Cool, wet weather has complicated thinning decisions. Remember that thinning is all about supply and demand for carbohydrates in the tree. Natural fruit drop occurs when demand is high (many developing fruitlets needing carbohydrates to grow) and supply is limited (small leave area on the tree to supply carbohydrates through photosynthesis). Because of this shortfall[Read More…]
Crop Management
We’re still in May and already it’s been a very challenging year for many growers. Freezing temperatures blanketed much of the state April 15-17 and again more recently on May 9. Damage ranges from moderate to extreme. Even a week after the most recent freeze, damage is still not obvious unless you cut fruit. Fruit[Read More…]
Got mold? Gray mold, caused by the fungus Botrytis cinerea and many other cryptic Botrytis spp., is one of the most important disease of strawberry, along with many other plants. To say this fungus is ubiquitous might be understating it! Although its damage (and name) is recognized when fruit become infected, either pre- or postharvest, the fungus[Read More…]
The horticultural entomology team is happy to report that we’re continuing efforts to support Indiana apple growers by monitoring tree fruit pests and reporting what we find! On April 22, 2020, we placed pheromone-baited monitoring traps for two important tree fruit pests, the codling moth and Oriental fruit moth at the Meigs Purdue Agricultural Center[Read More…]
As we’ve talked about previously, once winter chilling is fulfilled, the rate of tree growth and development is largely dependent on temperature. This is clearly evident in the data over the last 10 years (see Figure 1). In 2012, we had an extremely early and warm spring, rapid accumulation of Growing Degree Days, and very[Read More…]
The recent spate of cool, wet weather has left one organism happy, Venturia inaequalis, the fungus that causes apple scab. Most of the state just underwent an extreme scab period, and unfortunately, few of us could do anything about it because of the combination of rain and wind. The revised Mill’s table (from http://www.fruit.cornell.edu/tfabp/revmills.htm )identifies[Read More…]
Due to the COVID crisis, all Purdue Extension meetings have been cancelled until further notice. Some may be offered by distance education, but no in-person meetings will be allowed. Most Purdue Extension staff are working from home. We are available to answer your questions by email, phone or through social media. Our contact information is[Read More…]
Growth and development in fruit crops is continuing slowly across the state due to cool temperatures and resulting low growing degree day accumulation. It’s been a rough start to spring to say the least. Frost and freeze damage from the April 15-16 events has become more obvious, and there are still risks of freezing temperatures in[Read More…]
There has been some talk about the use of promalin to help overcome the damaging effects of freezing temperatures. Only a small amount of research has been conducted on this. Dr. Steve McArtney showed that Promalin applied after damaging freeze events could increase parthenocarpic (seedless) fruit development, but not every time. Keep in mind this[Read More…]