Author Archives: aymanazag

Rain Impacts on Hay

Ayman M. Mostafa

With the rain events we had during the last few weeks, I have received questions about rain impacts on alfalfa hay yield and quality. Alfalfa must be dried or cured for safe storage as hay, and generally we do not have problems reaching this dryness in Arizona. Normally, field and harvesting losses of hay are as high as 20 to 30% due to cutting and curing. Rain can increase these yield losses and reduce quality. The event of rain that occurs between the time forage is cut and baled extends curing time. Consequently, yield and quality are decreased, reducing the value of the crop as an animal feed and marketable commodity. Weather-induced losses can be caused by: 1) increased and prolonged plant respiration that reduces soluble carbohydrates and the overall energy content of forage, 2) leaching of soluble carbohydrates, protein, and certain minerals, 3) leaf shattering and loss, removing the highly digestible and high protein portion of the forage, 4) microbial activity that metabolizes soluble carbohydrates, reduces forage energy content, and possibly produces harmful mycotoxins, and 5) color bleaching.

In a Utah study, artificial rain of 0.8 inches resulted in estimated yield loss of 9.7%, losses of available carbohydrate by 18.8%, 10.2% reduce of crude protein, 19.8% of lipids, and 14.0% of soluble minerals. Hay quality was reduced more by rain damage than by advancement in maturity.

In a study in Michigan to examine the effects of rainfall on field cured alfalfa, dry matter (DM) losses ranged from 4-13% with rainfall intensity that was kept constant at 0.7-inch but spread over periods of 1 to 7 hours, with highest losses occurring when the rain was spread over a longer duration.

Carotene, the precursor for Vitamin A, is sensitive to prolonged field exposure. Vitamin A is the most common vitamin deficiency in beef cows and horses.

You can also see:

Fonnesbeck, P.V., M.M. Garcia De Hernandez, J.M.Kaykay and M.Y.Saiady (1986) Estimating yield and nutrient losses due to rainfall on field-drying alfalfa hay. Animal Feed Science and Technology, 16: 7-15.

Lindquist, K. (2017) How Rain Affects Hay Quality – Frequently Asked Questions. Alberta Agriculture and Forestry.$Department/deptdocs.nsf/all/faq14011

Rankin, M. and D. Undersander (2000) Rain Damage to Forage During Hay and Silage Making. University of Wisconsin Extension.

Rotz, C.A. (1995) Loss Models for Forage Harvest. Transactions of the ASAE. 38: 1621-1631.

EPA Proposal “to Mitigate Exposure to Bees From Acutely Toxic Pesticide Products”

Al Fournier and Peter Ellsworth

To Growers, Beekeepers, and Other Concerned Stakeholders:

EPA is seeking comment on a proposal to adopt mandatory pesticide label restrictions to protect managed bees under contract pollination services from foliar application of pesticides that are acutely toxic to bees on a contact exposure basis. These label restrictions would prohibit applications of pesticide products, which are acutely toxic to bees, during bloom when bees are known to be present under contract. (The proposed label restrictions will not apply to situations where contracted pollination services are not in use.) EPA is also seeking comment on a proposal to rely on efforts made by states and tribes to reduce pesticide exposures through development of locally-based measures, specifically through managed pollinator protection plans. (More Details Below, including proposed label language and an extensive list of affected active ingredients.)

Comments must be received on or before June 29, 2015.

You may provide comments directly to EPA at in docket EPA-HQ-OPP-2014-0818.!docketDetail;D=EPA-HQ-OPP-2014-0818

The Arizona Pest Management Center is developing a coordinated response for the desert southwest on behalf of the Western IPM Center. We will be glad to incorporate into our response any comments, concerns, feedback or relevant data from interested stakeholders. Please forward your comments to me at or contact me at one of the phone numbers below. Individuals may also comment directly on the public docket linked above.

Your input on this important issue affecting agriculture is strongly encouraged! We have requested a 30-day extension of the June 29 deadline, but it is not clear at this time if an extension will be granted. Links to more information are at the bottom of this notice.

Important Considerations (extracted from EPA proposal):

“EPA encourages pollination service contracts established between growers and beekeepers that take into account the increased likelihood of bee colony exposure by including provisions to ensure that colonies will be protected and pollination services secured. If EPA receives evidence during the public comment period and/or through outreach at stakeholder meetings that such contract provisions are common or that there are other effective and mutually agreed upon stakeholder (i.e., beekeeper-to-grower) practices indicating that application of acutely toxic pesticides is not of risk concern for bees under contract, then EPA will consider this evidence in determining whether this scenario needs the mitigation indicated in the proposed language.” (From second paragraph on p 11 of the .pdf; last paragraph of section 5.2)

“EPA understands that there are some flowering crops and ornamentals that have an indeterminate period of bloom, i.e., these crops flower, set fruit and continue to flower throughout the year, and that for these crops bees are present under contract for pollination services for extended periods of time. Examples of indeterminate blooming crops which involve commercial pollination services include: cucurbits, strawberries, etc. EPA recognizes that the proposed prohibition on application of acutely toxic pesticides during the time when bees are present under contract may cause significant issues for the growers of these crops. Therefore, EPA requests input during the comment period on alternative mitigation approaches for these pollinator-attractive crops with indeterminate periods of bloom.” (From p 14 of the .pdf; Section 6.4, “Indeterminate Bloom”)

From EPA’s Proposal, here is the proposed Label language:

Appendix B – Proposed Labeling


It is a violation of Federal law to use this product in a manner inconsistent with its labeling.

