Initialism as a mechanism of weed interference: can a crop plant be blinded?

Abstract

-Initialism is a new word proposed to indicate the "shade-avoidance syndrome". Plants detect the presence of neighbor plants very early in the growing season through changes in light quality. They modify the allocation of photosynthesis products privileging shoot growth over the roots. One of the hypotheses of the authors is that, when weed management is timely scheduled, a "blind" crop could be more productive because it would avoid an imbalance on the shoot:root ratio (S:R). Two strategies were developed to test this hypothesis: a) to use the classical Yoda's Law to screen several crops for insensitivity to S:R imbalance; b) to evaluate several growth regulators to control the plant responses to crowding. Experimental results confirm that both strategies can yield insensitive plants. The possibilities of the use of this knowledge are discussed.Keywords: initialism, shade-avoidance syndrome, genetic, growth regulator. RESUMO -Inicialismo é uma palavra nova proposta para indicar a "síndrome de escape ao sombreamento". Plantas detectam a presença de outras plantas vizinhas muito cedo no seu ciclo de crescimento por meio das mudanças na qualidade da luz. Elas modificam a alocação de produtos da fotossíntese, privilegiando o crescimento de ramos sobre as raízes. Uma das hipóteses dos autores

Alterações morfológicas de plântulas de trigo, azevém e nabo quando em competição nos estádios iniciais de crescimento

“…Assim, a capacidade das plantas de detectar a qualidade da luz começa ainda muito cedo, e essa é a primeira forma de interferência negativa entre plantas (Vidal et al, 2012). No presente estudo, plantas de trigo, azevém e nabo foram capazes de perceber a presença de "plantas vizinhas competidoras" em estádios iniciais de desenvolvimento, alterando características morfológicas, como o aumento da estatura de planta em detrimento do comprimento radicular.…”

“…As alterações morfológicas e aquelas que ocorrem em detrimento da competição pela radiação luminosa na fase inicial de desenvolvimento das culturas foram denominadas de "Síndrome do Escape do Sombreamento" (Stoller & Woolley, 1985;Ballaré et al, 1987Ballaré et al, , 1990 ou "Inicialismo" (Vidal et al, 2012). As plantas apresentam desequilíbrio energético, o qual resulta em alongamento e redução do diâmetro de caule e do acúmulo de biomassa na parte aérea e radicular (Afifi & Swanton, 2012), bem como em mudança na orientação das folhas (Rajcan & Swanton, 2004).…”

QUALITY OF PROCESSING TOMATO FRUITS IN COMPETITION WITH Solanum americanum

“…Third, the presence of the weeds may have altered the light quality and availability to the crop, which would further impact the fruit quality (Gautier et al, 2008). Indeed, the weed present during the early stages of the crop development may have altered light quality, thus affecting the crop root morphology, as described on the initialism mechanism of weed-crop interaction (Vidal et al, 2012). When the weeds were removed latter in the growing season, the crop roots could not recover their original morphology, and during the time of weed-crop coexistence the sunlight damage to fruits would be restricted.…”

Initialism hypothesis: can gibberellin synthesis inhibitor increase the oat crop competitive ability?

“…The plant height is listed as one of the main crop characteristics for high competitiveness (Trezzi et al, 2013;Worthington et al, 2015). However, the knowledge of the mechanisms of crop-weed interaction indicates that physiological characteristics are the driving cause on competitive ability (Vidal et al, 2012;McKenzie-Gopsill et al, 2016). Indeed, the presence of neighboring plants decreases the ratio of red to far-red (R:FR) light, triggering a complex cascade of events, which leads to morphological changes in plants (altering shoot:root ratio).…”