Title
Growth, physiological, nutrient-uptake-efficiency and shade-tolerance responses of cacao genotypes under different shades
Date Issued
01 August 2021
Access level
open access
Resource Type
journal article
Author(s)
Farfán A.
Zúñiga-Cernades L.B.
Baligar V.C.
Publisher(s)
MDPI AG
Abstract
Cacao is an understory plant cultivated in full-sun monocultures, multistrata agroforestry systems, where cacao trees are planted together with fruit, timber, firewood, and leguminous trees, or within thinned native forests. In agroforestry systems of cultivation, cacao is subjected to excess shade due to high density, excess growth, and the unmanaged pruning of shade trees. Cacao is tolerant to shade, and the maximum photosynthetic rate occurs at an irradiance of around 400 μmol m−2 s−1. However, excess shade further reduces the irradiance, which is detrimental to photosynthesis and growth functions. Intra-specific variation is known to exist in cacao for the required saturation irradiance. A greenhouse study was implemented with 58 cacao genotypes selected from four geographically diverse groups: (i) wild cacao from river basins of the Peruvian Amazon (PWC); (ii) Peruvian farmers’ collection (PFC); (iii) Brazilian cacao collection (BCC); and (iv) national and international cacao collections (NIC). All of the cacao genotypes were subjected to 50% and 80% shade where photosynthetic photon flux density (PPFD) was 1000 and 400 μmol m−2 ּs−1, respectively. Intra-specific variations were observed for growth, physiological and nutritional traits, and tolerance to shade. Cacao genotypes tolerant to shade were: UNG-77 and UGU-130 from PWC; ICT-2173, ICT-2142, ICT-2172, ICT-1506, ICT-1087, and ICT-2171 from PFC; PH-21, CA-14, PH-990, and PH-144 from BCC; and ICS-1, ICS-39, UF-613, and POUND-12 from NIC. Genotypes that tolerate excess shade may be useful plant types for maintaining productivity and sustainability in agroforestry systems of cacao management.
Volume
11
Issue
8
Language
English
OCDE Knowledge area
Agricultura
Subjects
Scopus EID
2-s2.0-85112661772
Source
Agronomy
ISSN of the container
20734395
Sponsor(s)
Acknowledgments: The project 428-PNICP-PIAP-2014/Fincyt and the project NACA 58-1275-7-112F and 58-1275-2-090F of USDA-ARS-ICT partially supported the lab and greenhouse activities of this research project. We thank Dr. Andrew Daymond, School of Agriculture, Policy and Development, University of Reading, Whiteknights, Reading, UK for providing the CFC/ICCO/Biodiversity Clones used in this research; also, we thank Dr. Raul Valle of CEPLAC/CEPEC (Comissao Executiva do Plano da Lavoura Cacaueira/Centro de Pesquisas de Cacau), Ilhues/Itabuna, Bahia, Brazil for providing the Brazilian clones used for this research. We thank Lucinda Vela Vargas and Juan Aré-valo-Gardini, for management of the field research of ICT. Technical and logistical facilities for the field research and laboratory analytical facilities, provided by Instituto de Cultivos Tropicales (Tropical Crops Institute)—ICT/CITE Cacao y Otros Cultivos Tropicales (Productive Innovation and Technology Transfer Centre (CITE) of Cacao and Other Tropical Crops) and the Universidad Nacional Autonoma de Alto Amazonas (UNAAA), Yurimaguas, Peru are greatly appreciated. We thank Marshall Elson for an excellent review of this paper.
Funding: This research was supported by the project 428-PNICP-PIAP-2014/Fincyt and the project NACA 58-1275-7-112F and 58-1275-2-090F of USDA-ARS-ICT partially supported the lab and green-house activities of this research project.
Sources of information:
Directorio de Producción Científica
Scopus