ABSTRACT Most commercial apple orchards are established on either Marubakaido (Malus prunifolia Borkh.) (high vigor), M-9 (Malus pumila) (low vigor), or a combination of both rootstocks through the intergrafting technique. The Geneva® Series rootstocks were developed as an alternative to orchards modernization. The vigor of rootstocks influences the anatomical xylem formation and, therefore, the canopy cultivar’s hydraulic conductivity. When affected by embolism, hydraulic conductivity harms plant metabolism, reducing crop yield and fruit quality. This study aimed to evaluate four Geneva® Series rootstocks with potential use in southern Brazil, in terms of hydraulic conductivity (K) and percentage loss of conductance (PLC), during the winter period in two different years. The G.213 rootstock presented the best performance for the variables analyzed; however, higher values of xylem functionality loss were observed in G.814.

ABSTRACT Pecan crops has been expanding in recent years, mainly in southern Brazil. Genotypes that compose Brazilian orchards come from the USA and from selections of plants made by Brazilian producers. This study aimed to characterize with microsatellite markers pecan cultivars registered for cultivation in Brazil, including some selections made in the country. It is important to know the genetic variability of the pecan tree, as it facilitates the identification of possible phytotechnical deficiencies due to the genetic similarity between the plants, in addition to helping in the conservation of the species, among other. Thirty-four, out of forty collected accessions, were genotyped with 11 selected SSR (Simple Sequence Repeats) loci. Twenty-four polymorphic alleles were identified. The genetic similarity matrix, based on the Jaccard coefficient, ranged from 0.125 to 1.0; general mean of similarity was 0.46. The cluster analysis, which was carried out by the Unweighted Pair Group Method with Arithmetic Mean (UPGMA), classified pecan accessions into four main groups. Results showed that there is high genetic variability in germplasm evaluated, although some accessions may be duplicates.

ABSTRACT The production of strawberry seedlings in a soilless cultivation system can be an alternative for the production of seedlings of high physiological and sanitary quality. The objective of this study was to evaluate the influence of the use of different nutrient solutions in mother plants on the production and quality of strawberry seedlings of the Aromas and Camarosa cultivars. The experiment was carried out in two crop cycles: the first cycle in 2016/2017, where four different nutrient solutions (1; 2; 3 and 4) were used for the nutrition of the parent plants of the cultivars under study and the second in 2017/2018, when the most productive solutions (nutrient solution 3 and 4) based on the results of the first cycle were used, together with the two cultivars. The propagules produced were collected, evaluated and rooted in substrate-filled trays, forming plant plugs, which were evaluated for quality. Nutritional solutions influence the propagative potential of the parent plants more than the physiological quality of the plug plant seedlings produced, when they are formed on substrates that provide nutrients. The nutrient solution 4 is the most recommended for the production of strawberry seedlings of the cultivars Aromas and Camarosa, in a soilless system.

RESUMO: A diversificação do uso de variedades porta-enxerto, com a consequente redução de riscos fitossanitários, é de fundamental importância para a sustentabilidade da citricultura do Sul do Brasil. O objetivo deste trabalho foi avaliar o comportamento de 42 porta-enxertos na formação de mudas de laranjeira ‘Valência Late’ em fase de viveiro. Nesse sentido, seedlings (plantas oriundas da germinação de sementes) nucelares dos porta-enxertos estudados foram avaliados relativamente aos caracteres altura da planta, diâmetro do caule, taxa de mortalidade e percentagem de pegamento de borbulhas após a enxertia. O delineamento experimental foi inteiramente casualizado, com quatro repetições de 20 unidades amostrais. Genótipos não adaptados tiveram altas taxas de mortalidade, os híbridos LCR x CTSW - 009 e LVK x LCR - 038 apresentaram 100% e 90% de mortalidade, respectivamente. Mais 13 genótipos apresentaram mortalidade superior a 30%, destes, dez têm como parental feminino a tangerineira ‘Sunki’. O citrumelo ‘Swingle’ foi o porta-enxerto que apresentou maior desenvolvimento (altura da planta e diâmetro do caule), associado a uma baixa taxa de mortalidade. Quanto aos demais porta-enxertos, destacaram-se por atingir rapidamente o diâmetro de enxertia, associado a baixa taxa de mortalidade, os híbridos HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, citrandarins ‘Indio’, ‘Riverside’ e ‘San Diego’, assim como o limoeiro ‘Cravo’ e o Trifoliata. Além do Trifoliata, amplamente utilizado no Rio Grande do Sul, estes porta-enxertos são promissores para a citricultura do Sul do Brasil.

