Number Of Fruit Set Research Articles

Production and characterisation of tomato derived from interspecific hybridisation between cultivated tomato and its wild relatives

ABSTRACT Tomato (Solanum lycopersicum L.) is facing various problems of yield such as abiotic and biotic stresses. The wild tomato species are excellent source of economical traits which resistant to various types of stress and quality characters that can be transferred into cultivated tomato through intra and interspecific hybridisation. This study describes the development of inter and intraspecific hybrid tomato plants and screens the best hybrids. The interspecific hybrid tomato plants were developed by making a cross between wild tomato species and cultivated tomato. In the morphological traits, hybrids F1 showed intermediate values from both of their parents in fruit weight. Although wild parent male showed dominant impact in hybrids for many morphological characters such as leaf width and length, number of fruit set per truss, and fruit yield. The hybrids F1 also showed good characters in total soluble solids, total sugar, reducing and non-reducing sugar were enriched in cultivated tomato after crossing with wild relatives. The wild tomato has play important role in increased the lycopene level in hybrids. So, the hope that this study opens the new world gene pool for tomato breeding, ultimately contributing to the adapted of climate change and increase the tolerance to abiotic and biotic stress.

Biostimulant Application Enhances Fruit Setting in Eggplant—An Insight into the Biology of Flowering

Eggplant (Solanum melongena L.) is a warm climate crop. Its cultivation extends to temperate regions where low temperatures can affect the course of the generative phase, which is primarily sensitive to abiotic stress. The novelty of the present investigation consisted of characterising the heterostyly, pollination, and fertilisation biology of eggplants in field cultivations, which provided a basis for explaining the effect of a protective biostimulant on these processes. We aimed to investigate the flowering biology of three eggplant hybrids treated with Göemar BM-86®, containing Ascophylum nodosum extract, to determine the crucial mechanisms behind the increased flowering and fruit set efficiency and the final effect of increased yield. The flower phenotype (long, medium or short styled), fruit setting, and the number of seeds per fruit were recorded during the two vegetation periods. The numbers of pollen tubes and fertilised ovules in ovaries were evaluated during the generative stage of development to characterise the course of pollination and fertilisation for all types of flowers depending on the cultivar and biostimulant treatment. The expression of heterostyly depended on the eggplant genotype, age of the plant, fruit load, and biostimulant treatment. Domination by long-styled flowers was observed, amounting to 41%, 42%, and 55% of all flowers of “Epic” F1, “Flavine” F1, and “Gascona” F1, respectively. This flower phenotype contained the highest number of pollen tubes in the style and the highest number of fertilised ovules. The biostimulant had a positive effect on the flower and fruit set numbers, as well as on the pollination efficiency in all genotypes. Ascophylum nodosum extract could be used as an efficient stimulator of flowering and fruit setting for eggplant hybrids in field conditions in a temperate climatic zone.

Impact of enhanced Osmia bicornis (Hymenoptera: Megachilidae) populations on pollination and fruit quality in commercial sweet cherry (Prunus avium L.) orchards

The impact on pollination of supplementing wild pollinators with commercially reared Osmia bicornis in commercial orchards growing the self-fertile sweet cherry variety “Stella” was investigated in each of two years. The quality characteristics used by retailers to determine market value of fruit were compared when insect pollination was by wild pollinators only, or wild pollinators supplemented with O. bicornis released at recommended commercial rates. No effect of treatment on the number of fruit set or subsequent rate of growth was recorded. However, supplemented pollination resulted in earlier fruit set when compared to pollination by wild pollinators alone and offered the potential benefit of a larger proportion of the crop reaching optimum quality within a narrower time range, resulting in more consistent produce. Retailers use five key quality criteria in assessment of market value of cherries (the weight of individual fruit, width at the widest point, fruit colour, sugar content and firmness). Price paid to growers depends both on meeting the criteria and consistency between fruit in these characteristics. In both years, the commercial criteria were met in full in both treatments, but harvested fruit following supplemented pollination were consistently larger and heavier compared to those from the wild pollinator treatment. In the year where supplemented pollination had the greatest impact on the timing of fruit set, fruit size and sugar content were also less variable than when pollination was by wild species only. The implications for the commercial use of O. bicornis in cherry orchards are considered.

