Gas exchanges and photosynthetic pigments of ‘Tommy Atkins’ mango as a function of fenpropimorph

ABSTRACT The objective of the present study was to evaluate the influence of the application of fenpropimorph and paclobutrazol on gas exchanges and photosynthetic pigments of ‘Tommy Atkins’ mango grown in the semi-arid region in different evaluation periods. Two experiments were carried out in ‘Tommy Atkins’ mango orchards in the first production cycle between September and December 2018 (first experiment) and between September and December 2019 (second experiment) in Petrolina, PE, Brazil. The experimental design adopted was randomized blocks in split plots in time, 4 × 4 + 1, with four replicates. The plots corresponded to the concentrations of fenpropimorph: 0, 0.7, 1.0, and 1.3 g per linear meter of plant canopy diameter plus the additional paclobutrazol treatment (1 g per linear meter of plant canopy diameter), and the subplots corresponded to the evaluation dates (0, 30, 60, and 90 days after the first application of treatments). The following traits were evaluated: CO2 assimilation rate, stomatal conductance, internal CO2 concentration, transpiration, water use efficiency, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids. The fenpropimorph dose of 1.3 g per linear meter of plant canopy promotes a higher rate of CO2 assimilation; however, paclobutrazol was more effective in the accumulation of chlorophyll a and total chlorophyll, and the use of fenpropimorph did not interfere in the concentration of photosynthetic pigments.

Water restriction in cowpea plants [Vigna unguiculata (L.) Walp.]: Metabolic changes and tolerance induction

ABSTRACT Global climate change tends to intensify water unavailability, especially in semi-arid regions, directly impacting agricultural production. Cowpea is one of the crops with great socio-economic importance in the Brazilian semi-arid region, cultivated mainly under rainfed farming and considered moderately tolerant to water restriction. This species has physiological and biochemical mechanisms of adaptation to these stress factors, but there is still no clear vision of how these responses can not only allow survival, but also ensure yield advances in the field. Besides acclimation mechanisms, the exogenous application of abiotic (salicylic acid, silicon, proline, methionine, and potassium nitrate) and biotic (rhizobacteria) elicitors is promising in mitigating the effects of water restriction. The present literature review discusses the acclimation mechanisms of cowpea and some cultivation techniques, especially the application of elicitors, which can contribute to maintaining crop yield under different water scenarios. The application of elicitors is an alternative way to increase the sustainability of production in rainfed farming in semi-arid regions. However, the use of eliciting substances in cowpea still needs to be carefully explored, given the difficulties caused by genotypic and edaphoclimatic variability under field conditions.

Assessment of Cholinesterase inhibition activity of birds inhabiting pesticide exposed croplands and protected area in hot semi-arid region of Pakistan

Acetylcholinesterase (AChE) activity levels can be used as an indicator for AChE inhibition due to pesticide poisoning in bird species. We assessed the comparative brain cholinesterase (AChE) activity level of five bird species inhabiting pesticide exposed croplands and Protected Area i.e. Deva Vatala National Park (DVNP), Bhimber by using a spectrophotometric method. AChE activity levels ranged from 56.3 to 85.9 µmol/min/g of brain tissue of birds representing DVNP. However, AChE activity levels ranged from 27.6 to 79.9 µmol/min/g of brain tissue of birds representing croplands. AChE activity levels observed in Jungle babbler, Common babbler, and Red-vented bulbul showed significant differences (P < 0.05) at two sites. However, White wagtail and Black drongo demonstrated non-significant differences (P > 0.05). Maximum inhibition was recorded in Jungle babbler (53%) followed by Common babbler (35%), Red-vented bulbul (18%), White wagtail (15%), and Black drongo (7%). The brain cholinesterase inhibition levels under-protected ecosystems (DVNP, Bhimber) and agricultural landscape suggest insecticidal contamination and its impact on avifauna diversity. The study also emphasizes on the importance of pesticide-free zones to protect the biodiversity of birds.

