Art Burrell, working in the Champlain Valley of NY where spring temperatures are often cool, would agree with you. The sentences after the section that I quoted in the previous post says: “We have a period up to 60 or 70 hours, after the start of theinfection period, during which a heavy application of lime sulfur may prevent the appearance of lesions. Inevitably there will be some injury from the use of lime sulfur. Even in the absence of visible scorch, food manufacture by leaves is cut down for a few days by lime sulfur. This apperas to be chiefly from that part of the spray that reaches the lower survaces of the leaves. The injury is worst under high temperature, slow drying conditions, and on sensitive varieties such as Baldwins. Low-vigor trees have poor ability to recover from lime sulfur injury.”
I thought that I had read elsewhere that liquid-lime sulfur might provide up to 4 days (96-hr) of post-infection activity, but perhaps that was a figment of my imagination. On the other hand, you might eliminate scab on young leaves if you spray lime sulfur with a bit of oil while leaves are still wet, thereby causing enough burn to make the scab-infected leaves (and a probably a lot of other leaves) fall off of the tree before scab can begin sporulate :) Incidentally, a product called Sulforix is being promoted as an alternative to liquid lime sulfur, but so far as I know it will not be any safer or reach back any futher than the old lime sulfur that Art Burrell was using in the 1940’s. On Apr 7, 2016, at 1:18 PM, Vincent Philion <[email protected]<mailto:[email protected]>> wrote: If you worry about Captan phytotoxicity, then you should also worry about LLS being phytotoxic under the same conditions. Liquid lime sulfur is a ’normal’ (ie not emergency) choice for post infection (kickback). However, I wouldn’t trust it 96 hours after beginning of rain, unless the temperature was very low. Typically, we use DH (degree-hours) to describe the post infection efficacy. In Celsius, we consider LLS good for 250 DH, meaning 25 hours at 10°C. This is calculated once the infection is started. If you calculate from the beginning of the rain, then about 400DH (40 hours at 10, or 80 hours at 5°C) hope this helps. Vincent Le 7 avr. 2016 à 12:56, David Kollas <[email protected]<mailto:[email protected]>> a écrit : Does anyone have enough experience with liquid lime sulfur to comment on it as an emergency choice for application before rains have stopped during the current long infection period? It is listed as having 72-96 hours back-action in the New England Tree Fruits Management Guide. In my particular situation, Half-Inch Green stage tissues were exposed many hours during two of the previous three nights to 18-20 degrees F, and are probably extra sensitive to captan penetration and phytotoxicity. David Kollas Kollas Orchard Connecticut _______________________________________________ apple-crop mailing list [email protected]<mailto:[email protected]> http://virtualorchard.net/mailman/listinfo/apple-crop Vincent Philion, agr., M.Sc. Microbiologiste/Phytopathologiste (pomiculture) Institut de recherche et de développement en agro-environnement Research and Development Institute for the Agri-Environment www.irda.qc.ca<http://www.irda.qc.ca> Centre de recherche 335, Rang des Vingt-Cinq Est Saint-Bruno-de-Montarville (Québec) J3V 0G7 [email protected] Bureau: 450 653-7368 poste 350 Cellulaire: 514-623-8275 Skype: VENTURIA Télécopie: 450 653-1927 Verger expérimental 330, Rang des vingt-cinq Est Saint-Bruno-de-Montarville (Québec) J3V 4P6 Téléphone et télécopieur : 450 653-8375 Local pesticide: 450-653-7608 _______________________________________________ apple-crop mailing list [email protected] http://virtualorchard.net/mailman/listinfo/apple-crop
_______________________________________________ apple-crop mailing list [email protected] http://virtualorchard.net/mailman/listinfo/apple-crop