Effect of soil and foliar application of macro and micronutrients on flowering, fruit set and yield of mango cv. Dashehari

The experiment was carried out at Horticulture Research Centre, Pattharchatta, G. B. Pant University of Agriculture and Technology, Pantnagar, district- Udham Singh Nagar, Uttarakhand during the year 2015-16. The experiment was laid out in RBD (Randomized Block Design) with 10 treatments and 3 replications. The earlier (February10 - February 19) panicle emergence, maximum duration of flowering (27.66 days), number of fruit set per panicle at marble stage was found significantly higher (3.69), higher yield plant-1 (228.24 kg) and maximum shelf life (12.33 days) were found with the application of T10: RDF + NPK: 20:20:20 @ 1% (2 Spray: first-15 days and Second- 45 days after fruit set) + foliar spray of ZnSO4 @ 0.4% + Boric acid @ 0.2% + CuSO4 @ 0.2% (2 Spray at just before flowering and marble stage). The maximum flowering intensity percentage was found maximum (48.48 %) in T7 [RDF + ZnSO4 @ 100 g + CuSO4 @ 50 g + Boric acid @ 50 g (soil application) + Foliar spray of ZnSO4 @ 0.2 % + CuSO4 @ 0.1 % + Boric acid @ 0.1 % (2 sprays at just before flowering and marble stage], the minimum flowering intensity (32.66%) percentage was obtained in T1 [Control (RDF)].

Populasi Elaeidobius kamerunicus Faust (Coleoptera: Curculionidae) pada beberapa umur tanaman kelapa sawit

Kumbang Elaeidobius kamerunicus Faust merupakan serangga polinator kelapa sawit yang hidup pada bunga jantan dan mengunjungi bunga betina untuk melakukan penyerbukan karena ketertarikan terhadap senyawa volatil yang dikeluarkan. Kuantitas fruit set kelapa sawit yang dihasilkan berhubungan dengan populasi E. kamerunicus pada suatu lahan. Penelitian ini bertujuan untuk mempelajari pengaruh umur tanaman kelapa sawit terhadap populasi kumbang E. kamerunicus. Penelitian dilakukan di perkebunan kelapa sawit yang terletak di Pangkalan Lada, Kotawaringin Barat, Kalimantan Tengah. Metode penelitian yang digunakan adalah berupa penghitungan populasi E. kamerunicus pada bunga jantan dan pemasangan sticky trap pada bunga betina. Plot pengamatan berukuran 7000 m2 (100 pohon) dengan variasi umur tanaman kelapa sawit, yaitu 6, 10, dan 16 tahun. Setiap plot dihitung jumlah bunga jantan dan betina yang mekar dan ditentukan beberapa bunga untuk pengukuran populasi E. kamerunicus yang dilakukan setiap bulan selama tiga bulan pengamatan. Hasil penelitian menunjukkan bahwa umur tanaman kelapa sawit berpengaruh terhadap populasi E. kamerunicus pada bunga jantan tapi tidak pada bunga betina. Semakin tua umur kelapa sawit, populasi E. kamerunicus pada bunga jantan semakin meningkat. Rasio jenis kelamin E. kamerunicus yang ditemukan pada bunga jantan dan betina kelapa sawit cenderung bias betina. Berdasarkan perbandingan populasi E. kamerunicus pada bunga jantan dan betina pada setiap plot diperoleh bahwa nilai kunjungan E. kamerunicus paling tinggi ditemukan pada umur kelapa sawit muda. Sebagai kesimpulan, pertambahan umur kelapa sawit mempengaruhi peningkatan populasi E. kamerunicus pada bunga jantan tapi persentase kunjungan ke bunga betina menjadi semakin menurun.

