Abstract
In India, strawberry performs equally well in climates that are characteristically temperate in the northern latitudes, sub-tropical in the plains, or tropical at high altitude. In spite of attractive fruits and pleasing flavor, strawberry cultivation is still in its infancy in India primarily because of its perishable nature. Recently, some business houses have set up a number of pilot projects for large-scale strawberry production. Farmers in the sub-tropics in the vicinity of an urban center, such as New Delhi, have profitably cultivated strawberries during the winter months using plant material propagated in the hill states of India. Strawberry growers in the hills, thus, have a two-pronged earning potential from strawberry cultivation. Comparison of cultivars and economics of strawberry cultivation is presented.
INTRODUCTION
The cultivated strawberry (Fragaria x ananassa Duch.) has commanded a premier position in the world fruit market due to its attractive fruit and pleasant distinctive flavor. It has adapted well to highly varying climatic conditions. Today, strawberry is cultivated in regions that are characteristically temperate to sub-tropical plains to high altitudes in tropical regions and even in the desert-like areas of Israel. Being a shallow rooted crop, both crop damage and plant mortality can occur during dry seasons. Strawberry cultivation recently received some impetus in India with large business houses setting up a number of agro-based establishments primarily aimed at large scale production of strawberry fruits. Being an herbaceous annual fruit crop, it can also be grown easily in kitchen gardens, roof-top gardens, pots, etc. It is regarded as a valuable food in the diet of millions of people around the globe and is in special demand by the fruit processing industries for preparing the jams, ice cream, candy, toffee, and other products. A number of large fruited, high yielding varieties (e.g., ‘Chandler’, ‘Pajaro’, ‘Etna’, ‘Sweet Charlie’, ‘Selva’, ‘Douglas’, ‘Confictura’, ‘Dana’, ‘Belrubi’, ‘Gorella’, and ‘Addie’) have been introduced into India from Europe and North America. Some of the day-neutral cultivars (e.g., ‘Selva’, ‘Majestic’, ‘Phenomenal, ‘Brighton’, ‘Etna’, and ‘Fern’) may be adapted for Indian climate. Farmers in the vicinity of Delhi and in the states of Haryana, Punjab, Maharashtra, Karnataka, and Uttar Pradesh, a sub-tropical/tropical area, have been profitably cultivating strawberries during the winter months obtaining their planting materials from the hills of Himachal Pradesh and Uttarakhand (). Besides the income from strawberry fruits, growers in the hills, thus, can also earn by producing planting material for winter plantings in the plains. Strawberry is now grown in different agro-climatic conditions in India (e.g., states of Jharkhand, Meghalaya, Leh (Jammu and Kashmir), Lucknow, Chattisgarh, and Rajasthan).
FIGURE 1 Outline map of India showing areas where strawberry is being grown or strawberry cultivation is possible (color figure available online).
The use of polyethylene in commercial cultivation of strawberry can play a pivotal role in minimizing winter injury, plant mortality, and increasing productivity. Covering the strawberry beds with low clear plastic tunnels induced 1 month early cropping, prevented bed erosion, and increased total yields by 20%. The black polyethylene mulched beds did not require any weeding. During summers at high elevation locations, the polyethylene sheets of the tunnels were replaced by plastic anti-hail nets or anti-bird nets, which resulted in advanced harvest, increased yield, and improved fruit quality. This possibility has been reported under different agro-climatic conditions by CitationAlbregts and Chandler (1993).
Mulching is an important component of the strawberry production system. Many synthetic and organic types of mulch are being used for strawberry cultivation in different parts of the country based on the climatic conditions and availability of raw materials. CitationHimelrick (1982) showed that plants grown on black polyethylene produce more runners and fruits than with bare soil. Different workers have reported beneficial effects of organic mulches on strawberry production (CitationRebandel and Przysiccka, 1981, CitationBadiyala and Aggarwal, 1981, CitationHassan et al., 2000, CitationLille et al., 2003). Keeping this in view, the study was conducted to test the performance of the promising genotypes under different agro-climatic conditions in India.
