Novel organosilicone adjuvants to reduce agrochemical spray volumes on row crops

Abstract

Onion and potato crops require frequent applications of highvolume agrochemical sprays The use of two novel organosilicone adjuvant blends DuWett and Bond Xtra is being developed with the aim to halve conventional spray volumes on these crops Adjuvant use rates have been optimised through extensive studies of the physical characteristics of sprays These include leaf coverage retention foliar penetration and phytotoxicity Comparisons with conventional horticultural and other organosilicone adjuvants are made to illustrate the unique properties of DuWett and Bond Xtra which can improve the retention and coverage of sprays on onions and potatoes without increasing the risk of crop phytotoxicity

A comparison of sticker adjuvants for their effects on retention and rainfastening of fungicide sprays

“…Retention increased with increased concentration of the organosilicone/ latex blend type adjuvants; addition of Du-Wett Rainmaster, at the higher rate, provided maximum retention and more than Bond Xtra at that same rate (P<0.05, Table 1). Bond Xtra has been shown previously to increase retention and coverage of sprays on difficultto-wet foliage (Gaskin et al 2000). Both terpene stickers performed similarly on cabbage (P>0.05) and a large increase in their use rate had little effect on initial (pre-rain) spray deposits (Table 1).…”

“…data). Latex stickers blended with organosilicone superspreaders have been developed in recent years to provide better spreading properties (Gaskin et al 2000), but such blends can have disadvantages. For example, too much spreading may reduce the film thickness and protective properties of the latex sticker.…”

Potential and actual uses of zeolites in crop protection

“…On the other hand, low-volume spraying leads to very poor coverage of the leaf surface and results in insufficient biological activity and hence loss of efficacy. 51,52 Adding an appropriate surfactant will reduce the contact angle and enhance the degree of leaf coverage, which will improve crop protection. 50 In general, a good coverage becomes very important when using non-systemic products, such as zeolites.…”

Technologies to maximise preflower spray applications to control scale on kiwifruit

“…While spray coverage was not quantified in this study, it was visibly improved by DW adjuvant in the low volume spray. DW adjuvant has been shown to increase spray deposits on a variety of plants, particularly when sprays are concentrated and the target is difficult-to-wet (Gaskin et al 2000(Gaskin et al , 2004a. This adjuvant is not recommended for use in dilute sprays as run-off may occur, but its superspreading capacity ensures that concentrate spray will access fissures in bark that harbour scale more efficiently than sprays without the adjuvant.…”

“…Better targeting of leader wood was attempted by modifying nozzles and sprayer outputs. A super-spreading adjuvant was included in sprays to maximise spray deposits and coverage (Gaskin et al 2000) of leader wood bark and crevices. This provided the option of lowering spray application volumes, with the potential to reduce off-target spray drift.…”