The phenology of fruit trees allows us to understand their adaptive responses to the environment. The almond tree is widely cultivated, spreading through the incorporation of new plant materials, as is the case with late flowering cultivars in the arid regions of the province of San Juan (Argentina). The objective was to analyze the phenological and agronomic responses of Marinada, Tarraco and Vairo cultivars under arid environmental conditions in San Juan. Phenological stages were recorded using the BBCH scale and agronomic characteristics were evaluated by measuring trunk cross-sectional area (TCSA), linear floral density (FD) and fruit yield. The study was carried out in the experimental field of INTA EEA San Juan. The cultivars differed significantly in phenological stages during the period 2016 to 2021. Flowering (from start to finish) occurs between August and September, first in the cv. Vairo, then in the cv. Marinada and finally in the cv. Tarraco. FD differed significantly between cultivars since 2017, with higher mean values in Marinada and Vairo cultivars compared to Tarraco. TCSA differed significantly between cultivars only in the first crop cycles. The cv. Tarraco has problems in fruit set and/or fruit growth. Fruit ripening of the cultivars Vairo and Marinada ends in February. Cultivars Vairo and Marinada have higher fruit yields than cv. Tarraco. Leaf fall and winter dormancy in cultivars Vairo, Marinada and Tarraco were recorded from May onwards. Marinada, Tarraco and Vairo almond trees cultivars (during 5th and 6th year of field) needed between 685 HF and 857 HF (direct method) until the break of winter dormancy (from May to July).

Nutritional requirements of the‘Margarita’orange cultivar were determined under biophysical conditions of the Momposina Depression region of Colombia. The physical and chemical properties of the soils in the region were characterized. Then 18 experimental plots were chosen, where two tree populations were selected: The first, trees with yield greater than 250 kg of fruit, the second, with yield of less than 250 kg of fruit. The plots were monitored during three years of production (from October 2018 to December 2020). The production cycle was divided into three stages: the first, 35 days after flowering (DAF); the second, 70 DAF and the third, 100 DAF; moment which the fruits are in optimal state for their consumption. At each stage, the concentration of nutrients in leaf tissue and nutrient extraction by the fruit were quantified. Significant differences were found between nutrient extractions among the three stages evaluated (P <0.05). In the first stage, higher N extraction was observed, with 4.78 kg Mg-1 of fruit, followed by K and Ca. In the second and third stages, there was greater extraction of K, with 3.35 and 3.10 kg Mg-1 of fruit, respectively; followed by N and Ca. The highest extraction of microelements in the three stages was B and Fe. Significant correlations were identified between productivity and P, K, Zn, Ca, Fe and B concentrations in leaf tissue, from which general standards were generated to interpret foliar analyses.

Measurement of plant physiological response to stress or practices for its alleviation is useful for non-destructive evaluation and early diagnosis. The aim of this work was to study physiological effect of the use of phytohormones on tomato crop in soil infested by Nacobbus aberrans. The essay was carried out under a greenhouse located in EE Julio Hirschhorn (La Plata, Buenos Aires). Tomato Elpida was treated by drench, 24 hours pre-transplanting with 1 ml of: salicilic acid 0.50 x 10-4 M and 1.00 x 10-4 M, ethylen 0.35 x 10-3 M and 0.70 x 10-3 M, jasmonic acid 1.00 x 10-4 M and 1.00 x 10-5 M, using plants without treatment as control. It was recorded gas exchange: CO2 net assimilation rate, stomatal conductance, transpiration and instant water use efficiency, leaf temperature and greenness index. Statistical design was a randomized complete block with 4 replications. Variance analysis and Tukey test were applied. Gas exchange was not modified by treatments. Leaf temperature was significant lesser with salicylic acid 1.00 x 10-4 M, which increased the greenness index; variable that was lower in control plants. Increasing resistance in tomato against N. aberrans by salicylic acid and the measurement of physiological variables to check the response of the plant are promising possibilities.

It was observed in the walnut nursery of Valle Viejo department - Catamarca, symptoms coinciding with those caused by Agrobacterium tumefaciens circumscribed to the area of ​​the graft. The transmission of the pathogen causing these gills can be by means of tools during the grafting work. The nurserymen disinfect the tools with sodium hypochlorite between 2 and 5%, with the difficulty of deteriorating the blades, leaving them blunt. The objective of the present work was to corroborate the presence of the pathogenic organism that causes the gills observed, and to test, in the laboratory, the effectiveness of different tool disinfectant products. The bacterium was isolated by planting small pieces of gills in two different culture media: Nutritive Agar (AN) and Agar extract of yeast dextrose calcium carbonate (YDC). The ability of four antiseptics to disinfect the graft blade was also evaluated: Sodium Hypochlorite, Glutaraldehyde, 70 ° Alcohol and Quaternary Ammonium, at different concentrations, for 10 and 30 s. Colonies corresponding to A. tumefaciens were isolated and the pathogenicity tests on tomato seedlings reproduced the symptoms. The re-isolations confirm A. tumefaciens as causal agent of the gills in the walnut seedlings examined. The glutaraldehyde at 2% has an efficiency of 100% when submerging 10 s the tool. The glutaraldehyde does not oxidize the tools and does not remove the edge, an advantage over the hypochlorite rejected by the operators because it deteriorates the tools and they must be replaced more frequently.

