Asian Soybean Rust fungus confirmed in United States
Dr. Melvin Newman, UT Extension Specialist, sent me the following information about Asian Soybean Rust.
Soybean rust is a fungus disease of soybeans and many other cultivated legumes such as peas and beans. It has the ability to spread by wind-blown spores over long distances and under suitable climatic conditions, rapidly infect large production regions.
Soybean rust has the ability to quickly reduce yields significantly, but the extent of economic impacts in Tennessee will depend on the timing, spread and severity of rust establishment and outbreaks and on how soybean producers respond.
USDA researchers have now (Nov. 21) reported 10 findings of soybean rust (Phakopsora pachyrhizi) on soybean leaves in the U.S. These findings are located in Louisiana, Mississippi, Alabama, Georgia and Florida. There may be more findings as time goes on.
It was also found on kudzu in Florida. Kudzu is also a host for the fungus and could serve as an over-wintering host and give the spores an early start in the spring. The rust fungus cannot survive freezing temperatures, but where temperatures remain above freezing during the winter, the fungus could live and spread spores to early growing soybeans. As spores are produced in these areas, southerly winds could carry the disease further north into larger soybean growing areas.
Soybean rust can be managed with the judicious use of fungicides. There are two fungicides cleared for use for soybean rust at this time.
They are Quadris and Bravo or Echo. Tennessee and several other states have requested EPA to approve seven other fungicides and combinations in a Section 18 emergency quarantine exemption, to be used to help control soybean rust. The others are likely to be approved before spray time in the spring. To best control soybean rust, producers will need to be able to spray quickly once scouting reports indicate that rust is on its way.
Fungicides must be applied before rust gets a foot-hold on soybean leaves. Once 5-10 percent rust infection is observed, it will be very difficult to control and will surely take more fungicide sprayings than if the fungicide were applied before infection.
Brazilian soybean producers spray an average of two applications a season with fairly good results, but they start spraying early (first bloom) with another fungicide spray about 21 days later. Last season, they sprayed 95 percent of their 35 million acres with two applications. It was reported that early maturing varieties required less sprays than later maturing varieties. Producers should not wait until the last minute to get ready for quick spraying because the rust can move very fast.
Producers should plan to plant soybeans so that fungicide sprays can penetrate the canopy and give better control. Thirty inch-rows would be better than 15 inch-rows or broadcast, according to researchers and growers conducting tests in Brazil. Good coverage will be essential for adequate control.
During the winter, UT extension soybean pathologists and specialists will be having meetings and training as many persons as possible to be first detectors and triage personnel to help scout for rust symptoms. First detectors can be extension agents, field reps, company reps and any others that work in the field with soybeans. They will be trained to recognize soybean rust and other soybean foliar diseases and will be given instructions on how to submit suspect leaf samples.
Triage personnel across the state will be trained to use microscopes to ID rust samples. If samples are then suspected of have rust they will be submitted to the UT extension plant disease and pest lab in Nashville.
Discovery of this disease is not good news for U.S. soybean growers. It looks like we need to get ready to apply fungicides to soybean crops. More information will be available before planting time next spring.
FEEDER CALE SALE
Last week’s feeder calf sale results are listed below. While cattle are down some over the past several weeks over 2,100 head went through the ring Wednesday night. Tennessee feeder cattle were down about $5 per hundred last week. Future prices are down due to the BSE news last week.
This is the third instance of a false positive screening test. Final test results should be out this week. Most feeder cattle weights and grades are running $7 to $9 more per hundred than they were this time last fall.
Steers: Med & Lg 1
350-400 lbs ————-
400-450 lbs 119.00-120.00
450-500 lbs 115.00-118.75
500-550 lbs 116.25-117.50
550-600 lbs 108.25-111.50
600-700 lbs 101.75-102.50
700-800 lbs 99.75-104.00
Heifers: Med & Lg 1
350-400 lbs 115.00-118.00
400-450 lbs 103.00-104.50
450-500 lbs 103.00-104.85
500-550 lbs 99.00-102.00
550-600 lbs 95.60-97.00
600-700 lbs 96.00-97.25
700-800 lbs 94.00-95.25
Steers: Med & Lg 2
300-350 lbs 134.00
350-400 lbs 129.50-130.00
400-450 lbs 119.25-119.50
450-500 lbs 112.00-112.50
500-600 lbs 107.75-110.00
600-700 lbs 99.25-103.50
700-800 lbs 99.75-102.75
Heifers: Med & Lg 2
300-350 lbs 121.00-125.00
350-400 lbs 114.00-115.00
400-450 lbs 105.50-106.00
450-500 lbs 100.50-107.75
500-600 lbs 96.25-98.25
600-700 lbs 95.75-96.50
700-800 lbs 92.50-93.50