FOR FOLIAR APPLICATIONS OF THIS PRODUCT TO SITES WITH BEES ON-SITE FOR COMMERICAL POLLINATION SERVICES: Foliar application of this product is prohibited from onset of flowering until flowering is complete when bees are on-site under contract, unless the application is made in association with a government-declared public health response. If site-specific pollinator protection/pre-bloom restrictions exist, then those restrictions must also be followed.

From EPA’s Proposal, here is the list of active ingredients that are affected by the proposed Label changes:

“Appendix A – List of registered active ingredients that meet the acute toxicity criteria

Abamectin Dicrotophos Momfluorothrin
Acephate Dimethoate Naled
Acetamiprid Dinotefuran Oxamyl
Aldicarb Diuron Permethrin
Alpha-cypermethrin D-trans-allethrin Phenothrin
Amitraz Emamectin benzoate Phorate
Arsenic acid Endosulfan Phosmet
Azadirachtin Esfenvalerate Pirimiphos-methyl
Bensulide Ethoprop Prallethrin
Beta-cyfluthrin Etofenprox Profenofos
Bifenazate Fenazaquin Propoxur
Bifenthrin Fenitrothion Pyrethrins
Carbaryl Fenpropathrin Pyridaben
Carbofuran Fipronil Resmethrin
Chlorethoxyfos Fluvalinate Rotenone
Chlorfenapyr Fosthiazate Sethoxydim
Chlorpyrifos Gamma-cyhalothrin Spinetoram
Chlorpyrifos methyl Imidacloprid Spinosad
Clothianidin Imiprothrin Sulfoxaflor
Cyantraniliprole Indoxacarb Tefluthrin
Cyfluthrin Lambda-cyhalothrin Tetrachlorvinphos
Cypermethrin Malathion Tetramethrin
Cyphenothrin Metaflumizone Thiamethoxam
Deltamethrin Methiocarb Tolfenpyrad
Diazinon Methomyl Zeta-cypermethrin


A summary of EPAs proposed action is available at:!documentDetail;D=EPA-HQ-OPP-2014-0818-0003

The full Proposal is available at:!documentDetail;D=EPA-HQ-OPP-2014-0818-0002

A fact sheet about the proposal is available at:

Dr. Al Fournier
IPM Program Manager
University of Arizona
Maricopa Agricultural Center
37860 West Smith-Enke Rd.
Maricopa, Arizona 85238
office    520-374-6240
mobile 520-705-9903
fax        520-568-2556

Peter C. Ellsworth, Ph.D.
Full Specialist / Professor, IPM Coordinator &
Director, Arizona Pest Management Center
University of Arizona
Department of Entomology
Maricopa Agricultural Center
37860 W. Smith-Enke Road
Maricopa, AZ 85138
Tel: 480-331-APMC

The Benefits of Alfalfa to the Southwest Ecosystem

Ayman Mostafa

The possibility of “mega drought” in the southwest U.S. was the subject of a debate on NPR’s Diane Rehm Show on April 15, 2015. The guests went through the record, probable causes and possible solutions for the shortage in water in the region. The panel discussed how to harmonize environmental goals, urban expansion and agriculture needs. The share of water going toward alfalfa hay production that supports the dairy and livestock industry, and changing crop selections were among the topics of discussion.

This is a good opportunity to emphasize some facts. Alfalfa in the southwest ecosystem provides many environmental benefits: it is a rich habitat for wildlife; provides an insectary for diverse beneficial insects; improves soil characteristics; fixes atmospheric nitrogen; traps sediments and takes up nitrate pollutants; mitigates water and air pollution; and provides aesthetically pleasing open spaces.

  • Areas depleted of row crop or specialty crop production, like many agricultural areas in the western US would benefit environmentally by stabilizing soils when incorporating a perennial legume such as alfalfa.
  • Alfalfa fields are important contributors to the biodiversity of agricultural systems by functioning as insectaries for beneficial insects, many of which are pollinators or natural enemies that play important roles in the low desert agroecosystem. Beneficial insects move from alfalfa fields into other crops, where they play crucial roles in pollination and biological control.
  • Alfalfa also plays an important role in insecticide resistance management by acting as a refuge, especially for aphids and whiteflies. Low desert alfalfa production is quite different from production in other areas where non-dormant, irrigated varieties provide a year-round habitat for insects.
  • Non-dormant alfalfa hay varieties are uniquely adapted to the low desert climates of central and southern Arizona and the adjacent region of California along the Colorado River. Unlike many other production regions in the nation, low desert alfalfa is irrigated and produces an average of eight cuttings every year. Alfalfa acreage in the region is likely to increase given the importance of the dairy industry and other livestock enterprises and a reduction in cotton acreage due to low cotton prices.

You can access the show audio by Clicking Here.