First Harvest Research Articles

Genetic divergence, correlation and path coefficient analysis in okra

Twenty okra genotypes were evaluated for genetic divergence, correlation and path coefficient for yield and its contributing attributes. Differences for the studied characters among the selected genotypes were significant and indicated the existence of variability among them. The results indicated that genotype Sel.-7, 71-14 and KS-312 were among the tallest. The phenotypic variance and coefficient of variation were higher than their respective genotypic variance and coefficient of variation for all the traits indicated the environmental effects on their expression. The differences between genetic coefficient of variation (GCV) and phenotypic coefficient of variation (PCV) were high for fruit diameter (FD) followed by number of branches per plant (NB), days to 50% flowering (DF), fruit weight (FW) and days to first harvest (FH) indicating the vulnerability of traits to environmental influences reflects the possibilities of varietal improvement. The difference between genotypic and phenotypic correlation coefficient indicates the influence of environmental effects. Number of fruits per plant (NP) and fruit weight (FW) contributed major maximum direct positive effect to fruit yield per plot, whereas number of branches per plant (NB) and days to first harvest (FH) showed highest negative direct effect on yield component. Plant height, however, showed highest positive indirect effect via number of fruits per plant and negative indirect effect via fruit weight. Number of branches (NB) showed positive indirect effect via number of fruits per plant (0.7655) and plant height (0.2728) and negative indirect effect via fruit weight (-0.2830). The estimated residual effect found was 0.0118 indicated about 98.82% of variability in fruit yield was contributed by studied yield affecting characters.

Vernalization of Seed and Plantlets and Development of Globe Artichoke

Annual production of globe artichoke [Cynara cardunculus var. scolymus (L.) Fiori] requires vernalization of the plants, either through cold treatment of transplants or from natural temperature conditions in the spring. To evaluate cold treatment on productive traits in artichoke, two experiments were performed. In the first experiment, dry seeds, plantlets at the cotyledon stage, and plants with two expanded true leaves were subjected to 3°C for 10 days. In the second experiment, dry seeds, seeds soaked in water, and germinated seeds were subjected to 3°C for 10 days. Days to first harvest (FH), total yield (TY), number of buds (NB), and mean head weight (MW) were evaluated. Treatment did not affect FH, but treatment affected NB and TY in the first experiment. Plants developed from seedlings treated at the two-leaf stage had increased NB and TY. In the second experiment, vernalization decreased NB, bud weight, and TY below that of controls. Cold treatment of seedlings at the two expanded leaf stages may have the potential to enhance yield.

Yield formation and quality characteristics of early potatoes during a short growing period

The effects of nitrogen fertilization on the yield and quality of early potato (Solanum tuberosum L.) were studied at MTT Agrifood Research Finland during 1996–1997. Cultivars were harvested at three times. The experimental layout was a split-split-plot with harvest times as main plots and nitrogen fertilization and potato cultivars as the subplots. The fertilizer treatments were 60 and 120 kg N ha-1 and the cultivars tested were Timo, Gloria and Van Gogh. The harvest times were 57–62, 70–75 and 85–90 days after planting. Application of 120 kg N ha-1 intensifi ed canopy development and increased leaf area of the stands. At early harvest the tuber yield of all cultivars receiving the higher nitrogen application increased by 0.5–2.5 t ha-1. The highest yielding cultivar was Timo. At last harvest, the higher nitrogen treatment increased yield by 3.0–6.2 t ha-1. The highest yielding cultivars were Timo and Van Gogh. The dry matter content of tubers was very low, 13.8–17.2%, at the fi rst harvest and the higher nitrogen application reduced dry matter content by 0.3–1.0%. The highest fertilizer application rate resulted in the largest tuber size. Nitrogen application, however, affected the quality of potatoes by decreasing the dry matter content. The nitrate content in tubers increased signifi cantly with the increasing level of nitrogen. The range of nitrate content in tubers fl uctuated between 13 and 189 mg kg-1 fresh weight showing good controlling of nitrate values. Harvest time affected sucrose content and the reducing sugar content in tubers, but nitrogen fertilizer did not change the sugar content of tubers. As tuber yield and quality during a short growing season are affected mainly by intercepted radiation, methods to increase tuber yield should focus on reducing the time to emergence, improving haulm growth after emergence and increasing the harvest index.;

