Castor bean cake in top-dressing application as a source of nitrogen on the production and quality of zucchini organic seeds

Natália De Brito Lima Lanna,Priscilla Nátaly De Lima Silva,Pâmela Gomes Nakada-Freitas,Sayuri Beatriz Hara Noda,Ana Emília Barbosa Tavares,Antonio Ismael Inácio Cardoso,Estefânia Martins Bardiviesso

doi:10.14393/bj-v36n0a2020-53563

Natália De Brito Lima Lanna, Priscilla Nátaly De Lima Silva + Show 5 more

Open Access

https://doi.org/10.14393/bj-v36n0a2020-53563

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Abstract

Studies in vegetables show that fertilization influences seed production positively, however, when the quality of the seeds is analyzed, the results are mostly inconsistent. The objective of this study was to evaluate the effect of castor bean cake (CBC) dose splitting in top-dressing application on the production and quality of zucchini organic seeds, as well as its effect on the macronutrient content of fruits and seeds. The experimental design was a randomized block design and four replications. There were 13 treatments with four doses of CBC in top-dressing (1.7, 3.4, 5.1 and 6.8 t ha-1) per three applications (33.3-33.3-33.3%, 50-50% and 33-50-17%) and the control treatment without any kind of top-dressing fertilization. The study evaluated the number of ripe fruits per plant, the production (number and mass) of seeds per fruit and per plant, the mass of one hundred seeds, seed germination, first germination count, and macronutrient content in the diagnosis leaf, in mature fruits (without seeds) and seeds. The number of ripe fruits per plant was not affected by the CBC doses in top-dressing, neither by the splitting of the applications. It was observed that the number of seeds per fruit, mass of seeds per fruit and mass of seeds per plant showed quadratic behavior. Regarding seed quality, only the 1.7; 3.4 and 5.1 t ha-1 doses produced seed with superior quality than the other doses. In conclusion, the CBC doses increased the number of seeds per fruit, mass of seeds per fruit and per plant up to the 4.5t ha-1 dose, approximately.

Highlights

Organic production is increasing more and more, but there is still a lack of management information on the production of organic seeds
The interaction between the splittings and the doses of castor bean cake was not significant, and neither was the split factor for the production of ripe fruits and seeds
The number of ripe fruits per plant was not influenced by the doses of castor bean cake in topdressing or by the splittings, obtaining an average of 1.7 fruits

Summary

Introduction

Organic production is increasing more and more, but there is still a lack of management information on the production of organic seeds. According to the Normative Instruction 64/2008 of the Ministry of Agriculture, Livestock and Food Supply (MAPA) of December 2008, if there is no availability of organic seeds and seedlings, the use of other materials on the market may be authorized. The few studies available indicate that fertilization influences seed production positively. According to Carvalho and Nakagawa (2012), a well-nourished plant is able to produce more well-formed seeds. There are reports that even with insufficient fertilization seed quality is not significantly affected, production can be reduced (MAGRO et al, 2010; KANO et al, 2012). It is reported that the effect of plant nutrition on seed quality can be observed only after the seeds have been stored for some time (KANO et al 2011; MAGRO; CARDOSO; FERNANDES, 2012)

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