- Basil downy mildew has been reported in New Jersey.
- Rhizoctonia root rot has been reported in tomato and other vegetable crops.
- Phomopsis and Phytophthora fruit rot has been reported in eggplant.
- Collar rot has been reported on tomato. For more information please click here.
- Pythium cottony leak has been reported on pepper. For more information on controlling Pythium and Phytophthora please click here.
- Pepper anthracnose has been reported in southern New Jersey. For more information on controlling anthracnose fruit rot please click here.
- Cucurbit downy mildew has been reported on cucumber and cantaloupe in New Jersey with more being reported on the East Coast and Ontario, Canada. For more information on CDM control please click here.
- Blackleg has been reported on potato in New Jersey.
- There have been no reports of Late blight in potato or tomato in the region to date. Late blight has been reported in Ontario, Canada. To follow the progress of Late blight in the US please click here.
- Bacterial leaf spot has been reported in pepper. More more information on BLS control please click here. Rutgers is surveying tomato and pepper fields throughout the state this summer to help determine the makeup of the bacterial population and for copper resistance development.
- Powdery mildew has been reported in cucurbit crops. For more information on the control of CPM please click here.
- Southern blight has been reported on pepper.
- Bacterial canker has been reported in tomato. For more information on diagnosing important tomato diseases please click here.
- For information on diagnosing important diseases in pepper, tomato, and cucurbit crops please click on links.
- The 2022/2023 Commercial Vegetable Production Recommendations Guide is available for free online or for sale in hardcopy form at many County offices.
- For a quick review on managing fungicide resistance development using tank mixes and fungicide rotations, and information on FRAC group 4, FRAC group 7, and FRAC group 3 and FRAC group 11 fungicides please click on hyperlinks.
Archives for July 2023
Vegetable Disease Update: 07-29-23
What do the terms in a feed analysis mean?
We have had a requests for information about heat damaged hay and forage. Forage put up too wet will overheat and may result in unavailable protein and hay unsuitable for ruminant digestion. A definition of the terms in a feed analysis may be useful. Some of these terms are useful for ruminant animals (cattle, sheep, goats) only.
Dry Matter or DM is the part of the forage that is not water. Because of a large variation in moisture content of feeds, dry matter maintains a base line when expressing feed values and nutrient requirements of the animal. Feed analysis is usually presented in both an As-Fed (contains moisture) and a DM basis. Succulent feeds such as silage or green chop are much higher in moisture, and lower in DM, than are feed grains such as corn or barley.
Protein is represented as Crude Protein or CP and is a measure of the nitrogen content of the feed. CP is essential for normal growth and body function of all animals, it is essential for meat, milk, eggs, and wool production. Unfortunately, CP does not distinguish the nitrogen contained as “amino acid nitrogen” or “non-protein nitrogen.” Most CP measured in feed analyses is made up of “amino acid nitrogen.” Because of this, there are other measurements which will describe different protein fractions or non-protein nitrogen in feed. Amino acids are the building blocks that make up proteins in meat, milk, eggs, and wool. Ruminating animals can convert non-protein nitrogen into amino acids through fermentations that occur in the rumen of cattle, sheep, and goats.
Unavailable Protein is calculated from the nitrogen which is bound to the fiber in the feed. Normally about 1 percent on a dry matter basis is found in this fraction. Values greater than 1 percent may indicate heat damage. Often referred to as heat damaged protein.
Degradable Protein is protein that is broken down in the rumen, mainly into ammonia. Most rumen microbes need ammonia to produce rumen amino acids, maintain adequate microbial growth, and produce proteins that can be used by a ruminating animal for meat, milk, and wool production.
Undegradable Protein is also referred to as bypass protein. It is protein fraction that is resistant to rumen microbial degradation and therefore bypasses the rumen. Most of it can be digested in the small intestine.
Soluble Protein is that protein or non-protein nitrogen fraction which is degraded in the rumen rapidly. Soluble protein is converted into ammonia in the rumen within a short time after being ingested, it is this ammonia that is made into microbial protein. The remainder of the degradable protein fraction may take hours to be broken down.
High producing ruminants require all these forms of protein in their diets. This is essential to promote proper functioning of the rumen and to ensure that the maximum amount of digestion occurs in the rumen.
Neutral Detergent Fiber or NDF represents all of the cell wall material containing hemicellulose, cellulose and lignin. NDF has been identified as being highly related to dry matter intake. The NDF appearing on feed analyses is probably aNDF, referring to amylase treated NDF. Amylase is an enzyme used to pre-treat the chemical’s used in NDF analysis. a-NDF is currently the standard treatment used in NDF analysis.
Acid Detergent Fiber or ADF is the cell wall portion of a feedstuff that includes cellulose and lignin as primary components. The higher the ADF content, the lower the digestibility of the feed stuff. The most indigestible fractions of feed are the cellulose and lignin components which are often linked.
Acid Detergent Insoluble Nitrogen or ADIN may be referred to in a feed analysis as ADFCP, ADICP, or heat damaged protein (unavailable protein above). The residue remaining in the ADF fraction is analyzed for nitrogen. This value is an estimate of the protein that is unavailable to the animal and can be an estimate of overheating of forage that is put up too wet. Hay put up too wet can undergo a process called enzymatic browning that occurs in the presence of protein and sugars when forage overheats. The level of heat damage is determined by analyzing the forage for ADIN (Acid Detergent Insoluble Nitrogen).