Época de colheita e qualidade pós-colheita do caqui cv. Fuyu com a aplicação pré-colheita de ácido giberélico e aminoetoxivinilglicina

Harvest time and post-harvest quality of Fuyu persimmon treated before harvest with gibberellic acid and aminoetoxyvinilglycine. The aim of this work was to evaluate the effects of gibberellic acid (GA 3 ) and aminoetoxyvinilglycine (AVG) applied in preharvest spraying, on the retardation of the harvest and on the quality of persimmon fruits cv. Fuyu. The experiment was carried in randomized complete block design. The treatments were: control, 136 mgL -1 of AVG, 272 mgL -1 of AVG, 36 mgL -1 of GA 3, 72 mgL -1 of GA 3 and 136 mgL -1 of AVG + 36 mgL -1 of GA 3 , spraying 30 days before the fi rst harvest. The fruits were harvested twice

`Valencia': A New Pepino (Solanum muricatum) Cultivar with Improved Fruit Quality

Pepino (Solanum muricatum Aiton), also known as melon-pear, is a vegetatively propagated vegetable crop grown for its juicy and aromatic fruit. Great variation in fruit weight, shape, and color can be found among cultivars of pepino (Anderson et al., 1996; Heiser, 1985). Despite being an important crop in Pre-Columbian times in the Andean region, it has not achieved the same relevance as other New World cultivated Solanaceae such as tomato, pepper or potato (Prohens et al., 1996). However, during the last two decades, its cultivation has spread to many countries as a crop for diversifying greenhouse horticultural production. Two types of pepino cultivars can be distinguished: sweet fruit with at least 8% soluble solids concentration (SSC) and a fruity intense aroma appropiate for use as a dessert fruit for which fruit sweetness is a key factor (El-Zeftawi et al., 1988); cultivars producing less sweet but more fi rm-fl eshed fruit with a grassy (green) aroma suitable for use in salads in the same way as cucumber (Cucumis sativus L.). In several areas of the Mediterranean region, pepino (in particular sweet cultivars) is being introduced as a new crop (Prohens et al., 2000). The main limitation to pepino production is the availability of sweet pepino cultivars with combined high yield and good fruit quality. Clones producing fruit with high SSC (8% to 10%) suited for use as a dessert fruit, usually have a low yield ( 40 t·ha) have an unacceptably SSC (<7%) (Rodriguez-Burruezo et al., 2002). A research group of the Centro de Conservacion y Mejora de la Agrodiversidad Valenciana (COMAV) of the Universidad Politecnica de Valencia has conducted a pepino breeding program since the early 1990s. The clonal hybrid cultivar Valencia is a result of this program. ‘Valencia’ has a higher fruit yield and better fruit quality than other current sweet pepino cultivars, and is adapted to a wide range of environmental conditions. either parental clone (Table 1) and, occasionally, close to the high yielding ‘Puzol’. Fruit of ‘Valencia’ ripen earlier than other pepino cultivars. The time elapsed between transplanting and fi rst harvest ranges between 23 and 25 weeks in the autumn-winter growing season. ‘Valencia’ fruit weigh between 125 and 250 g (Table 1), adequate for dessert fruit. Fruit shape is elongated (Fig. 2), with a length/width ratio of 2.0 to 2.2 (1.3 for Sm-26 and 3.0 for ‘Sweet Long’). Both attributes (medium size and elongated shape) favor fruit packing and optimize box space. Fruit are attractive, with a golden color and narrow purple stripes covering less than 10% of fruit surface. The fl esh also exhibits an intense yellow color (Fig. 2). The fl avor of ‘Valencia’ is appropriate for a dessert fruit. SSC levels of ‘Valencia’ fruit range from 8.6 to 10.0%, values that are higher and statistically signifi cant in most cases than those of Sm-26 and ‘Sweet Long’. Furthermore, ascorbic acid concentration (AAC) levels are high, (between 400 and 600 mg·kg) (Table 1). Titratable acidity (TA, mmol·kg citric acid) values are comparable to the usual values for this species and always signifi cantly lower than Sm-26 (Nuez and Ruiz, 1996). Most trials were conducted under autumnwinter growing season conditions (Prohens et al., 2000), since this is the best growing season for good fruit quality and yield (RodriguezOrigin