EFFECT OF NITROGEN AND POTASSIUM FERTILIZATION ON YIELD AND FRUIT QUALITY OF MANGO KEITT CV. TREES GROWN UNDER OPEN FIELD AND SHADING CONDITIONS

This study was carried out during three successive seasons of 2010/2011, 2011/2012 and 2012/2013 in a private orchard at 76 km Cairo, Alex. Desert road to investigate the effect of nitrogen and potassium fertilization treatments and shading with white net on yield, and fruit quality of three-years-old mango (Mangifica indica L.) cv. Keitt grafted on sucary seedling rootstocks planted at 2.5×2.5 meters apart grown in sandy soil under drip irrigation system with wells water .This experiment included nine treatments of fertilization: T1= N 80+ K2O 80 Kg/Fed., T2= N 80+ K2O 100 Kg/Fed., T3= N 100+ K2O 80 Kg/Fed., T4= N 100+ K2O 100 Kg/Fed., T5= N 120+ K2O 80 Kg/Fed., T6= N 120+ K2O 100 Kg/Fed.,T7= N 150+ K2O 80 Kg/Fed., T8= N 150+ K2O 100 Kg/Fed. and control (T9) = N 133+ K2O 90 Kg/Fed.. The results cleared that mango Keitt cv. trees grown under white net shading condition significantly increased yield (kg)/ tree, number of fruit set/ panicle, fruit weight, TSS and ascorbic acid content. Trees supplied with 150 Kg/Fed. nitrogen + 100 Kg/Fed. potassium exhibited the highest yield (kg)/tree, number of fruit set/panicle and fruit weight under shade . Moreover, the best fruit peel color was achieved with trees received 100 kg/feddan of nitrogen +100 kg/feddan of potassium and grown under screenhouse conditions during the three studied seasons. The higher significant value of acidity and TSS were recorded in trees supplied by 120 units of nitrogen + 100 units of potassium during first and third season. Whereas, the control treatment attained a maximum ascorbic acid content.

Root-zone cooling improves fruit production in high sugar content tomato

The high-sugar content tomato is becoming popular because of its sweetness in Japan. However, the production of high-sugar content tomatoes in summer has been unstable especially in number of fruit set. Root-zone cooling is known to have an advantage to increase tomato yield in the summer and the effect of root zone cooling was evaluated in the production of high-sugar content tomato. High-sugar content tomatoes were grown at 2 kinds of plots, 15 and 25°C, in root-zone temperatures (RZT) from December 12, 2015 to February 13, 2016. During the experiment, the average air temperature was 21.8°C. During the daytime (9:00-17:00) the temperature was on average 24.2°C and during the nighttime (17:00-9:00) it was 20.7°C. The number of fruits per cluster was 3.3 in 15°C-RZT and 2.6 in 25°C-RZT. The floret number was larger and the flowering rate (the number of anthesis/floret emerged) was higher in the 25°C-RZT than in the 15°C-RZT. This phenomenon showed the possibility to improve the yield of high-sugar content tomatoes. The present examination was done in winter. It is necessary to perform this kind of examination in summer, over 30°C day temperature.