Too little fiber can result in improper rumen functioning and off feed and other health problems, such as displaced abomasum and foot problems. Too much fiber will mean decreased diet digestibility, decreased feed intake and decreased production. Minimum target levels of ADF and NDF for dairy cows are 21 percent and 28 percent of the total diet, respectively.
Non-Structural Carbohydrates or NSC represent contents of plant cells and contains sugars, starches and pectins. These are carbohydrates which are rapidly fermented in the rumen and utilized by rumen microorganisms. It is essential to balance NSC with the different protein fractions to ensure proper microbial growth in the rumen. If NSC is inadequate, the degradable and soluble protein will not be utilized to the greatest extent possible.
Energy Values are measured as Total Digestible Nutrients (TDN) or Net Energy. Net Energy is expressed as megacalories per pound of dry matter. There are different NE calculations for maintenance, gain and lactation. Almost all nutrient requirements used today and in feed testing are expressed as NE. (Digestible energy is used for horses). Units of NE are expressed as megacalories or mcal/lb. These are usually determined by equation based on ADF, NDF, and the protein fractions.
Understanding and controlling Rhizoctonia root rot
Even though much of New Jersey has had wet weather recently, which is more favorable to Pythium and Phytophthora development, Rhizoctonia root rot has been reported over the past few weeks in a number of crops. Rhizoctonia root rot, caused by Rhizoctonia solani, is an important soil-borne fungal pathogen with a very large host range. The pathogen can survive saprophytically on living or dead plant material (organic matter) or as sclerotia in the soil (for more than 3 years). Disease development is favored by warm temperatures, dry (or very well drained) soils and stressed plants. Symptoms of Rhizoctonia root rot may begin as stunted plant growth (with poor root systems) with the appearance of brown lesions at the base of the stem causing wilting with lesions eventually girdling the stem and killing the infected plant. Rhizoctonia root rot infections only extend about an inch above the soil surface (Figure 1), unlike Phytophthora blight infection which can extend much farther up the stem. [Read more…]
Testing for heat damaged protein in hay/forage put up too wet
Two regional laboratories that could test for heat damaged proteins are:
Cumberland Valley Analytical Services (CVAS)
Below is some information and factsheets below that may be useful about hay and forage that is put up too wet.
- High temperatures in bales (>170°F) can result in reactions between proteins and sugars called the Maillard reaction
- Hay impacted by Maillard reactions will be sweet/tobacco smelling and brown/caramel colored
- While highly palatable, the reaction creating this hay ties up protein, making it unusable for animal digestion
- If significant signs of Maillard reactions are seen in your hay, add a Head Damaged Protein (HDP) test to your forage analysis to get accurate Crude Protein contents for feeding decisions
- Caramelized hay also has a high likelihood of containing larger than normal amounts of mold growth. Feeding free choice is a good option to minimize risk when feeding moldy hay
- Please don’t forget other contaminants that can be concerns in wet or dry years such as mycotoxins, nitrates, etc.
- Diluting the bad forage with good forage or grain is a possibility
- Check with an extension agent or other authority before feeding
Heat damaged protein in hay/forage put up too wet.
Below is some information and factsheets below that may be useful about hay and forage that is put up too wet.
- High temperatures in bales (>170°F) can result in reactions between proteins and sugars called the Maillard reaction
- Hay impacted by Maillard reactions will be sweet/tobacco smelling and brown/caramel colored
- While highly palatable, the reaction creating this hay ties up protein, making it unusable for animal digestion
- If significant signs of Maillard reactions are seen in your hay, add a Head Damaged Protein (HDP) test to your forage analysis to get accurate Crude Protein contents for feeding decisions
- Caramelized hay also has a high likelihood of containing larger than normal amounts of mold growth. Feeding free choice is a good option to minimize risk when feeding moldy hay
- Please don’t forget other contaminants that can be concerns in wet or dry years such as mycotoxins, nitrates, etc.
- Diluting the bad forage with good forage or grain is a possibility
- Check with an extension agent or other authority before feeding
Controlling Phytophthora blight in eggplant
Phytophthora blight, caused by Phytophthora capsici, can cause crown and fruit rot in eggplant. Unfortunately, most of New Jersey has been plagued by heavy rains and pop-up thunderstorms these past few weeks making conditions ideal for pathogens such as Phytophthora blight on pepper, eggplant, tomato, and cucurbit crops.
Control of Phytophthora blight is extremely difficult (even with the use of fungicides) in the very hot, wet weather conditions that most of New Jersey has been through during the month of July. In the past few years a number of new fungicides, with new active ingredients, have become commercially-available for use on multiple crops. Mefenoxam and metalaxyl, both once widely-used to effectively control Phytophthora blight have been hit by resistance issues around much of Southern New Jersey. Growers with a known history of mefenoxam-insensitivity on their farm should use Presidio or Ranman plus a Phosphite fungicide in rotation in their drip application programs for the control of the crown rot phase of Phytophthora blight. Importantly, if mefenoxam has not been used in particular fields on any crop for a number of years (more than 5+) the fungus may revert back to being mefenoxam-sensitive and control with these products may return. Mefenoxam, metalaxyl, and the phosphite fungicides are the most systemic of the group and should readily be taken up the by plant via application through the drip. Orondis Gold (OXTP + mefenoxam) is also systemic. Presidio is locally systemic, and Ranman has protectant activity and can also be applied via drip.
[Read more…]