Strawberry

Earlier fall planting dates for strawberry (Fragaria ×ananassa) in west-central Florida tend to promote earlier onset of flowering and fruiting. However, warm air temperatures (>28 °C) can result in excessive growth and runner production. Sprinkler irrigation is a common practice to reduce air temperature in the first 10 to15 days after transplanting, requiring large volumes of irrigation water. An alternative to sprinkler irrigation is the application of crop protectants such as kaolin clay after transplanting. The objectives of this study were to determine the optimal planting dates and to assess the most appropriate establishment practices for strawberry bare-root transplants in Florida. Four establishment practices—10 days of sprinkler irrigation (DSI), 10 DSI + kaolin clay, 7 DSI, and 7 DSI + kaolin clay were evaluated for ‘Florida Radiance’ and Sweet Sensation® ‘Florida127’ transplanted in mid September, late September, and early October in consecutive seasons. For ‘Florida127’, September planting dates increased early yield compared with early-October traditional planting dates, with no difference in total yield. Seven DSI followed by the foliar application of kaolin clay at day 8 was also found to increase early yield compared with 10 DSI for strawberry establishment, with annual water savings of 108.7 mm.

Fragaria ananassa (Duchesne ex Weston) Duchesne ex Rozier (Strawberry) variety chandler of Agriculture Research Station (ARS) Baffa, Mansehra was evaluated for different growth and yield parameters under five treatments. In this experiment Potassium was used in 5 different treatments of 3 replications (T0 = Control, T1 = 200 g/6.75m², T2 = 400 g/6.75m², T3 = 600 g/6.75m², T4 = 800 g/6.75m²). The results showed maximum value under T3 (405g/6.75m²) for characteristics like survival percentage (83.54%), plant height (32.05cm), canopy size (13.62cm), crown diameter (2.73cm), number of branches (35.83), number of leaves (67.00), leaf length (5.87cm), root length (3.51cm), total number of fruits (43.93), days to 50% fruiting (233.67), fruit diameter (3.96cm), fruit weight (411.40g). Moreover, transplanting date (20 th Sep, 2013) is suitable to get maximum yield of strawberry variety " Chandler ". The findings of this experiment showed that great variations in morphological, physical and agronomic traits of strawberry variety and can be utilized to develop high yield and better quality of strawberry.

Methods of strawberry cultivation have undergone many improvements, and this book
covers aspects from plant propagation, architecture, genetic resources, breeding, abiotic
stresses and climate change to evolving diseases and their control. The book is aimed at
those involved in strawberry research and development, and also to those who are interested
in cultivation of strawberry for commercial gain.
The first chapter gives a general introduction to strawberry with some important statistics.
It is followed by Section 1 on Genetics, Breeding and Omics, which contains five
chapters. Chapters 2 and 3 discuss modern aspects related to available genetic resources
and breeding for yield, quality and disease traits. The scope of metabolomics is discussed
with special reference to white strawberry in Chapter 4. Chapter 5 is an interesting study
on the transcriptomic profile of some key genes in relation to systemic acquired resistance,
while Chapter 6 discusses different aspects of genetic transformation in strawberry. Section 2
on Cultivation Systems and Propagation contains three chapters. These chapters discuss
at length the plant growth, flowering, root growth and architecture, replant problems and
plant propagation techniques. Section 3 on Disease and Stress Management contains six
chapters dealing with biotic and abiotic stresses of strawberry. The first four chapters discuss
traditional and emerging fungal diseases, their diagnosis and modern biointensive
management strategies. Chapters 14 and 15 deal with the emerging challenges posed due to
climate change and its impact on the changing magnitude and dimensions of abiotic stresses
on strawberry.