ABSTRACT: Diversification of rootstock varieties, with consequent reduction in phytosanitary risks, has great importance to the sustainability of citrus cultivation in the south of Brazil. This study evaluated the performance of 42 rootstocks in the nursery phase to generate ‘Valencia Late’ sweet orange seedlings. Therefore, nucellar seedlings from the rootstocks under study were analyzed in relation to plant height, stem diameter, mortality rate and percentage of bud set after grafting. The experimental design was completely randomized with four replications of 20 sample units. Not adapted genotypes had high mortality rates, and the ones of both hybrids LCR x CTSW - 009 and LVK x LCR - 038 were 100% and 90%, respectively. Other 13 genotypes had mortality rates above 30%, and ‘Sunki’ mandarin was the female genitor of ten of them. ‘Swingle’ citrumelo was the rootstock with the highest development (plant height and stem diameter), associated with low mortality rate. In relation to the other rootstocks, the best results were the fast grafting diameter, associated with low mortality rate obtained by hybrids HTR - 053, LRF x (LCR x TR) - 005, CLEO x TRBN - 245, CLEO x TRSW - 287, and citrandarins ‘Indio’, ‘Riverside’ and ‘San Diego’, as well as Trifoliate orange and ‘Rangpur’ lime. In addition to Trifoliate orange, which is widely used in Rio Grande do Sul, these rootstocks have great potential in citriculture in the south of Brazil.

Resumo A qualidade do porta-enxerto de nogueira-pecã com segurança genética, fitossanitária e com bom desenvolvimento vegetativo é de suma importância para o sucesso na formação do pomar. O porta-enxerto com vigoroso sistema radicular influencia no crescimento da muda. O objetivo deste trabalho foi avaliar o crescimento do porta-enxerto em função da poda de raiz e de diferentes recipientes para a produção de muda de nogueira-pecã em sistema orgânico. O experimento foi conduzido com o porta-enxerto da cultivar Barton, na área experimental da Embrapa Clima Temperado, Estação Experimental Cascata, nos anos de 2018, 2019 e 2020. Os porta-enxertos foram avaliadas em sacos plásticos, tubetes e diretamente no solo, associado ao manejo da poda de raiz. Avaliaram-se, após 280 e 480 dias do transplante: altura da parte área, comprimento do sistema radicular primário e secundário, diâmetro de caule, área foliar e massa seca da parte aérea e do sistema radicular, e secundárias, e o Índice de qualidade de mudas de Dickson. Verificou-se que o uso do saco plástico para a produção de porta-enxertos de nogueira-pecã enovela as raízes no final do recipiente. Os recipientes e a poda de raiz não afetam o diâmetro do caule, característica importante para a execução da enxertia. Os porta-enxertos de nogueira-pecã com sistema radicular não podado e cultivado em saco plástico desenvolvem maior raiz principal e parte aérea. A poda do sistema radicular da nogueira-pecã, em recipientes e no solo, promove o aumento do número de raízes principais, mas diminui o comprimento das raízes das mudas.

