Odair José Schmitt

Concentração da solução nutritiva no crescimento da planta, na produtividade e na qualidade de frutas do morangueiro

The objective of the research was to determine the effect of nutrient solution concentration on plant growth, fruit yield and quality of the strawberry crop grown in a closed hydroponic growing system. Treatments were five nutrient solutions at electrical conductivities (EC) of 0.9; 1.8; 2.5; 3.2 and 3.8dS m-1, in a randomised experimental design with three replications. Fruit yield and quality during the harvest period and shoot and root growth at the end of the experiment were determined. Fruit yield, fruit size and plant growth were reduced by increasing nutrient solution concentration, whereas titratable acidity and total soluble solids were increased. The EC of 0.9dS m-1 reduces plant growth and maximizes fruit yield of the strawberry crop in the closed soilless growing system.

Crown size and transplant type on the strawberry yield

Strawberry (Fragaria x ananassa D.) yield is affected by vigor of transplants. Those young and vigorous at planting lead to plants reaching higher vegetative growth and fruit yield than weak or old ones. This study aimed at determining plant growth, development, and fruit yield of the strawberry plant from bare root and plug transplants with different crown diameters. Bare root transplants were produced by rooting stolons and plug transplants from runner tips collected and rooted in a substrate growing bed. Three classes of crown diameters were compared in a 2 × 3 factorial and randomized block experimental design, with four replications, 16 plants per plot and a density of 6.6 plants m-2. For bare root transplants, crown diameters were between 3.0 and 5.0 mm (class 1); 5.1 and 8.0 mm (class 2) and greater than 8.1 mm (class 3). For plug transplants, runner tips were screened between 2.0 and 3.9 mm (class 1); 4.0 and 5.5 mm (class 2) and 5.6 to 7.0 mm (class 3). Transplants of both types were planted at April 16th, 2008, and at this date, crown diameter, shoot and root dry mass and number of leaves were higher in all classes of plug transplants. Ripe fruits were harvested from June 15th to November 7th, 2008, and fresh fruit yield was determined. Plant growth and development were determined at last harvest. Higher growth, development and fruit yield were obtained in plants from plug transplants. For bare root transplants, crown diameters higher than 5.1 mm can be used while for plug transplants the crown diameter of runner tips does not affect plant growth and fruit yield.

Doses de potássio e cálcio no crescimento da planta, na produção e na qualidade de frutas do morangueiro em cultivo sem solo

In order to evaluate the effect of potassium doses supplied by fertigation and of calcium by foliar spray on plant growth, fruit yield and quality of soilless grown strawberries, plants were supplied with nutrient solutions at K+ concentrations of 9 (T1); 6 (T2, control) and 4.28mmol L-1 (T3) and with the control nutrient solution (T2) supplemented once a week by spraying CaCl2 on shoot at concentrations of 2.5 (T4) and 5g L- 1 (T5). Plant growth was lower in the higher potassium concentration (T1) and the highest LAI was recorded in the higher CaCl2 dose (T5). Fruit yield was higher in T2 and T3, the titratable acidity (TA) was higher in T1, while total soluble solids (TSS) and the ratio TTS/TA did not differ among treatments. It was concluded that high potasium concentration in the nutrient solution reduces plant growth, fruit yield and quality and that calcium supplied on shoot by CaCl2 reduces fruit production.

Avaliação de genótipos de morangueiro quanto à qualidade e potencial de armazenamento

