Effects of Biodynamic Preparation 500 (P500) Cow Horn Manure on Early Growth of Barley, Pea, Quinoa, and Tomato under Saline Stress Conditions

Large areas of salt-affected soils are found in tropics, especially in Africa, South America and the Middle East. While soil salinity might lead to food insecurity in those regions and affect farmers who are most vulnerable to environmental stress, however, little is known how the abiotic stress can be managed with locally available resources without involving high cost. Decades of practical evidence have demonstrated the benefits of the farm input, called biodynamic preparation 500 (P500) cow horn manure, such as improving crop performance and providing resilience against various stress conditions. Organic agriculture is already seen as an important issue in sustainable crop production in the tropics, but also biodynamic philosophy and agricultural practices are discovering tropical countries. Biodynamic preparations in tropical crop production are already in use, while there is a lack of research concerning their performance. This study was conducted to quantitatively determine the effects of P500 on the early growth of different crops under saline condition. A randomised block design with six replicates in a green house chamber pot trial consisting of two factors, viz., SALT (stressed and control) and PREP (P500 and blank) was run with four crop species that have importance in temperate and tropical countries, viz., barley, pea, quinoa and tomato. Plants were harvested 38 days after sowing and aerial biomass dry matter (DM g) was measured. Results suggest that the application of P500 significantly enhanced the initial biomass production of all tested crops, even under saline conditions (except for tomato). In all crops the biomass yield was significantly improved, average 18.5 % and 16.7 % for non-saline and saline treatments, respectively. Findings suggest that P500 may be a measure to mitigate the stress from adverse environmental conditions for crop plants. Thus, future research with more genotypes, varieties, and crop species, in field conditions where the soils suffer from extreme abiotic stress, should be followed

Besides variety, also season and ripening stage have a major influence on fruit pulp aroma of cacao (Theobroma cacao L.)

More than 1000 different cacao varieties are described. Only few are considered as fine or flavour cocoas, meaning they have the potential to develop special flavour characteristics after appropriate fermenta-tion and drying. It is assumed that aroma compounds located in the fruit pulp migrate into the seed during fermentation. We studied the fine aroma potential of five cacao varieties selected at CATIE, Costa Rica, by analysing aroma compounds in their fresh fruit pulps using Headspace SPME-GCMS. Pulps of unripe, ripe and overripe fruits harvested in the dry and rainy season, respectively, were compared to the control genotypes EET 62 and SCA-6, both known for high amounts of fine aromas described as e.g. “fruity”, “floral” or “spicy”. All genotypes contained a basic content of the two dominating esters 2-pentanol acetate and 2-heptanol acetate, combined with a mixture of aroma-active compounds with small peak areas that form the variety-specific aroma character. Total aroma diversity and intensity increased during ripening. Aroma profiles were more diverse when fruits ripened during the dry season, whereas aroma intensity was higher in the rainy season. Thus, the fruit and environmental condi-tions prior to harvest can already play a decisive role for the aroma potential of the cacao pulp. Due to their aroma profiles, the varieties from CATIE can be classified as fine or flavour cocoas

The effect of short-term vs. long-term soil moisture stress on the physiological response of three cocoa (Theobroma cacao L.) cultivars

Understanding water stress signaling mechanisms and screening for tolerant cocoa cultivars are major challenges when facing prolonged dry and rainy seasons in cocoa-producing areas. While abscisic acid (ABA) and proline are supposed to enhance drought tolerance in cocoa, the role of polyamines remains unclear. The aim of this study was to investigate the biochemical response and phenological adaptation of cocoa (Theobroma cacao) on different soil moisture conditions, with a focus on short-term (20 days) and long-term (89 days) stress conditions, and to compare the performance of three cocoa cultivars. In a split plot design with four blocks, cocoa seedlings of an international high-yielding cultivar (TSH-565) and two locally selected cultivars (IIa-22 and III-06) from the drought-exposed Alto Beni region, Bolivia, were arranged in pots under a roof shelter (cultivar: three levels). The seedlings were exposed to strong (VERY DRY) and moderate (DRY) soil moisture deficits, water logging (WET) and regular irrigation (MOIST) that served as a control (moisture: four levels). We examined the growth performance and the levels of ABA, proline, and polyamines in the leaves. Growth was reduced already at a moderate drought, while severe drought enhanced seedling mortality. Severe drought increased the levels of ABA by 453% and of proline by 935%, inducing a short-term stress response; both compounds were degraded over the long-term period. The polyamine concentration was unrelated to soil moisture. The cocoa cultivars did not differ in their biochemical response to soil moisture stress (proline: p-value = 0.5, ABA: p-value = 0.3), but the local cultivar III-06 showed a stronger height growth increment than the international cultivar TSH-565 (237%, p-value = 0.002) under drought conditions