Abstract Quality pecan rootstocks that ensure genetic and phytosanitary safety, besides having good vegetative development, are extremely important to implant a successful orchard. Rootstocks with vigorous radicular systems affect plant growth. This study aimed at evaluating rootstock growth as the result of root pruning and the use of different containers to grow pecan rootstocks in an organic system. The experiment was conducted with “Barton” rootstocks in the experimental area at the Embrapa Clima Temperado in Pelotas, RS, Brazil, in 2018, 2019 and 2020. Rootstocks were evaluated in plastic bags and tubes and in the soil, associated with root pruning. Evaluation 280 and 480 days after transplant comprised the following: height of the aerial part, length of primary and secondary radicular systems, stem diameter, leaf area, dry mass of the aerial part, dry mass of the radicular system, dry mass of secondary roots and the Dickson Quality Index. The use of plastic bags to produce pecan rootstocks was found to coil roots at the bottom of the container. Neither containers nor root pruning affected stem diameter, an important parameter to carry out grafting. Pecan rootstocks with a non-pruned radicular system grown in plastic bags developed large main root and aerial part. Pruning of pecan radicular systems in containers and in the soil leads to increase in the number of main roots but decreases root length.

ABSTRACT In the last decades, several biochemical and molecular studies in pear (Pyrus spp.) have revealed processes associated with dormancy establishment and release, leading to the identification of several MADS-box family genes related to bud dormancy regulation. Thus, the aim of this study was to evaluate a preliminary expression pattern of the PpDAM13-1 and PpDAM13-2 MADS-box genes in pear leaf buds (Pyrus pyrifolia Nakai, cultivars Hosui and Nijisseiki; and Pyrus communis L., cultivars Rocha and Santa Maria), grown in the subtropical climate of Southern Brazil. Lateral leaf buds were collected from June to September, and RNA was extracted for evaluation of gene expression by reverse transcription polymerase chain reaction (RT-qPCR). It was found that these two genes decreased the expression as leaf buds are release from dormancy. The Hosui cultivar for both genes and the Nijisseiki cultivar for PpDAM13-2 gene showed peaks of expression in early June, indicating that leaf buds are in a transition dormancy phase. The two European cultivars showed this transition dormancy phase between the end-July and the mid-August. It was concluded that the expression analysis of PpDAM13-1 and PpDAM13-2 genes can be used as a marker to evaluate changes of dormancy phase in pear trees in subtropical climate conditions, and it can be suitable to assist management strategies for overcoming pears’ bud dormancy.

Abstract: Blueberry cultivation is a recent economic activity in Brazil. The productive and commercial systems still need improvement, especially to maintain the regularity of quality and productivity and the transparency of costs and prices. There is no study dedicated to analyze the economic viability of blueberry production under Brazilian conditions. Therefore, the objective of this study is to survey the costs and analyze the economic and financial viability of this crop in a farm located in Pelotas, state of Rio Grande do Sul (RS), Brazil. The data collection and analysis followed the procedure adopted by the Policy Analysis Matrix, and the viability indicators were net present value (NPV), internal rate of return (IRR) and payback period. The results showed a production cost of US$ 7,394.61 per hectare or US$ 2,310.88 per ton and financial viability for production, since the NPV for the 10-year period was US$ 26,214.81, the IRR was 26.36%, the net income was US$ 7,180.25 hectare/year-1, and the payback was 4.9 years. Therefore, blueberry production in southern RS is profitable, and the production chain can receive new investments given the technological and market conditions of this study.

Resumo: O cultivo do mirtilo é uma atividade econômica recente no Brasil. O sistema produtivo e comercial ainda precisa de melhorias, principalmente para oferecer regularidade, qualidade produtiva e transparência de custos e preços. Não se tem conhecimento de estudos dedicados a analisar a viabilidade econômica da produção de mirtilo nas condições brasileiras. Portanto, o objetivo deste trabalho é levantar os custos e analisar a viabilidade econômico-financeira desta cultura em uma fazenda localizada em Pelotas (RS). A coleta e análise dos dados seguiram o procedimento adotado pela Matriz de Análise de Política e os indicadores de viabilidade utilizados foram o Valor Presente Líquido (VPL), a Taxa Interna de Retorno (TIR) e o Payback. Os resultados mostraram um custo de produção de US$ 7.394,61 por hectare ou US$ 2.310,88 por tonelada e viabilidade financeira na produção, dado que o VPL para o período de 10 anos foi de US$ 26.214,81, a TIR de 26,36%, a renda líquida foi de US$ 7.180,25 hectare/ano-1 e o Payback foi de 4,9 anos. Desse modo, a produção de mirtilo no sul do RS é lucrativa e a cadeia produtiva pode receber novos investimentos, segundo as condições tecnológicas e mercadológicas indicadas neste estudo.