MATERIAL AND METHODS
Strawberry cultivars representing diverse fruit and plant characteristics constituted the material for the present study (Tables ). The investigation was carried out at the Indian Agricultural Research Institute (IARI) Regional Station (Horticulture), Shimla (in hills), where all 39 cultivars were studied during 2007–2009. The study was also conducted at the Horticulture and Agro-Forestry Research Program (HARP), Indian Council for Agricultural Research in Ranchi, India in plains with 33 of these cultivars. The observations were recorded from randomly selected five plants from each cultivar in each replication. Observations were recorded for plant height, number of leaves, plant spread, date of harvest, fruit weight, total soluble solids (TSS), number of fruits per plant, yield per plant, yield per hectare, runner production, and disease reaction (leaf spot). The Mcoysphaerella fragariae leaf spot severity was recorded in a nursery as well as in pots by selecting 50 leaves
TABLE 1 Plant Characteristics of Strawberry Cultivars Grown in the Sub-Tropical Plains with Three Kinds of Ground Covers (Jharkhand, Ranchi, N 85.33°, E 23.35°; Elevation, 629 m)
TABLE 2 Yield Characteristics of Strawberry Cultivars Grown in the Sub-Tropical Plains with Three Kinds of Ground Cover (Jharkhand, Ranchi, N 85.33°, E 23.35°; Elevation, 629 m)
TABLE 3 Characteristics of Strawberry Cultivars Grown in Hills (Himachal Pradesh, Shimla, N 31.68°, E 77.13°; Elevation, 2000 m)
at random and categorizing them into a 0–5 scale, and percent disease intensity was computed according to CitationMcKinney (1923). All the disease ratings were further utilized for calculation of disease severity on the individual genotype.
The strawberry plants were planted 30 cm apart in rows that were 45 cm apart. Ten plants were planted in a bed of 150 × 60 cm. All runners were removed as soon as they appeared for better fruit production. In the same experiments, five other beds were kept for fruit production as well as runner production. There were three replications with five beds of each cultivar in each replicate. Other recommended agronomic, drip-irrigation, and plant protection measures were followed for successful strawberry cultivation. The effect of soil mulching with black and transparent polyethylene sheet covering was studied on weed growth, earliness, fruit yield, and fruit quality in Shimla hills.
The experiment in the plains (HARP) was laid out in a split-plot design with three mulches comprising of black polyethylene, paddy straw, and Deenanath grass (Pennisetum pedicellatum Trin.) as the main plots and 33 strawberry genotypes as subplot with three replications per treatment. Each replication consisted of raised beds of 20 cm height, 1.0 m width, and 2.0 m length having plants (runners) of one genotype planted on a mulching material at the spacing of 30 cm × 30 cm accommodating 10 plants/m2 (20 plants per bed). For black polyethylene mulching, UV-stabilized polyethylene sheets with a thickness of 150 microns having 6.0-cm diameter holes made at a spacing of 30 cm × 30 cm were fixed on the raised beds before planting. The runners were planted in each hole after the mulching material was laid out. Both the organic mulches were laid out on the bed with a thickness of approximately 10 cm after the plants have established (emergence of new leaf). Other recommended agronomic, drip-irrigation, and plant protection measures were followed for successful strawberry cultivation.
RESULTS AND DISCUSSION
Performance of over 30 strawberry cultivars in the sub-tropical plains is presented in Tables for plant and yield characteristics, under black polyethylene and two organic mulches (). Maximum plant height, number of leaves per plant, and plant spread were observed under black polyethylene mulch. The plants in two organic mulches did not differ significantly for plant height and spread, but the number of leaves per plant in paddy straw mulch was superior to those with Deenanath grass mulch. ‘Seascape’ exhibited maximum plant height (14.6 cm) and spread (29.5 cm). ‘Pusa Sweet’ exhibited the least plant height (8.57 cm) and spread (17.03 cm). Maximum number of leaves per plant was exhibited by ‘Douglas’ (35 per plant), while ‘Pusa Pride’ put forth the least number of leaves (19 per plant). None of the yield characteristics studied was appreciably affected by any of the three mulch treatments (data not presented). Percent of total yield before peak fruiting is an indicator of the pattern of yield distribution in a cultivar. The cultivars with higher percent of total yield before peak fruiting stage (>80%) were generally prolonged bearers. Irrespective of mulches, ‘Pusa Sweet’ had the maximum percent of total yield produced before the peak fruiting stage (data not presented). Significant differences in yield distribution pattern within a cultivar on different mulching was observed in ‘Florida-90’, ‘Dana’, ‘Douglas’, ‘Larson’, ‘Blakemore’, ‘Himalayan Scarlet’, ‘Addie’, ‘Majestic’, V.L., and ‘Fern’ (data not presented). Different mulches probably led to differences in canopy temperature; moisture content; and the quantity and quality of light transmitted, reflected, or absorbed (CitationWang et al., 1998).These differences, in turn, may have affected plant growth, development, and fruit quality in the strawberry plants.
