Carrot seed production is an important seed activity in the arid central west of Argentina. Stecklings are small roots produced by growing a crop from seed sown at high density. When carrot stecklings are planted, they develop into large plants suitable for seed production. The goal of this study was to determine the effects of sowing and transplant date moreover, crop planting density of steckilngs on carrot seed production. The assay was carried out at La Consulta, Mendoza (S 33º 42’; W 69º 04’) during two years with the cultivar Beatriz INTA. It was assayed three sowing dates for stecklings production: December, January and February. Then, mini-roots were transplanted at two different dates: April and August with three distinct densities (16.7; 8.3 and 5.6 steckings·m-2), the split plot design was adopted. The variables measured before transplant was steckilngs size, and after transplant sprout roots and plant flowering percentage. Also was determined, plant number at harvest, seed yield per plant and area, and seed quality. For statistical purposes, a factorial analysis with tree factors was performed. Results demonstrated that stecklings fresh weigh decreased as sowing date is delayed, while it increased at the August transplant. August transplanting increased flowering. High density, February sown and August transplant, produced the highest yields per area in both years, at this moment the stecklings characteristics, at first and second year, were: fresh weigh 8.3 and 7.5 g; diameter 16.0 and 14.7 mm; large 6.2 and 6.6 cm; sprouting 69.5 and 88.1 % and flowering 82.8 and 94.7 %.

This work aimed to evaluate the effects of light type on in vitro multiplication and rooting of blackberry (Rubus sp.) cv. Tupy. Blackberry shoots were grown for 30 days on MS medium supplemented by 100 mg·L-1 myo-inositol, 7 g·L-1 agar, 0.8 mg·L-1 BAP an 30 g·L-1 sucrose. The pH was adjusted to 5.8. For rooting it was used MS medium supplemented by 30 g·L-1 sucrose, 100 mg·L-1 myo-inositol, 7 g·L-1 agar and 0.5 mg·L-1 ANA. The treatments used during multiplication and rooting process were five light of types (blue-EDEB 3LA1 470 nm LEDs, green-EDET 3LA1 530 nmLEDs, red-EDER 3LA3 630 nm, Growlux lamps and fluorescent lamps). Experimental design was entirely randomized, with ten replications. The shoot number per explant was higher under the red Led (6.07), Growlux lamps (6.03) and blue Led (5,59), which were higher than those of white fluorescent lamp. The shorter length of shoot was observed under the lamps Growlux. The percentage of rooting was high, the lowest percentage was observed under the green LEDs (93.08 %). The red LEDs showed a trend of higher average in the variables of rooting, but confirmation of superiority over fluorescent lamps occurred in the number of roots.

Coriander produces seeds with heteregeneous maturity range at harvest and long germination period. The priming is a technique to improve speed and uniformity of germination. Were evaluated effects on germination of seed in two trials: 1. Varying preimbibition time: 0, 5, 48 and 144 hours and 2. Type of solutions: KNO3 (0.2 %); NaCl (-1 MPa); gibberellic acid (200 mg·L-1); deionized water and witness without priming. Depending on the treatment, the seeds were imbibited on paper, at 20 °C and darkness, and then dried up to 10-11 % of moisture. Twenty days later they were sown on paper, at 20 °C with 8 hours a day of light. In both trials, four repetitions of 100 seeds were used for treatment, completely randomized design, analysis of variance and comparison of means of treatment according to Tukey (P ≤ 0.05). Every 24 hours seeds with emitted radicle were extracted. The index of germination speed (IVG), the percentage and the average time of germination (TMG) were calculated. With 48 to 144 hours of priming, the germination of the seeds began to 72 hours, with maximum rate to 120 and 96 hours respectively. The percentage of germination of 336 hours had no differences in times of hydropriming. Imbibition time of 48 hours presented the largest IVG and germinated 50 % of seeds two days in advance compared to the witness. The percentage of germination of seeds without priming had no difference with priming with KNO3 and water treatments. Gibberellic acid increases the IVG and the percentage of germination of coriander seeds. According to these results, we encourage the development of technologies of application of priming on coriander seeds to achieve greater speed and efficiency of establishment.

Plectranthus ornatus Codd is a plant populary known as “paraguayan boldo”, “false boldo” and “creeping boldo”, widespread as medicinal in Paraguay and Brazil, having proven its anti-ulcer properties, digestive and hepatoprotective. The objective of this research was to determine the possibility of propagating this species by cuttings. For this purpose three experiments were conducted to evaluate the behavior of the stems cuttings: i) from different parts of the mother plant (apical, middle and basal); ii) with different quantity of leaves (without leaves, with two leaves and four leaves) and iii) of different lengths (5, 10 and 15 cm). The experiment was carried out in Corrientes, Argentina Republic. Rooting variables (Number, Maximum length and Roots fresh weight) and sprouting variables (Fresh weight and Maximum length of shoots and Percentage of sprouting buds by cutting) were measured. The cuttings of all treatments successfully rooted and grew, consecuently it can be inferred that the best results are obtained from those that come from the middle part of the plant, with 5 cm in length or with 2 to 4 leaves per cutting.

Accumulation of salts and sodium in the soil for the continued use of poor quality water affects the structural stability, hydraulic conductivity and infiltration rate of the soil, causing a reduction in their productive capacity. In the greenhouse, all water must be provided in the form of irrigation, so it is important to know the water quality to be used. This is defined in terms of salinity, sodicity and toxicity. There are records reporting changes in the chemical properties of soils irrigated with water of questionable quality. According to these, the use of such water brings about changes in physical and chemical properties of soil. The higher the SAR, the lower is the hydraulic conductivity and decrease soil infiltration and surface crust appears damaging the germination and crop emergence. Lettuce is moderately resistant to salinity, although in greenhouses, the development of the crop can be affected by the increase in soluble salts. Saline-sodic soils can be restored using chemicals amendments. These counteract the increased levels of sodium and stabilize the soil structure.