ABSTRACT The objective of this study was to investigate the effect of different rates of ethephon on return bloom and yield, and fruit quality of ‘Fuji’ apple trees. The experiment was performed during the 2014/2015 and 2015/2016 growing seasons. Eighteen-year-old Fuji Standard apple trees grafted on M.9 were sprayed with different rates of ethephon (300 mg L-1, 400 mg L-1, and 500 mg L-1) 30 days after full bloom (DAFB) and compared to an unsprayed control. Yield components (number of fruit per tree, yield, fruit weight, and estimated yield) and fruit quality attributes (fruit firmness, total soluble solids and starch-iodine index) were evaluated in both seasons. Return bloom (percentage of flowering spurs and 1-year-shoots) was assessed only the year following the application. Our results show that ethephon increases return bloom and yield of ‘Fuji Standard’ apple trees, without affecting fruit quality attributes.

Abstract The aim of this study was to evaluate the effect of different aminoethoxyvinilglycine (AVG), thidiazuron (TDZ) and prohexadione calcium (P-Ca) rates sprayed at different timings on fruit set, yield, and fruit quality of ‘Rocha’ pear trees in different climatic conditions of Southern Brazil. The study was performed in two commercial orchards located in São Joaquim, SC (2015/2016) and Antônio Prado, RS (2016/2017). Plant material consisted of ‘Rocha’ pear trees grafted onto Pyrus calleryana and quince rootstock ‘BA29’ in São Joaquim and Antônio Prado, respectively. Treatments consisted of AVG, TDZ and P-Ca sprayed at different rates and timings. Trunk cross-sectional area increase, fruit set, thinned fruit, fruit per tree, yield, average fruit weight, projected yield, yield efficiency, fruit length, fruit diameter, L/D ratio, seed number, flesh firmness, and soluble solids content were assessed. Fruit set and yield were consistently increased by AVG in all experiments. Fruit set was not affected by P-Ca and was significantly decreased by TDZ. However, yield was positively affected by P-Ca 100 mg L–1 sprayed at full bloom + 7 days after full bloom and TDZ 10 mg L–1 at full bloom. Fruit size was consistently increased by TDZ.

Abstract Pecan trees require adequate soil moisture conditions to produce nuts with good yield and quality. Irrigation should be an important considered practice in orchards management plan, mainly in regions with water deficit periods. The objective of this research was to evaluate irrigation on pecan nuts growth and yield. This study was conducted in Uruguay, during the fast development phase until the pecan nuts harvest. Three irrigation treatments were used: 0 L (control), 70 L and 140 L plant-1 of water every two days, applied via drip irrigation in seven-year-old pecan trees of the cultivar Success. The number of nuts per cluster and nuts’ diameter and length were evaluated during nut growth. After harvesting, peeled nuts’ width and length were measured, and after peeling, the kernel length, width, height and filling and the kernel and peel percentage were evaluated. According to the results, it was possible to identify that periods of water deficit during pecan nuts development affected the kernel filling stageand size. Irrigation in pecan plants provides greater dimensions and nuts mass. With the use of 140 L plant-1, there was an increase in the nut mass of more than 100% in relation to the nuts from plants without irrigation.

Resumo O objetivo deste trabalho foi avaliar a influência do uso de radiação UV-C na intensidade de 0,53 KJ m-2, durante o cultivo de morango (Fragaria x ananassa), sobre os parâmetros físico-químicos e fitoquímicos dos frutos. O delineamento experimental utilizado foi inteiramente casualizado, em arranjo unifatorial, com 11, 19, 29 e 39 aplicações de UV-C e sem aplicação de UV-C. A tonalidade dos frutos apresentou menor ângulo ao final do período de estudo. O pH variou em morangos que receberam 39 aplicações de UV-C, e o conteúdo de sólidos solúveis diferiu com 19 aplicações. A atividade antioxidante foi menor nas frutas com 11, 19 e 29 aplicações de UV-C, enquanto o teor de vitamina C foi menor apenas nas frutas que receberam 29 aplicações. O uso de radiação UV-C de 0,53 KJ m-2, durante o cultivo de morango, afeta os parâmetros físico-químicos e fitoquímicos dos frutos, mas não leva à perda de sua qualidade.

