Xtremehorticulture

Wormy Apples a Problem with Honeycrisp Apples

Q. I have had wormy apples in our ‘Honey Crisp’ apple tree. Last year we had the same problem. I was told to spray a fungicide. I also sprayed Neem oil. I waited until the apples started to form. I still have these worms in every apple on my tree. HELP!!!  This is codling moth stuck on the sticky side of a pheremone trap. It is about 3/8 inch long and a true moth. Since the adult is a moth, the juvenile or immature form is a “worm” or larva. When populations are large they produce “wormy apples”.  A. I am guessing that you are dealing with codling moth. This is a common pest of apples and pears. They appear as “wormy apples”. They are creamy white and about 3/8 inch long when they are mature. Usually, they have a brown head. They start getting into the fruit when the fruit is small and may continue to feed as the fruit gets larger. You can read more about codling moth control by searching for “codling moth” and “IPM”.  https://ipm.ucanr.edu/PMG/PESTNOTES/pn7412.html The most reliable site is from the University of California. If this is codling moth, then picking and get rid of small fruit which is infested is the first step.  When the codling moth is flying, the moth will “sting” a small fruit causing it to drop. If it happens when the fruit is larger, it may stay on the tree. Look up for “stung” fruit or look at the ground for fallen fruit. Fruit produced later will have a larger percentage of stung fruit. Look for fruit tree species that are produced and harvested early.  Otherwise, their population continues to increase as the apple stays on the tree longer. Apples that stay on the tree longest are the most heavily infested. On the flip side, apples harvested early are the least infested. Populations of this pest increase with each generation produced. In our climate, expect codling moth to have three or four generations each year so start getting rid of infested fruit when the fruit is small. With each generation the numbers of these moths will increase and increase as the year progresses.  Start picking and getting rid of infested fruit starting about six weeks after it flowers. You can recognize infested fruit because of the brown frass coming out of it. The places where frass coming from the fruit are called “stings”. Stings are egg-laying sites by the female moth. Fruit that has frass coming from it will either fall from the tree or stay on the tree and get “wormier”. When you remove this fruit early, the population of “worms” has a better chance of staying low.  As fruit gets older, the “worms” get bigger and tunnel into the fruit deeper. They might feed on the seeds of these fruit before they pupate into a moth.  I have had good luck spraying either Bt or Spinosad several times over one season. Follow label directions. I have also had good luck if I use pheromone traps and get rid of them using these traps. I use one trap for every three or four trees.  This codling moth has already exited. Notice the “frass” left behind when it exited. Usually, pheremone traps are used for timing the application of sprays but when populations are low, I have had good luck “trapping them out”. Those traps should be put in the trees when the trees begin flowering or at least a couple weeks after they start to flower. Pheremone traps for codling moth can be bought from several places online. Look for them. The pheromone must be replaced regularly as per the instructions. Those wormy apples you got probably came from a neighbor who did not control them. This is a winged trap. More popular are the three sided “delta traps”. The winged traps, in my opinion, are better for repelling the moths. That is, better for using pheremones to keep fruit free of “worms”. The pheromones have better air circulation in those kinds of traps, the pheremones must be changed out more regularly, and the traps more concentrated. The delta traps are best for monitoring moths and telling you when to spray pesticides.

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Granular Fertilizer, Fertilizer Stakes or Compost for Fruit Trees?

Q. Last week we planted several fruit trees and have established trees as well. Would you recommend applying fertilizer around these trees now? Spikes or granular type of fertilizer? A. Fertilizers will benefit fruit trees the most if applied to the soil just before spring growth. But if you haven’t applied any, then do it now during spring growth.             The least expensive way is using granular fertilizers in a single application in the spring.             Fertilizer stakes or spikes are granular fertilizers compressed into a stake you can drive into the ground. They are not messy, convenient, and no open bags that can spill but more expensive per pound of fertilizer. Jobes does a good job with fertilizer stakes but a bit on the expensive side.             Drive them into the ground near drip emitters or in the irrigation basin; one for each emitter. They release nutrients slowly. Apply them only once in the spring. This is a cheaper version we were using at the orchard for trials. The soil should be wetted and the plastic cap put on top and the stake pounded into wet soil just under the emitter or in the irrigation basin. Small trees two will do. Larger trees would require four or more, one in each quadrant of the basin or under an emitter.             For new trees, if you mixed in good quality compost with the soil in the planting hole you can skip a fertilizer application this season. If you put a smidgen in the ground then apply a fertilizer now if you haven’t.             You can split granular fertilizer applications in half if you want. Apply half now and the other half after you harvest or in a couple of months if there is no fruit. Fruit trees that are tender to winter cold should not be fertilized after mid-summer so apply the second half earlier than this.             If you are using organic fertilizers that release nutrients slowly then apply it once in the early spring.  Young fruit tree fertilized with compost at the orchard. The tree is watered with an irrigation basin and a bubbler. The water from the bubbler moves the compost into the basin through the mulch. The compost acts like a “fertilizer tea”.             Foliar sprays of fertilizers are a great way to fertilize trees if they are in difficult places. Foliar applications should be done more frequently because their results are short-lived. Apply foliar sprays every 6 to 8 weeks until it gets hot.             Keep fertilizers away from tree trunks but in contact with water. Apply them no closer than a foot from the trunk and just under the soil surface. Make sure they are watered in thoroughly after application. Compost applied to the base of the fruit trees by volunteers at the Orchard. Two five gallon buckets are applied to each of the larger trees. One five gallon bucket for the smaller ones.             I have seen new trees killed by applications of fertilizers applied too close to the trunk. Salt damage from fertilizers can kill newly planted trees.             Don’t forget iron. Newly planted trees normally don’t need it the first couple of years but may develop iron shortages beginning in the third to the fifth years. This plum tree had iron chlorosis really severe after it leafed out in the spring. Four applications of iron sprays, spaced one week apart, turned it completely green again. Next year it received iron chelate applied to the soil in January to prevent this.

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