Relationship of Lygus Infestations and Fruit Size in Strawberry

Jul 21, 2022

By Mark Bolda

While we are all familiar with the fruit twisting and "monkey facing" caused by lygus bugs in strawberry fruit, we may have been kept unaware of other possible effects of these pests because of low treatment efficacy. Since I am working with an insecticide (as yet, unregistered) with very high and long lasting suppression of lygus bugs, I am now able to compare, side by side, what is going in berries with lots of lygus and berries with very few to no lygus.

Outside of the giant reductions in twisted fruit and marvelous maintenance of yield by this insecticide, I am also finding that fruit size, outside of those which are already twisted, is also benefiting from a low lygus presence. Dividing plot fruit weight by the number harvested revealed that this is indeed the case. If you think about it, it makes sense since lygus nymphal feeding on the flower results in lessened achene ("seed") formation, and we know for a fact that smaller fruit have less achenes - you can easily check this for yourself.

Apparently, not all of the failed achenes caused by lygus feeding result in fruit twisting, it's looking like some of the failures just end up making the fruit smaller in size. See graphic number 2 below.

lygus feeding result in fruit twisting

Comparison of average fruit size from July 18 harvest. Difference is statistically significant.

Comparison of average fruit size from July 18 harvest. Difference is statistically significant.

Source : ucanr.edu

Video: Western Canadian Agriculture: Hard Times Made the World's Best Farmers

Western Canadian agriculture produced the most advanced farmers in the world not through abundance but through adversity. The crow rate fell. The wheat price went nowhere. The brown envelopes stopped.

When the subsidies disappeared, the bad farmers left and the good ones stayed. And the ones who stayed could not just grow wheat anymore. They started growing lentils and canola and peas and flax and faba beans. They built crop rotation. They got serious about agronomy because there was no government backstop. That process produced the Western Canadian agriculture Dennis Bulani describes in this clip: the most advanced, most educated farming culture in the world.

His contrast with Iowa corn and soybean farmers is sharp. At a DeKalb farmer meeting in Okoboji, Iowa, he asked what crop rotation they ran. Beans on corn stubble, corn on bean stubble. How do you fertilize? The co-op agronomist handles it. Have you considered other crops? No need. We make so much money on corn and soybeans. Western Canadian agriculture was never allowed that comfort. And now those Iowa farmers are watching soybean markets lock up with China and corn prices slide, and they do not have the agronomy knowledge or the research base to pivot. Western Canadian farmers adapted on a dime because they had done it before.

Dennis also makes the case that Western Canadian agriculture keeps adapting in real time. Low commodity prices over the past year have pushed growers to look seriously at precision spot-spray technology. He knows a neighbor who bought a sprayer with the seeing-eye system and sprayed only 80 out of 320 acres. As a chemical retailer Dennis acknowledges that will affect his sales. He supports it anyway, because if it advances Canadian agriculture and makes farmers money, that is a good outcome.

The lesson Dennis draws from the tale of two farms: continuous improvement is the only durable strategy. When canola was $22 a bushel some growers went to Arizona instead of the Crop Production Show. When the price came down those same growers came back to the research and the discipline. Products do not go on Rack Petroleum's shelves unless they pass a replicated trial first. That is what Western Canadian agriculture built through hard times: farmers who do the work whether the times demand it or not.

Dennis Bulani is CEO of Rack Petroleum and Ultimate Yield in Biggar, Saskatchewan. Dan Aberhart hosts GTF Productions, Western Canadian Agriculture's foremost live briefing platform and its foremost AI training platform for ag operators