The use of plants grafted on resistant rootstocks can help to reduce losses caused by biotic and abiotic factors. This experience evaluated the performance of Solanum sisymbriifolium Lam. (popularly named “tutiá”) as a rootstock in combination with two commercial tomato hybrids. Genetic materials evaluated were Elpida and Superman, grafted on “tutiá” (ELPg, SUPg) and the same materials without grafting (ELP, SUP). Plants were transplanted (august/2012) in a greenhouse into biosolarizated plots (treated November/2011) and into control plots without soil disinfection. A split splot experimental design with four replicates in blocks was used. ELP y SUP showed higher yields (kg·plant-1) (30.6 % higher general mean), than ELPg y SUPg. In control plots, grafted plants had better performance with means of ELPg = 4.53 ± 1.27, SUPg = 4.19 ± 1.49, SUP = 2.49 ± 0.28 and ELP = 1.89 ± 0.68. Grafted plants also showed less blossom end rot percentage (P < 0.01) and dead plants (DP) at the end of the crop cycle (P < 0.01) than no grafted plants, means for DP were SUPg = 18.80 ± 12.40, ELPg = 23.44 ± 7.55, SUP = 43.19 ± 9.64 and ELP = 46.00 ± 9.12. Roots of grafted plants had higher total dry matter weight (P < 0.05) and lower rots percentages (P < 0.01) caused by Fusarium spp., although gall number caused by Nacobbus aberrans did not differ. The use of Solanum sisymbriifolium as rootstock could be considered a tool for integrated tomato pest management.

Two experiments were done in apples cv. Royal Gala to evaluate different hormones for fruit thinning. In one of them, the cultivar was grafted over rootstock M9 and in the other one on M4. Treatments applied in both experiments were: 1: Benzyladenine (BA) 100 ppm when mean fruit diameter (FD) was between 8 to 12 mm; 2: Naftalen Acetic Acid (NAA) 10 ppm at 5 mm FD; 3: NAA 10 ppm at 5 mm FD + BA 50 ppm when FD was between 8 to 12 mm; 4: NAA10 ppm at 5 mm FD + BA 75 ppm when FD was between 8 to 12 mm; 5: NAA 10 ppm at 5 mm FD + BA 100 ppm when FD was between 8 to 12 mm; 6: Control: hand thinning. Response variables were: number of fruit per cm2 Branch Cross Sectional Area (BCSA) and per 100 flower clusters; and fruit set distribution (percentage of spurs where fruit set was 0, 1 or +1). At commercial harvest fruit weight, mayor and minor diameter and length of each fruit were measured and classified according to commercial sizes of the standard box (18 kg). Data were analyzed using the procedure of analysis of Variance (ANOVA); Chi-square test and principal component analysis. All the combinations of NAA + BA were effective for fruit thinning and resulted in similar fruit set and fruit sizes, thus applications of NAA at 10 ppm + BA at 50 ppm were a good alternative to thin fruits with lower costs and less environmental impact due to lower doses. Apples treated with BA had higher commercial sizes than control ones.

Entre Ríos province is well known for its citrus fruit production; however there is a lack of information in the phenological description and quantification for the area of Concordia. The aim of this study was to quantify the degree-day accumulation from flowering to harvest for different oranges and mandarins varieties. The study was conducted during four consecutive growing seasons (2005/06 to 2008/09), and the phenological stages were registered every 2 weeks in Newhall, Lane Late, Valencia Late, and Salustiana oranges; Satsuma Okitsu and Clemenules mandarins, and Ellendale and Nova hybrids, all grafted on trifoliate orange rootstock. Degree days (DD) were calculated over a base temperature of 12.5 °C. The beginning of flowering changed significantly with the year (P = 0.0002) being earlier during the 2006/07 growing cycle and later during the year 2007/08. There were also significant differences in the DD accumulation between cultivars (P = 0.0001) and year (P = 0.0029). The earliest maturing Satsuma Okitsu and Clemenules mandarins reached 2,029.37 and 2,112.35 ± 57 DD accumulation, respectively, whereas Valencia Late orange had the highest value (2,526.35 ± 57) DD accumulation.

The aim of this study was to detect superior genotypes of lentil by morphological traits. 28 recombinant inbred lines of our breeding program were used as experimental material. Sowing was done in pots maintained in greenhouse under irrigation. Fourteen morphological and phenological traits were evaluated. An analysis of variance, a principal component analysis (PCA) and cluster analysis were performed by Infogen software. High heritability values for days to flowering (73 %), days to maturity (74 %), weight of 100-seeds (82 %) and size of seeds (86 %) indicated the presence of genetic variability. The PCA showed that four principal components explain 80 % of the total variation. The cluster analysis revealed four groups. The best group (group 4 with 13 varieties) showed early flowering, high weight, size and yield. This characterization will allow selecting superior genotypes for use as potential commercial varieties.