Arbuscular mycorrhizal fungi (AMF) increase the uptake of soluble phosphates, while phosphorus solubilizing fungi (S) promote the solubilization of insoluble phosphate complexes, together benefiting plant nutrition. The use of these organisms in combination with minerals or rocks that provide nutrients is another alternative to maintain crop productivity. The objective of this work was to combine AMF and S with pyroclastic materials (ashes and pumicites) from the Puyehue volcano and phosphoric rocks (PR) from the Río Chico Group (Chubut) and to evaluate the performance of these mixtures as substrates for potted production of Lactuca sativa. To formulate the substrates, a mixture of Ter-rafertil® with ashes was used as a base. Penicillium thomii was the S and spores of the fungus Rhizophagus intraradices (AEGIS® Irriga) served as the source of AMF. Various combinations of microorganisms and the addition or not of RP were evaluated. The treatments were: (1) substrate; (2) substrate + AMF; (3) substrate + S; (4) substrate + AMF + S; (5) substrate: PR; (6) substrate: PR + AMF; (7) substrate: PR + S, and (8) substrate: PR + AMF + S. There were 3 replicates per treatment. The parameters evaluated were total and assimilable P content in the substrate, P in plant tissue and dry biomass. All of them were significantly higher in the plants grown in the substrate added with PR and inoculated with S and AMF. This work confirms that the S/AMF combination with volcanic ashes from Puyehue and PR from Grupo Río Chico formulated with a commercial substrate promote the growth of L. sativa. Thus, it is possible to increase the added value of geomaterials of national origin.

The objective of this work was to evaluate the combined effect of bovine manure, Pseudomonas putida and Trichoderma aureoviride on the development of lettuce (Lactuca sativa). The promotion of plant growth by microorganisms may be a viable and sustainable alternative for lettuce crop management. The experimental design was entirely randomized with five treatments: T0 (witness without fertilization, P. putida and T. aureoviride), TE (cattle manure), TEB (cattle manure + P. putida), TEF (cattle manure + T. aureoviride), TEFB (cattle manure + P. putida + T. aureoviride) and ten repetitions each. The following variables were analyzed: germination velocity index (GVI), first count (FC), germination percentage (GP), leaf area index and productivity. The TEFB treatment proved to be a viable alternative for the production of lettuce, especially for small producers, since all the vegetable production in the region comes from family farming.

Cucumber Variety ‘Drite L108’ (Cucumis sativus L. Cv. Derit L108) was selected as the test material. In the solar greenhouse, different days (1, 3, 5, 7, 9 d) of light (PAR < 200 µmol·m^-2·s^-1) and normal light conditions were designed with shading nets to observe the growth indexes of cucumber plants and the changes of antioxidant enzyme activities in leaves. The results showed that: (1) continuous low light increased the SPAD (relative chlorophyll) value of cucumber leaves and decreased the net photosynthetic rate. The longer the continuous low light days are, the smaller the net photosynthetic rate of cucumber leaves and the worse the photosynthetic recovery ability would be. (2) The plant height, stem diameter and leaf area per plant were lower than CK, and the above indexes could not return to the normal level after 9 days of normal light recovery; the yield and marketability of cucumber fruit decreased under continuous low illumination. (3) The activities of SOD (superoxide dismutase) and POD (peroxidase) in cucumber leaves increased, the activities of CAT (catalase) first increased and then decreased, and the content of MDA (malondialdehyde) continued to increase. The longer the days of continuous light keep, the more seriously the cucumber leaves were damaged by membrane lipid peroxidation. After continuous light for more than 7 days, the metabolic function of cucumber leaves was difficult to recover to the normal level.

The objective of this work was to evaluate the effect of potassium concentrations applied via fertigation on the growth, yield and chemical composition of eggplant ‘Ciça’ in a distroferric red Latosol. The treatments were composed of five concentrations of K₂O (0, 36, 72, 108 and 144 kg ha^-1 supplied via fertigation), using potassium chloride as a source, divided into six applications. The irrigation system was of the drip type and irrigation management was done via a “Class A” evaporometer tank. Harvest started at 62 days after transplanting (DAT) and lasted for five months. The variables evaluated were: plant height, number of leaves, fresh fruit mass, number of fruits per plant, yield per plant, productivity and classification of the fruits according to their length and diameter. At 85 DAT, fruit were collected for characterization as to the percentage of lipids, proteins and fibers. Although the potassium fertigation in cover provided a reduction in the production and productivity, the concentrations of 36 kg ha^-1 and 72 kg ha^-1 of K₂O applied via fertigation, increased the physical-chemical characteristics of the fruits.

The use of saline water in agriculture is a viable alternative, considering the increased demand for fresh water. The objective of this study was to evaluate the growth and phytomass production of sugar beet under irrigation with water of different saline concentrations in a field experiment on the campus of the Federal University of Alagoas in Arapiraca. The treatments were five levels of electrical conductivity (1.0, 2.0, 3.0, 4.0 and 5.0 dS m^-1). The design was in randomized blocks, with four repetitions. The maximum yield of sugar beet at 27 days after the application of saline treatments was obtained with a salinity of 3.0 dS m^-1, for the variables plant height (PA), stem diameter (CD), root length (RC), aboveground dry phytomass (FSPA) and total dry phytomass (FST). At 42 days after the application of saline treatments, the variables aboveground fresh phytomass (FFPA), root fresh phytomass (FFR), total fresh phytomass (FFT), aboveground dry phytomass (FSPA) and total dry phytomass (FST) increased with increasing water salinity. Rain may have influenced the results obtained for the evaluations, performed at 42 days after the application of the saline treatments.

This study was carried out at the Teaching and Research Farm of Landmark University, Omu-Aran. Treatments consisted of 3 levels of cocoa pod husk ash (0, 2 and 4 tonnes CPHA ha^-1), 3 levels of cocoa pod husk powder (0, 2 and 4 tonnes CPHP ha^-1), NPK and the control. The experiment was laid out in a Randomized Complete Block Design (RCBD) replicated four times. The following parameters were taken plant height, number of leaves (at 2, 3, and 4 weeks after sowing), total plant weight, root weight, leaf weight, roots girth and roots length. Data collected were subjected to Analysis of Variance (ANOVA) Using S.A.S, 2000. Treatment means were compared using Duncan Multiple Range Test (DMRT) at 0.05 level of probability. Results showed that chemical analysis of cocoa pod ash and powder contained plant nutrients as N, P, K, Ca, Mg and some other micronutrients in varying proportions. Application of CPHA 4 + CPHP 2 gave higher values for all the vegetative parameters. The implication of this study is that high level of cocoa pod husk powder in combination with high level of cocoa pod husk ash is detrimental to radish cultivation. In the same vein, the nutrition of radish was incomplete when NPK fertilizer was applied. It can therefore be recommended that the use of combined application of cocoa pod ash and cocoa pod powder at CPHA4 + CPHP2 was sufficient for the cultivation of radish (Raphanus sativus) in the study area as it compete favorably with application of NPK fertilizer.