Effect of Climate Change on Apple Productivity

India with its unique agro climate conditions favours cultivation of number of fruits. For decades together typical temperate fruits like apple, pear, stone and nut fruits were grown with adequate production and productivity. However, during the past 10-15 years on account of global warming many of the sites which were potential hub for temperate fruit cultivation have been rendering unfit for their cultivation. The productivity of temperate fruits especially apple in Himachal Pradesh is declining at a faster rate. Average yield of apple in India has been estimated at about 7.0 t/ha which is far below the level of 30 t/ha in most of advanced countries. The productivity has also not kept pace with the expansion in area under temperate fruits due to various biotic and abiotic problems faced by the farmers in the Himalayas. This has caused a serious concern not only to the hill farmer community but also to researchers, development agencies and policy planners. With the global warming, the decline in productivity is being mainly attributed to changing climatic scenario. It is clearly reflected that standard apple cultivar 'Starking Delicious' and 'Red Delicious' would not flower and fruit when chilling units are not adequately fulfil. Hence there is an urgent need to select appropriate low chill cultivars for plantation at low elevation location so that consistent yields are obtained and crop failures avoided. Results obtained revealed that cultivar 'Tropical Beauty' was the best genotype for the characters like plant height (6.60m), plant spread (5.67m), trunk girth (64.50cm), tree volume (111.20m3), leaf area (60.67cm2), number of fruit set per unit shoot length (15.25%), yield per plant (15.82Kg), fruit weight (129.80g), total sugar (8.48%) and non-reducing sugar (1.92%). Cultivar 'Parlin's Beauty' was the best genotype for characters like fruit breadth, reducing sugar and was recorded as promising next to 'Tropical Beauty' for many desirable traits. Cultivar 'Chahla' was superior for high number of flowers per unit shoot length, shoot length, fruit length and long duration of flowering. Earliest flowering was observed in cultivars 'Anna'. Maximum phenotypic coefficient of variability was observed for fruit yield per plant. High heritability and high genetic advance indicated presence of additive gene action for these traits. To meet the bulk requirements of the processing units and horticultural diversification, apple cultivation can be extended to mid hills by planting suitable low chilling cultivars. The low productivity of apple has become a serious concern for the farmers, research workers and development agencies at national and state level for the last two decades. Several factors can be attributed to the declining trend in productivity like expansion of apple cultivation to marginal areas, monoculture of Delicious varieties, declining standards of orchard management, improper chilling requirements and the fluctuating abnormal climatic conditions.

Variation in morphology and yield traits of Cucurbita landraces in northern KwaZulu-Natal, South Africa

Pumpkins, represented by various Cucurbita species, are important traditional leafy vegetable crops that are widely eaten in KwaZulu-Natal, South Africa, and elsewhere. Cucurbita landraces are exceptionally variable in morphology and productivity. Although these vegetables are grown extensively in South Africa, the quantitative traits of local pumpkin germplasm have not been recorded previously. Eight Cucurbita landraces, representing three species, were morphologically characterised. The variability among the landraces was significantly different for all assessed traits. The ranges recorded were: the number of lateral branches, 9.1–26.8; number of pistillate flowers, 7.0–47.6; number of staminate flowers, 73.8–169.5; number of fruit set, 0.1–1.1; number of fruit harvested, 0.3–17.0; number of fully developed seeds per fruit, 330–423; fruit mass, 3.5–5.0 kg; 100-seed mass, 10.7–14.7 g; and total seed mass, 48.3–70.2 g. The fruit length varied from 27.4 to 38.6 cm and diameter from 51.8 to 68.5 cm. Future research is desirable to improve the productivity selectively of these particular landraces. Diversity among these landraces could potentially form the basis for future breeding programmes and thereby contribute significantly towards hunger alleviation, nutritional benefits and income generation, particularly among rural people.

Examination of self-compatibility in promising plum (Prunus domestica L.) genotypes developed at the Fruit Research Institute, Čačak

The self-compatibility of six promising plum genotypes (hybrids 38/62/70, IV/63/81, 32/21/87, 34/41/87 and 22/17/87 and cultivar ʻNada’) was examined during the period 2009–2011 through quantitative evaluation of parameters of in vivo pollen tube growth and fruit set. Mean daily temperatures were recorded during the flowering period. All genotypes showed good average in vitro pollen germination (36.34–38.63%) except the cultivar ʻNadaʼ (25.64%). The lowest values for in vivo pollen tube growth parameters – except with respect to number of pollen tubes in the upper third of the style ‐ were found in hybrid 32/21/87 and cultivar ʻNada’. The same genotypes also had the highest numbers of incompatible pollen tubes. The average number of fruit set ranged from 1.25% (hybrid 32/21/87) to 31.08% (hybrid 34/41/87). All studied parameters depended on genotype, year and their interaction. There was a significant positive correlation between the number of fruit set and the number of pollen tubes in the base of the style. The number of pollen tubes in the ovary had a significant positive impact on percentage of pistils with pollen tube penetrating the nucellus 240h after pollination and on number of fruit set. Based on these data hybrid 32/21/87 and cultivar ʻNadaʼ were classed as partially self-compatible and hybrids 38/62/70, IV/63/81, 34/41/87 and 22/17/87 as self-compatible.

