Posts Tagged: stone fruit
Spider mites, fruit moth and twig borer larvae, aphids, and bark cankers are just a few pests that can wreak havoc on stone fruit trees. With spring well underway and trees in full bloom and beginning to develop fruit, it's time to monitor and take action before these pests get out of hand.
UC IPM teamed up with UC farm advisors to develop a series of how-to videos that can help growers and pest control advisers monitor for pests and damage and determine if and when treatment is needed.
In one video, Sacramento Area IPM Advisor Emily Symmes gives a brief overview of how to monitor for webspinning spider mites. Spider mites build up in stone fruit trees as the weather warms up. Late spring through summer is the ideal time to monitor for mites and their damage, which includes leaf stippling and webbing. If mites build up too much, leaves can drop, fruit may not fully develop, and branches and fruit can be exposed to sunburn.
Shoot strikes, or dead drooping leaf tips, are often seen on young peach and nectarine trees. In a second video, UC Sutter and Yuba County Farm Advisor Janine Hasey explains how to monitor for shoot strikes and how to distinguish the culprits, oriental fruit moth and peach twig borer. Although Oriental fruit moth and peach twig borer can bore into both foliage and fruit, they cause the most devastating damage by feeding on fruit. Early season monitoring and treatment can prevent future fruit loss.
In plum and prune orchards, leaf curl aphids and mealy plum aphids cause leaves to curl and become distorted. Aphids produce honeydew, which can lead to the development of sooty mold, causing fruit to crack and blacken. Aphids are often present when leaves start to grow. In his video, Rick Buchner, UC farm advisor for Tehama County, discusses how to monitor for aphids and explains how to decide when treatment is warranted.
In a final video, UC Sacramento County Farm Advisor Chuck Ingels teaches how to distinguish Phytophthora root and crown rot from bacterial canker. The two diseases are often confused because they both cause bark cankers. Phytophthora root and crown rot is confined to the lower trunk, but when a bacterial canker infection occurs in the tree trunk, the diseases can often be confused. Bacterial canker can be confirmed by cutting away the outer bark and looking for characteristic red flecks on the inner bark. Correct identification of these diseases will help in choosing a management strategy.
Webbing caused by webspinning spider mites.
Shoot strike caused by oriental fruit moth.
Leaf distortion caused by leaf curl plum aphid.
Reddish flecking symptoms of bacterial canker.
For the past 17 years, Kevin Day, a UC Cooperative Extension farm advisor for Tulare County, and Ted DeJong, UCCE specialist in the Department of Plant Sciences at UC Davis, have been comparing the quality of fruit on conventional peach and nectarine trees and smaller trees grown on size controlling rootstock, reported KSEE Channel 24 news and KMJ Farm Report in Fresno. The impact of plant spacing and limb training were also assessed.
The goal is to have trees below 8 to 9 feet with traditional scion cultivars on size controlling rootstock. With reduced yield per tree due to the size, the distance between rows and trees in the row can be reduced to get the same or higher yield per acre. Controller 9 is currently being planted commercially. Farmers can get some yield the second year after planting.
Shorter trees can eliminate ladder work, reducing labor costs and increasing worker safety. For more information, please see the ANR News blog.
See the video on the KSEE Channel 24 website.
Listen to a podcast of the KMJ Farm Report with the story on the peaches and nectarines on 8/12/2014 located at 44:30 minutes into the podcast./span>
Stonefruit rootstocks evaluated by UC Scientists help control tree size.
A newly redesigned website, the UC Fruit Report, was launched at the beginning of 2012 with comprehensive information for Central Valley tree fruit producers. The website contains research and photos that three UC Cooperative Extension advisors and specialists developed and collected over the past 30 years.
Website visitors will find useful horticultural information about establishing and managing fresh market peach, plum and nectarine orchards. UC pomology specialist Scott Johnson, who is based at the Kearney Agricultural Research and Extension Center, devoted half of his year-long sabbatical in 2011 to aggregating the information online.
“The website has a lot of information that will help farmers,” Johnson said. “If they’re seeing symptoms on their leaves that they think is a nutrient deficiency, they can go into the site and look at pictures and compare. If they’re planning future orchards, they can go through 35 different rootstocks, from dwarfing rootstocks to those that are resistant to certain diseases.”
The basic information on the website is concise and easy to read. The entries include links to detailed research reports for those who wish to explore the topics further.
The site is maintained by Johnson, Tulare County UCCE farm advisor Kevin Day and UC Davis-based pomology specialist Ted De Jong. They will periodically update the website to reflect the newest research findings and post timely news.
“For example, if we’re seeing a problem with mites,” Johnson said. “We can put that up on the web, where farmers can find solutions to the problem.”
Separate sections in the website are devoted to:
- Orchard establishment
- Pruning and training
- Nutrition and fertilization
The new UC Fruit Report website contains information collected over 30 years.