TABLE 4 Effect of Plastic Soil Mulch on Weed Growth on Strawberry Plots in Hills; the Values are Presented as the Percentage of the Weed Biomass Weighed in the Naked/Bare (Unmulched) Plots
The maximum average fruit weight was observed in cv. Douglas (7.4 g), which was almost at par with that in the case of cvs. Etna, Redcoat, Hayward-17, Catskill, Fairfax, and Selva. Among the mulches, the fruit weight did not differ significantly. Significant effects of mulches were observed on the yield of several cultivars. On all the mulches, cv. Etna recorded the maximum yield. On polyethylene mulches, the yield of cv. Douglas was the highest followed by cv. Etna, but on paddy straw and Deenanath grass mulches, the yield of cv. Douglas followed that of cv. Etna. The average yield of strawberry cultivars was highest on black polyethylene mulch, but on paddy and Deenanath grass mulch, yield did not differ significantly. ‘Etna’ and ‘Douglas’ plants were found to be most suitable for cultivation in all the three mulch types under the sub-humid sub-tropical plateau region of eastern India (data not presented). However, during the summer months, heavy mortality of plants on black polyethylene mulches was observed due to heat injury, but not in paddy straw and Deenanath grass mulches.
Black polyethylene mulch in the strawberry beds (in hills) resulted in considerable reduction in weed growth (). This is in agreement with the findings of CitationWang et al. (1998). The weed growth under the black polyethylene mulch was limited (29.3 to 15.9% of the weed growth observed on un-mulched strawberry beds). The translucent/transparent polyethylene mulch was less effective in preventing weed growth. The black polyethylene mulched beds did not require any weeding, while the un-mulched beds required weeding at 20- to 30-day intervals. Being a shallow rooted crop, strawberry was prone to extremes of weather. The plastic mulch played a pivotal role in minimizing plant mortality and increasing productivity. Black polyethylene mulching resulted in a better soil moisture regime and considerably reduced weed growth, which reduced the labor cost for weeding by 25 to 30% (data not presented). Covering the strawberry bed with mini-plastic tunnels induced early cropping and total yield by 20% and reduced winter injury (data not presented).
During summers (in the hills), the plastic sheets of the tunnels were replaced by plastic anti-hail nets/anti bird nets, which resulted in higher yields and better fruit quality (CitationHimelrick, 1982; CitationPramanick et al., 2003; CitationLocascio and Smart, 1968). The adoption of protected systems for strawberry production tested in Brazil must be carefully evaluated in India. A number of reports described the occurrence of high temperatures under protected environments in relation to field conditions (CitationMontero et al., 1985), which could be adverse for strawberry production, such as reduction in fruit size (CitationIuchi, 1993). In the present study, comparisons were made among the cultivars/lines for their fruit weight, TSS, no. of fruits per plant, yield per plant, and yield per hectare (), but no significant yield differences were observed among mulch types.
