Coffee Orchard Response to Enhanced Efficiency Phosphate Fertilizer

Phosphorus (P) plays a crucial role in plant growth by aiding in the development of strong roots, promoting flower and fruit formation, and aiding in photosynthesis. Studies to improve P fertilizers efficiency in coffee orchards are necessary due to the need for better efficiency and the lack of information on enhanced efficiency P fertilizers. This study aimed to investigate the effect of MAP coated with anionic polymers (Policote) on coffee orchard development. A coffee trial was carried out in a randomized block design with three replications. The treatments, applied at coffee planting, were arranged in an incomplete factorial (2 × 4) + 1, using two P sources (MAP and Policote coated MAP), four P rates (40, 80, 120, and 160 g P2O5 plant-1) and control (without application of P fertilizer). Plant height was evaluated in the 2016/2017, 2017/2018, and 2018/2019 seasons, while coffee bean maturation, yield, and agronomic P efficiency use were evaluated in the last two seasons. P fertilization did not affect coffee bean maturation and increased coffee yield in 31-month-old plants when differences among P sources and rates were observed. Using Policote-coated P fertilizer resulted in higher yields at the same P rate, as well as similar yields at a lower P rate, compared to conventional fertilizer. Policote-coated P fertilizer can be used as an enhanced efficiency fertilizer and is an efficient way to deliver required P to plants. The target for reducing farm investment, increasing agricultural profits, preserving phosphatic rock reserves, and avoiding the overuse of phosphate fertilizer could be realized through the rational use of enhanced efficiency fertilizers.

Enhanced Efficiency Phosphorus Fertilizer Impact on Physiological Characteristics of Coffee Seedlings

The effects of phosphorus (P) nutrition on various aspects of photosynthetic metabolism have been examined for coffee plants (Coffea arabica) grown under greenhouse conditions. The experimental design was completely randomized, and the treatments were carried out in a 2 × 5 factorial scheme: two P sources [Triple Superphosphate - TSP (46% P2O5) and Policote coated TSP - TSP + Policote (43.7% P2O5)] and five P rates (0;5;10;15 and 20 g P2O5 plot-1), with three replications. The net photosynthetic rate (A), the leaf temperature (LT), the atmospheric CO2 concentration (Ca), the stomatal conductance (gs), the transpiration rate (E), the substomatal CO2 concentration (Ci) and carboxylation efficiency (Ce) were measured in the youngest fully expanded leaf, with the use of an infrared gas analyzer. All photosynthesis measurements were affected by P fertilization. P fertilization increased net photosynthetic rate, leaf temperature, substomatal CO2 concentration, stomatal conductance, transpiration rate, and carboxylation efficiency. Policote coated P fertilizer resulted in a higher net photosynthetic rate, leaf temperature, stomatal conductance, and transpiration rate than conventional P fertilizer. The data indicated that Policote coated P fertilizer, a kind of enhanced efficiency P fertilizer (EEPF), alters the plant’s photosynthetic carbon metabolism, explaining higher crop development and yield resulted from this EEPF.

Inductors of Resistance and Their Role in Photosynthesis and Antioxidant System Activity of Coffee Seedlings

We investigated the effects of formulations based on phosphite products on gas exchange and activity of antioxidant enzymes in coffee plants. Seedlings of the Mundo Novo cultivar were submitted to various treatments composed of different formulations of with potassium phosphite (ADB 120), manganese phosphite (Reforce Mn), and fungicide (PrioriXtra&reg). For coffee seedlings, the combination of potassium phosphite and citrus by-products, isolated or in a combination with other products elicited the antioxidant system. Besides the high activity of antioxidant enzymes, the photosynthetic rates were higher than other treatments. The better performance of coffee seedlings treated with those formulations occurred even in absence of pathogens.

Cultivation of “Roxo de Valinhos” Fig Tree in Different Plant Densities for Production of Green Figs for Industry in the Region of Campo Das Vertentes-MG

The objective of this work was to study the effect of different planting densities on the development and production of “Roxo de Valinhos” green figs for industry, in the Campo das Vertentes-MG region. The experiment was installed at the Risoleta Neves Experimental Field—CERN/EPAMIG. The plants used were three years old and were arranged in three randomized blocks, subject to three different planting densities, with spacings ranging from 1 m (4000 plants·ha-1), 1.5 m (2666 plants·ha-1), and 2 m (2000 plants·ha-1) between plants in the planting line and 2.5 m between row for all planting densities. The average length of the branches (m), average number of fruits per branch, average number of fruits per plant, average weight of fruits, average yield per plant and the average yield per hectare (kg) were evaluated. It was verified that, there were no significant differences in the length of branch and in the average weight of fruit, in the three densities of fig tree planting. (4000 plants·ha-1), the average number of fruits per branch (7.5), per plant (55.87) and yield per plant (878.93 kg) were lower, however. The average yield per hectare (3515.73 kg) was higher than in other growing densities. It is concluded that, the higher density of plants (4000 plants·ha-1), provides the highest productivity per area, without damages to the quality of the fruits.