INNOVATION IN AGRICULTURAL SUPPORT ON SUSTAINABILITY FOR FRESH FRUIT BUNCH (FFB) OF ELAIS GUINEESIS IN MALAYSIA USING ARTIFICIAL DOMESTIC POLLINATION SYSTEM (ADOPSY™)

Sustainability of the Fresh Fruit Bunch (FBB) is one of the most important elements at the plantation level. Most of Oil Palm planters at this stage do not get the desired result of output production due to inconsistency of number of fresh fruit bunch on the plants. The main element to ensure plants producing FBB at a sustainable level is to keep the existence of the weevil for pollination. Nowadays it is hard to ensure the population of the weevil in right condition constantly due to misconduct of the biodiversity as well as ecosystem in the plantation areas. Weevil species (Elaeidodius kamerunicus) brought by an entomologist, Syed Anwar Rahman, from Cameroon to Malaysia managed to increase the number of fruit set in 1981. Hence, this research is carried out to determine the new method of pollination that should help planters to get sustainable output of FBB in term of quantity. The main purpose of the research is to get sufficient numbers of FBB at individual oil palm plant using Artificial Domestic Pollination System (ADOPSY™) that was invented by the researcher. Applied research base on case study undertaken in Felda Cawangan Tembangau 6, Pahang, under the management of Felda Global Venture (FGV). Data collection completed by the FGV staff by using standard format so called “Bancian tandan hitam” or Fresh Fruit Bunch Census Format without influences by the researcher, ensuring data corroborated. The data is analyzed to examine the development in term of production referring to the increased quantity of fresh fruit bunch. FGV was chosen due to its worldwide establishment among the biggest oil palm production conglomerate in Malaysia. The most vital finding of this research is to confirm that the technology (ADOPSY™) and supported product (PreMix-SP) used in this research, would produce sustainable output production of FBB. The research demonstrated the increasing value of production of FBB by implementing check and control method under treated test plot compared to untreated test plot for period of one year. This research will also facilitate opportunity profit by eliminating defect, referring to decreasing numbers of abortion in plantation production.

Effect of growing methods on seed yield and quality in bottle gourd (Lagenaria siceraria)

The present investigation was planned to know the feasibility of trailing method of growing vis-a-vis traditional method and their effects on growth, flowering, fruit set, seed yield and quality traits in bottle gourd [Lagenaria siceraria (Mol.) Standl]. The results revealed that trailing method had significantly higher vine length (4.56 m), number of leaves/vine (40.48), leaf area (42 807 cm2) and number of nodes/vine (40.48) at 55 DAS. The reduction in number of days to anthesis to first male flower (49.8 days) and female flower (54.6 days) in trailing as compared to traditional method. The fruit development attributes, viz. number of fruit set (4.08), matured fruits/vine (3.55), fruit weight (2.30 kg) were recorded significantly higher in trailing but significantly less fruit width (9.56 cm), fruit cavity (7.21 cm) and cavity volume (1996.2 cm3) were recorded in trailing method. Seed yield attributes, i.e. the number of total seeds/fruit (723.01), number of filled seeds/fruit (651.88), seed yield/fruit (98.33 g), seed yield/vine (346.16 g) and seed yield/acre (410.13 kg) was significantly higher in trailing method. The significant increase in germination (97.54%) was recorded in trailing system as compared to traditional system (95.21%). Similarly, seedling length (42.66 cm), seedling dry weight (6.56 mg) and embryo weight (7.49 mg) were significantly higher in trailing. Vigour index I (4161.07) and VI II (63.92) were also significantly superior in trailing. The presence of fungi was lower in trailing than traditional among the infected fruits.

