Influência de pontas de pulverização e adjuvante no controle químico da ferrugem asiática da soja

Abstract

RESUMO.Este trabalho teve como objetivo otimizar o controle químico da ferrugem asiática da soja, avaliando a deposição de fungicida no dossel da cultura ao utilizar diferentes pontas de pulverização, em dois volumes de calda, com e sem a adição de adjuvante à calda. O ensaio foi conduzido no delineamento em blocos casualizado, com quatro repetições, em esquema fatorial (3 x 2 x 2): três tipos de ponta de pulverização (jato plano defletor, jato plano duplo e jato plano duplo com indução de ar), dois volumes de calda (200 e 250 L ha , avaliou-se a deposição de calda no dossel da cultura, a severidade da ferrugem, a massa de 1.000 grãos e a produtividade. Concluiu-se que as pontas de jato plano defletor e jato plano duplo apresentaram-se superiores à ponta de jato plano duplo com indução de ar quanto a produtividade. O uso do adjuvante testado resultou em maior densidade de gotas nos terços superior e médio do dossel e maior produtividade. O aumento do volume de calda de 200 para 250 L ha of commercial product, spray deposition on the plant canopy, rust severity, 1000-grain weight and yield were evaluated. The results showed that turbo flat fan and twin flat fan were better than twin flat fan with air induction in yield increase. The adjuvant increased the droplet deposition on top and middle parts of the canopy and soybean yield. The increase of spray volume from 200 to 250 L ha -1 did not provide better Asian rust control and yield increase.

Adjuvantes em pulverizações de fungicidas na cultura do trigo

“…A associação de fungicidas e adjuvantes foi testada na cultura da soja (CUNHA & PERES, 2010;AGUIAR-JÚNIOR et al, 2011) e milho (JADOSKI et al, 2009;WOLF et al, 2009); entretanto, os autores não encontraram trabalhos relacionados à cultura do trigo. O objetivo deste trabalho foi verifi car se a adição de adjuvantes à calda com fungicidas favorece o controle químico das doenças foliares e da espiga da cultura do trigo.…”

Evaluation of spray deposits with twin flat tip with air induction in two soybean stages

“…Butler-Ellis (2000) argue that the droplets formed by the tips with air induction technology are more sensitive to changes in the physical properties of the spray when forming the droplets, which is precisely what occurs when the adjuvant is added. In a similar study, Cunha and Peres (2010) observed no increase in the deposition in the lower stratum. The effects of adjuvants vary greatly according to each application situation.…”

“…Antuniassi et al (2004) found that the worst deposition results in the lower stratum of soybean plants were obtained using air induction tips. Cunha and Peres (2010) found no difference in droplet deposition in the upper and middle canopy strata, whether they used a deflector tip, a twin flat tip or a twin flat tip with air induction, which produce medium-thick, fine-medium, and very thick droplets, respectively, showing that an air induction tip can often have the same deposition performance obtained by a tip that produces finemedium droplets. All these authors used 200 and 250 L ha -1 of application rate, while the current trend is to reduce this rate to levels such as the 120 L ha -1 applied in the present study.…”

“…This procedure also reduces the sprayers' operational field capacity. Currently, the trend is to a reduction of the application rate, thereby increasing the sprayers' autonomy and operational field capacity and reducing the application cost (Cunha et al, 2008;Peres, 2010;Roman et al, 2009). Therefore, more studies are needed to understand the acceptable spray deposits inside the crop canopy with the use of adjuvants.…”

Meta-analysis of scientific studies related to pesticide application techniques - air assistance and adjuvant addition

“…For example, BUTLER ELLIS et al (2004) reported higher retention of spray solution on wheat leaves with a reduced surface tension and attributed this phenomenon to a decrease in the size of sprayed droplets, which is allied with a reduced impact when droplets hit the leaves. CUNHA et al (2010) verified that adjuvants do not change the deposition of droplets on soybean plants but reduce the incidence of Asian soybean rust. This effect depends on the type of spraying nozzle used.…”