The objective of this study was to evaluate the quality of strawberry cultivars and clones, and their potential for storage under refrigeration. The experimental design was a randomized block design with four replicates of approximately 150 g each. The treatments consisted in the evaluation of three cultivars and four clones, namely: LBH 15.1 Araza, SGH 140.3 Guenoa, LBF 236.3 Yvapita, LBG 121.4, LBK 16.1, LBK 35.1 and LBK 28.1. Evaluations were made at harvest and after ten days of storage at -0.5oC, plus two days at 20oC. The parameters evaluated were firmness, acidity, soluble solids, TSS/ TTA ratio, ascorbic acid, presence of rotting and weight loss. In terms of quality, cv. Guenoa presented low acidity and high TSS e ascorbic acid, high TSS/TTA ratio and also showed better conservation, presenting low incidence of decay during storage. The cultivar LBF 236.3 Yvapita and the clone LBK 28.1 showed the lowest vitamin C content and TSS/TTA ratio, which compromises its quality. The quick reduction of firmness and increased susceptibility to decay presented by LBF236.3 Yvapita and LBK 28.1 show a low potential for conservation under refrigeration. Cultivars and clones that had higher quality at harvest, also showed better post-harvest conservation.

Fruit yield of strawberry stock plants after runner tip production by different cultivars

ABSTRACT The main objective of this research was to determine fruit yield of strawberry ( Fragaria x ananassa ) stock plants in a cropping system after producing runner tips and plug plants. Micropropagated stock plants were planted in a soilless growing system. Runner tips bearing at least one visible root nodule were harvested at 43, 66 and 87 days after planting, rooted and planted as multiplied stock plants for producing plug plants. Treatments consisted of micropropagated stock plants of cultivars INIA Araza, INIA Guenoa and INIA Yvapita, planted on October 1 st , 2008 (T1); multiplied stock plants planted on November 28 th (T2) and on December 21 st , 2008 (T3), and on January, 10 th , 2009 (T4). On May 22 nd , 2009, stock plants were defoliated and plug plants of the same cultivars were planted as control for fruit production. Early fruit yield and number of fruits were higher on stock plants, but fresh fruit yield was higher on control plants. Total fruit yield and number were higher on stock plants of ‘INIA Araza’ and ‘INIA Guenoa’. We concluded that strawberry stock plants reach higher early and total fresh fruit yield than plug transplants in the second cropping year after producing runner tips in a soilless growing system. Therefore, plants should not be discarded after the production of runner tips.

Cultivo sem solo do morangueiro com três métodos de fertirrigação

This research aimed to compare growth and fruit yield of strawberry plants grown in a closed substrate soilless system under three fertigation methods. The experiment was carried out at the Fitotecnia Department of the Federal University of Santa Maria, between May 14th and November 16th, 2007, in a bifactorial 3 x 2 randomised split plot experimental design and three replications. The main plots were the three fertigation methods and the split plots were the clones LBD 15.1 and LBG 168.1. The growing bed was the organic substrate Plantmax PXT®. The control (T1) was a complete nutrient solution. In T2, absorbed quantities of P, K, Ca and Mg were estimated and added in the substrate before planting. Nitrogen was supplied by fertigation during the cropping period. In T3, quantities of nutrients estimated for T2 were split in fortnight doses and delivered by fertigation using the same fertilizers employed in the complete nutrient solution. Fruit number and yield during the cropping period and vegetative dry matter at the end of the experiment were determined. Early and total fruit yield were lower in T2. It was concluded that for both clones, the fertigation using a complete nutrient solution can reach similar fruit yield as well as the supplying nutrients in fortnight doses, with a reduction in the consumption of fertilizers.

Produção de estolhos de cultivares de morangueiro em função da condutividade elétrica da solução nutritiva

