Percorrer por autor "Trindade, D."
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- Effects of planting density and soil management on pitaya (S. undatus) yield in an outdoor plantationPublication . Trindade, Ana Rita; Matias, Pedro; Zarcos Duarte, Beatriz; Trindade, D.; Duarte, AmilcarIn regions with advanced pitaya (Selenicereus spp.) cultivation, the crop is popular due to its rapid production cycle and favourable fruit prices. The Mediterranean offers favourable cultivation conditions, but more research is needed on agronomic practices like spacing and soil management, which affect profitability and sustainability. A trial was conducted in an outdoor plantation to assess the effect of two planting spacings (PS-0.5, plant spacing of 0.5 m; PS-1, plant spacing of 1 m) and two weed management methods (SC-BS, soil cover with black screen; SC-M, soil cover with mulch) on pitaya production parameters (fruits plant‑1; kg plant‑1; average fruit weight; kg m‑2), in the first and second production years. The use of mulching (SC-M) resulted in a higher number of fruits plant‑1 compared to the black screen (SC-BS), but this effect was only observed in the 1st production year. However, PS-1 and SC-BS obtained higher yield (kg plant‑1) compared to the PS-0.5 and SC-M plants. Neither plant spacing nor soil cover strongly influenced fruit size variation over time. Ultimately, the spacing that proved to be the most productive was the tightest (PS-0.5) with an average value of 0.82±0.04 kg m‑2, compared to PS-1 (0.60±0.04 kg m‑2). Results show that pitaya productivity is increasing annually, even under tighter spacings. Adding organic matter to the soil significantly boosts production, and consistent mulching improves soil fertility and controls weeds efficiently.
- Efficiency of triple emitter source (TES) for irrigation experiments of horticultural cropsPublication . Beltrão, José; Jesus, S. B.; Silva, V.; Sousa, P. B.; Carvalho, Isabel Saraiva de; Trindade, D.; Rodrigues, M. H.; Machado, A.Triple emitter source TES experimental irrigation was designed. Three trickle laterals were connected together in order to form a triple joint lateral. Two of them and their emitters are connected to two tanks of stock solutions. The third lateral contains only fresh water. The emitters of the two solution lines have different and varying discharges to obtain several mixings of the two stock solutions. The third line is necessary to obtain constant water application rates for each trickling point along the lateral. This method was tested for several experiments involving the study of the combined effects of salinity and fertilizers on the yield function of horticultural crops, namely lettuce and cabbage. As concluding remarks, it was shown the high uniformity of the factor to be evaluated, through the use of Christiansen coefficient of uniformity distribution CUC, which value was always larger than 90%. Main advantage of this experimental design is its smaller experimental plots (reducing pollution and research costs).
- Flowering and fruiting of pitaya ( S. undatus ): insights into reproductive processes and farming potential for the Algarve, PortugalPublication . Trindade, Ana Rita; Matias, Pedro; Zarcos Duarte, Beatriz; Trindade, D.; Duarte, AmilcarThe pitaya (Selenicereus spp.), valued for its unique appearance and health benefits, ranks among the most commercially valuable fruits. However, its complex reproductive biology affects crop productivity, especially outside its native habitat. Understanding this is crucial for optimizing fruit set, fruit growth and yield. The reproductive biology of pitaya involves several key processes. Floral induction, triggered by environmental factors like temperature and photoperiod, signals the shift from vegetative growth to flowering. To better understand the reproductive processes of pitaya, this study explores floral induction to provide insights for optimizing agricultural practices. Flower induction trials were carried out in Algarve, Portugal, in which shading and artificial lighting were tested for their effect on production (extension of the productive period and yield). Shading reduced production, as plants in direct sunlight performed better. While lighting increased floral buds and fruits, it did not extend the productive period, due to temperature constraints. However, plants grown in full sun, without supplementary lighting, yielded significantly more. This study suggests a promising outlook for pitaya cultivation in Algarve’s climatic conditions without artificial lighting or shading.
- Lettuce yield response to salinity of sprinkle irrigation waterPublication . Beltrão, José; Trindade, D.; Correia, P. J.The objective of this work is to study the effect of saline water on the yield of lettuce (Lactuca sativa L., var. longifolia Lam., cv. Nevada), under an experimental design known as double sprinkler line source (DLS), in two different soil types. A saline gradient was created, shown by an electrical conductivity from 1 up to 8 dS/m, and a precise distribution of the salt with a minimal experimental area was obtained. Experiments were carried out in the Campus of Gambelas, University of Algarve, Fare, South Portugal. Lettuce yields were expressed in ton/ha and in fresh weight per plant. It is concluded the main several aspects: 1 - A steep yield reduction from 1 up to 2 dS/m; 2 - A slow yield reduction from 2 up to 5 dS/m; 3 - From 5 up to 8 dS/m yield is very low and near constant. Regression curves had r(2) values not lower than 0.80.
- Sustainable management of pitaya (Selenicereus spp.) pruning residues: exploring composting as a sustainable solutionPublication . Trindade, Ana Rita; Matias, Pedro; Silva, Soraia; Zarcos Duarte, Beatriz; Trindade, D.; Duarte, Amilcar; Reis, Mário; Guerreiro David Coelho, Luísa IsabelPitaya (Selenicereus spp.) thrives in less fertile soils and has lower water requirements than other fruit crops. Therefore, is gaining popularity among farmers in Portugal (Algarve). Although there are some outdoor plantations, most are cultivated in greenhouses, for a higher and more constant growth. Pruning is performed throughout the year due to vigorous shoot production, resulting in substantial waste that requires proper disposal. Since most of these cladodes aren't suitable for vegetative propagation, or present sanitary problems, composting can be a sustainable solution for managing this waste. To evaluate the compost produced from pitaya pruning waste, a trial was conducted using three mixtures: P-1 (grass clippings, cladodes, grape pomace, and orange waste in a 4:1:1:1 ratio v/v); P-2 (grass clippings and cladodes in a 4:1 ratio v/v); and P-3 (cladodes and orange waste in a 1:1 ratio v/v). Composting took place in cylindrical piles for over four months, with continuous temperature monitoring and periodic determination of pH, electrical conductivity, moisture, C/N ratio and organic matter. Chemical, physical and biological analysis were performed at the end of the processes. P-2 and P-1 produced composts with high organic matter content (≥80%), with near-neutral pH (7.4 and 7.7 respectively) and low electrical conductivity (1.5 and 1.7 dS m-1 respectively), making them suitable for soil application. In contrast, P-3 had a higher pH and conductivity (9.3 and 3.1 dS m-1), potentially limiting its use. All composts showed good physical properties. The results indicate that composting pitaya cladodes is a viable farming practice, suitable for various agricultural contexts. Overall, composting pitaya pruning waste promotes circular agriculture, contributing to the recovery of soil fertility and increasing its organic matter content.