CitationGast and Pollard (1991) found that row covers could enhance yield of marketable fruits in ‘Earliglow’ strawberry but not the number of flowers. Yield increase was primarily due to increase in development of tertiary berries in trusses. ‘Darrow’, ‘Earliglow’, and ‘Sparkle’ strawberries grown under spun-bounded polypropylene, polyester, polyamide, or silted polyethylene films, flowered 13 days earlier and their fruits were ready for harvest 10 days earlier than uncovered plants (CitationPollard et al., 1989). Fruiting in plastic-covered ‘Rahnyaya’ and ‘Redgauntlet’ strawberries was hastened by 20 days (CitationKopylov, 1991). In the present study, the hastening of flowering in strawberry genotypes varied from16 days in cv. Shasta to 50 days in cv. Selva under transparent polyethylene tunnels (data not presented). Overall mean value for early flowering was 29 days. The low plastic tunnels also tended to extend the harvest period by 5 to 6 days (data not presented). The fruit weight varied from 3.0 in cv. Amartara Red to 24.2 g in cv. Etna. The large fruited varieties were ‘Etna’, ‘Chandler’, ‘Selva’, ‘Douglas’, ‘Dana’, ‘Belrubi’, ‘Confictura’, ‘Brighton’, ‘Pajaro’, ‘Fern’, ‘Adie’, ‘Gorilla’, ‘Sweet Charlie’, and ‘Seascape’. Long fruit length was exhibited by ‘Selva’ (38 mm) followed by ‘Gorella’ (37 mm), ‘Douglas’ (35 mm), and ‘Etna’ (34 mm), whereas small size was recorded in ‘Fairfax’ (17 mm) followed by ‘Howard-17’ (18 mm). The fruit length varied from 17 to 38 mm. Wide fruit width was observed in ‘Etna’ (35 mm) followed by ‘Douglas’ (30 mm), and ‘Chandler’ (29 mm), whereas narrow width was recorded in ‘No. A’ (13 mm) followed by ‘North West’ (13 mm). According to CitationNitsch (1950), CitationJanick and Eggert (1968), and CitationMoore et al. (1970), those differences in fruit size were primarily due to plant vigor, competition among fruits in the inflorescence number and size of developed achenes, climatic conditions, irrigation, and plant nutrient status. ‘Shimla Delicious’ exhibited high TSS (11.3%) followed by cv. Pusa Pride (12.8%), cv. Pusa Sweet (12.6%), cv. Jutogh Special (12.5%), and cv. Himalayan Scarlet (12.4%). Low TSS was recorded in ‘Chandler’ (8.0) followed by ‘Etna’ (8.2) and ‘Selva’ (8.5). These results are in agreement with the findings of CitationPerkins-Veazie (1995) who reported that TSS content varies from 4o to 12oBrix in strawberry. According to CitationShaw (1990), environmental conditions rather than genetic inheritance during production influenced the soluble solids content. The high number of fruits per plant was harvested from ‘Shimla Delicious’ (30 fruit/plant) followed by ‘Amartara Red’ (24/fruit/plant), whereas few fruit was harvested from ‘Selva’, ‘Etna’, and ‘Douglas’ (<12 fruit/plant). Yield per plant varied tremendously (∼39 to 256 g/plant). The highest yield was observed in ‘Etna’, followed by ‘Sweet Charlie’, ‘Chandler’, ‘Belrubi’, ‘Douglas’, ‘Seascape’, and ‘Selva’. ‘North West’, ‘Larson’, and ‘Phenomenal’ produced less than 60 g of fruit per plant. These variations in yielding potential are markedly influenced by environmental parameters like photoperiod, temperature, and light intensities (CitationAvidov, 1986).
Large-scale runner production was undertaken by establishing runner beds in fields prone to spring frosts as damage to the flowers does not matter. Generally, a production of 7 to 32 runners was obtained per plant. Runner production ranged from 32 to 24 in ‘Jutogh Special’, ‘Larson’, ‘Shimla Delicious’, and ‘Phenomenal’. Runner production was less than 11 in the following cultivars: ‘Douglas’, ‘Fern’, ‘Selva’, and ‘Shasta’.
Strawberry cultivars were also evaluated for their disease reaction to leaf spot (c.o. Mycosphaerella fragariae) under natural disease pressure during the period under report. Large-fruited varieties were more susceptible than small- to medium-fruited varieties. Protected cultivation has been used for strawberry cultivation in order to protect plants from harsh weather and for a better control of diseases (CitationPassos, 1997).
Commercialization of Strawberry
Strawberry is a highly commercialized fruit crop being sold at a premium price of Rs 200 (1 US $ = 44.43 Indian Rupee INR, Rs) to Rs 300 per kg as an early crop and Rs 80 to Rs 100 as a late crop. Subject to prevailing weather conditions and following the recommended package of practices, the net profit from one bigha (one-fifth of an acre) area may vary from Rs 4.19 lakhs (1 lakh is equivalent to 100,000; Rs 4.19 lakh = US $9,430.85 at current rates of conversion) per annum in the hills to Rs 8.48 lakhs ($19,086.78) per season in the plains at the end of 6 years ( and ). Strawberry enterprise cost analysis was reported by CitationFonsah et al. (2002) and profitability of different technologies of strawberry cultivation was mentioned by CitationLille et al. (2003).
