic or synthetic applications of minerals. There may be some evidence that organic forms of minerals are more readily absorbed and put to use by the plant, according to Kempf.
“It is obvious that plants absorb the organic acid and amino acid chelates far more effectively, and far more efficiently, than they do the synthetic chelates,” Kempf said, indicating that sap analysis has clearly shown this difference. “In general, we find that the organic acid and amino acid chelates tend to produce a much bigger crop response” than the other forms that are available.
By enhancing plant health through adequate nutrients – including the essential trace minerals – growers have a proactive tool to provide a general baseline of disease resistance. Enhanced management of trace minerals can help crops fight off disease-causing organisms intrinsically, promote efficient photosynthesis, enhance fruit yield and perhaps provide some peace of mind when each growing season is anything but predictable.
The goal is to obtain “disease resistance, based on how you manage nutrients,” Kempf said – a goal all farmers can work toward fulfilling.