Strawberry is one of the most popular fruits due to its delicious flavor and attractive aspect, and the demand for strawberries, as well as its culture, is continuously increasing worldwide. This crop, however, is not absent of problems that compromise yield or fruit quality. Actually, strawberry is considered by the consumers as one of the most inconsistent commodities in the marketplace. The use of highly producer cultivars with large but poorly flavored fruits, incorrect crop management practices such as harvesting the fruits before full ripening, the short postharvest life of strawberry fruits or the extensive use of dangerous fumigants to control pest are among the main problems of this crop. Nowadays, people demand plant biology researchers to focus more efforts on safer and sustainable agriculture, avoiding as much as possible the use of chemicals, and to improve fruit quality traits. The implementation of biotechnological approaches within traditional breeding programs can be helpful to reach this goal. Besides this practical view, strawberry has been adopted as a model crop for some molecular and physiological studies, such as the ripening of non climacteric fruits, increasing their importance in the scientific world. The aim of this volume is to provide updated information about the current stage of genomics, transgenesis and biotechnology in strawberry, through the inclusion of reviews and research papers wrote by leader groups in these areas. Molecular markers have been explored in strawberry from the 80´s but in recent years the development of high throughput sequencing technologies has increased dramatically the amount of genomic data in this species. These advances in structural genomics in the genus Fragaria have been reviewed by Bonet and Monfort, and the release of the first draft of the strawberry genome is expected very soon. Most strawberry cultivars show seasonal flowering, requiring short photoperiod and/or low temperature for the induction of flowering, while the opposite environmental signals are needed for runnering. Hytönen and Elomaa have reviewed our current knowledge about candidate genes involved in flowering induction. This review is complemented by the paper of Massetani et al. who examine the effect of abiotic stresses, nutritional factors and propagation techniques on strawberry plant architecture. These studies can provide efficient tools to extend cropping season and increase berry yields. Besides attractive flavor, strawberries are a rich source of phytochemicals beneficial for human health. Hanhieneva et al. and Schmeda et al. have reviewed recent advances in metabolomics of both, cultivated strawberry and the Chilean strawberry Fragaria chiloensis, respectively. While both papers highlight the chemical composition of fruits, data about metabolomics of vegetative organs are also included. Increasing postharvest shelf life of strawberry fruit is central to strawberry research, which is very short mainly due to its fast softening rate and enhanced pathogen susceptibility usually associated with this process. Cell wall disassembly and loss of cell turgor during fruit ripening are considered the main factors responsible for fruit softening. Posé et al. have reviewed the main features of the disassembly cell wall process, and how the manipulation of some cell wall genes through transgenesis can reduce fruit softening without affecting other fruit quality parameters, while Alleva et al. examine the role of the water channel aquaporins in the loss of cell turgor during fruit ripening. For a limited number of genes, their role on fruit ripening has been assessed by stable genetic transformation. However, the increased knowledge of genes involved in fruit ripening requires efficient and fast systems for gene function analysis. Schawb et al. show how gene down-regulation by RNA interference in agroinfiltration experiments has been successfully used to assess the role of several fruit specific genes, avoiding time-consuming and labor-intensive stable transformation systems. Genetic modification could be a successful approach in improving quality of strawberry crop, as has been demonstrated with several fruit ripening genes. The application of this technology requires robust regeneration and transformation systems for each particular genotype. Currently, Agrobacterium tumefaciens infection in combination with a leaf disk regeneration system is the most popular method to get transgenic strawberry plants. Husaini et al. analyze key factors determining the success of genetic transformation in this species, and describe a general transformation protocol that has been proven useful in several strawberry cultivars. However, the toughest impediment in the development of this technology is the poor consumer perception of transgenic crops. These concerns are examined by Schaart et al. They describe the results of a recent consumer survey indicating that transgenic crops would be better accepted if only genes from the species itself, the so called intragenic or cisgenic plants, were used. This review also describes the attempts to get intragenic strawberry plants resistant to Botrytis cinerea. Intragenic modification requires the use of native promoters to drive gene expression. In their research article Schaart et al. describe the characterization of a promoter sequence of the strawberry fruit expansin FaExp2 gene. One of the main problems of the strawberry industry is the high amount of pesticides required to avoid loss of production, mainly due to fungal infections. Natural resistance against important diseases is scarce within the genus Fragaria, and therefore, alternative approaches to get tolerant cultivars are quite desirable. Garrido et al. summarize recent advances in the methods for detection and identification of strawberry fungal pathogens as well as strategies for their biocontrol using microorganisms. In a research paper, Matsubara et al. show that arbuscular mycorrhizal colonization enhances tolerance to Fusarium wilt and this effect is related to an increased level of antioxidative ability. Finally, Shokaeva et al. describe a method for the obtainment of plants tolerant to Botrytis cinerea or Phytophtora cactorum, and also to salinity stress, through screening and selection of somaclonal variants developed after exposure to these stressors under in vitro conditions. As many people that enjoy consuming strawberries, for us too it has been a pleasure to work in the preparation of this project. We hope that readers of this special issue, biotechnologists, physiologists, breeders or simply strawberry lovers, enjoy the reviews and find them useful. We are thankful to our families for having adjusted with us, while we were busy for long hours during the preparation of this volume. We finally thank all authors for their excellent contributions, and also for their patience during the long time required to complete this hybrid book, and to the GSB Editor-in-Chief Dr. Jaime Teixeira da Silva for his generous support.

Investigations were conducted to determine the insect pollinators visiting strawberry blossoms and their impact on fruit production. Various pollinators observed during the blooming period of strawberry were viz. Apis mellifera, Apis cerana, Apis florea. Apis dorsata, soil nesting solitary bees such as Andrena leana and A. ilerda, butterflies, houseflies, syrphid flies and some beetles. The percentage of fruit set was much higher in open pollinated plants than control. There was 11.20 per cent malformed fruit in open polli-nated plots as compared to 17.44 per cent in controlled one. Further the fruits obtained from the open pollinated plants were of good quality and large as compared to the controlled plants. Growers are recommended to take advantage of the several pollinators, either the honey bee or the native pollinators (Syrphidae and native bees). The importance of diversifying pollination sources, avoiding the dependence on a single specific group is stressed. This study also suggests measures which envisage the conservation, establishment and increase of native pollinators' populations in the typical agro-ecosystem of region.

The objective of this study was to analyze the distribution pattern of the different causes of the production of non-marketable fruit throughout the harvest season for several strawberry cultivars grown in a sub-tropical climate: ‘Carmela’,
‘Elyana’, ‘Florida Festival’, ‘Radiance’, ‘Macarena’ and ‘Candonga’. Fruit was harvested 2-3 times a week between June and October. In June, the main cause of non-marketable fruit production was fruit rot (90%). In July and August, fruit was
mostly discarded because of small size (40%), or it was malformed (40%). In September and October the primary cause of non-marketable fruit was small size (65-87%). ‘Elyana’ had least discarded fruit (9 fruits/plant), while ‘Florida Festival’
had the highest rate of non-marketable fruit (18 fruits/plant); however, this cultivar had a marketable yield 31% higher than ‘Elyana’. Knowing what causes the production of non-marketable fruit in different months allows the establishment of correlations between losses and weather factors, the genotype, the phonological stage, and the physiology of the plant. Such knowledge contributes to decision making for the implementation of crop management measures that mitigate fruit losses.