The characteristics of the nutrient solution used in soilless culture systems with the use of substrates is one of the factors which influence the emission of runner tips. The electrical conductivity (EC) of the nutrient solution is related to the concentration of nutrients, but still few reported in the literature for production of strawberry plug transplants in Brazil. The objective of this research was to determine the effects of the nutrient solution electrical conductivity on growth of strawberry stock plants and on production of runner tips for plug transplants. The completely randomized experimental design was used in a (5x2) factorial scheme. Five concentrations of the nutrient solution measured by means of its EC of 0.4; 0.8; 1.2; 1.6 and 2.0 dS/m and strawberry cultivars Camino Real and Oso Grande were compared, with 20 replications of one stock plant. Planting was carried out in pots in October and plants were fertigated with the five concentrations. Runner tips were collected weekly and counted, necrotic ones being discarded. A sample of 15 runner tips from plants of each treatment was collected at two-week intervals to determine the number of leaves, crown diameter and dry mass. In February, a sample of 45 runner tips from each treatment was rooted in polystyrene trays with 40 cm3 of organic substrate to determine the transplant survival rate, crown diameter, number of expanded leaves, shoot and root dry mass of transplants. At the end of the experiment, leaf area and dry mass of roots, crown, petioles and leaves were determined. We concluded that increasing the concentration of the nutrient solution reduces the growth of strawberry stock plants and the production of runner tips and transplants is higher in the EC range between 0.8 and 1.1 dS/m.

Nitrogen accumulation and monitoring by strawberry stock plants for runner tips production

The composition and concentration of the nutrient solution can affect growth of strawberry stock plants and runner tips production. The aim of this research was to determine runner tips production and nitrogen (N) accumulation by strawberry stock plants grown under five N concentrations in the nutrient solution and its relationships with chlorophyll meter readings. From September 2010 to March 2011, strawberry stock plants of cultivar Oso Grande and Camino Real were grown on sand polyethylene bags. Nitrogen was supplied by nutrient solutions at concentrations of 5.12 (C1), 7.6 (C2), 10.12 (C3), 12.62 (C4) and 15.12 (C5) mmol L-1. Runner tips bearing at least one expanded leaf were collected weekly and counted. The chlorophyll index (ICF) was measured fortnightly using a digital chlorophyll meter on the last second full expanded leaf of stock plant. A polynomial relationship was adjusted between the chlorophyll index and the N concentration in leaflets, which can be used for monitoring the N status of this crop. Leaflets and petioles are the organs of the strawberry stock plants with the higher N accumulation and runner tips production is not affected by N concentrations of the nutrient solution in the range of 5.12 to 15.12 mmol L-1.

Multiplication of strawberry stock plants at different planting times

The objective of this research was to determine the effectiveness of the multiplication of micropropagated strawberry stock plants as a method for producing runner tips to be used in the production of plug transplants. Micropropagated stock plants of cultivars INIA-Araza, INIA-Guenoa and INIA-Yvapita were planted at October 1st, 2008. Runner tips emitted by the micropropagated stock plants were harvested and planted as multiplied stock plants at 37; 40; 46; 51; 58; 64; 67; 75 and 87 days after planting the micropropagated stock ones. Runner tips emitted by all plants between October, 2008 and April, 2009, were harvested and counted, the number of root nodules counted and the crown diameter measured. The number of runner tips decreased linearly on all stock plants by delaying planting time, while crown diameter and number of root nodules were not affected. Higher number of runner tips was produced by micropropagated stock plants. The cultivar INIA-Araza was the most prolific. Multiplying stock plants may be a new propagation method than can be used for reducing the number of micropropagated stock plants required for the production of strawberry commercial plug transplants.

Frigoconservação das pontas de estolões na produção de muda com torrão e frutas de morangueiro

The objective of this research was to determine the effects of cold storage of strawberry runner tips used for production of plug plants and fruit yield in the field. The experiment was conducted in Santa Maria, RS, using plug plants rooted after 0; 7; 14; 21; 28 and 35 days of cold storage of runner tips at 0,5±0,3°C temperature and 95±1% air humidity. After the cold storage period, runner tips were rooted for plug plant production and planted in the field for fruit production. The survival rate and number of leaves of plug plants were recorded after rooting. Fruit and stolon number and fruit yield were determined from June to December 2010. It was concluded that the cold storage of runner tips for further rooting and plug plant production did not affect growth and survival of plug plants. Fruit yield of plants originated from such plug plants is reduced when the cold storage period is increased while emission of stolons is linearly enhanced, but these effects are cultivar dependent.