재래호박 대목을 이용한 단호박 접목묘의 수량 증대 효과

Results on growth, fruit set number and fruit weight, yield by rootstock sort of sweetpumpkin; Growth, fruit set number and weight of upper part of sweet pumpkin was than self-root seedlings and among grafted seedlings, Goksung collection variety were better than Shintozoa. Yield was higher grafted seedlings than self-root seedlings, 17% in semiforcing, 16% in nursery cultivation and 28% in retarding. Powdery mildew distinctive decreased grafted seedlings than self-root seedlings for growth duration

Efficacy of ipm modules against mango hopper complex

Field experiments were conducted to evaluate the efficacy of Integrated Pest Management (IPM) modules against mango hopper during 2009–10 to 2012–13 in south Gujarat region. The module-V consisting first spray of acephate (0.04%) at panicle emergence stage followed by second spray 21 days after first spray with spinosad (0.004%) and third need based spray of carbaryl (0.15%) was found to be the most effective in reducing the hopper population (3.81 hoppers/twig or panicle). This was followed by module-III (4.35 hoppers/twig or panicle) containing first spray of thiamethoxam (0.008%) at panicle emergence stage followed by second spray 21 days after first spray of profenophos (0.05%) and third need based spray of carbaryl (0.15%) and module-IV (4.91 hoppers/twig or panicle) first spray of spinosad (0.004%) at panicle emergence stage followed by second spray 21 days after first spray with thiamethoxam (0.008%) and third need based spray of Neem Azal (10000 ppm @ 3 ml/lit. of water). The maximum number of fruit set at marble stage was recorded in module-Vfruits set at harvest stage was highest in module-V followed by module-III. Highest yield was recorded in module-V (72.63 kg/tree).

Influence of harvest date on fruit yield and return bloom in ‘Marsh’ grapefruit trees (Citrus paradisi Macf.) grown under a tropical climate

SummaryGrapefruit grown in tropical climates reach a suitable fruit size and juice content for fresh consumption during August – October in the northern hemisphere. However, some tropical plantations delay harvesting until November or December, with the fruit then being used for processing. In our experiments, delaying the harvest from October to December reduced the average mature fruit weight by 10% and increased abscission from 29 to 70 fruit per tree. Juice contents decreased slightly, from 44.5% (w/w) to 43.2% (w/w), while total soluble solids (TSS) contents barely changed, from 10.4 ºBrix to 10.2 ºBrix. Delaying the harvest date also reduced return flowering by 20% in the following Spring, and the number of fruit set by 20%. Mature fruit abscission and reduced flowering were not dependent on weather conditions. The former was spontaneous and due to senescence, while the latter was due to fruit remaining on the tree. Over a 4-year period, our results showed an average reduction of 30% in fruit yield per tree when harvest dates were delayed from October (153 kg tree–1) to December (105 kg tree–1). As juice content and TSS content values were suitable for processing in October, there was no reason to delay the harvest date.

SELECCIÓN TEMPRANA EN FAMILIAS DE MEDIOS HERMANOS MATERNOS DE TOMATE DE CÁSCARA DE LA RAZA PUEBLA

Indirect selection was performed on 100 maternal half-sib families of husk tomato based on early identification characters. The aim was to identify families with higher performance based on two or more early expression traits and high yield, under the assumption that their high genetic correlation will allow appropriate selection of superior families. At 40 days after transplanting, first bifurcation height (FBH) and fruit set number (FSN) were recorded. At 76 days after transplanting, yield (YP) and fruit number per plant (FP) were also recorded. Analysis of variance showed significant differences in FBH and FSN. Selection of the upper 10 % of families using the four traits separately was difficult. Cluster analysis formed four sets of families, whose characteristics were corroborated by discriminant analysis. This description enabled selecting the best families, which showed low FBH and FSN, and higher YP and FP. Early selection, supported by multivariate analysis, allowed selecting family groups with similar characteristics and identifying superior families.

The effect of pollenizer on the fruit set of plum cultivar Cacanska Najbolja

In this paper, during a 4-year period (2003-2006) effects of six pollenizers (President, Italian Prune, Stanley, Cacanska Rodna, Agen 707, and California Blue) on the degree of fruit set in the plum cultivar Cacanska Najbolja were examined. Besides the controlled pollination of this cultivar, open pollination was investigated. Functional pollen ability in pollenizer-cultivars was established by in vitro pollen germination. Degree of fruit set was determined comparing the number of fruit set (10 days after pollination, 21 days after pollination and number of harvested fruits) against the number of pollinated flowers. The results indicated that all pollenizer cultivars, studied in this paper, possessed satisfactory in vitro pollen germination (30.1-67.4%). The number of fruit set determined 10 days after pollination was very high and did not differ among pollenizers. Highly significant differences were found between the pollenizers in the number of fruit set 21 days after pollination and significant ones in relation to the number of harvested fruits. Compared to open pollination, higher number of fruit set 21 days after pollination and higher number of harvested fruits were obtained when cultivars Stanley (17.0%; 7.6%) and Italian Prune (14.6%; 6.9%) were used as pollenizers, therefore those cultivars are recommendable as good pollenizers for the cultivar Cacanska Najbolja.