Abstract The objective of this work was to evaluate the influence of the use of UV-C radiation at an intensity of 0.53 KJ m-2, during strawberry (Fragaria x ananassa) cultivation, on the physicochemical and phytochemical parameters of the fruits. The used experimental design was completely randomized, in a single-factor arrangement with 11, 19, 29, and 39 UV-C applications and without UV-C application. The hue of the fruits was smaller at the end of the study period. pH varied in strawberries that received 39 applications of UV-C, and the soluble solids content differed with 19 applications. Antioxidant activity was lower in fruits with 11, 19, and 29 UV-C applications, whereas vitamin C content was lower only in fruits that received 29 applications. The use of UV-C radiation at an intensity of 0.53 KJ m-2, during strawberry cultivation, affects the physicochemical and phytochemical parameters of the fruits, but does not cause losses in their quality.

Resumo O objetivo deste trabalho foi avaliar o efeito do raleio químico com metamitron em frutos de pessegueiro (Prunus persica) das cultivares Maciel e Sensação, bem como a sua relação com o teor de carboidratos nos seus ramos. O delineamento experimental foi de blocos ao acaso, e os tratamentos foram plantas sem raleio, raleio manual de frutos e raleio químico com 200 mg L-1de metamitron aos 20, 40 e 60 dias após a plena floração. As variáveis analisadas foram: percentagem de abscisão, produção por planta, número de frutos, presença de lignina nos frutos e teores de carboidratos nos ramos. O teor de carboidratos foi avaliado em plantas com e sem raleio químico, sete dias após a aplicação do produto. O uso de metamitron promove raleamento dos frutos dos pessegueiros ‘Maciel’ e 'Sensação', com redução no conteúdo de carboidratos nos seus ramos. A aplicação de metamitron aos 20 e 40 dias após a plena floração favorece a abscisão dos frutos de ambas as cultivares estudadas.

Abstract The objective of this work was to evaluate the effect of chemical thinning with metamitron on fruit of the Maciel and Sensação peach (Prunus persica) tree cultivars, as well as to identify its relation to the carbohydrate content in their branches. The experimental design was randomized complete blocks, and the treatments were trees with no thinning, manual fruit thinning, and chemical thinning with 200 mg L-1 metamitron applied at 20, 40, and 60 days after full blooming. The evaluated variables were: abscission percentage, yield per plant, number of fruit, presence of lignin in fruit, and carbohydrate content in the branches. The carbohydrate content was evaluated in trees with and without chemical thinning seven days after the application of the product. The use of metamitron promotes fruit thinning in the ‘Maciel’ and ‘Sensação’ peach trees, with a decrease in the carbohydrate content in their branches. Metamitron application 20 and 40 days after full blooming favors fruit abscission in both studied cultivars.

Resumo A falta de indutores de brotação é um grande problema na produção orgânica de frutos de clima temperado. No presente trabalho, foi avaliado o efeito de compostos alternativos na indução de brotação em quivizeiros da cultivar Bruno implantados em um pomar, no município de Pelotas, Estado do Rio Grande do Sul, Brasil. A eficiência dos compostos foi testada nos ciclos produtivos de 2016-2017 e 2017-2018. No primeiro ciclo, aplicaram-se dez tratamentos, consistindo em extrato de alho em diferentes concentrações, associado ou não ao óleo mineral, extrato de cebolinha em diferentes concentrações, associado ou não ao óleo mineral, somente óleo mineral e controle (sem aplicação). No segundo ciclo, foram aplicados os tratamentos que se destacaram no primeiro ciclo: extrato de alho em diferentes concentrações, associado ao óleo mineral, somente óleo mineral e controle (sem aplicação). Avaliaram-se o porcentual de brotação, a fenologia (brotação e floração), a frutificação efetiva, o número de frutos/planta, a massa dos frutos/planta, a produção estimada, a massa média, o comprimento e o diâmetro dos frutos. Concluiu-se que o extratode alho a 10% + óleo mineral a 2% induziu maiores percentuais de brotação nos dois anos deestudo; a posição da gema no ramo influencia diretamente na brotação; gemas apicais apresentam maior percentual de brotação; concentrações de 15% de extrato de alho causam fitotoxidade àsgemas; e o extrato de cebolinha é ineficiente na indução da brotação.