TABLE 5 Economics for Strawberry Production in the Hills for 1 bighaFootnote z (Himachal Pradesh, Shimla, N 31.68°, E 77.13°; Elevation, 2000 m)
TABLE 6 Cost Estimates of Strawberry Cultivation in the Plains (Jharkhand, Ranchi, N 85.33°, E 23.35°; Elevation, 629 m ASL) per BighaFootnote z
Strawberries are a high-value crop, but they also have special production requirements, a short shelf life, and a brief marketing season. Initial investment in land preparation, irrigation, and other equipment can cost about $2,000 per acre for a matted row system (Ernst, 2003) to $10,000 per acre for a plasticulture system (Karcher, 2002). However, plasticulture systems produce earlier and have higher yields—up to double the yield of matted row systems. Earlier harvest may allow producers to receive the higher prices available at the beginning of the season. Continuous cropping of strawberries is not possible in an organic system that relies on crop rotations. The production cycle is shorter (1 to 2 fruiting years) and yields are both lower and more variable than in conventional systems. Labor requirements may be as much as twice those of a conventional system (CitationPritts and Handley, 1999). Since they face higher costs of production, organic growers must secure a premium price in order to make a profit.
CONCLUSION
Covering the strawberry beds with mini plastic tunnels induced 1 month of early cropping and increased total yields by 20%. Winter injury and consequent mortality was also appreciably reduced. During summers (in the hills) the plastic sheets of the tunnels were replaced by plastic anti-hail nets or anti-bird nets, which resulted in higher yields and better fruit quality. Black polyethylene mulching resulted in a better soil moisture regime and considerably reduced weed growth and irrigation. Otherwise, being a shallow rooted crop it requires irrigation almost daily during the summer season. Considering all these factors, it may be concluded that the genetic stock of strawberry used in these investigations had a wide range of variability of fruit and yield characters. As such, there is enough scope for improvement of these characters by selection/breeding.
Farmers in the tropical and sub-tropical area have been profitably cultivating strawberries during the winter months obtaining their planting materials from the hills. Besides the income from strawberry fruits, growers in the hills can, thus, also earn by producing planting material for winter plantings in the plains. The growers in the plains cannot produce their own disease-free planting material as these plants do not survive in the extreme summer, even if they do so, they are prone to various diseases, particularly those transmitted by aphids or other insect pests. It is a highly commercialized fruit crop being sold at a premium price of Rp 200 to Rs 300 per Kg as an early crop and Rs 80 to Rs 100 as a late crop. Subject to prevailing weather conditions and following the recommended package of practices, the net profit from one bigha (one-fifth of an acre) area may vary from Rs 4.19 lakhs (hundred thousand) per annum in the hills to Rs 8.48 lakhs per season in the plains at the end of the 6th year.
ACKNOWLEDGMENT
We wish to acknowledge the Indian Council of Agricultural Research and Indian Agricultural Research Institute for funding this research.
LITERATURE CITED
- Albregts , E.E. and Chandler , C.K. 1993 . Effect of polyethylene mulch color on fruiting response of strawberry . Proc. Soil Crop Sci. Florida , 52 : 40 – 43 .
- Avidov , H.A. 1986 . “ Strawberry ” . In Handbook of fruit set and development , Edited by: Monselise , S.P. Boca Raton , FL : CRC Press, Inc .
- Badiyala , S.D. and Aggarwal , G.C. 1981 . Note on the effect of mulches on strawberry production . Ind. J. Agric. Sci. , 51 : 832 – 834 .
- Ernst, M. 2003. Kentucky strawberry profitability: Estimated costs and returns. New Crops Opportunity Center. University of Kentucky Cooperative Extension. August, 2006. < www.uky.edu/Ag/NewCrops/strawberries.pdf (http://www.uky.edu/Ag/NewCrops/strawberries.pdf)
- Fonsah , E.G. , Krewer , G. , Harrison , K. and Jennings , R. 2002 . Strawberry enterprise cost analysis . Bul. AGECON-02-072. Coop. Extn. Serv. Univ. Ga, Coll. of Agric. Environ. Sci. 1–9. ,
- Gast , K.L.B. and Pollard , J.E. 1991 . Row covers enhance reproductive and vegetative yield components in strawberries . HortScience , 26 : 1467 – 1469 .
