Avaliação de fita fotodegradável para enxertia em mudas de citros

Abstract

RESUMO -O trabalho avaliou os efeitos do uso de fita fotodegradável de enxertia em mudas de laranjeira 'Valência' enxertadas em limoeiro 'Cravo' e citrumeleiro 'Swingle', em viveiro telado, em Bebedouro-SP, durante os meses de setembro a novembro de 2009. Para cada porta-enxerto, foram avaliados três tratamentos, que incluíram o uso da fita convencional de polietileno para a fixação da borbulha e a fita fotodegradável, por sua vez aplicada sob duas formas: com e sem envolvimento completo da gema. As variáveis avaliadas foram: tempo consumido na operação de amarrio da fita, porcentagem de borbulhas brotadas, comprimento e diâmetro do enxerto e porcentagem de mudas prontas para comercialização. O delineamento experimental adotado foi o de blocos ao acaso, com seis tratamentos e quatro repetições. Cada parcela foi representada por 12 plantas. Os tratamentos com a fita fotodegradável, com e sem envolvimento da gema, anteciparam a brotação do enxerto, apesar de o tempo gasto no amarrio da fita ser significativamente maior em relação ao método convencional. Quando o porta-enxerto utilizado é o citrumeleiro Swingle, menos vigoroso, recomenda-se manter a gema descoberta para evitar redução acentuada da brotação do enxerto. Termos de indexação: Citrus spp.; propagação; borbulha. EVALUATION OF PHOTODEGRADABLE TAPE ON GRAFTING IN CITRUS NURSERY TREESABSTRACT -The use of a photodegradable tape was evaluated on 'Valencia' sweet orange nursery trees budded both on Rangpur lime and Swingle citrumelo in a greenhouse in Bebedouro-SP, Brazil, from September to November 2009. On both rootstocks three wrapping procedures were evaluated: i) conventional polyethylene tape wrapped around the bud eye; ii) photodegradable tape wrapped around the bud eye, and iii) photodegradable tape wrapped around the graft junction without covering the bud eye. The following variables were measured: time spent for wrapping, percentage of bud sprouting, length and stem diameter of the scion shoot, and percentage of commercially valuable nursery trees. The trial was conducted following a randomized complete block design, with six treatments, four replications and 12 trees per plot. The use of photodegradable tape, with or without covering the bud eye, anticipated bud sprouting; despite of the longer time spent with wrapping when the photodegradable tape was used. Plants grafted onto the less vigorous Swingle citrumelo rootstock showed lower bud sprout percentages when the bud eye was covered with the photodegradable tape.

Impact of edible coatings based on cassava starch and chitosan on the post-harvest shelf life of mango (Mangifera indica) ‘Tommy Atkins’ fruits

“…Nine formulations of different edible coatings were developed by combining three levels of cassava starch (0%, 0.25% and 0.5%) and with three levels of chitosan (0%, 0.25% and 0.5%), by means of a complete factorial design (Hayashi et al, 2012), resulting in obtaining the 9 treatments as specified in Table 1.…”

Adjusting the Minigrafting Technique Applied to Citrus by Using Rootstocks Grown in vitro

“…According to Pina et al (2012), these responses will involve several structural, biochemical and physiological interactions between these tissues. Hayashi et al (2012) assessed the grafting technique in different citrus genotypes and pointed out higher bulb formation rates in 'Valencia' orange grafted onto 'Santa Cruz Rangpur' lemon (98%), when it is compared to citrus 'Swingle' (66.70%) at 49 days measured with photodegradable tape.…”

“…Rootstocks were 19.73 cm, 16.58 cm and 14.58 cm long 120 days after minigrafting in 'Pera' sweet orange, 'Sunki Mandarin' tangerine and 'Santa Cruz Rangpur' lemon, respectively (Table 6). According to Hayashi et al (2012) the least height essential for seedlings' trading is 30 cm. This height was already reached by more than 50% of 'Pera' sweet orange and 'Sunki Mandarin' tangerine.…”

Advances in citrus propagation in Brazil

“…Bras. Frutic., Jaboticabal, 2019, v. 41, n. 6: (e-422) use of photodegradable tape, which eliminates the need for manual tape removal after grafting and thus saves labor in the nursery (OLIVEIRA et al, 2004;HAYASHI et al, 2012).…”