Yield of prickly pear cactus irrigated with saline water in soils of the semi-arid region

Knowing the tolerance of plants grown in the Brazilian semi-arid region to salt stress is of paramount importance for the sustainability of regional agriculture. This study was developed to examine the growth and yield of prickly pear cactus ‘Orelha de Elefante Mexicana’ (Opuntia stricta Haw) irrigated with increasing water salinity levels (0.75, 3.0, 5.25 and 7.50 dS m-1 to 25 ºC) and grown on soils representative of the Brazilian semi-arid region (chromic Luvisol, Solonetz and Fluvisol). Total fresh weight decreased linearly, with a 21.42% reduction when we compare the average fresh weight per plant in the lowest and highest saline level treatments. The chromic Luvisol and Solonetz soils showed the best fresh weight and dry matter yields under the present experimental conditions.

A Multi-Methodological Analysis of Jabuticaba’s Supply Chain in an Agricultural Cooperative Production

Background: In the late 1990s, the idea of fighting drought gave way to the concept of how to live with drought in the Brazilian semi-arid region. From this perspective, the Brazilian Federal Government’s investment in social technology and education encouraged local agricultural production and subsistence agriculture began to have a surplus for commercialization and income generation. However, there are still difficulties in the development of the productive chain, as perceived in Alagoas, Brazil, with the jabuticaba fruit and its derivatives. In this locus, problems related to the creation of value and distributions of the product were identified. Methods: This study proposed a participant observation in a rural producers’ association and a multimethodological approach based on VFT (Value-Focused Thinking) and SWOT analysis aiming to structure the problem, identify communities’ objectives and develop alternatives to solve these problems so that they can get more out of their production. Results: showed that the product has marketing potential due to its differential, but the producers are limited in the process of distributing the goods. Conclusions: So, this study was able to analyze the problems of this productive system in a structured way, generating suggestions for actions to achieve the strategic objectives of the cooperative.

VOLUMETRIC PRODUCTION OF EUCALYPTUS SPP. CLONES UNDER DIFFERENT SPACING IN A SEVERE DROUGHT PERIOD IN THE SEMI-ARID REGION OF PERNAMBUCO, BRAZIL

The adaptation of Eucalyptus clones in the Chapada of Araripe, PE, Brazil was observed after implementing experiments with fast-growing forests. This region has a high demand for alternative energy sources due to the Gypsum Pole, basically maintaining its energy matrix from the exploitation of Caatinga vegetation. Therefore, as a way to increase the gains in volumetric productivity in planting Eucalyptus spp. clones, it is important to understand which spacing levels provide the best competition between individuals. Thus, the objective of this study was to evaluate if the volumetric productivity of Eucalyptus spp. clones is affected by different spacing levels in stands implanted under severe weather conditions in Chapada of Araripe, PE, Brazil. The experiment was carried out at the Experimental Station of the Pernambuco Agronomic Institute (IPA) in the municipality of Araripina, PE, Brazil. Three Eucalyptus clones (C11, C39 and C41) with five spacing levels (2 m x 1 m, 2 m x 2 m, 3 m x 2 m, 3 m x 3 m and 4 m x 2 m) were arranged in a completely randomized design with factorial arrangement (3 x 5). The survival rate of the experiment was higher than 94%, even under conditions of water stress. The highest volume productivity was obtained with the C39 clone in the 2 m x 1 m spatial arrangement. The spatial arrangement strongly influences productivity. Even with the severe drought condition regulating productivity, the C39 clone showed MAI values of 15.92 m3 ha-1 year-1.

Water requirement and growth of sorghum over semi-arid region in Deccan Plateau

Based on the result of an experiment conducted from 1978-86 during post-rainy crop season at Solapur, crop coefficients for sorghum during different stages of growth were determined. A model has been developed for relating consumptive use of water at different phenological stages in relation to climatic parameters and crop water needs. The extent to which water requirements of the crop are met and water use efficiency have been discussed. The water requirement appears to be maximum at tasseling/flowering phases of sorghum growth. It works out at 4 mm per day under Solapur environment. The seasonal rainfall in post-rainy season does not appear to furnish a reliable estimate of the yield.