<b>Growth effects of water excess on coffee seedlings (<i>Coffea arabica</i> L.)

Abstract

The objective of the present study was to evaluate the interference of water excess in soil on the growth of young coffee plants of the Mundo Novo and Catuaí cultivars.Plants were subjected to the following three different substrate water availability conditions: control (wellwatered), continuous substrate waterlogged, and intermittent substrate waterlogged. Several growthrelated traits were evaluated over the course of 19 weeks. Based on the number and quality of the affected variables from all forms of analyses, the Catuaí cultivar showed greater sensitivity to waterlogging. Both cultivars exhibited growth inhibition in response to substrate waterlogging stress, which was exacerbated by premature leaf dropping.Efeitos do excesso de água no crescimento de mudas de cafeeiro (Coffea arabica L.) RESUMO. O presente trabalho visou avaliar a interferência do excesso hídrico do solo sobre o crescimento de plantas jovens de café, cultivares Mundo Novo e Catuaí. As mudas foram submetidas a três condições de disponibilidade de água no substrato: controle (mudas irrigadas), encharcamento contínuo do substrato e encharcamento intermitente do substrato. Diversas características de crescimento foram analisadas ao longo de 19 semanas. Baseado no número e qualidade das variáveis afetadas em todas as análises, a cultivar Catuaí mostrou maior sensibilidade ao encharcamento.. Ambas as cultivares de café apresentaram inibição do crescimento em resposta ao estresse por encharcamento do substrato, que foi agravado pela queda prematura das folhas.Palavras-chave: encharcamento do solo, hipoxia, cultivar mundo novo, cultivar catuaí.

Gas Exchange and Carbohydrate Partitioning in Coffee Seedlings Under Waterlogging

“…Coffee plants submitted to waterlogging accumulate reducing sugars more quickly in leaves than roots. This finding helps explain the results of Silveira et al (2014), in which there was higher shoot growth than root growth in coffee plants submitted to the same condition of hypoxic stress. In general, plants submitted to waterlogging show a range of responses to the oxygen deficiency in the soil, such as yellowing of leaves and reductions in the photosynthetic rate and stomatal conductance (Bertoldi et al, 2012;Ferner;Kreuzwieser, 2012).…”

“…This suggests that Catuaí seedlings suffered negative effects of hypoxic stress earlier than did the Mundo Novo seedlings. The decrease in photosynthesis was likely related to the lower growth rates of the seedlings under intermittent and continuous waterlogging (Silveira et al, 2014).…”

“…Meanwhile, carbohydrates accumulated in leaves due to lower rates of sugar translocation through the phloem, and there was a consequently lower carbohydrate supply to the roots. Thus, the death of absorbent roots and the inhibition of plant development (Silveira et al, 2014) of coffee seedlings under soil waterlogging may originate from the reduced translocation of sugars from the leaves to the roots (Bertolde et al, 2012;Papadopoulou;Rennenberg, 2004).…”

“…Despite the benefits for coffee cultivation, poorly planned irrigation can lead to excessive water in the soil, compromising seedling development and even reducing the yield of coffee trees. Water excess affects the growth of coffee seedlings, leading to premature leaf fall and reduced numbers of absorbent roots (Silveira et al, 2014). Furthermore, excessive irrigation during the reproductive stage leads to the desynchronization of flowering, affecting the uniformity of fruit maturation and thus resulting in poorer quality coffee (DaMatta et al, 2007).…”

Hybrid coffee cultivars may enhance agroecosystem resilience to climate change

“…Some research has explored underlying mechanisms of how coffee generally responds to water stress without focussing on differences among cultivars ( Meinzer et al . 1990 ; Ramos and Carvalho 1997 ; DaMatta 2004 ; Silveira et al . 2014 ).…”