The impacts of pollination mode, plant characteristics and local density on the reproductive success of a scarce plant species, Salix arbuscula

Pollination failure represents one stage at which sexual reproduction of plants may be limited. It is therefore important to understand the pollination mechanism of the plant and how this may be affected by plant and population characteristics. This study examined the reproductive biology of a scarce montane willow species, Salix arbuscula, as part of a programme to determine ecological strategies for the conservation of montane willow scrub, an endangered habitat in the UK. The relative importance of insect and wind pollination, and the role of plant characteristics including plant size, catkin length, number of flowers and local density in determining reproductive success (number of fruit set) were investigated in three populations. Insect exclosures were used to determine the pollination mechanism. Our results suggest that S. arbuscula is predominantly insect-pollinated. In naturally pollinated plants, catkins with a higher proportion of ripe fruit were longer. Plants with more than two males in the local area and unbrowsed plants had a higher proportion of ripe fruit per catkin. The extent of wind pollination was very low, but differed between populations. The success of wind-only pollination was dependent on the number of males nearby, indicating that local density is more important in this type of pollination. Pollination mechanism and fruit set varied between the three populations observed, demonstrating the importance of multi-site comparisons. The number of males in the surrounding area had a positive effect on fruit set in both types of pollination, suggesting that Allee effects are likely to be operating in this species.

PAPAYA GROWTH IN DOUBLE-ROW SYSTEMS ESTABLISHED DURING THE DRY SEASON

Papaya production in the Virgin Islands is hindered by the lengthy dry season in this semi arid environment where fresh water is lacking. Three selected papaya cultivars, 'Maradol', 'Tainung 5' and 'Yuen Nong 1' were grown in 1×1, 1×2 or 1×3 m double-row spacing regime randomized block design incorporating drip irrigation with 4 L/h emitters at 1 m intervals and grass-hay mulch. The objective was to determine water usage, plant growth and fruit set during the first six months establishment in the dry season of the U.S. Virgin Islands. Data collected included: rainfall, irrigation water applied, plant height, height to first flower, height to first fruit, stem diameter at 1 m and number of fruit set after six months. Plants grown in the 1×1 m double row were taller, had thinner stems and significantly fewer fruit set for all cultivars during the six months of plant establishment and growth. The 1×2 m double row grown papaya were similar to the 1 x3 m double row plants for height, stem diameter and fruit set. The 1×2 m double row growing system is recommended to increase production where space and water are limiting factors. A grass/hay mulch is very effective in controlling weeds, conserving soil moisture and protecting the soil from erosion during sudden short heavy tropical rains.

GENETIC PARAMETERS OF THE HUSK TOMATO (Physalis ixocarpa Brot.) CHF1 CULTIVAR

The objective of this research was to estimate the genetic parameters of the husk tomato (Physalis ixocarpa Brot.) CHF1-Chapingo cultivar. Two hundred maternal half sib families were evaluated under three environments, in a complete randomized block design with two replications, and 22 plants by experimental plot. The narrow sense heritability of the 13 studied traits varied between 37.1 and 57.8 %; the genetic additive variation coefficient presented values between 8.2 and 24.4 %; for the total yield, values were 37.5 and 10.4 %. The fruit number and weight at the first harvest, and the total plant fruit number were the most important yield components. High additive genetic correlation absolute values were found for the total yield with: the first harvest yield (0.67), fruits per plant in the first harvest (0.50), total fruits per plant (0.58), fruit set number (0.38), and first stem bifurcation height (-0.49).