- Hassan , G.I. , Godara , A.K. , Kumar , J. and Huchche , A.D. 2000 . Effect of different mulches on the yield and quality of ‘Oso Grande’ strawberry (Fragaria x ananassa) . Ind. J. Agric. Sci. , 70 : 184 – 185 .
- Himelrick , D.G. 1982 . Effect of polyethylene mulch color on soil temperatures and strawberry plant response . Adv. Strawberry Prod. , 1 : 15 – 16 .
- Iuchi , T. 1993 . Plant growth and fruit of strawberry (Fragaria x ananassa Duch.) in different water regimes , 187 Vicosa , , Brazil : Ph.D. Dissertation, Federal University of Vicosa .
- Janick , J. and Eggert , D.A. 1968 . Factors affecting fruit size in the strawberry . Proc. Amer. Soc. Hort. Sci. , 93 : 311 – 316 .
- Karcher, M. 2002. Strawberry plasticulture offers sweet rewards. Ohio State University Cooperative Extension News Online. 7 August 2002. < www.ag.ohio-state.edu/˜news/story.php?id=2126 (http://www.ag.ohio-state.edu/~news/story.php?id=2126)
- Kopylov , L.I. 1991 . Early strawberry crop under plastic covers . Sadovodstvo vinogradarstvo , 3 : 25 – 26 .
- Lille , T. , Karp , K. and Varnik , R. 2003 . Profitability of different technologies of strawberry cultivation . Agronomy Res. , 1 : 75 – 83 .
- Locascio , S.J. and Smart , G.C. Jr. 1968 . Influence of polyethylene mulch colors and soil fumigants on strawberry production . Adv. Strawberry Prod. , 1 : 29 – 31 .
- McKinney , H.H. 1923 . Influence of soil temperature and moisture on infection of wheat seedlings by Helminthosporium sativum . J. Agric. Res. , 26 : 195 – 217 .
- Montero , J.I. , Castilla , N. , Gutierrez de Rave , E. and Bretones , F. 1985 . Climate under plastic in the Almeria area. Acta Hort , 170 : 227 – 234 .
- Moore , J.N. , Brown , G.R. and Brown , E.D. 1970 . Comparison of factors influencing fruit size in large fruited and small fruited clones of strawberry . J. Amer. Soc. Hort. Sci. , 95 : 827 – 831 .
- Nitsch , J.P. 1950 . Growth and morphogenesis of the strawberry in relation to auxin . Amer. J. Bot. , 37 : 211 – 215 .
- Passos , F.A. 1997 . Influência de alguns sistemas de cultivo na cultura do morango (Fragaria x ananassa Duch.) , Piracicaba : USP/ESALQ, 106 p . Tese–Doutorado
- Perkins-Veazie , P. 1995 . Growth and ripening of strawberry fruit . Hort. Rev. , 17 : 267 – 297 .
- Pollard , J.E. , Gast , K.L.B. and Chundari , C.M. 1989 . Overwinter row covers increase yield and earliness in strawberry . Acta Hort. , 265 : 229 – 234 .
- Pramanick , K.K. , Kishore , D.K. and Sharma , Y.P. 2003 . Effect of polyethylene on the behavior and yield of strawberry (Fragaria x ananassa) . J. Appl. Hort. , 2 ( 2 ) : 130 – 131 .
- Pritts , M. and Handley , D. 1999 . The strawberry production guide for the Northeast, Midwest, and Eastern Canada , Ithaca , , New York : NRAES-88. NRAES .
- Rebandel , Z. and Przysiccka , M. 1981 . Evaluation of the suitability of some organic materials in strawberry cultivation. Informator o hadaniach prowadzonych w Zakladzie Sadownictwa Akadernii Rolniczej w Poznaniu 113 – 118 .
- Shaw , D. 1990 . Response to selection and associated changes in genetic variance for soluble solids and titratable acid contents in strawberries . J. Amer. Soc. Hort. Sci. , 115 : 839 – 843 .
- Wang , S.Y. , Galletta , G.J. and Camp , M.J. 1998 . Mulch types affect fruit quality and composition of the strawberry genotypes . HortScience , 33 : 636 – 640 .