- HUANGLONGBING: DEVASTATING DISEASE OF CITRUS 339
Table 7.1. Products and amounts in 163.19 L ha−^1 of the Boyd nutrient/SAR cocktail in
2012.
Foliar applied products
Amount per
haGround applied
products Amount per haSerenade max WP 2.4 kg N (Calcium nitrate) 242.12 kg
Sonata 4.7 L P 48.19 kg
Di-Oxy Solv Organic
(hydrogen peroxide)
4.7 L K (MOP)+K-Mag 298.16 kgRenewz 93.4 L Magnesium 9.6 kg
Epsom salts (magnesium
sulfate)
8.4 kg Boron w/herbicide
boom annually1.7 kgTechmangam (manganese
sulfate)
11.2 kg Iron where needed Fe-EDTA or DTPA
(9.98 kg ton−^1 )
Zinc sulfate 2.8 kg Copper nutritional
only
As neededSodium molybdate 70.0 g
13-0-44 (spray grade
potassium nitrate)
11.2 kgTurfpro 9.3 L (spring)
435 Citrus spray oil 42.0 L
zRenew (Plant Food Systems, Zellwood, FL) is a combination of products 14-7-8 w/K-Phite
(473 mL/3.78 L)+Saver (salicylate) on spring flush or 3-18-20 w/K-Phite (473 mL/3.78 L) Saver (sali-
cylic acid) on summer and fall flush.
mixture of fertilizer with a salicylate or salicylic acid, which are sys-
temic acquired resistance (SAR) compounds, along with a number of
minor elements (Table 7.1), which became known as the “Boyd cock-
tail.” Soon thereafter the “Boyd cocktail” or similar variants were
adopted by a significant portion of Florida citrus growers who believed
that these “enhanced nutritional programs” (ENPs) could slow, or even
stop, HLB decline and thereby extend the productive life of mature
trees. It was estimated in 2012 that more than 90% of Florida citrus
growers were using foliar nutrition and ACP management to maintain
HLB-affected trees (Rouse et al. 2012). Currently, the use of these ENPs
makes fertilizers the single greatest cost for citrus production (Spreen
et al. 2014). As with the Chinese findings on the effects of fertility on
HLB-affected trees, there have been no convincingly consistent results
to substantiate beneficial effects of nutritional programs in the West-
ern Hemisphere, although agricultural chemical company advertising
strongly suggests otherwise.
According to Rouse et al. (2010) combined psyllid management and
foliar nutrition/SAR (Boyd cocktail) sprays are maintaining tree health
and production in the presence of HLB. In a subsequent report (Rouse
et al. 2012), it was concluded that rejuvenation of HLB-affected trees