Below- and aboveground production in cocoa monocultures and agroforestry systems

Farmers expect yield reduction of cash crops like cocoa when growing in agroforestry systems compared to monocultures, due to competition for resources, e.g. nutrients and water. However, complementarities between species in the use of resources may improve resource use efficiency and result in higher system performance. Cocoa trees have a shallow rooting system while the rooting characteristics of the associated trees are mainly unknown. This work investigates fine root distribution and production in five cocoa production systems: two monocultures and two agroforestry systems under conventional and organic farming, and a successional agroforestry system. In the organic systems a perennial leguminous cover crop was planted and compost was added, while herbicides and chemical fertilizers were applied in the conventional ones. We measured cocoa fine root parameters in the top 10 cm of soil and annual total fine root production at 0–25 and 25–50 cm depth. We related the root data with both the aboveground performance (tree and herbaceous biomass), and the cocoa and system yields. Cocoa fine roots were homogenously distributed over the plot area. Around 80% of the total fine roots were located in the upper 25 cm of soil. The total fine root production was 4-times higher in the agroforestry systems and the organic monoculture than in the conventional monoculture. The roots of the associated tree species were located in the same soil space as the cocoa roots and, in principle, competed for the same soil resources. The cocoa yield was lower in the agroforestry systems, but the additional crops generated a higher system yield and aboveground biomass than the conventional cocoa monocultures, implying effective resource exploitation. The leguminous cover crop in the organic monoculture competed with the cocoa trees for nutrients, which may explain the lower cocoa yield in this system in contrast with the conventional monoculture

Características morfométricas de tres especies de pacay (Inga spp.) que afectan la calidad de la sombra en sistemas agroforestales de cacao (Theobroma cacao)

Trees of the genus Inga are used in agroforestry systems with cocoa and coffee because of their ecosystem services. In agroforestry systems, the canopy closure and the morphological characteristics of the shade trees are crucial for the growth of the cocoa. This study aims to show that species from the genus Inga are not similar, though in many places only one common name describes the whole genus (e.g. “pacay” in Bolivia), but that they show specific traits that affect the canopy. The objective was to evaluate the function of genus Inga trees, specifically the I. ingoides, I.marginata and I. spectabilis species, regarding the quality of shade for the development of Theobroma cacao. The study area is located in Sara Ana, in the municipality of Alto Beni, in northeastern department of La Paz, at an altitude of 430 meters above sea level, in the Subandean Amazonian forest ecoregion. To this end, we compared both the percentage of shade of Inga spp. between two cocoa Agroforestry Systems - conventional and organic - as well as the morphometric characters. The evaluation of the shade effectiveness with the functional species in cocoa Agroforestry Systems with the genus Inga, showed a similar proportion of canopy closure in conventional plots and in organic plots. The I. ingoides species has an average of 73% closed canopy, I. spectabilis a closed canopy of 59% and I. marginata 84% closed canopy. The morphometric analysis of I. ingoides showed a linear positive increase in diameter at breast height (DBH) with plant height. Similarly, the canopy increased linearly with height, and a positive relationship was also recorded between canopy and DBH. In the case of I. marginata, no statistically significant relationship was observed between the morphometric characters. I. spectabilis only showed a linear increase in DBH as the total height increased. The three Inga species showed interspecies specific differences according to their shading characteristics that affect their applicability in agroforestry systems with cocoa: producers have to consider climatic situations (sun-shine hours per day) and their ability to manage a certain species before species selection and planting

Cocoa agroforestry systems versus monocultures: A multi-dimensional meta-analysis

Scientific knowledge, societal debates, and industry commitments around sustainable cocoa are increasing. Cocoa agroforestry systems are supposed to improve the sustainability of cocoa production. However, their combined agronomic, ecological, and socio-economic performance compared to monocultures is still largely unknown. Here we present a meta-analysis of 52 articles that directly compared cocoa agroforestry systems and monocultures. Using an inductive, multi-dimensional approach, we analyzed the differences in cocoa and total system yield, economic performance, soil chemical and physical properties, incidence of pests and diseases, potential for climate change mitigation and adaptation, and biodiversity conservation. Cocoa agroforestry systems outcompeted monocultures in most indicators. Cocoa yields in agroforestry systems were 25% lower than in monocultures, but total system yields were about ten times higher, contributing to food security and diversified incomes. This finding was supported by a similar profitability of both production systems. Cocoa agroforestry contributed to climate change mitigation by storing 2.5 times more carbon and to adaptation by lowering mean temperatures and buffering temperature extremes. We found no significant differences in relation to the main soil parameters. The effect of the type of production system on disease incidence depended on the fungal species. The few available studies comparing biodiversity showed a higher biodiversity in cocoa agroforestry systems. Increased and specific knowledge on local tree selections and local socio-economic and environmental conditions, as well as building and enabling alternative markets for agroforestry products, could contribute to further adoption and sustainability of cocoa agroforestry systems