Abstract Lack of budburst inducers is a major problem in organic production of temperate fruits. This study aimed at evaluating the effect of alternative budburst inducers on kiwifruit vines of cultivar Bruno grown in an orchard in Pelotas, Rio Grande do Sul (RS), Brazil. Inducers efficiency was investigated in both 2016-2017 and 2017-2018 seasons. The first season comprised of ten treatments, which used garlic extract at different concentrations, both, associated with and without mineral oil; Welsh onion extract at different concentrations, both associated with and without mineral oil; just mineral oil; and control (no application). In the second season, evaluation was carried out ith treatments that performed well in the first season, garlic extract atdifferent concentrations associated with mineral oil, just mineral oil and control. The followingvariables were evaluated: budburst percentage, phenology (budburst and flowering), fruit set, number of fruit/plant, fruit mass/ plant, estimate production, mean mass, fruit length and diameter. Results showed that 10% garlic extract + 2% mineral oil induced the highest budburst percentages in both seasons; the position of buds on branches influences budburst; apical buds exhibit the highest budburst percentage; 15% garlic extract causes phytotoxicity to buds; and Welsh onion extract is inefficient to induce budburst.

ABSTRACT Kiwifruit vines are an alternative approach to diversify Brazilian fruit farming because of the low supply and increase in the demand for their fruits. Hydrogenated cyanamide, which is the most common rest-breaking agent, is highly toxic and its use is not allowed in organic production systems. This study aimed at evaluating the efficiency of alternative rest-breaking agents in kiwifruit vines by using the biological method of single node cutting. Twigs of the cultivar Bruno were collected in an organic orchard in Pelotas, a city located in Rio Grande do Sul state, Brazil. Seven-centimeter-long cuts with a single shoot at the ends were segmented. Cuttings were placed on plastic trays with phenolic foam and soaked in water, at 85% relative humidity on average, and kept in bio-oxygen demand (BOD) incubators at 25± 1 °C and a 16-h photoperiod. Budbreak was evaluated in 2-day and 3-day intervals. The experiment was conducted in a completely randomized design with ten treatments and three replications of ten sampling units each. The following variables were analyzed: average budbreak time (ABT), final budbreak rate (FBR), vigorous budbreak rate (VBR), velocity of budbreak (VB), percentage of open buds (POB) and dormancy index (DI). The rest-breaking agent garlic extract (GE) 10% + mineral oil (MO) 2% was the most efficient one in budbreak induction in both production cycles. Thus, this dose is recommended for budbreak induction in kiwifruit vines grown in an organic system.

ABSTRACT Pears are the most imported fruit from Brazil and thus, being an important opportunity to Brazilian growers. However, there are still some problems that restrict pear production, such as the lack of suitable rootstocks. The aim of this study was to assess growth, yield efficiency and fruit quality of ‘William’s’ pear grafted on quinces ‘Champion’ and ‘Melliforme’ and P. calleryana. The experiment was performed during 2009/2010 growing season at the Centro Agropecuário da Palma, FAEM/UFPel. The experimental design was a completely randomized block with three replications per treatment. The assessed parameters were trunk cross sectional area, shoot length, yield efficiency, number of fruit per tree, soluble solids, flesh firmness, fruit weight and fruit size. It was found that ‘William’s’ pear is more efficient and less vigorous when grafted on ‘Champion’ quince, thus being a potential scion x rootstock combination for commercial pear planting at medium densities. Moreover, fruit of trees grafted on quince rootstocks accumulated higher amount of soluble solids.